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16 results on '"Camila Rivera‐Cárcamo"'

1. Preparation of Few-Layer Graphene/Carbon Nanotube Hybrids Using Oxide Spinel Catalysts

Author

Bruno F. Machado, Revathi R. Bacsa, Camila Rivera-Cárcamo, and Philippe Serp

Subjects
carbon nanotubes, few-layer graphene, hybrid, catalytic chemical vapor deposition, Al-doping, cobalt ferrite, Organic chemistry, QD241-441
Abstract

Functional 3D materials can be developed from graphene-based hybrids by introducing other nanomaterials, with multi-walled carbon nanotubes (CNTs) being the most studied additive. For large-scale applications, few-layer graphene (FLG)-CNT hybrids are produced by catalytic chemical vapor deposition (c-CVD) starting from a mixture of catalysts (one for FLG and one for CNTs) in the required proportions. Due to the difference in growth kinetics between CNTs and FLG, the composition of such hybrids is not well controlled. In this study, we report the single-step preparation of FLG-CNT hybrid materials by a fixed-bed c-CVD process using a single catalyst with the formula AlxCo1 − xFe2O4 (x = 0.025−0.10). Different catalysts (with varying x) were prepared by the citrate−nitrate gel combustion method. Then, c-CVD synthesis was carried out at 650 °C in a horizontal fixed-bed reactor using ethylene as the carbon source. Only FLG was obtained when using CoFe2O4. However, the introduction of small amounts of Al (x < 0.05) induced the simultaneous production of CNTs, leading to the formation of uniform FLG-CNT hybrids. For catalysts with higher Al content (e.g., AlCoFeO4), CNTs were selectively produced. Thus, we observed the existence of a narrow Al-doping window, where CNTs and FLG can be obtained simultaneously. Our results can pave the way to developing high-yield single catalyst-based CVD synthesis of FLG-CNT hybrid materials.

Published
2019
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2. Deactivation of Pd/C catalysts by irreversible loss of hydrogen spillover ability of the carbon support

Author

Laurent Vanoye, Boris Guicheret, Camila Rivera-Cárcamo, Jérémy Audevard, Javier Navarro-Ruiz, Iker del Rosal, Iann C. Gerber, Cristian H. Campos, Bruno Fernandes Machado, Jérôme Volkman, Régis Philippe, Philippe Serp, Alain Favre-Réguillon, Catalyse, Polymérisation, Procédés et Matériaux (CP2M), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción - University of Concepcion [Chile], Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia (LSRE-LCM), Universidade do Porto = University of Porto, Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), and ANR-19-CE07-0030,COMET,Catalyse Coopérative Entre Atomes Et Nanoparticules Métalliques(2019)

Subjects
[CHIM]Chemical Sciences, [CHIM.CATA]Chemical Sciences/Catalysis, Physical and Theoretical Chemistry, Catalysis
Abstract

International audience; General interest in solvent-free catalytic processes is driven by the development of environmentally and economically acceptable procedures. Such processes require the use of highly active and stable catalysts. This study reports on the synthesis, characterization, and kinetic evaluation of two highly active Pd catalysts supported on different carbons support, i.e., multi-walled carbon nanotubes (CNT) and few-layer graphene (FLG). These catalysts, with similar Pd loading (∼2 wt%) and containing both Pd single atoms (PdSA) and nanoparticles (PdNP), were systematically tested for solvent-free total hydrogenation of squalene (SQE) to obtain high-purity squalane (SQA). Thanks to the unique cooperative catalysis between PdSA and PdNP involving H-spillover, the activities of both catalysts were high compared to catalysts described in the literature. Solvent-free total hydrogenation of SQE could be performed under mild conditions (120 °C, 20 bar H2, 4 h) using ultralow Pd loading (60 ppm). However, since this reduction reaction is highly exothermic (ΔHR= − 765 kJ.mol−1), heat management during the reactor operation with these highly active catalysts is crucial to avoid deactivation and thermal runaway. Under these conditions, Pd/FLG was highly active but deactivated, unlike Pd/CNT, which still has high activity, but does not deactivate. Characterizations (ICP, XPS, Raman, TPD-MS, HAADF-STEM) of the Pd/FLG catalyst before and after reaction, supported by calculations based on density functional theory, allowed us to propose a new mechanism of catalyst deactivation involving the chemical reduction of specific surface oxygen groups of the carbon support induced by H-spillover.

Published
2023

4. Solvent‐Free Hydrogenation of Squalene Using Parts per Million Levels of Palladium Supported on Carbon Nanotubes: Shift from Batch Reactor to Continuous‐Flow System

Author

Boris Guicheret, Laurent Vanoye, Camila Rivera‐Cárcamo, Claude de Bellefon, Philippe Serp, Régis Philippe, and Alain Favre‐Réguillon

Subjects
Squalene, General Energy, Nanotubes, Carbon, General Chemical Engineering, Solvents, Environmental Chemistry, General Materials Science, Hydrogenation, Catalysis, Palladium
Abstract

The transition from batch catalytic processes to continuous flow processes requires highly active and stable catalysts that still need to be developed. The preparation and characterization of catalysts where palladium single atoms and nanoparticles are simultaneously present on carbon nanotubes were recently reported by us. These catalysts are considerably more active than commercial or previously described catalysts for the liquid phase hydrogenation of terpenes. Herein is shown that under solvent-free conditions, squalene (SQE) could be converted into squalane (SQA,98 %) using only 300 ppm of Pd in less than 1.4 h at 20 bar H

Published
2022

5. Control of the single atom/nanoparticle ratio in Pd/C catalysts to optimize the cooperative hydrogenation of alkenes

Author

Camila Rivera‐Cárcamo, Alain Favre-Réguillon, C. de Bellefon, Iann C. Gerber, Boris Guicheret, Régis Philippe, J. Audevard, I. del Rosal, Bruno F. Machado, R. Castro Contreras, Laurent Vanoye, Philippe Serp, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Laboratoire de Génie des Procédés Catalytiques (LGPC), École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Conservatoire National des Arts et Métiers [CNAM] (CNAM), Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM) Departamento de Tecnologia Quimica e Biologica Escola Superior de Tecnologia e Gestao (LSRE-LCM), Instituto Politecnico de Braganca, Fundação para a Ciência e a Tecnologia, CONICYT, Région Auvergne-Rhône-Alpes (contract number 15 021131 01 – CNR006), ANR-19-CE07-0030,COMET,Catalyse Coopérative Entre Atomes Et Nanoparticules Métalliques(2019), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS), and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)

Subjects
chemistry.chemical_classification, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Chemistry, Alkene, Inorganic chemistry, Nanoparticle, chemistry.chemical_element, [CHIM.CATA]Chemical Sciences/Catalysis, 02 engineering and technology, Orders of magnitude (numbers), 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Oxygen, Catalysis, 0104 chemical sciences, Hydrogen spillover, 0210 nano-technology, Dispersion (chemistry), Isomerization
Abstract

International audience; We recently reported (R. Castro Contreras, B. Guicheret, B. F. Machado, C. Rivera-Cárcamo, M. A. Curiel Alvarez, B. Valdez Salas, M. Ruttert, T. Placke, A. Favre Réguillon, L. Vanoye, C. de Bellefon, R. Philippe and P. Serp, J. Catal., 2019, 372, 226–244) that a structure/activity correlation exists in Pd/C catalysts for myrcene hydrogenation, which integrates the Pd dispersion, and the surface concentration of oxygen groups and defects of the support. Here, through a combined experimental–theoretical study, we provide an explanation of the influence of these three structural characteristics of Pd/C catalysts for alkene hydrogenation. Highly dispersed Pd nanoparticles (PdNP) are necessary to activate dihydrogen. A high concentration of surface defects on the support is necessary to stabilize Pd single atoms (PdSA), which coexist with PdNP on Pd/C catalysts. A high concentration of oxygenated surface groups is also necessary on the support to allow hydrogen spillover. We demonstrate that such a combination allows cooperative catalysis to operate between PdNP and PdSA that involves the formation of PdSA–H species, which are much more active than PdNP–H for alkene hydrogenation but also isomerization. Importantly, we also report an efficient method to control the ratio between PdSA and PdNP in Pd/C catalysts of similar loadings and show that the control of this ratio allows the development of a new generation of stable and highly active catalysts integrating the ultra-rational use of precious metals in short supply. Indeed, for myrcene hydrogenation, activity variations of several orders of magnitude were measured as a function of the value of this ratio.

Published
2021

6. Ru single atoms and nanoparticles on carbon nanotubes as multifunctional catalysts

Author

Philippe Serp, Diana M. Fernandes, Camila Rivera‐Cárcamo, Mariana Rocha, Cristina Freire, LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Reducing agent, Inorganic chemistry, Oxygen evolution, Selective catalytic reduction, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 01 natural sciences, 7. Clean energy, 0104 chemical sciences, Catalysis, Inorganic Chemistry, chemistry.chemical_compound, Sodium borohydride, Reaction rate constant, chemistry, 13. Climate action, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Methanol, 0210 nano-technology
Abstract

International audience; In the last decade we have witnessed increasing interest in the production of renewable energy and value-added chemicals through sustainable and low-cost technologies where catalysts play a crucial role. Herein, we report the application of a Ru/CNT material containing a mixture of Ru single atoms and Ru nanoparticles as a multifunctional catalyst for both the catalytic reduction of nitroarenes and the electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The catalytic activity of the Ru-CNT material was evaluated in the reduction of 4-nitrophenol (4-NP), 4-nitroaniline (4-NA) and 2-nitrophenol (2-NP) in the presence of sodium borohydride as a reducing agent at room temperature, showing high catalytic activity with normalized rate constants (knor) of 19.0 × 103, 57.7 × 103 and 16.6 × 103 min−1 mmol−1 respectively. Furthermore, the catalyst could be reused in at least 10 cycles without catalytic activity loss, confirming the high stability and robustness of the material. The Ru/CNT material also showed good ORR electrocatalytic activity in alkaline medium with Eonset of 0.76 V vs. RHE, a diffusion-limited current density of 3.89 mA cm−2 and ñO2 of 3.3. In addition, Ru/CNT was remarkably insensitive to methanol with a current retention of 93% (51% for Pt/C) and competitive electrochemical stability of 80% after 20 000 s. Moreover, Ru/CNT was active for the OER with jmax = 29.5 mA cm−2 at E = 1.86 V vs. RHE, η10 = 0.50 V and good stability (η10 changed to 0.01 V and jmax only decreased by ≈12% after 500 cycles).

Published
2020

7. Computational Design of Pd Nanocluster and Pd Single-Atom Catalysts Supported on O-Functionalized Graphene

Author

Bruno F. Machado, Iker del Rosal, Iann C. Gerber, Philippe Serp, Javier Navarro-Ruiz, Camila Rivera‐Cárcamo, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia (LSRE-LCM), Universidade do Porto = University of Porto, ANR-19-CE07-0030,COMET,Catalyse Coopérative Entre Atomes Et Nanoparticules Métalliques(2019), Institut National des Sciences Appliquées (INSA)-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées (INSA)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées (INSA)-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Universidade do Porto

Subjects
Nanocluster, Materials science, Single atom, Atom (order theory), Functionalized graphene, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Nanoclusters, Catalysis, Crystallography, Oxygen functional group, Supported catalyst, Computational design, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Hydrogenation, Graphene, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Palladium
Abstract

International audience; A crucial step in the preparation of supported metal catalysts is related to the choice of support, since it regulates the anchoring of the metal species in an environment of strong interactions. In this sense, the binding on the support, which may present defects, as well as induced modifications of the electronic structure, helps to determine efficient metal/support combinations for catalysis applications. In this work, first-principles studies have been carried out to model and describe the geometric and electronic properties of O-functionalized graphene as a model carbon support, in addition to a single Pd atom and Pd13 nanocluster (experimentally observed on various carbon supports) as supported metal catalysts. The carbon-based nanomaterial includes experimentally probed abundant oxygen functional groups and point defects, demonstrating high thermal stability at room temperature. The characterization confirms the structural motifs presented in the model, distinguishing the organic functionalities and various defects using spectroscopy techniques. Interestingly, the oxygenated carbon-based support presents a metallic character when the formal charges in the embedded Pd atom and nanocluster have been determined to be [Pd]+ and [Pd13]3+. The hydrogenation process of the adsorbed cluster is also presented, with the determination of a ratio between the adsorbed hydrides and the surface metal atoms close to unity at room temperature, thanks to ab initio molecular dynamics.

Published
2021

8. Process intensification of the catalytic hydrogenation of squalene using a Pd/CNT catalyst combining nanoparticles and single atoms in a continuous flow reactor

Author

Laurent Vanoye, Boris Guicheret, Camila Rivera-Cárcamo, Ruben Castro Contreras, Claude de Bellefon, Valérie Meille, Philippe Serp, Régis Philippe, Alain Favre-Réguillon, Catalyse, Polymérisation, Procédés et Matériaux (CP2M), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), 'DEEPER' project / Region Auvergne-Rhône-Alpes (contract number 15 021131 01 – CNR006) - 20th FUI call, and ANR-19-CE07-0030,COMET,Catalyse Coopérative Entre Atomes Et Nanoparticules Métalliques(2019)

Subjects
Squalene, Seamless scale-up, [CHIM.GENI]Chemical Sciences/Chemical engineering, [CHIM.ORGA]Chemical Sciences/Organic chemistry, General Chemical Engineering, Structured reactors, Environmental Chemistry, Catalytic hydrogenation, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, Palladium, Carbon nanotube support, Industrial and Manufacturing Engineering
Abstract

International audience; A process intensification study for the full hydrogenation of bio-derived platform molecule squalene (SQE) into squalane (SQA), using commercial heterogeneous Pd catalysts and Pd supported on carbon nanotubes (CNT) is reported. Pd/CNT shows a substantial improvement of the catalytic activity for the total hydrogenation of SQE into SQA thanks to cooperativities between Pd nanoparticles and single atoms simultaneously present on the CNT. However, the stirred reactor's productivity, scalability, and operability are limited by the exothermicity of the reaction (ΔrH = − 765 kJ.mol−1). The implementation of the Pd/CNT catalyst in flow was then studied after coating this catalyst on metallic open cell foams. Using the foam-based milli-reactor's characteristics, including high mass and heat transfer rates and safety, fully reduced SQA (>99 %) was obtained at 180 °C and 30 bar of H2 for a contact time of 1.45 min with a space–time yield of 68 molSQA.molPd−1.min−1. Finally, a scale-up strategy (7 fold) was successfully attempted in a commercially available pilot-scale reactor that meets further seamless scale-up requirements. A production capacity of 2 kg per day using a commercial intensified reactor with a reacting volume of 43.2 mL was obtained under mild conditions (120 °C and 30 bar of H2).

Published
2022

9. Catalysis to discriminate single atoms from subnanometric ruthenium particles in ultra-high loading catalysts

Author

Pierre Lecante, M. R. Axet, Romuald Poteau, Vincent Collière, I. del Rosal, Iann C. Gerber, Camila Rivera‐Cárcamo, Divya Nechiyil, Wolfgang Bacsa, Faqiang Leng, Philippe Serp, Anna Corrias, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), University of Kent [Canterbury], Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Extended X-ray absorption fine structure, chemistry.chemical_element, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Materials for Energy and Electronics, 01 natural sciences, Catalysis, 0104 chemical sciences, Ruthenium, symbols.namesake, chemistry, X-ray photoelectron spectroscopy, symbols, Physical chemistry, Density functional theory, [CHIM.COOR]Chemical Sciences/Coordination chemistry, 0210 nano-technology, High-resolution transmission electron microscopy, Raman spectroscopy
Abstract

International audience; We report a procedure for preparing ultra-high metal loading (10–20% w/w Ru) Ru@C60 nanostructured catalysts comprising exclusively Ru single atoms. We show that by changing the Ru/C60 ratio and the nature of the solvent used during the synthesis, it is possible to increase the Ru loading up to 50% w/w, and to produce hetero-structures containing subnanometric Ru nanoparticles. Several techniques such as high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy-high angle annular dark field (STEM-HAADF), Raman spectroscopy, wide-angle X-ray scattering (WAXS), extended X-ray absorption fine structure (EXAFS) and X-ray photoelectron spectroscopy (XPS) together with theoretical calculations were used to characterize these materials. At such high metal loadings, the distinction between Ru single atoms and clusters is not trivial, even with this combination of techniques. We evaluated the catalytic properties of these materials for the hydrogenation of nitrobenzene and 2,3-dimethyl-2-butene. The catalysts containing only Ru single atoms are much less active for these reactions than the ones containing clusters. For nitrobenzene hydrogenation, this is because electron-deficient Ru single atoms and few atom Run clusters are not performant for H2 activation compared to larger clusters (n ≥ 13), as shown by density functional theory (DFT) calculations. For the more crowded substrate 2,3-dimethyl-2-butene, DFT calculations have shown that this is due to steric hindrance. These simple tests can thus be used to distinguish samples containing metallic subnanometric nanoparticles. These novel catalysts are also extremely active for the hydrogenation of tetra-substituted 2,3-dimethyl-2-butene.

Published
2020

10. Preparation of Few-Layer Graphene/Carbon Nanotube Hybrids Using Oxide Spinel Catalysts

Author

Philippe Serp, Revathi Bacsa, Camila Rivera‐Cárcamo, Bruno F. Machado, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Ethylene, Materials science, Oxide, 02 engineering and technology, Carbon nanotube, engineering.material, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Nanomaterials, Catalysis, law.invention, lcsh:QD241-441, chemistry.chemical_compound, lcsh:Organic chemistry, cobalt ferrite, law, Al-doping, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Aldoping, carbon nanotubes, hybrid, Graphene, Spinel, General Medicine, 021001 nanoscience & nanotechnology, 0104 chemical sciences, few-layer graphene, Chemical engineering, chemistry, catalytic chemical vapor deposition, engineering, 0210 nano-technology, Hybrid material
Abstract

Functional 3D materials can be developed from graphene-based hybrids by introducing other nanomaterials, with multi-walled carbon nanotubes (CNTs) being the most studied additive. For large-scale applications, few-layer graphene (FLG)-CNT hybrids are produced by catalytic chemical vapor deposition (c-CVD) starting from a mixture of catalysts (one for FLG and one for CNTs) in the required proportions. Due to the difference in growth kinetics between CNTs and FLG, the composition of such hybrids is not well controlled. In this study, we report the single-step preparation of FLG-CNT hybrid materials by a fixed-bed c-CVD process using a single catalyst with the formula AlxCo1 &minus, xFe2O4 (x = 0.025&ndash, 0.10). Different catalysts (with varying x) were prepared by the citrate&ndash, nitrate gel combustion method. Then, c-CVD synthesis was carried out at 650 &deg, C in a horizontal fixed-bed reactor using ethylene as the carbon source. Only FLG was obtained when using CoFe2O4. However, the introduction of small amounts of Al (x &lt, 0.05) induced the simultaneous production of CNTs, leading to the formation of uniform FLG-CNT hybrids. For catalysts with higher Al content (e.g., AlCoFeO4), CNTs were selectively produced. Thus, we observed the existence of a narrow Al-doping window, where CNTs and FLG can be obtained simultaneously. Our results can pave the way to developing high-yield single catalyst-based CVD synthesis of FLG-CNT hybrid materials.

Published
2019
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11. Influence of Carbon Supports on Palladium Nanoparticle Activity toward Hydrodeoxygenation and Aerobic Oxidation in Biomass Transformations

Author

Sergio Navalón, Hermenegildo García, Bruno F. Machado, Mercedes Alvaro, Ruben Castro Contreras, Juan C. Espinosa, Camila Rivera‐Cárcamo, Philippe Serp, CSIC-Universidad de Valencia, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia (LSRE-LCM), Universidade do Porto, and Universitat Politècnica de València (UPV)

Subjects
Heterogeneous catalysis, 010405 organic chemistry, Biomass transformation, Carbon support, Biomass, Nanoparticle, chemistry.chemical_element, Nitrogen adsorption, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Palladium nanoparticles, 0104 chemical sciences, Inorganic Chemistry, QUIMICA ORGANICA, chemistry, Organic chemistry, Christian ministry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Carbon, Hydrodeoxygenation, Palladium
Abstract

[EN] Three palladium catalysts at similar loadings supported on few-layers graphene (FLG), carbon nanotubes (CNT) and carbon nanofibers (CNF) have been prepared by wet impregnation of palladium nitrate with the purpose of determine the influence of the support on Pd catalytic activity. The supports and catalysts have been characterized by chemical analysis, Raman spectroscopy, XRD, electron microscopy and XPS. The average Pd particle size depends on the carbon support, ranging from 1.6 nm for CNF to 2.6 nm for FLG. The catalytic activity of these catalysts was evaluated for two different reactions of interest for biomass transformations, namely hydrodeoxygenation of vanillin to 2-methoxy-4-methyl-phenol (creosol) that requires a bifunctional catalyst with hydrogenating and Lewis acid sites, and aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid. Both compounds have application either as food flavouring additive and polyester co-monomer. For the two reactions the activity order of the fresh catalyst was Pd/FLG > Pd/CNF > Pd/CNT, indicating that FLG contributes favorably to the activity in spite of the larger Pd size of the nanoparticles on this support, a fact that has been attributed to the interaction with the prismatic planes on where Pd nanoparticles are located., Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa GTQ2015-65163-C02-R1 and CTQ2014-53292-R) is gratefully acknowledged. Generalidad Valenciana is also thanked for funding (Prometeo 2017/063). S. N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016). C. R. C. thanks CONICYT for the financial support (Becas de doctorado en el extranjero "Becas Chile" - no 72170200). The authors thank Dr. Tobias Placke (Universitat Munster, Germany) for nitrogen adsorption measurements and adsorptive potential distributions calculations.

Published
2019

12. Effect of mesoporous carbon support nature and pretreatments on palladium loading, dispersion and apparent catalytic activity in hydrogenation of myrcene

Author

Tobias Placke, Mirco Ruttert, C. de Bellefon, Philippe Serp, M.A. Curiel Alvarez, Laurent Vanoye, A. Favre Réguillon, R. Castro Contreras, Bruno F. Machado, Camila Rivera‐Cárcamo, Régis Philippe, Boris Guicheret, B. Valdez Salas, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Catalyse Synthèse et Environnement (CASYEN), Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), Instituto de Ingenieria UABC, Universidad Autónoma de Baja California (UABC), Institute of Physical Chemistry & MEET Battery Research Centre, Laboratoire de Génie des Procédés Catalytiques (LGPC), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-École Supérieure Chimie Physique Électronique de Lyon, Faculdade de Engenharia, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia (LSRE-LCM), and Universidade do Porto

Subjects
Carbon materials, chemistry.chemical_element, Metal dispersion, Nanotecnologia [Ciências da engenharia e tecnologias], 010402 general chemistry, 01 natural sciences, Catalysis, law.invention, symbols.namesake, X-ray photoelectron spectroscopy, law, Nanotecnologia, Catálise heterogénea, Nanotecnologia, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, 010405 organic chemistry, Graphene, Nanotechonology, Heterogeneous catalysis, Nano-technology, Nano-technology [Engineering and technology], [CHIM.ORGA]Chemical Sciences/Organic chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 0104 chemical sciences, chemistry, Chemical engineering, symbols, Particle size, Hydrogenation, Dispersion (chemistry), Raman spectroscopy, Carbon, Palladium
Abstract

International audience; The influence of the carbon support characteristics on Pd loading, dispersion and activity in Pd/C catalysts has been analyzed. Several carbon nanomaterials, including multi-walled CNTs, nitrogen-doped CNTs, sulfur-doped CNTs, large- and small-diameter nanofibers, few-layer graphene, and a fibrous carbon have been produced, functionalized, defunctionalized and characterized using several techniques (e.g., nitrogen adsorption, Raman spectroscopy, XPS, TGA, and elemental analysis). These supports present different surface chemistry, arising from different features (defect concentration, inter-defect distances, long-range order, and orientation of the graphene layers) and specific surface areas. The most relevant parameters were obtained by characterization of the materials by Raman, XPS, nitrogen adsorption, and XRD. Twenty-four palladium catalysts with the same nominal loading (2%w/w) were prepared by wet impregnation using an acetone solution of Pd nitrate. These 24 catalysts were characterized by ICP, XRD, XPS and TEM. The final Pd loading varied between 1 and 2%w/w and the Pd particle size ranged from 1.5 to 3.3 nm, depending on the nature of the support. The parameters influencing both Pd loading and dispersion are discussed, and their very high activity for the myrcene complete hydrogenation are reported.

Published
2019

13. Stabilization of Metal Single Atoms on Carbon and TiO2Supports for CO2Hydrogenation: The Importance of Regulating Charge Transfer

Author

Ana B. García, Walid Baaziz, Camila Rivera‐Cárcamo, Yann Tison, Philippe Serp, Canio Scarfiello, Hervé Martinez, Carole Le Berre, Ovidiu Ersen, Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (France), Agence Nationale de la Recherche (France), García Suárez, Ana Beatriz, and García Suárez, Ana Beatriz [0000-0003-0935-334X]

Subjects
Materials science, single-atom catalysis, chemistry.chemical_element, 02 engineering and technology, Carbon nanotube, 010402 general chemistry, 7. Clean energy, 01 natural sciences, law.invention, Metal, chemistry.chemical_compound, law, [CHIM]Chemical Sciences, titania, carbon nanotubes, Mechanical Engineering, charge transfer, carbon dioxide, Charge (physics), [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, chemistry, Chemical engineering, Mechanics of Materials, visual_art, Carbon dioxide, visual_art.visual_art_medium, 0210 nano-technology, Carbon
Abstract

Supported single atoms constitute excellent models for understanding heterogenous catalysis and have achieved breakthroughs during the past years. How to prevent the aggregation and modulate activity of these species via metal-support interaction should be considered for practical applications. This work presents simple methods involving the creation of carbon- (on carbon nanotube (CNT)) or oxygen-vacancies (on TiO2) to stabilize nickel and ruthenium single atoms. The defective supports and the resulting catalysts are characterized by a large variety of techniques. These analyses show that this strategy is efficient for the preparation of ultra-dispersed catalysts. Comparison of the catalytic performances of these catalysts for the CO2 hydrogenation reaction is also reported. Catalysts supported on TiO2 are more active and sometimes more stable than those deposited on CNT. Nickel catalysts are very selective for the production of CO, and ruthenium catalysts are more selective for the production of methane. Most importantly, it is shown that, in the case of Ru, a direct correlation exists between the electronic density on the metal and the selectivity; electron-rich species produce selectively methane, while electron-deficient species orientate the selectivity toward CO. This work may figure a new way for the synthesis of ultra-dispersed catalysts for various applications., C.R.C. thanks CONICYT for the financial support (Becas de doctorado en el extranjero Becas Chile – no. 72170200). CNRS is acknowledged for financial support (PEPS Energie program 2019). Part of this work was supported by the Agence Nationale de la Recherche (ANR project ANR-19, COMET), which is gratefully acknowledged.

Published
2020

14. Single atom catalysts on carbon-based materials

Author

Philippe Serp, Camila Rivera‐Cárcamo, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université Fédérale Toulouse Midi-Pyrénées

Subjects
Materials science, Graphene, Organic Chemistry, chemistry.chemical_element, Atom (order theory), 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 7. Clean energy, 01 natural sciences, Catalysis, 0104 chemical sciences, law.invention, Inorganic Chemistry, chemistry, law, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, 0210 nano-technology, Carbon
Abstract

International audience; Metal particle size is an important parameter to consider when looking at supported catalyst performances. As for other properties, surface reactivity of metallic nanoparticles is thus highly size-dependent. The smallest size that can be reached for this type of object is of course the isolated atom deposited on a support. The preparation of single-atom catalysts (SAC) is not trivial, since to avoid clustering, the mean adsorption energy of the metal on the support should be higher than its cohesive energy. The choice of a support that allows a strongly interacting environment with the metal is therefore a key step in the preparation of such catalysts. The spectrum of carbon (nano)materials is very broad, and their structure as well as their surface chemistry, although sometime complex, can be tuned and exploited for the stabilization of SAC. This Review summarizes in a comprehensive manner experimental and computational studies aiming at: i) preparing SAC on carbon materials, ii) understanding the metal-support interactions in SAC, and iii) studying how this relates to catalytic performances. The use of SAC follows well the needs dictated by society (energy and environment issues), and many studies have already been published in various fields, such as thermal catalysis, photocatalysis and electrocatalysis.

Published
2018

15. Cover Feature: Single Atom Catalysts on Carbon‐Based Materials (ChemCatChem 22/2018)

Author

Camila Rivera‐Cárcamo and Philippe Serp

Subjects
Materials science, Graphene, Organic Chemistry, Atom (order theory), chemistry.chemical_element, Catalysis, law.invention, Inorganic Chemistry, Chemical engineering, chemistry, law, Feature (computer vision), Cover (algebra), Physical and Theoretical Chemistry, Carbon
Published
2018

16. Ir supported over carbon materials for the selective hydrogenation of chloronitrobenzenes

Author

Antonio Sepúlveda-Escribano, Laura Pastor-Pérez, Camila Rivera‐Cárcamo, A.B. Dongil, Pablo Reyes, Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Instituto Universitario de Materiales, and Materiales Avanzados

Subjects
Química Inorgánica, Chemistry, Graphitic character, Inorganic chemistry, Oxide, chemistry.chemical_element, General Chemistry, Carbon nanotube, Iridium, Catalysis, law.invention, chemistry.chemical_compound, law, Graphite, Mesoporous material, Chloronitrobenzene, Nitrobenzene hydrogenation, Carbon
Abstract

In the present work we have studied the effect of carbon supports with different graphitic character (carbon nanotubes, mesoporous graphite and activated carbon) on the catalytic performance of iridium nanoparticles on the liquid phase chemoselective hydrogenation of para-chloronitrobenzene at room temperature. The effect of the oxygen groups was also evaluated by oxidizing a portion of the carbon nanotubes. The Raman and XRD spectra showed that the mesoporous graphite displayed the strongest graphitic character. The characterization of the catalysts by HR-TEM, XPS and TPR-H2, showed that the catalysts had similar particle size and that the catalysts prepared over the previously oxidized support, Ir/CNTox, was not fully reduced. The activity and selectivity achieved with the catalyst Ir/CNT was the best among the samples and the presence of irdium oxide on Ir/CNTox diminished the yield to p-chloroaniline, being the worse catalyst. The reactivity of different isomers was also studied over Ir/CNT and it followed the order m > o > p. Authors thank to CONICYT (Chile, FONDECYT 3130483) and Generalitar Valenciana (Spain, PROMETEOII/2014/004–FEDER) for financial support.

Published
2015

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