158 results on '"Frédéric Jaouen"'
Search Results
2. Selective electrochemical reduction of nitric oxide to hydroxylamine by atomically dispersed iron catalyst
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Dong Hyun Kim, Stefan Ringe, Haesol Kim, Sejun Kim, Bupmo Kim, Geunsu Bae, Hyung-Suk Oh, Frédéric Jaouen, Wooyul Kim, Hyungjun Kim, and Chang Hyuck Choi
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Science - Abstract
Electrocatalytic conversion of nitrogen oxides to value-added chemicals is a promising strategy for mitigating the imbalance in the global nitrogen cycle. Here, the authors present iron–nitrogen-doped carbon as an efficient and durable electrocatalyst for selective nitric oxide reduction to hydroxylamine.
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- 2021
- Full Text
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3. Understanding how single-atom site density drives the performance and durability of PGM-free Fe–N–C cathodes in anion exchange membrane fuel cells
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Horie Adabi, Pietro Giovanni Santori, Abolfazl Shakouri, Xiong Peng, Karam Yassin, Igal G. Rasin, Simon Brandon, Dario R. Dekel, Noor Ul Hassan, Moulay-Tahar Sougrati, Andrea Zitolo, John R. Varcoe, John R. Regalbuto, Frédéric Jaouen, and William E. Mustain
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PGM-free ,AEM ,Fuel cell ,Oxygen reduction ,High performance ,Fe–N–C ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
One of the most important needs for the future of low-cost fuel cells is the development of highly active platinum group metal (PGM)-free catalysts. For the oxygen reduction reaction, Fe–N–C materials have been widely studied in both acid and alkaline media. However, reported catalysts in the literature show quite different intrinsic activity and in-cell performance, despite similar synthesis routes and precursors. Here, two types of Fe–N–C are prepared from the same precursor and procedure – the main difference is how the precursor was handled prior to use. It is shown that in one case Fe overwhelmingly existed as highly active single-metal atoms in FeN4 coordination (preferred), while in the other case large Fe particles coexisting with few single metal atoms were obtained. As a result, there were drastic differences in the catalyst structure, activity, and especially in their performance in an operating anion exchange membrane fuel cell (AEMFC). Additionally, it is shown that catalyst layers created from single-atom-dominated Fe–N–C can have excellent performance and durability in an AEMFC using H2/O2 reacting gases, achieving a peak power density of 1.8 W cm−2 – comparable to similar AEMFCs with a Pt/C cathode – and being able to operate stably for more than 100 h. Finally, the Fe–N–C cathode was paired with a low-loading PtRu/C anode electrode to create AEMFCs (on H2/O2) with a total PGM loading of only 0.135 mg cm−2 (0.090 mgPt cm−2) that was able to achieve a very high specific power of 8.4 W mgPGM−1 (12.6 W mgPt−1).
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- 2021
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4. Identification of catalytic sites in cobalt-nitrogen-carbon materials for the oxygen reduction reaction
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Andrea Zitolo, Nastaran Ranjbar-Sahraie, Tzonka Mineva, Jingkun Li, Qingying Jia, Serban Stamatin, George F. Harrington, Stephen Mathew Lyth, Petr Krtil, Sanjeev Mukerjee, Emiliano Fonda, and Frédéric Jaouen
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Science - Abstract
Nitrogen-doped carbon materials with atomically dispersed iron or cobalt are promising for catalytic use. Here, the authors show that cobalt moieties have a higher redox potential, bind oxygen more weakly and are less active toward oxygen reduction than their iron counterpart, despite similar coordination.
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- 2017
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5. Effect of ZIF-8 Crystal Size on the O2 Electro-Reduction Performance of Pyrolyzed Fe–N–C Catalysts
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Vanessa Armel, Julien Hannauer, and Frédéric Jaouen
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metal organic framework ,electrocatalysis ,fuel cell ,oxygen reduction ,non precious metal ,templating ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
The effect of ZIF-8 crystal size on the morphology and performance of Fe–N–C catalysts synthesized via the pyrolysis of a ferrous salt, phenanthroline and the metal-organic framework ZIF-8 is investigated in detail. Various ZIF-8 samples with average crystal size ranging from 100 to 1600 nm were prepared. The process parameters allowing a templating effect after argon pyrolysis were investigated. It is shown that the milling speed, used to prepare catalyst precursors, and the heating mode, used for pyrolysis, are critical factors for templating nano-ZIFs into nano-sized Fe–N–C particles with open porosity. Templating could be achieved when combining a reduced milling speed with a ramped heating mode. For templated Fe–N–C materials, the performance and activity improved with decreased ZIF-8 crystal size. With the Fe–N–C catalyst templated from the smallest ZIF-8 crystals, the current densities in H2/O2 polymer electrolyte fuel cell at 0.5 V reached ca. 900 mA cm−2, compared to only ca. 450 mA cm−2 with our previous approach. This templating process opens the path to a morphological control of Fe–N–C catalysts derived from metal-organic frameworks which, when combined with the versatility of the coordination chemistry of such materials, offers a platform for the rational design of optimized Metal–N–C catalysts.
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- 2015
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6. The Challenge of Achieving a High Density of Fe-Based Active Sites in a Highly Graphitic Carbon Matrix
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Jingkun Li, Qingying Jia, Sanjeev Mukerjee, Moulay-Tahar Sougrati, Goran Drazic, Andrea Zitolo, and Frédéric Jaouen
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oxygen reduction reaction ,Fe–N–C ,active site ,graphitic carbon ,Chemical technology ,TP1-1185 ,Chemistry ,QD1-999 - Abstract
As one of the most promising platinum group metal-free (PGM-free) catalysts for oxygen reduction reaction (ORR), Fe⁻N⁻C catalysts with a high density of FeNx moieties integrated in a highly graphitic carbon matrix with a proper porous structure have attracted extensive attention to combine the high activity, high stability and high accessibility of active sites. Herein, we investigated a ZnCl2/NaCl eutectic salts-assisted ionothermal carbonization method (ICM) to synthesize Fe⁻N⁻C catalysts with tailored porous structure, high specific surface area and a high degree of graphitization. However, it was found to be challenging to anchor a high density of FeNx sites onto highly graphitized carbon. Iron precursors with preexisting Fe⁻N coordination were required to form FeNx sites in the nitrogen-doped carbon with a high degree of graphitization, while individual Fe and N precursors led to a Fe⁻N⁻C catalyst with poor-ORR activity. This provides valuable insights into the synthesis-structure relationship. Moreover, the FeNx moieties were identified as the major active sites in acidic conditions, while both FeNx sites and Fe2O3 were found to be active in alkaline medium.
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- 2019
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7. Operando Spectroscopic Analysis of Axial Oxygen-Coordinated Single-Sn-Atom Sites for Electrochemical CO2 Reduction
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Yachen Deng, Jian Zhao, Shifu Wang, Ruru Chen, Jie Ding, Hsin-Jung Tsai, Wen-Jing Zeng, Sung-Fu Hung, Wei Xu, Junhu Wang, Frédéric Jaouen, Xuning Li, Yanqiang Huang, and Bin Liu
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Colloid and Surface Chemistry ,General Chemistry ,Biochemistry ,Catalysis - Published
- 2023
8. Doped Graphene To Mimic the Bacterial NADH Oxidase for One-Step NAD+ Supplementation in Mammals
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Xi Liu, Jingkun Li, Andrea Zitolo, Meng Gao, Jun Jiang, Xiangtian Geng, Qianqian Xie, Di Wu, Huizhen Zheng, Xiaoming Cai, Jianmei Lu, Frédéric Jaouen, Ruibin Li, ABiMS - Informatique et bioinformatique = Analysis and Bioinformatics for Marine Science (ABIMS), Fédération de recherche de Roscoff (FR2424), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Shandong Academy of Sciences (SDAS), Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Nagoya University, and Guangdong Provincial Center for Disease Control and Prevention
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Colloid and Surface Chemistry ,[CHIM]Chemical Sciences ,General Chemistry ,Biochemistry ,Catalysis - Abstract
International audience
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- 2023
9. Fe–N–C Electrocatalyst and Its Electrode: Are We Talking about the Same Material?
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Viktoriia A. Saveleva, Kavita Kumar, Pascal Theis, Nicole Segura Salas, Ulrike I. Kramm, Frédéric Jaouen, Frédéric Maillard, and Pieter Glatzel
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Materials Chemistry ,Electrochemistry ,Energy Engineering and Power Technology ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering - Published
- 2023
10. Modulating the Fe–N4 Active Site Content by Nitrogen Source in Fe–N–C Aerogel Catalysts for Proton Exchange Membrane Fuel Cell
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Hongxin Ge, Nicolas Bibent, Keyla Teixeira Santos, Kavita Kumar, Julien Jaxel, Moulay-Tahar Sougrati, Andrea Zitolo, Marc Dupont, Frédéric Lecoeur, Michel Mermoux, Vincent Martin, Laetitia Dubau, Frédéric Jaouen, Frédéric Maillard, and Sandrine Berthon-Fabry
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General Chemistry ,Catalysis - Published
- 2023
11. FeNC Oxygen Reduction Electrocatalyst with High Utilization Penta‐Coordinated Sites
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Jesús Barrio, Angus Pedersen, Saurav Ch. Sarma, Alexander Bagger, Mengjun Gong, Silvia Favero, Chang‐Xin Zhao, Ricardo Garcia‐Serres, Alain Y. Li, Qiang Zhang, Frédéric Jaouen, Frédéric Maillard, Anthony Kucernak, Ifan E. L. Stephens, Maria‐Magdalena Titirici, Imperial College London, Department of Chemistry [Imperial College London], Department of Chemical Engineering, Tsinghua University, Physiochimie des Métaux (PMB), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Bolin Centre for Climate Research, Stockholm University, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Electrochimie Interfaciale et Procédés (EIP), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI), Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), WPI Advanced Institute for Materials Research (WPI-AIMR), Tohoku University [Sendai], ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), European Project: 866402,NitroScission, European Project: 892614,HAEMOGLOBIN, and European Project: 896637 ,DimerCat
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,[CHIM.MATE]Chemical Sciences/Material chemistry - Abstract
International audience; Atomic Fe in N-doped carbon (FeNC) electrocatalysts for oxygen (O$_2$) reduction at the cathode of proton exchange membrane fuel cells (PEMFCs) are the most promising alternative to platinum-group-metal catalysts. Despite recent progress on atomic FeNC O$_2$ reduction, their controlled synthesis and stability for practical applications remains challenging. A two-step synthesis approach has recently led to significant advances in terms of Fe-loading and mass activity; however, the Fe utilisation remains low owing to the difficulty of building scaffolds with sufficient porosity that electrochemically exposes the active sites. Herein, we addressed this issue by coordinating Fe in a highly porous nitrogen doped carbon support (~3295 m$^2$ g$^{-1}$), prepared by pyrolysis of inexpensive 2,4,6triaminopyrimidine and a Mg$^{2+}$ salt active site template and porogen. Upon Fe coordination, a high electrochemical active site density of 2.54×10$^{19}$ sites g$_{FeNC}$$^{-1}$ and a record 52% FeN$_x$ electrochemical utilisation based on in situ nitrite stripping was achieved. The Fe single atoms are characterised pre-and post-electrochemical accelerated stress testing by aberration-corrected high-angle annular dark field scanning transmission electron microscopy, showing no Fe clustering. Moreover, ex situ X-ray absorption spectroscopy and low-temperature Mössbauer spectroscopy suggest the presence of penta-coordinated Fe sites, which were further studied by density functional theory calculations.
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- 2023
12. Electrocatalysis with Single‐Metal Atom Sites in Doped Carbon Matrices
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Tristan Asset, Frédéric Maillard, and Frédéric Jaouen
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- 2022
13. Structural and Reactivity Effects of Secondary Metal Doping into Iron-Nitrogen-Carbon Catalysts for Oxygen Electroreduction
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Frédéric Jaouen, Fang Luo, Aaron Roy, Moulay Tahar Sougrati, Anastassiya Khan, David Cullen, Xingli Wang, Mathias Primbs, Andrea Zitolo, and Peter Strasser
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While improved activity was recently reported for bimetallic iron-metal-nitrogen-carbon (FeMNC) catalysts for the oxygen reduction reaction (ORR) in acid medium, the nature of active sites and interactions between the two metals are poorly understood. Here, FeSnNC and FeCoNC catalysts were structurally and catalytically compared to their parent FeNC and SnNC catalysts. While CO cryo-chemisorption revealed a twice lower site density of M-Nx sites for FeSnNC and FeCoNC relative to FeNC and SnNC, the mass activity of both bimetallic catalysts is 50–100% higher than that of FeNC, due to a larger turnover frequency in the bimetallic catalysts. Electron microscopy and X-ray absorption spectroscopy identified the coexistence of Fe-Nx and Sn-Nx or Co-Nx sites, while no evidence was found for binuclear Fe-M-Nx sites. 57Fe Mössbauer spectroscopy revealed that the bimetallic catalysts feature a higher D1/D2 ratio of the spectral signatures assigned to two distinct Fe-Nx sites, relative to the FeNC parent catalyst. Thus, the addition of the secondary metal favored the formation of D1 sites, associated with the higher turnover frequency.
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- 2023
14. Unravelling the Electronic Structure and Dynamics of the Atomically Dispersed Iron Sites in Electrochemical CO2 Reduction
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Frédéric Jaouen, Yaqiong Zeng, Jian Zhao, Shifu Wang, Xinyi Ren, Yuanlong Tan, Ying Rui Lu, Shibo Xi, Junhu Wang, Xuning Li, Yanqiang Huang, Tao Zhang, and Bin Liu
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Single-atom catalysts with a well-defined metal center open unique opportunities for exploring the catalytically active site and reaction mechanism of chemical reactions. However, understanding of the electronic and structural dynamics of single-atom catalytic centers under reaction condition is still limited due to the challenge of combining operando techniques that are sensitive to such sites and model single-atom systems. Herein, supported by state-of-the-art operando techniques, we provide an in-depth study of the dynamic structural and electronic evolution during electrochemical CO2 reduction reaction (CO2RR) of a model catalyst comprising iron only as a high-spin (HS) Fe(III)N4 center in its resting state. Operando 57Fe Mössbauer and X-ray absorption spectroscopies clearly evidence the change from a HS Fe(III)N4 to a HS Fe(II)N4 center with decreasing potential, CO2- or Ar-saturation of the electrolyte leading to different adsorbates and stability of the HS Fe(II)N4 center. With operando Raman spectroscopy and cyclic voltammetry, we identify that the phthalocyanine (Pc) ligand coordinating the iron cation center undergoes a redox process from Fe(II)Pc to Fe(II)Pc−. Altogether, the HS Fe(II)Pc− species is identified as the catalytic intermediate for CO2RR. Furthermore, theoretical calculations reveal that the electroreduction of the Pc ligand modifies the d-band center of the in situ generated HS Fe(II)Pc− species, resulting in an optimal binding strength to CO2 and thus boosting the catalytic performance of CO2RR. This work provides both experimental and theoretical evidence towards the electronic structural and dynamics of reactive sites in single-Fe-atom materials and shall guide the design of novel efficient catalysts for CO2RR.
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- 2023
15. FeNC Oxygen Reduction Electrocatalyst with High Utilisation Penta-coordinated sites
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Jesus Barrio, Angus Pedersen, Saurav Ch. Sarma, Alexander Bagger, Mengjun Gong, Silvia Favero, Chang-Xin Zhao, Ricardo Garcia-Serres, Alain You Li, Qiang Zhang, Frédéric Jaouen, Frédéric Maillard, Anthony Kucernak, Ifan E. L. Stephens, and Magda Titirici
- Abstract
Atomic Fe in N-doped carbon (FeNC) electrocatalysts for oxygen (O2) reduction at the cathode of proton exchange membrane fuel cells (PEMFCs) are the most promising alternative to platinum-group-metal catalysts. Despite recent progress on atomic FeNC O2 reduction, their controlled synthesis and stability for practical applications remains challenging. A two-step synthesis approach has recently led to significant advances in terms of Fe-loading and mass activity; however, the Fe utilisation remains low owing to the difficulty of building scaffolds with sufficient porosity that electrochemically exposes the active sites. Herein, we addressed this issue by coordinating Fe in a highly porous nitrogen doped carbon support (~3295 m2 g-1), prepared by pyrolysis of inexpensive 2,4,6-triaminopyrimidine and a Mg2+ salt active site template and porogen. Upon Fe coordination, a high electrochemical active site density of 2.54×10^19 sites gFeNC-1 and a record 52% FeNx electrochemical utilisation based on in situ nitrite stripping was achieved. The Fe single atoms are characterised pre- and post-electrochemical accelerated stress testing by aberration-corrected high-angle annular dark field scanning transmission electron microscopy, showing no Fe clustering. Moreover, ex situ X-ray absorption spectroscopy and low-temperature Mössbauer spectroscopy suggest the presence of penta-coordinated Fe sites, which were further studied by density functional theory calculations.
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- 2022
16. Iron and cobalt containing electrospun carbon nanofibre-based cathode catalysts for anion exchange membrane fuel cell
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Vambola Kisand, Marek Mooste, Andres Krumme, Alexey Treshchalov, Maike Käärik, Sara Cavaliere, Steven Holdcroft, Jekaterina Kozlova, Aile Tamm, Kaido Tammeveski, Frédéric Jaouen, Päärn Paiste, Arvo Kikas, Andri Sokka, Jaan Aruväli, Jaan Leis, Viktoria Gudkova, University of Tartu, Institute of Physics [Tartu], Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
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Materials science ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,law.invention ,Catalysis ,chemistry.chemical_compound ,law ,[CHIM]Chemical Sciences ,ComputingMilieux_MISCELLANEOUS ,Ion exchange ,Renewable Energy, Sustainability and the Environment ,Oxygen evolution ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Cathode ,0104 chemical sciences ,Fuel Technology ,Membrane ,chemistry ,Chemical engineering ,Ionic liquid ,0210 nano-technology ,Carbon ,Cobalt - Abstract
The use of Pt-based cathode catalyst materials hinders the widespread application of anion exchange membrane fuel cells (AEMFCs). Herein, we present a non-precious metal catalyst (NPMC) material based on pyrolysed Fe and Co co-doped electrospun carbon nanofibres (CNFs). The prepared materials are studied as oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts in alkaline and acidic environments. High activity towards the ORR in alkaline solution indicated the suitability of the prepared NPMCs for the application at the AEMFC cathode. In the AEMFC test, the membrane-electrode assembly bearing a cathode with the nanofibre-based catalyst prepared with the ionic liquid (IL) (Fe/Co/IL–CNF–800b) showed the maximum power density (Pmax) of 195 mW cm−2, which is 78% of the Pmax obtained with a commercial Pt/C cathode catalyst. Such high ORR electrocatalytic activity was attributed to the unique CNF structure, high micro-mesoporosity, different nature of nitrogen species and metal-Nx active centres.
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- 2021
17. Unraveling the complex causality behind the Fe-N-C degradation in fuel cell
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Geunsu Bae, Song Jin, Man Ho Han, Hyung-Suk Oh, Moulay Tahar Sougrati, Kug-Seung Lee, Min Ho Seo, Frédéric Jaouen, and Chang Hyuck Choi
- Abstract
Beyond great advances in initial activity, Fe-N-C catalysts face the next challenge of stability issue in acidic medium that must be overcome to replace Pt in fuel cell cathode. However, the complex phenomena in fuel cells and consequential difficulty in understanding deactivation mechanisms of Fe-N-C cathodes impede solutions for prolonged stability. Here, we show time-resolved changes in active site density (SD) and turnover frequency (TOF) of Fe-N-C along with concurrent decrease in oxygen reduction reaction (ORR) current in temperature/gas controllable gas-diffusion electrode (GDE) flow cell. In operando diagnosis of Fe leaching identifies a strong dependence of SD changes on operating parameters, and draws a lifetime-dependent stability diagram that reveals a shift in prime degradation mechanism during the operations. A proof-of-concept strategy with site-isolated Pt ions as a non-catalytic stabilizer, supported by theoretical calculation, demonstrates enhanced fuel cell stability with reduced Fe dissolution, offering new design principle for durable Fe-N-C catalysts.
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- 2022
18. Response to systemic therapies in granulomatous cheilitis: Retrospective multicenter series of 61 patients
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Stéphane Nahon, Selma Azib-Meftah, Saskia Ingen-Housz-Oro, Frédéric Jaouen, Marie-Helene Tessier, Jean-Christophe Fricain, Didier Bessis, Vincent Sibaud, Marie Masson-Regnault, Nathalie Beneton, Amina Kaddour, Céline Girard, Loïc Vaillant, Laurent Misery, Emmanuel Delaporte, Mahtab Samimi, Université Francois Rabelais [Tours], Hôpital Henri Mondor, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Henri Mondor-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Institut Universitaire du Cancer de Toulouse - Oncopole (IUCT Oncopole - UMR 1037), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM), Pathogenesis and Control of Chronic and Emerging Infections (PCCEI), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Université des Antilles (UA)-Etablissement français du don du sang [Montpellier]-Université de Montpellier (UM)
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Series (stratigraphy) ,medicine.medical_specialty ,business.industry ,[SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology ,MEDLINE ,Medicine ,Dermatology ,business ,[SDV.MHEP.DERM]Life Sciences [q-bio]/Human health and pathology/Dermatology - Abstract
International audience
- Published
- 2022
19. Bifunctional Zinc-Molybdate or Zinc molybdenum Oxide/Metal-Nitrogen-Carbon catalytic layers with improved four-electron selectivity for oxygen reduction in acidic medium
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Aaron Roy, Leonardo Girardi, Dario Mosconi, Moulay Tahar Sougrati, Deborah Jones, Stefano Agnoli, and Frédéric Jaouen
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General Chemical Engineering ,Electrochemistry - Published
- 2023
20. Multi-atom Pt and PtRu catalysts for high performance AEMFCs with ultra-low PGM content
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Horie Adabi, Abolfazl Shakouri, Andrea Zitolo, Tristan Asset, Anastassiya Khan, Jasmine Bohannon, Raphaël Chattot, Christopher Williams, Frédéric Jaouen, John R. Regalbuto, and William E. Mustain
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Process Chemistry and Technology ,Catalysis ,General Environmental Science - Published
- 2023
21. Chemical vapour deposition of Fe–N–C oxygen reduction catalysts with full utilization of dense Fe–N4 sites
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Moulay Tahar Sougrati, Deborah J. Myers, Qingying Jia, Sichen Zhong, Jingkun Li, Magali Ferrandon, Fan Yang, Yu Huang, Sanjeev Mukerjee, Li Jiao, Qiang Sun, Ershuai Liu, Thomas Stracensky, David A. Cullen, Hui Xu, Jaehyung Park, Frédéric Jaouen, Lynne Larochelle Richard, Zipeng Zhao, Northeastern University [Boston], Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and Argonne National Laboratory [Lemont] (ANL)
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Inorganic chemistry ,chemistry.chemical_element ,Proton exchange membrane fuel cell ,02 engineering and technology ,Chemical vapor deposition ,010402 general chemistry ,01 natural sciences ,Redox ,Catalysis ,General Materials Science ,biology ,Mechanical Engineering ,Substrate (chemistry) ,Active site ,[CHIM.MATE]Chemical Sciences/Material chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Oxygen reduction ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,biology.protein ,0210 nano-technology ,Platinum - Abstract
Replacing scarce and expensive platinum (Pt) with metal–nitrogen–carbon (M–N–C) catalysts for the oxygen reduction reaction in proton exchange membrane fuel cells has largely been impeded by the low oxygen reduction reaction activity of M–N–C due to low active site density and site utilization. Herein, we overcome these limits by implementing chemical vapour deposition to synthesize Fe–N–C by flowing iron chloride vapour over a Zn–N–C substrate at 750 °C, leading to high-temperature trans-metalation of Zn–N4 sites into Fe–N4 sites. Characterization by multiple techniques shows that all Fe–N4 sites formed via this approach are gas-phase and electrochemically accessible. As a result, the Fe–N–C catalyst has an active site density of 1.92 × 1020 sites per gram with 100% site utilization. This catalyst delivers an unprecedented oxygen reduction reaction activity of 33 mA cm−2 at 0.90 V (iR-corrected; i, current; R, resistance) in a H2–O2 proton exchange membrane fuel cell at 1.0 bar and 80 °C. Replacing platinum with metal–nitrogen–carbon catalysts for the oxygen reduction reaction in proton exchange membrane fuel cells has been impeded by low activity. These limitations have now been overcome by the trans-metalation of Zn–N4 sites into Fe–N4 sites.
- Published
- 2021
22. Oxygen Reduction Reaction in Alkaline Media Causes Iron Leaching from Fe-N-C Electrocatalysts
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Yu-Ping Ku, Konrad Ehelebe, Andreas Hutzler, Markus Bierling, Thomas Böhm, Andrea Zitolo, Mykhailo Vorokhta, Nicolas Bibent, Florian D. Speck, Dominik Seeberger, Ivan Khalakhan, Karl J. J. Mayrhofer, Simon Thiele, Frédéric Jaouen, and Serhiy Cherevko
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Colloid and Surface Chemistry ,General Chemistry ,Biochemistry ,Catalysis - Abstract
The electrochemical activity of modern Fe-N-C electrocatalysts in alkaline media is on par with that of platinum. For successful application in fuel cells (FCs), however, also high durability and longevity must be demonstrated. Currently, a limited understanding of degradation pathways, especially under operando conditions, hinders the design and synthesis of simultaneously active and stable Fe-N-C electrocatalysts. In this work, using a gas diffusion electrode half-cell coupled with inductively coupled plasma mass spectrometry setup, Fe dissolution is studied under conditions close to those in FCs, that is, with a porous catalyst layer (CL) and at current densities up to -125 mA·cm
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- 2022
23. Quantification of Active Site Density and Turnover Frequency: From Single-Atom Metal to Nanoparticle Electrocatalysts
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Kug-Seung Lee, Hyung Suk Oh, Frédéric Jaouen, Han Chang Kwon, Pyeonghwa Jeong, Hansol Choi, Donghyun Kim, Haesol Kim, Geunsu Bae, Chang Hyuck Choi, and Minkee Choi
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Cyanide ,Inorganic chemistry ,Nanoparticle ,chemistry.chemical_element ,engineering.material ,Article ,Catalysis ,Metal ,Fe−N−C catalysts ,chemistry.chemical_compound ,Adsorption ,QD1-999 ,oxygen reduction reaction ,biology ,Chemistry ,turnover frequency ,Active site ,visual_art ,engineering ,biology.protein ,visual_art.visual_art_medium ,Noble metal ,Platinum ,active site density ,Single-atom catalysts - Abstract
Single-atom catalysts (SACs) featuring atomically dispersed metal cations covalently embedded in a carbon matrix show significant potential to achieve high catalytic performance in various electrocatalytic reactions. Although considerable advances have been achieved in their syntheses and electrochemical applications, further development and fundamental understanding are limited by a lack of strategies that can allow the quantitative analyses of their intrinsic catalytic characteristics, that is, active site density (SD) and turnover frequency (TOF). Here we show an in situ SD quantification method using a cyanide anion as a probe molecule. The decrease in cyanide concentration triggered by irreversible adsorption on metal-based active sites of a model Fe-N-C catalyst is precisely measured by spectrophotometry, and it is correlated to the relative decrease in electrocatalytic activity in the model reaction of oxygen reduction reaction. The linear correlation verifies the surface-sensitive and metal-specific adsorption of cyanide on Fe-N x sites, based on which the values of SD and TOF can be determined. Notably, this analytical strategy shows versatile applicability to a series of transition/noble metal SACs and Pt nanoparticles in a broad pH range (1-13). The SD and TOF quantification can afford an improved understanding of the structure-activity relationship for a broad range of electrocatalysts, in particular, the SACs, for which no general electrochemical method to determine the intrinsic catalytic characteristics is available.
- Published
- 2021
24. Potential‐Induced Spin Changes in Fe/N/C Electrocatalysts Assessed by In Situ X‐ray Emission Spectroscopy
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Viktoriia A. Saveleva, Kathrin Ebner, Lingmei Ni, Grigory Smolentsev, Daniel Klose, Andrea Zitolo, Elena Marelli, Jingkun Li, Marisa Medarde, Olga V. Safonova, Maarten Nachtegaal, Frédéric Jaouen, Ulrike I. Kramm, Thomas J. Schmidt, and Juan Herranz
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General Medicine - Published
- 2021
25. High loading of single atomic iron sites in Fe-NC oxygen reduction catalysts for proton exchange membrane fuel cells
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Asad Mehmood, Mengjun Gong, Frédéric Jaouen, Aaron Roy, Andrea Zitolo, Anastassiya Khan, Moulay-Tahar Sougrati, Mathias Primbs, Alex Martinez Bonastre, Dash Fongalland, Goran Drazic, Peter Strasser, Anthony Kucernak, Engineering & Physical Science Research Council (E, and Commission of the European Communities
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CONDENSED MATTER ,Science & Technology ,Chemistry, Physical ,Process Chemistry and Technology ,Bioengineering ,PERFORMANCE ,Biochemistry ,Catalysis ,NITROGEN-CARBON CATALYSTS ,Chemistry ,DOPED CARBON ,TURNOVER FREQUENCY ,METAL ,Physical Sciences ,RAY-ABSORPTION SPECTROSCOPY ,BODY DISTRIBUTION-FUNCTIONS ,C CATALYSTS ,ACTIVE-SITES - Abstract
Non-precious iron-based catalysts (Fe-NCs) require high active site density (SD) to meet the performance targets as cathode catalysts in proton exchange membrane fuel cells (PEMFCs). SD is generally limited to that achieved at 1-3 wt%(Fe) loading due to the undesired formation of iron-containing nanoparticles at higher loadings. Here we show that by pre-forming a carbon-nitrogen matrix using a sacrificial metal (Zn) in the initial synthesis step and then exchanging iron into this preformed matrix we achieve 7 wt% iron coordinated solely as single atom Fe-N4 sites as identified by 57Fe cryo Mössbauer spectroscopy and X-ray absorption spectroscopy. SD values measured by in situ nitrite stripping and ex situ CO chemisorption methods are 4.7x1019 and 7.8x1019 sitesg-1, with a turnover frequency of 5.4 electrons̭sites-1s-1 at 0.80 V in 0.5M H2SO4 electrolyte. The catalyst delivers excellent PEMFC performance with current densities of 41.3 mAcm-2 at 0.90 ViR-free using H2-O2 (10.6 Ag-1) and 145 mA cm-2 at 0.80 V (199 mAcm-2 at 0.80 ViR-free) using H2-air.
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- 2022
26. Reduced formation of peroxide and radical species stabilises iron-based hybrid catalysts in polymer electrolyte membrane fuel cells
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Frédéric Jaouen, Marc F. Tesch, Alexander Schnegg, Dongyoon Shin, Sonia Chabbra, Christoph Pratsch, Sabita Bhandari, Shannon A. Bonke, Anna K. Mechler, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
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Energy Engineering and Power Technology ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,01 natural sciences ,Peroxide ,Catalysis ,law.invention ,chemistry.chemical_compound ,law ,Electrochemistry ,Electron paramagnetic resonance ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,Reactive oxygen species ,Polymer ,[CHIM.CATA]Chemical Sciences/Catalysis ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Fuel Technology ,Membrane ,chemistry ,Chemical engineering ,Transmission electron microscopy ,0210 nano-technology ,Energy (miscellaneous) - Abstract
The incorporation of Pt into an iron-nitrogen-carbon (FeNC) catalyst for the oxygen reduction reaction (ORR) was recently shown to enhance catalyst stability without Pt directly contributing to the ORR activity. However, the mechanistic origin of this stabilisation remained obscure. It is established herein with rotating ring disc experiments that the side product, H2O2, which is known to damage FeNC catalysts, is suppressed by the presence of Pt. The formation of reactive oxygen species is additionally inhibited, independent of intrinsic H2O2 formation, as determined by electron paramagnetic resonance. Transmission electron microscopy identifies an oxidised Fe-rich layer covering the Pt particles, thus explaining the inactivity of the latter towards the ORR. These insights develop understanding of FeNC degradation mechanisms during ORR catalysis, and crucially establish the required properties of a precious metal free protective catalyst to improve FeNC stability in acidic media.
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- 2022
27. Engineering Fe–N Doped Graphene to Mimic Biological Functions of NADPH Oxidase in Cells
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Ruibin Li, Weili Wang, Di Wu, Jingkun Li, Huizhen Zheng, Xiaoming Cai, Meng Gao, Frédéric Jaouen, Qianqian Xie, Shujuan Xu, Jia Li, Ronglin Ma, Yanxia Pan, Xi Liu, Washington State University (WSU), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ABiMS - Informatique et bioinformatique = Analysis and Bioinformatics for Marine Science (FR2424), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Guangdong Provincial Center for Disease Control and Prevention, Soochow University, and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
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Models, Molecular ,Enzyme complex ,THP-1 Cells ,Interleukin-1beta ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Chronic granulomatous disease ,Biomimetic Materials ,Superoxides ,Doping ,NADPH oxidase ,biology ,Superoxide ,[CHIM.MATE]Chemical Sciences/Material chemistry ,respiratory system ,Transmembrane protein ,cardiovascular system ,Graphite ,Signal transduction ,Oxidation-Reduction ,Signal Transduction ,circulatory and respiratory physiology ,inorganic chemicals ,Nitrogen ,Iron ,010402 general chemistry ,Catalysis ,Immune system ,medicine ,Humans ,[SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM] ,NOx ,Fluorescent Dyes ,Peroxidase ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,Nanozyme ,NADPH Oxidases ,[CHIM.CATA]Chemical Sciences/Catalysis ,General Chemistry ,medicine.disease ,0104 chemical sciences ,chemistry ,Nanocatalyst ,biology.protein ,Graphene ,Reactive Oxygen Species ,NADP - Abstract
International audience; NADPH oxidase (NOX) as a transmembrane enzyme complex controls the generation of superoxide that plays important roles in immune signaling pathway. NOX inactivation may elicit immunodeficiency and cause chronic granulomatous disease (CGD). Biocompatible synthetic materials with NOX-like activities would therefore be interesting as curative and/or preventive approaches in case of NOX deficiency. Herein, we synthesized a Fe–N doped graphene (FeNGR) nanomaterial that could mimic the activity of NOX by efficiently catalyzing the conversion of NADPH into NADP+ and triggering the generation of oxygen radicals. The resulting FeNGR nanozyme had similar cellular distribution to NOX and is able to mimic the enzyme function in NOX-deficient cells by catalyzing the generation of superoxide and retrieving the immune activity, evidenced by TNF-α, IL-1β, and IL-6 production in response to Alum exposure. Overall, our study discovered a synthetic material (FeNGR) to mimic NOX and demonstrated its biological function in immune activation of NOX-deficient cells.
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- 2020
28. On the Influence of Oxygen on the Degradation of Fe‐N‐C Catalysts
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Jingkun Li, Kavita Kumar, Michel Mermoux, Frédéric Jaouen, Jaysen Nelayah, Frédéric Maillard, Andrea Zitolo, Laetitia Dubau, Electrochimie Interfaciale et Procédés (EIP), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI), Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Matériaux Interfaces ELectrochimie (MIEL), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Projet ANR CAT2CAT (ANR-16-CE05-0007)Projet ANR ANIMA (ANR-19-CE05-0039), ANR-16-CE05-0007,CAT2CAT,Des catalyseurs aux cathodes: Une approche d'architecture contrôlée d'électrode pour pile PEM à base de métaux abondants(2016), ANR-19-CE05-0039,ANIMA,Aérogels de carbone poreux dopés à l'azote et avec des métaux abondants pour des assemblages membrane-électrodes efficaces et durables(2019), Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and ANR-19-CE05-0039,ANIMA,ANR-19-CE05-0039 - ANIMA - Aérogels de carbone poreux dopés à l'azote et avec des métaux abondants pour des assemblages membrane-électrodes efficaces et durables
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Inorganic chemistry ,Proton exchange membrane fuel cell ,chemistry.chemical_element ,Electrolyte ,02 engineering and technology ,010402 general chemistry ,Oxygen ,7. Clean energy ,01 natural sciences ,Catalysis ,Corrosion ,symbols.namesake ,010405 organic chemistry ,General Medicine ,[CHIM.CATA]Chemical Sciences/Catalysis ,[CHIM.MATE]Chemical Sciences/Material chemistry ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,13. Climate action ,symbols ,Reversible hydrogen electrode ,Degradation (geology) ,Raman spectroscopy ,0210 nano-technology - Abstract
International audience; Precious metal-free catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells are gaining momentum, with Fe-N-C catalysts comprising atomic FeN x sites the most promising candidate. Research and development is shifting from activity targets to improved stability of Fe-N-C catalysts in fuel cells. Their durability has hitherto been extensively studied using accelerated stress tests (AST) performed at room temperature and in inert-gas saturated acidic pH electrolyte. Here, we reveal stronger degradation of the Fe-N-C structure and four times higher ORR activity loss when performing load cycling AST in O2-vs. Ar-saturated pH 1 electrolyte. Raman spectroscopy results point towards strong carbon corrosion after AST in O2 , even when cycling at low potentials of 0.3-0.7 V vs. the reversible hydrogen electrode, while no corrosion occurred after any load cycling AST in Ar. The load cycling AST in O2 leads to the loss of a significant fraction of FeN x sites, as shown by energy dispersive X-ray spectroscopy analyses, and to the formation of Fe oxides. The results support that the unexpected carbon corrosion occurring at such low potential in the presence of O2 is due to reactive oxygen species produced between H 2 O 2 and Fe sites via Fenton reactions.
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- 2020
29. Establishing reactivity descriptors for platinum group metal (PGM)-free Fe–N–C catalysts for PEM fuel cells
- Author
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Moulay Tahar Sougrati, Giorgia Daniel, Tomasz Kosmala, Christian Durante, Asad Mehmood, Aaron Roy, Peter Strasser, Mathias J.M. Primbs, Yanyan Sun, Daniel Malko, Frédéric Jaouen, Jonathan Sharman, Gaetano Granozzi, Pierre-Yves Blanchard, Plamen Atanassov, Anthony Kucernak, Deborah J. Jones, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Center For Emerging Energy Technologies [Albuquerque] (CEET), The University of New Mexico [Albuquerque], Department of Chemistry [Imperial College London], Imperial College London, Technische Universität Berlin (TU), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2), Department of Chemical Sciences, Universita degli Studi di Padova, Johnson Matthey Technology Centre, and Commission of the European Communities
- Subjects
Inorganic chemistry ,Proton exchange membrane fuel cell ,Context (language use) ,02 engineering and technology ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Catalysis ,[CHIM]Chemical Sciences ,Environmental Chemistry ,Reactivity (chemistry) ,ComputingMilieux_MISCELLANEOUS ,Energy ,Renewable Energy, Sustainability and the Environment ,Chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,Microporous material ,021001 nanoscience & nanotechnology ,Pollution ,0104 chemical sciences ,Nuclear Energy and Engineering ,13. Climate action ,Chemisorption ,ddc:540 ,0210 nano-technology ,Mesoporous material - Abstract
International audience; We report a comprehensive analysis of the catalytic oxygen reduction reaction (ORR) reactivity of four of today's most active benchmark platinum group metal-free (PGM-free) iron/nitrogen doped carbon electrocatalysts (Fe-N-Cs). Our analysis reaches far beyond previous such attempts in linking kinetic performance metrics, such as electrocatalytic mass-based and surface area-based catalytic activity with previously elusive kinetic metrics such as the active metal site density (SD) and the catalytic turnover frequency (TOF). Kinetic ORR activities, SD and TOF values were evaluated using in situ electrochemical NO 2 À reduction as well as an ex situ gaseous CO cryo chemisorption. Experimental ex situ and in situ Fe surface site densities displayed remarkable quantitative congruence. Plots of SD versus TOF (''reactivity maps'') are utilized as new analytical tools to deconvolute ORR reactivities and thus enabling rational catalyst developments. A microporous catalyst showed large SD values paired with low TOF, while mesoporous catalysts displayed the opposite. Trends in Fe surface site density were linked to molecular nitrogen and Fe moieties (D1 and D2 from 57 Fe Mössbauer spectroscopy), from which pore locations of catalytically active D1 and D2 sites were established. This cross-laboratory analysis, its employed experimental practices and analytical methodologies are expected to serve as a widely accepted reference for future, knowledge-based research into improved PGM-free fuel cell cathode catalysts. Broader context Polymer electrolyte membrane fuel cells (PEMFC) have reached the commercial stage and ever wider deployment is imminent. To further reduce the loading of platinum group metal (PGM) catalysts in PEMFC electrodes, PGM-free, iron and nitrogen-doped carbon oxygen reduction (ORR) electrocatalysts (Fe-N-C) were developed over past decades. Recent advances in activity and stability of Fe-N-C are impressive, yet methods to evaluate the number of catalytic active Fe sites at the surface and intrinsic turn over frequency remained elusive. This changed with the advent of CO cryo-sorption and in situ nitrite stripping techniques that yielded these intrinsic reactivity descriptors. Never before, however, have these two complementary specific adsorption/stripping techniques been compared and combined with other chemical and spectroscopic analytics for an in-depth analysis of catalytic reactivity of Fe-N-C ORR electrocatalysts. The present study addresses this issue and presents a comprehensive analysis of the reactivity of the four state-of-the-art Fe-N-C PEMFC electrocatalysts. The study provides a deeper understanding of the origin and difference in catalytic performance through the combination of a host of different surface sensitive and bulk analysis methods. The methodologies and analyses of this benchmark catalyst study will benefit future developments in Fe-N-C catalysis.
- Published
- 2020
30. What is Next in Anion-Exchange Membrane Water Electrolyzers? Bottlenecks, Benefits, and Future
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Carlo Santoro, Alessandro Lavacchi, Piercarlo Mustarelli, Vito Di Noto, Lior Elbaz, Dario R. Dekel, Frédéric Jaouen, Santoro, C, Lavacchi, A, Mustarelli, P, Di Noto, V, Elbaz, L, Dekel, D, and Jaouen, F
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Anions ,water electrolysi ,General Chemical Engineering ,platinum-group metal-free ,anion-exchange membrane ,electrocatalysis ,electrolyzers ,water electrolysis ,Water ,Membranes, Artificial ,Electrolysis ,electrolyzer ,General Energy ,electrocatalysi ,Environmental Chemistry ,General Materials Science ,Hydrogen - Abstract
As highlighted by the recent roadmaps from the European Union and the United States, water electrolysis is the most valuable high-intensity technology for producing green hydrogen. Currently, two commercial low-temperature water electrolyzer technologies exist: alkaline water electrolyzer (A-WE) and proton-exchange membrane water electrolyzer (PEM-WE). However, both have major drawbacks. A-WE shows low productivity and efficiency, while PEM-WE uses a significant amount of critical raw materials. Lately, the use of anion-exchange membrane water electrolyzers (AEM-WE) has been proposed to overcome the limitations of the current commercial systems. AEM-WE could become the cornerstone to achieve an intense, safe, and resilient green hydrogen production to fulfill the hydrogen targets to achieve the 2050 decarbonization goals. Here, the status of AEM-WE development is discussed, with a focus on the most critical aspects for research and highlighting the potential routes for overcoming the remaining issues. The Review closes with the future perspective on the AEM-WE research indicating the targets to be achieved.
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- 2022
31. Time‐Resolved Potential‐Induced Changes in Fe/N/C‐Catalysts Studied by In Situ Modulation Excitation X‐Ray Absorption Spectroscopy
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Kathrin Ebner, Adam H. Clark, Viktoriia A. Saveleva, Grigory Smolentsev, Jingfeng Chen, Lingmei Ni, Jingkun Li, Andrea Zitolo, Frédéric Jaouen, Ulrike I. Kramm, Thomas J. Schmidt, Juan Herranz, Paul Scherrer Institute (PSI), Institut de chimie et procédés pour l'énergie, l'environnement et la santé (ICPEES), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), and AIGLe, ICG
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In situ spectroscopy ,CO2-reduction reaction ,Renewable Energy, Sustainability and the Environment ,Fe/N/C-Catalysts ,[CHIM.CATA] Chemical Sciences/Catalysis ,[CHIM.CATA]Chemical Sciences/Catalysis ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,electrochemistry ,Fe/N/C-catalysts ,in situ spectroscopy ,O2 reduction reaction ,platinum group metal-free ,[CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry ,Electrochemistry ,General Materials Science ,Platinum group metal-free ,CO 2-reduction reaction - Abstract
To advance the widespread implementation of electrochemical energy storage and conversion technologies, the development of inexpensive electrocatalysts is imperative. In this context, Fe/N/C-materials represent a promising alternative to the costly noble metals currently used to catalyze the oxygen reduction reaction (ORR), and also display encouraging activities for the reduction of CO2. Nevertheless, the application of these materials in commercial devices requires further improvements in their performance and stability that are currently hindered by a lack of understanding of the nature of their active sites and the associated catalytic mechanisms. With this motivation, herein the authors exploit the high sensitivity of modulation excitation X-ray absorption spectroscopy toward species undergoing potential-induced changes to elucidate the operando local geometry of the active sites in two sorts of Fe/N/C-catalysts. While the ligand environment of a part of both materials' sites appears to change from six-/five- to fourfold coordination upon potential decrease, they differ substantially when it comes to the geometry of the coordination sphere, with the more ORR-active material undergoing more pronounced restructuring. Furthermore, these time-resolved spectroscopic measurements yield unprecedented insights into the kinetics of Fe-based molecular sites' structural reorganization, identifying the oxidation of iron as a rate-limiting process for the less ORR-active catalyst., Advanced Energy Materials, 12 (14)
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- 2022
32. Understanding the Effects of Operating Conditions on the Water Management in Anion Exchange Membrane Fuel Cells
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Björn Eriksson, Pietro Giovanni Santori, Frédéric Lecoeur, Marc Dupont, Frédéric Jaouen, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), and European Project: 721065,CREATE
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Fe-N-C ,Water management ,Renewable Energy, Sustainability and the Environment ,Humidity sensors ,Energy Engineering and Power Technology ,Anode flooding ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,[CHIM.OTHE]Chemical Sciences/Other ,AEMFC - Abstract
International audience; While water management in Anion Exchange Membrane Fuel Cells (AEMFCs) is seen as crucial for performance and durability, measurements of water management within operating cells remain few. In this work, we measured the performance of an H2/O2 AEMFC based on a low-density polyethylene membrane AEM, PtRu/C anode and Fe-N-C cathode for various combinations of inlet relative humidities, gas pressures and flow rates. Simultaneously, the anode and cathode outlet relative humidities were measured using humidity sensors, from which the amount of water removed from the cell could be quantified for each side. The data shows that back-diffusion of water from anode to cathode results in increasing outlet relative humidity with increased current density, both at anode and cathode. Water produced in the AEMFC was thus removed from both sides. The maximum current density was found to be strongly connected to anode flooding, which is also the main cause for hysteresis during potentiodynamic scans. However, under atypical operating conditions, the cell performance may also be limited by low humidity at the cathode, with associated low ionomer conductivity. Overall, it is concluded that water management of AEMFC with thin AEMs can be achieved by playing with both the anode and cathode operating conditions
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- 2022
33. Oxygen reduction reaction mechanism and kinetics on M-NxCy and M@N-C active sites present in model M-N-C catalysts under alkaline and acidic conditions
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Edson A. Ticianelli, Andrea Zitolo, Frédéric Maillard, Kavita Kumar, Ricardo Sgarbi, Frédéric Jaouen, Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, SP, Brazil, Electrochimie Interfaciale et Procédés (EIP), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI), Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), ANR-16-CE05-0007,CAT2CAT,Des catalyseurs aux cathodes: Une approche d'architecture contrôlée d'électrode pour pile PEM à base de métaux abondants(2016), and ANR-19-CE05-0039,ANIMA,Aérogels de carbone poreux dopés à l'azote et avec des métaux abondants pour des assemblages membrane-électrodes efficaces et durables(2019)
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Kinetics ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,Reaction intermediate ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,7. Clean energy ,Catalysis ,Metal ,Oxygen reduction reaction ,General Materials Science ,Electrical and Electronic Engineering ,COMBUSTÍVEIS ,[CHIM.CATA]Chemical Sciences/Catalysis ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,chemistry ,visual_art ,Electrode ,visual_art.visual_art_medium ,0210 nano-technology ,Carbon - Abstract
International audience; M-N-C electrocatalysts (where M is Fe or Co) have been investigated for mitigating the dependence on noble metals when catalyzing the oxygen reduction reaction (ORR) for fuel cell technologies in acidic or alkaline conditions. Rotating disc and rotating ring-disk electrodes measurements for Fe-N-C and CoN -C catalysts demonstrate promising performances and stability for the ORR, while the activity of main suspected active sites (M-NxCy and M@N-C) has been discussed on the basis of the known physical-chemical properties of the catalysts in acid and alkaline media. Thereupon, it is observed that atomically-dispersed Fe-NxCy sites reach the highest ORR activity in acid media when amplified by an adequate energy binding between the metallic center and the oxygenated reaction intermediates. In contrast, Fe@N-C core-shell sites reach a maximum ORR mass activity in alkaline media through a synergistic effect involving catalyst particles with metallic iron in the core and nitrogen-doped carbon in the shell.
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- 2019
34. Selective electrochemical reduction of nitric oxide to hydroxylamine by atomically dispersed iron catalyst
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Wooyul Kim, B. Kim, Geunsu Bae, Frédéric Jaouen, Hyung Suk Oh, Hyungjun Kim, Chang Hyuck Choi, Se-Jun Kim, Stefan Ringe, Donghyun Kim, Haesol Kim, Gwangju Institute of Science and Technology (GIST), Daegu Gyeongbuk Institute of Science and Technology (DGIST), Korea Advanced Institute of Science and Technology (KAIST), Pohang University of Science and Technology (POSTECH), Korea Advanced Institute of Science and Technology (KIST), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), and Sookmyung Women's University , Seoul 04310, Korea.
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Science ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Overpotential ,010402 general chemistry ,Electrocatalyst ,Electrochemistry ,7. Clean energy ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Catalysis ,Ferrous ,chemistry.chemical_compound ,Hydroxylamine ,[CHIM]Chemical Sciences ,Multidisciplinary ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemical engineering ,chemistry ,13. Climate action ,Density functional theory ,Electrocatalysis ,0210 nano-technology ,Carbon ,Faraday efficiency - Abstract
Electrocatalytic conversion of nitrogen oxides to value-added chemicals is a promising strategy for mitigating the human-caused unbalance of the global nitrogen-cycle, but controlling product selectivity remains a great challenge. Here we show iron–nitrogen-doped carbon as an efficient and durable electrocatalyst for selective nitric oxide reduction into hydroxylamine. Using in operando spectroscopic techniques, the catalytic site is identified as isolated ferrous moieties, at which the rate for hydroxylamine production increases in a super-Nernstian way upon pH decrease. Computational multiscale modelling attributes the origin of unconventional pH dependence to the redox active (non-innocent) property of NO. This makes the rate-limiting NO adsorbate state more sensitive to surface charge which varies with the pH-dependent overpotential. Guided by these fundamental insights, we achieve a Faradaic efficiency of 71% and an unprecedented production rate of 215 μmol cm−2 h−1 at a short-circuit mode in a flow-type fuel cell without significant catalytic deactivation over 50 h operation., Electrocatalytic conversion of nitrogen oxides to value-added chemicals is a promising strategy for mitigating the imbalance in the global nitrogen cycle. Here, the authors present iron–nitrogen-doped carbon as an efficient and durable electrocatalyst for selective nitric oxide reduction to hydroxylamine.
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- 2021
35. The effect of membrane thickness on AEMFC Performance: An integrated theoretical and experimental study
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Karam Yassin, John C. Douglin, Igal G. Rasin, Pietro G. Santori, Björn Eriksson, Nicolas Bibent, Frédéric Jaouen, Simon Brandon, and Dario R. Dekel
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Fuel Technology ,Nuclear Energy and Engineering ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology - Published
- 2022
36. Author Correction: P-block single-metal-site tin/nitrogen-doped carbon fuel cell cathode catalyst for oxygen reduction reaction
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Fang Luo, Aaron Roy, Luca Silvioli, David A. Cullen, Andrea Zitolo, Moulay Tahar Sougrati, Ismail Can Oguz, Tzonka Mineva, Detre Teschner, Stephan Wagner, Ju Wen, Fabio Dionigi, Ulrike I. Kramm, Jan Rossmeisl, Frédéric Jaouen, and Peter Strasser
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,General Chemistry ,Condensed Matter Physics - Published
- 2022
37. Electrochemical transformation of Fe-N-C catalysts into iron oxides in alkaline medium and its impact on the oxygen reduction reaction activity
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Ricardo Sgarbi, Kavita Kumar, Viktoriia A. Saveleva, Laetitia Dubau, Raphaël Chattot, Vincent Martin, Michel Mermoux, Pierre Bordet, Pieter Glatzel, Edson A. Ticianelli, Frédéric Jaouen, and Frédéric Maillard
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ELETROQUÍMICA ,Process Chemistry and Technology ,Catalysis ,General Environmental Science - Published
- 2022
38. Metal Oxide Clusters on Nitrogen-Doped Carbon are Highly Selective for CO2Electroreduction to CO
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Tristan Asset, Jingkun Li, Frédéric Jaouen, José Ramón Galán-Mascarós, Pengyi Tang, Jordi Arbiol, Felipe A. Garcés-Pineda, Iryna V. Zenyuk, Plamen Atanassov, Moulay Tahar Sougrati, Mounika Kodali, Andrea Zitolo, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institute of Chemical Research of Catalonia (ICIQ), The University of New Mexico [Albuquerque], Departament d'Electrònica (EME/CeRMAE/IN2UB), Universitat de Barcelona (UB), University of California [Irvine] (UCI), and University of California
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Inorganic chemistry ,Oxide ,chemistry.chemical_element ,Nitrogen doped ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Catalysis ,Metal ,chemistry.chemical_compound ,[CHIM]Chemical Sciences ,Materials ,ComputingMilieux_MISCELLANEOUS ,Catalysts ,General Chemistry ,Transition metals ,021001 nanoscience & nanotechnology ,Highly selective ,X-ray absorption near edge spectroscopy ,0104 chemical sciences ,chemistry ,Metals ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Carbon - Abstract
The electrochemical reduction of CO2 (eCO2RR) using renewable energy is an effective approach to pursue carbon neutrality. The eCO2RR to CO is indispensable in promoting C-C coupling through bifunctional catalysis and achieving cascade conversion from CO2 to C2+. This work investigates a series of M/N-C (M = Mn, Fe, Co, Ni, Cu, and Zn) catalysts, for which the metal precursor interacted with the nitrogen-doped carbon support (N-C) at room temperature, resulting in the metal being present as (sub)nanosized metal oxide clusters under ex situ conditions, except for Cu/N-C and Zn/N-C. A volcano trend in their activity toward CO as a function of the group of the transition metal is revealed, with Co/N-C exhibiting the highest activity at -0.5 V versus RHE, while Ni/N-C shows both appreciable activity and selectivity. Operando X-ray absorption spectroscopy shows that the majority of Cu atoms in Cu/N-C form Cu0 clusters during eCO2RR, while Mn/, Fe/, Co/, and Ni/N-C catalysts maintain the metal hydroxide structures, with a minor amount of M0 formed in Fe/, Co/, and Ni/N-C. The superior activity of Fe/, Co/, and Ni/N-C is ascribed to the phase contraction and the HCO3- insertion into the layered structure of metal hydroxides. Our work provides a facile synthetic approach toward highly active and selective electrocatalysts to convert CO2 into CO. Coupled with state-of-the-art NiFe-based anodes in a full-cell device, Ni/N-C exhibits >80% Faradaic efficiency toward CO at 100 mA cm-2., The research leading to these results has received funding from the A-LEAF Project, which is funded by the European Union’s H2020 Programme under grant agreement no. 732840. ICN2 and ICIQ acknowledge funding from the FEDER/Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (projects ENE2017-85087-C3 and RTI2018-095618-B-I00) and the Generalitat de Catalunya (2017 SGR 327 and 2017- SGR-1406) and by the CERCA Programme / Generalitat de Catalunya. ICN2 and ICIQ are supported by the Severo Ochoa program from Spanish MINECO (grants no. SEV-2017-0706 and CEX2019-000925-S).
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- 2021
39. Effect of Ball-Milling on the Oxygen Reduction Reaction Activity of Iron and Nitrogen Co-doped Carbide-Derived Carbon Catalysts in Acid Media
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Väino Sammelselg, Maido Merisalu, Moulay Tahar Sougrati, Mihkel Rähn, Maike Käärik, Arvo Kikas, Sander Ratso, Päärn Paiste, Kaido Tammeveski, Jaan Leis, Vambola Kisand, Frédéric Jaouen, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
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Materials science ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,Electrocatalyst ,01 natural sciences ,7. Clean energy ,Catalysis ,Metal ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering ,Ball mill ,ComputingMilieux_MISCELLANEOUS ,[CHIM.CATA]Chemical Sciences/Catalysis ,021001 nanoscience & nanotechnology ,Nitrogen ,0104 chemical sciences ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Carbide-derived carbon ,0210 nano-technology ,Carbon ,Co doped - Abstract
Iron- and nitrogen-doped carbon-based catalysts are one of the most promising alternatives to platinum-group metal-based ones currently used in the fuel cell industry. Here, we study the effect of ...
- Published
- 2019
40. Designing the 3D Architecture of PGM-Free Cathodes for H2/Air Proton Exchange Membrane Fuel Cells
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Jingkun Li, Sara Cavaliere, Dinesh C. Sabarirajan, Sebastian Brüller, Moulay Tahar Sougrati, Deborah J. Jones, Andrea Zitolo, Frédéric Jaouen, Nastaran Ranjbar-Sahraie, Iryna V. Zenyuk, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE05-0007,CAT2CAT,Des catalyseurs aux cathodes: Une approche d'architecture contrôlée d'électrode pour pile PEM à base de métaux abondants(2016)
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inorganic chemicals ,Mass transport ,Materials science ,Energy Engineering and Power Technology ,Proton exchange membrane fuel cell ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,law.invention ,Catalysis ,law ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Oxygen reduction reaction ,Electrical and Electronic Engineering ,ComputingMilieux_MISCELLANEOUS ,organic chemicals ,[CHIM.CATA]Chemical Sciences/Catalysis ,021001 nanoscience & nanotechnology ,Cathode ,Electrospinning ,0104 chemical sciences ,Chemical engineering ,0210 nano-technology - Abstract
Metal–nitrogen–carbon catalysts have emerged as the most promising platinum group metal-free catalysts toward oxygen reduction reaction for proton exchange membrane fuel cell (PEMFC) applications. ...
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- 2019
41. Electroreduction of CO 2 on Single‐Site Copper‐Nitrogen‐Doped Carbon Material: Selective Formation of Ethanol and Reversible Restructuration of the Metal Sites
- Author
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Dilan Karapinar, Ngoc Tran Huan, Nastaran Ranjbar Sahraie, Jingkun Li, David Wakerley, Nadia Touati, Sandrine Zanna, Dario Taverna, Luiz Henrique Galvão Tizei, Andrea Zitolo, Frédéric Jaouen, Victor Mougel, and Marc Fontecave
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General Medicine - Published
- 2019
42. Accurate Evaluation of Active-Site Density (SD) and Turnover Frequency (TOF) of PGM-Free Metal–Nitrogen-Doped Carbon (MNC) Electrocatalysts using CO Cryo Adsorption
- Author
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Nathaniel Leonard, Chang Hyuck Choi, Peter Strasser, Wen Ju, Shuang Li, Frédéric Jaouen, Mathias J.M. Primbs, Arne Thomas, Fang Luo, Technische Universität Berlin (TU), Gwangju Institute of Science and Technology (GIST), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), European Project: 779366,CRESCENDO, Technical University of Berlin / Technische Universität Berlin (TU), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
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biology ,Cryo-adsorption ,Inorganic chemistry ,chemistry.chemical_element ,Active site ,Sorption ,[CHIM.CATA]Chemical Sciences/Catalysis ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Metal ,chemistry ,visual_art ,Desorption ,visual_art.visual_art_medium ,biology.protein ,0210 nano-technology ,Carbon ,ComputingMilieux_MISCELLANEOUS - Abstract
The number of catalytically active sites (site density, SD) and the catalytic turnover frequency (TOF) are critical for meaningful comparisons between catalytic materials and their rational improvement. SD and TOF numbers have remained elusive for PGM-free, metal/nitrogen-doped porous carbon electrocatalysts (MNC), in particular, FeNC materials that are now intensively investigated and widely utilized to catalyze the oxygen reduction reaction (ORR) in fuel cell cathodes. Here, we apply CO cryo sorption and desorption to evaluate SD and TOF numbers of a state-of-art FeNC ORR electrocatalyst with atomically dispersed coordinative FeNx (x ≤ 4) sites in acid and alkaline conditions. More specifically, we study the impact of thermal pretreatment conditions prior to assessing the number of sorption-active FeNx sites. We show that the pretreatment temperature sensitively affects the CO sorption uptake through a progressive thermal removal of airborne adsorbates, which, in turn, controls the resulting catalytic S...
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- 2019
43. Strategies to Hierarchical Porosity in Carbon Nanofiber Webs for Electrochemical Applications
- Author
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Sara Cavaliere, Deborah J. Jones, Frédéric Jaouen, Svitlana Yarova, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), The research leading to these results has received funding from the French National Research Agencyunder the CAT2CAT contract (ANR-16-CE05-0007). SC acknowledges the financial support from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC GrantAgreement n. 306682 and the French IUF., European Project: 306682,EC:FP7:ERC,ERC-2012-StG_20111012,SPINAM(2013), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE05-0007,CAT2CAT,Des catalyseurs aux cathodes: Une approche d'architecture contrôlée d'électrode pour pile PEM à base de métaux abondants(2016)
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Materials science ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,medicine ,micropore ,mesopore ,porogen ,Porosity ,electrospinning ,Polyvinylpyrrolidone ,Carbon nanofiber ,Polyacrylonitrile ,carbon nanofiber ,ammonia activation ,surface area ,[CHIM.CATA]Chemical Sciences/Catalysis ,Microporous material ,021001 nanoscience & nanotechnology ,Electrospinning ,0104 chemical sciences ,chemistry ,Chemical engineering ,porous fiber ,0210 nano-technology ,Mesoporous material ,Carbon ,medicine.drug - Abstract
Morphology and porosity are crucial aspects for designing electrodes with facile transport of electrons, ions and matter, which is a key parameter for electrochemical energy storage and conversion. Carbon nanofibers (CNFs) prepared by electrospinning are attractive for their high aspect ratio, inter-fiber macroporosity and their use as self-standing electrodes. The present work compares several strategies to induce intra-fiber micro-mesoporosity in self-standing CNF webs prepared by electrospinning polyacrylonitrile (PAN). Two main strategies were investigated, namely i) a templating method based on the addition of a porogen (polymethyl methacrylate, polyvinylpyrrolidone, Nafion®, or ZnCl2) in the electrospinning solution of PAN, or ii) the activation in ammonia of previously formed CNF webs. The key result of this study is that open intra-fiber porosity could be achieved only when the strategies i) and ii) were combined. When each approach was applied separately, only closed intra-fiber porosity or no intra-fiber porosity was observed. In contrast, when both strategies were used in combination all CNF webs showed high mass-specific areas in the range of 325 to 1083 m2·, g&minus, 1. Selected webs were also characterized for their carbon structure and electrical conductivity. The best compromise between high porosity and high electrical conductivity was identified as the fibrous web electrospun from PAN and polyvinylpyrrolidone.
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- 2019
44. Engineering catalytic dephosphorylation reaction for endotoxin inactivation
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Meng Gao, Xi Liu, Zhenzhen Wang, Hui Wang, Tristan Asset, Di Wu, Jun Jiang, Qianqian Xie, Shujuan Xu, Xiaoming Cai, Jia Li, Weili Wang, Huizhen Zheng, Xingfa Gao, Nikolai Tarasenko, Benjamin Rotonnelli, Jean-Jacques Gallet, Frédéric Jaouen, and Ruibin Li
- Subjects
Biomedical Engineering ,Pharmaceutical Science ,General Materials Science ,Bioengineering ,Biotechnology - Published
- 2022
45. Narrow resection margins are not associated with mortality or recurrence in patients with Merkel cell carcinoma: a retrospective study
- Author
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Eric Estève, Brigitte Dréno, Mahtab Samimi, Hervé Maillard, Yannick Le Corre, Agnès Caille, Astrid Blom, Monica Dinulescu, Philippe Saiag, Thibault Kervarrec, E. Wierzbicka-Hainaut, Frédéric Jaouen, Université de Tours (UT), Service de dermatologie, Centre Hospitalier Régional Universitaire de Tours (CHRU Tours), Service de Pathologie [CHRU Tours], Infectiologie et Santé Publique (UMR ISP), Université de Tours (UT)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), MethodS in Patients-centered outcomes and HEalth ResEarch (SPHERE), Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR des Sciences Pharmaceutiques et Biologiques, Université de Nantes (UN)-Université de Nantes (UN), Centre d’Investigation Clinique [Tours] CIC 1415 (CIC ), Centre Hospitalier Régional Universitaire de Tours (CHRU Tours)-Hôpital Bretonneau-Université de Tours (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Département de dermatologie [CHU Angers], Centre Hospitalier Universitaire d'Angers (CHU Angers), PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Nantes Angers Le Mans (UNAM), Service de dermatologie [Nantes], Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes), Service de Dermatologie [Orléans], Centre Hospitalier Régional d'Orléans (CHRO), Département de Dermatologie [CHU Poitiers], Centre hospitalier universitaire de Poitiers (CHU Poitiers), Service de dermatologie [CH Le Mans], Centre Hospitalier Le Mans (CH Le Mans), Service de Dermatologie [Rennes] = Dermatology [Rennes], CHU Pontchaillou [Rennes], Service de Dermatologie Générale et Oncologique [AP-HP Hôpital Ambroise-Paré, Paris], Hôpital Ambroise Paré [AP-HP], Université de Tours, Centre Hospitalier Régional Universitaire de Tours (CHRU TOURS), Université de Tours-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Tours-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR des Sciences Pharmaceutiques et Biologiques, Centre Hospitalier Régional Universitaire de Tours (CHRU Tours)-Hôpital Bretonneau-Université de Tours-Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Versailles Saint-Quentin-en-Yvelines - UFR Sciences de la santé Simone Veil (UVSQ Santé), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and CCSD, Accord Elsevier
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Male ,Wide Local Excision ,Neoplasm, Residual ,medicine.medical_treatment ,[SDV]Life Sciences [q-bio] ,Cohort Studies ,030207 dermatology & venereal diseases ,0302 clinical medicine ,Merkel cell carcinoma ,Surgical margins ,Wide local excision ,Hazard ratio ,Margins of Excision ,Merkel Cell Carcinoma ,Middle Aged ,Prognosis ,Combined Modality Therapy ,Primary tumor ,3. Good health ,[SDV] Life Sciences [q-bio] ,030220 oncology & carcinogenesis ,Cohort ,Female ,France ,medicine.medical_specialty ,[SDV.CAN]Life Sciences [q-bio]/Cancer ,Dermatology ,Disease-Free Survival ,03 medical and health sciences ,[SDV.CAN] Life Sciences [q-bio]/Cancer ,medicine ,Humans ,Mortality ,General surgery ,Survival rate ,Aged ,Proportional Hazards Models ,Retrospective Studies ,business.industry ,Retrospective cohort study ,[SDV.MHEP.DERM] Life Sciences [q-bio]/Human health and pathology/Dermatology ,medicine.disease ,Skin neoplasms ,Survival Analysis ,Surgery ,Carcinoma, Merkel Cell ,Radiation therapy ,Multivariate Analysis ,Radiotherapy, Adjuvant ,Neoplasm Recurrence, Local ,business ,[SDV.MHEP.DERM]Life Sciences [q-bio]/Human health and pathology/Dermatology ,Follow-Up Studies - Abstract
Wide local excision constitutes the standard of care for Merkel cell carcinoma, but the optimal margin width remains controversial.To assess whether narrow margins (0.5-1 cm) were associated with outcome.Patients were recruited from a retrospective French multicentric cohort and included if they had had excision of primary tumor with minimum lateral margins of 0.5 cm. Factors associated with mortality and recurrence were assessed by multivariate regression.Among the 214 patients included, 58 (27.1%) had undergone excision with narrow margins (0.5-1 cm) versus 156 (72.9%) with wide margins (1 cm). During a median follow-up of 50.7 months, cancer-specific survival did not differ between groups (5-year specific survival rate 76.8% [95% confidence interval 61.7%-91.9%] and 76.2% [95% confidence interval 68.8%-83.6%], respectively). Overall survival, any recurrence-free survival, and local recurrence-free survival did not significantly differ between groups. Cancer-specific mortality was associated with age, male sex, American Joint Committee on Cancer stage III, and presence of positive margins.Retrospective design, heterogenous baseline characteristics between groups.Excision with narrow margins was not associated with outcome in this cohort, in which most patients had clear margins and postoperative radiation therapy. Residual tumor, mostly found on deep surgical margins, was independently associated with prognosis.
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- 2021
46. Understanding how single-atom site density drives the performance and durability of PGM-free Fe–N–C cathodes in anion exchange membrane fuel cells
- Author
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Dario R. Dekel, Xiong Peng, Simon Brandon, Karam Yassin, Frédéric Jaouen, Noor Ul Hassan, William E. Mustain, Horie Adabi, Moulay Tahar Sougrati, Andrea Zitolo, John R. Regalbuto, Igal G. Rasin, John R. Varcoe, Pietro Giovanni Santori, Abolfazl Shakouri, University of South Carolina [Columbia], Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), University of Surrey (UNIS), European Project: 721065,CREATE, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
- Subjects
Materials science ,Oxygen reduction ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Catalysis ,law.invention ,Metal ,High performance ,law ,PGM-free ,General Materials Science ,Materials of engineering and construction. Mechanics of materials ,Power density ,Fe–N–C ,Ion exchange ,AEM ,Mechanical Engineering ,Fuel cell ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Cathode ,0104 chemical sciences ,Anode ,Fe-N-C ,Membrane ,Chemical engineering ,Single-atom ,visual_art ,Electrode ,visual_art.visual_art_medium ,TA401-492 ,0210 nano-technology ,[CHIM.OTHE]Chemical Sciences/Other - Abstract
International audience; One of the most important needs for the future of low-cost fuel cells is the development of highly active platinum group metal (PGM)-free catalysts. For the oxygen reduction reaction, Fe–N–C materials have been widely studied in both acid and alkaline media. However, reported catalysts in the literature show quite different intrinsic activity and in-cell performance, despite similar synthesis routes and precursors. Here, two types of Fe–N–C are prepared from the same precursor and procedure – the main difference is how the precursor was handled prior to use. It is shown that in one case Fe overwhelmingly existed as highly active single-metal atoms in FeN4 coordination (preferred), while in the other case large Fe particles coexisting with few single metal atoms were obtained. As a result, there were drastic differences in the catalyst structure, activity, and especially in their performance in an operating anion exchange membrane fuel cell (AEMFC). Additionally, it is shown that catalyst layers created from single-atom-dominated Fe–N–C can have excellent performance and durability in an AEMFC using H2/O2 reacting gases, achieving a peak power density of 1.8 W cm−2 – comparable to similar AEMFCs with a Pt/C cathode – and being able to operate stably for more than 100 h. Finally, the Fe–N–C cathode was paired with a low-loading PtRu/C anode electrode to create AEMFCs (on H2/O2) with a total PGM loading of only 0.135 mg cm−2 (0.090 mgPt cm−2) that was able to achieve a very high specific power of 8.4 W mgPGM−1 (12.6 W mgPt−1)
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- 2021
47. Deactivation of Fe-N-C catalysts during catalyst ink preparation process
- Author
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Frédéric Jaouen, Minhee Suk, Chang Hyuck Choi, Min Wook Chung, Gajeon Chon, Gwangju Institute of Science and Technology (GIST), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Max-Planck-Institut für Eisenforschung GmbH, and Max-Planck-Gesellschaft
- Subjects
Chemistry ,Membrane electrode assembly ,Proton-exchange membrane fuel cells ,Proton exchange membrane fuel cell ,02 engineering and technology ,General Chemistry ,Ink preparation ,[CHIM.CATA]Chemical Sciences/Catalysis ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Suspension (chemistry) ,Oxygen reduction reaction ,Solvent ,Sonication ,Non-precious metal catalysts ,Chemical engineering ,Zeta potential ,Fe-N-C catalysts ,Wetting ,0210 nano-technology ,Dispersion (chemistry) - Abstract
International audience; The membrane electrode assembly (MEA) is a core component of low-temperature fuel cells. The first step of MEA manufacturing is the preparation of a catalyst ink suspension in which the catalyst powder is homogeneously dispersed in a liquid solvent through mechanical or sonic agitation. In this work, we have studied the effects of catalyst dispersion in water or alcohol solutions and subsequent drying processes on the physicochemical properties of Fe-N-C catalysts and their electrocatalytic oxygen reduction activities. We find that dispersing the model Fe-N-C catalyst comprising only FeNxCy moieties in water and subsequent drying treatment change neither its bulk structure nor surface composition, as indicated by various spectroscopic measurements before and after treatment. However, zeta potential measurements, which are very sensitive to the chemistry of functionalities present on the carbon surface, reveal that the Fe-N-C catalyst becomes slightly more acidic, and that the change in their acido-basicity is magnified with a) increasing treatment temperature and b) repetitions of a same wetting/drying treatment. This small change in the surface acido-basicity of the Fe-N-C catalyst results in a measurable and reproducible decrease in its electrocatalytic activity, which shows a positive correlation with the zeta potential changes measured at pH = 1. Observed on the Fe-N-C catalyst but not on Pt/C, it is surmised that the electrocatalytic activities of the oxygen-reducing FeNxCy moieties are influenced by the surface chemistry of the carbonaceous support. Since catalyst wetting and drying processes are essential for MEA fabrication for fuel cells, these results suggest that careful attention should be paid to the conditions employed to prepare and dry catalytic inks for the family of Fe-N-C catalysts in order to obtain their highest possible ORR activity.
- Published
- 2021
48. Influence of the synthesis parameters on the proton exchange membrane fuel cells performance of Fe–N–C aerogel catalysts
- Author
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Moulay Tahar Sougrati, Mikkel Juul Larsen, Youling Wang, Sergio Rojas, Diego Gianolio, Frédéric Jaouen, Pilar Ferrer, Sandrine Berthon-Fabry, Centre Procédés, Énergies Renouvelables, Systèmes Énergétiques (PERSEE), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), IRD Fuel Cells A/S [Denmark] (IRD), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), DIAMOND Light source, MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
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Materials science ,Absorption spectroscopy ,Energy Engineering and Power Technology ,Proton exchange membrane fuel cell ,02 engineering and technology ,Resorcinol ,010402 general chemistry ,01 natural sciences ,Catalysis ,Oxygen reduction reaction ,chemistry.chemical_compound ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Rotating disk electrode ,Carbon aerogel ,Renewable Energy, Sustainability and the Environment ,Supercritical drying ,Aerogel ,[CHIM.MATE]Chemical Sciences/Material chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,021001 nanoscience & nanotechnology ,Acidic media ,PEMFCs ,0104 chemical sciences ,chemistry ,Chemical engineering ,Chemisorption ,0210 nano-technology ,Non-precious metal catalyst - Abstract
International audience; Fe–N–C aerogel catalysts were prepared by sol–gel polycondensation of resorcinol, melamine and formaldehyde precursors in the presence of FeCl3 salt, followed by supercritical drying and thermal treatments. The effect of the mass ratio of precursors on the microstructure, iron speciation and oxygen reduction reaction (ORR) performance of the Fe–N–C aerogels was investigated by N2 sorption, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, X-ray absorption spectroscopy, CO chemisorption and rotating disk electrode in acidic medium. The best ORR performance (activity and mass transport) was obtained by an optimum balance between pore structure and active Fe-Nx species. Through acid washing, the durability of the catalyst was further improved by eliminating unstable and inactive species, particularly iron nanoparticles and iron carbide. From the CO chemisorption and turnover-frequency value, the surface sites were comparable with the highest values reported in literature. Finally, Fe–N–C aerogel catalyst was implemented a in membrane–electrode assembly with an active area of 25 cm2 and tested in single cell, emphasizing the importance of the ink formulation on the performance.
- Published
- 2021
49. Non-precious metal cathodes for anion exchange membrane fuel cells from ball-milled iron and nitrogen doped carbide-derived carbons
- Author
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Vambola Kisand, Andrea Zitolo, Arvo Kikas, Maido Merisalu, Päärn Paiste, Frédéric Jaouen, Kaido Tammeveski, Jaan Leis, Mihkel Rähn, Väino Sammelselg, Maike Käärik, Steven Holdcroft, Sander Ratso, University of Tartu, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Tartu], Simon Fraser University (SFU.ca), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
- Subjects
Materials science ,Oxygen reduction ,020209 energy ,02 engineering and technology ,Electrolyte ,Electrocatalyst ,7. Clean energy ,Carbide ,law.invention ,Catalysis ,Fe-Nx site ,law ,Anion exchange membrane fuel cell ,0202 electrical engineering, electronic engineering, information engineering ,0601 history and archaeology ,Rotating disk electrode ,060102 archaeology ,Renewable Energy, Sustainability and the Environment ,06 humanities and the arts ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Cathode ,Ball-milling ,Chemical engineering ,Carbide-derived carbon ,Electrocatalysis ,[CHIM.OTHE]Chemical Sciences/Other ,Pyrolysis - Abstract
International audience; Iron and nitrogen doping of carbon materials is one of the promising pathways towards replacing Pt/C in polymer electrolyte fuel cell cathodes. Here, we show a synthesis method to produce highly active non-precious metal catalysts and study the effect of synthesis parameters on the oxygen reduction reaction (ORR) activity in high-pH conditions. The electrocatalysts are prepared by functionalizing silicon carbide-derived carbon (SiCDC) with 1,10-phenanthroline, iron(II)acetate and, optionally polyvinylpyrrolidone, by ball-milling with ZrO2 in dry or wet conditions, followed by pyrolysis at 800 °C. The catalysts are characterized by scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, N2 physisorption and inductively coupled plasma mass spectrometry. By optimizing the ball-milling conditions, we achieved a reduction in the size of SiCDC grains from >1 μm to 200 nm without negatively affecting the high BET area of catalysts derived from SiCDC. This resulted in increased ORR activity in both rotating disk electrode and anion exchange membrane fuel cell (AEMFC) environments, and improved mass-transport properties of the cathode layer in fuel cell. The ORR activity at 0.9 V in AEMFC of the optimized iron and nitrogen-doped SiCDC reaches 52 mA cm−2, exceeding that of a Pt/C cathode at 36.5 mA cm−2.
- Published
- 2021
50. Chemical Vapor Deposition of Fe-N-C Oxygen Reduction Catalysts with Full Utilization of Dense Fe-N4 Sites
- Author
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Moulay Tahar Sougrati, Li Jiao, Zipeng Zhao, Yu Huang, Ershuai Liu, Fan Yang, Thomas Stracensky, Frédéric Jaouen, Sichen Zhong, Qingying Jia, David A. Cullen, Hui Xu, Sanjeev Mukerjee, Deborah J. Myers, Lynne Larochelle Richard, Jingkun Li, Qiang Sun, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), and Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)
- Subjects
Materials science ,010405 organic chemistry ,Proton exchange membrane fuel cell ,chemistry.chemical_element ,Substrate (chemistry) ,Chemical vapor deposition ,[CHIM.CATA]Chemical Sciences/Catalysis ,010402 general chemistry ,01 natural sciences ,Oxygen reduction ,0104 chemical sciences ,Catalysis ,Chemical engineering ,chemistry ,Platinum ,Current density ,Bar (unit) - Abstract
Replacing scarce and expensive platinum (Pt) with metal-nitrogen-carbon (M-N-C) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) has largely been impeded by the low activity of M-N-C, in turn limited by low site density and low site utilization. Herein, we overcome these limits by implementing chemical vapor deposition (CVD) to synthesize Fe-N-C, an approach fundamentally different from previous routes. The Fe-N-C catalyst, prepared by flowing iron chloride vapor above a N-C substrate at 750 ℃, has a record Fe-N4 site density of 2×1020 sites·gram-1 with 100% site utilization. A combination of characterizations shows that the Fe-N4 sites formed via CVD are located exclusively on the outer-surface, accessible by air, and electrochemically active. This catalyst delivers an unprecedented current density of 33 mA·cm-2 at 0.90 ViR-free (iR-corrected) in an H2-O2 PEMFC at 1.0 bar and 80 ℃.
- Published
- 2020
Catalog
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