1,426 results on '"Nørskov, A. K."'
Search Results
2. Phenol as proton shuttle and buffer for lithium-mediated ammonia electrosynthesis
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Fu, Xianbiao, Xu, Aoni, Pedersen, Jakob B., Li, Shaofeng, Sažinas, Rokas, Zhou, Yuanyuan, Andersen, Suzanne Z., Saccoccio, Mattia, Deissler, Niklas H., Mygind, Jon Bjarke Valbæk, Kibsgaard, Jakob, Vesborg, Peter C. K., Nørskov, Jens K., and Chorkendorff, Ib
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- 2024
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3. Calcium-mediated nitrogen reduction for electrochemical ammonia synthesis
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Fu, Xianbiao, Niemann, Valerie A., Zhou, Yuanyuan, Li, Shaofeng, Zhang, Ke, Pedersen, Jakob B., Saccoccio, Mattia, Andersen, Suzanne Z., Enemark-Rasmussen, Kasper, Benedek, Peter, Xu, Aoni, Deissler, Niklas H., Mygind, Jon Bjarke Valbæk, Nielander, Adam C., Kibsgaard, Jakob, Vesborg, Peter C. K., Nørskov, Jens K., Jaramillo, Thomas F., and Chorkendorff, Ib
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- 2024
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4. Combined Dexamethasone and Dexmedetomidine as Adjuncts to Popliteal and Saphenous Nerve Blocks in Patients Undergoing Surgery of the Foot or Ankle: A Randomized, Blinded, Placebo-controlled, Clinical Trial
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Maagaard, Mathias, Funder, Kamilia S., Schou, Nikolaj K., Penny, Jeannette Ø., Toquer, Peter, Laigaard, Jens, Stormholt, Emma R., Nørskov, Anders K., Jæger, Pia, Andersen, Jakob H., and Mathiesen, Ole
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- 2024
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5. Stability and Activity of Cobalt Antimonate for Oxygen Reduction in Strong Acid
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Zhou, Lan, Li, Hao, Lai, Yungchieh, Richter, Matthias, Kan, Kevin, Haber, Joel A, Kelly, Sara, Wang, Zhenbin, Lu, Yubing, Kim, R Soyoung, Li, Xiang, Yano, Junko, Nørskov, Jens K, and Gregoire, John M
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Affordable and Clean Energy - Abstract
Guided by computational Pourbaix screening and high-throughput experiments aimed at the development of precious-metal-free fuel cells, we investigate rutile CoSb2O6 as an electrocatalyst for oxygen reduction in 1 M sulfuric acid. Following 4 h of catalyst conditioning at 0.7 V vs RHE, operation at this potential for 20 h yielded an average current density of −0.17 mA cm-2 with corrosion at a rate of 0.04 nm hour-1 that is stoichiometric with catalyst composition. Surface Pourbaix analysis of the (111) surface identified partial H coverage under operating conditions. The Sb active site has an HO* binding free energy of 0.49 eV, which is near the peak of the kinetic 4e- ORR volcano for transition-metal oxides in acidic conditions. The experimental demonstration of operational stability and computational identification of a reaction pathway with favorable energetics place rutile CoSb2O6 among the most promising precious-metal-free electrocatalysts for oxygen reduction in acidic media.
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- 2022
6. Efficient Pourbaix diagrams of many-element compounds
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Patel, Anjli, Nørskov, Jens K., Persson, Kristin A., and Montoya, Joseph H.
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Condensed Matter - Materials Science - Abstract
Pourbaix diagrams have long been an essential tool for determining the phase stability of solids and their associated ionic species under electrochemical conditions. In recent years, Pourbaix diagrams have been used for applications ranging from corrosion-resistance alloy design to electrocatalysis, and the data from which they are generated has been enhanced by the availability of materials data in various online databases. However, generation of multi-element Pourbaix diagrams has a critical bottleneck which makes 3-element systems difficult to analyze quickly, and 4 and 5 element systems intractable. In this work, we present a method for constructing Pourbaix diagrams which uses a pre-processing step to circumvent the most egregious computational bottleneck and make many-element Pourbaix diagrams computationally efficient.
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- 2019
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7. Two-Dimensional Conductive Ni-HAB as a Catalyst for the Electrochemical Oxygen Reduction Reaction
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Park, Jihye, Chen, Zhihua, Flores, Raul A, Wallnerström, Gustaf, Kulkarni, Ambarish, Nørskov, Jens K, Jaramillo, Thomas F, and Bao, Zhenan
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metal-organic frameworks ,electrical conductivity ,electrocatalysis ,active sites ,oxygen reduction reactions ,density functional theory ,metal−organic frameworks ,Chemical Sciences ,Engineering ,Nanoscience & Nanotechnology - Abstract
Catalytic systems whose properties can be systematically tuned via changes in synthesis conditions are highly desirable for the next-generation catalyst design and optimization. Herein, we present a two-dimensional (2D) conductive metal-organic framework consisting of M-N4 units (M = Ni, Cu) and a hexaaminobenzene (HAB) linker as a catalyst for the oxygen reduction reaction. By varying synthetic conditions, we prepared two Ni-HAB catalysts with different crystallinities, resulting in catalytic systems with different electric conductivities, electrochemical activity, and stability. We show that crystallinity has a positive impact on conductivity and demonstrate that this improved crystallinity/conductivity improves the catalytic performance of our model system. Additionally, density functional theory simulations were performed to probe the origin of M-HAB's catalytic activity, and they suggest that M-HAB's organic linker acts as the active site with the role of the metal being to modulate the linker sites' binding strength.
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- 2020
8. Active Learning Accelerated Discovery of Stable Iridium Oxide Polymorphs for the Oxygen Evolution Reaction
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Flores, Raul A, Paolucci, Christopher, Winther, Kirsten T, Jain, Ankit, Torres, Jose Antonio Garrido, Aykol, Muratahan, Montoya, Joseph, Nørskov, Jens K, Bajdich, Michal, and Bligaard, Thomas
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Affordable and Clean Energy ,Chemical Sciences ,Engineering ,Materials - Abstract
The discovery of high-performing and stable materials for sustainable energy applications is a pressing goal in catalysis and materials science. Understanding the relationship between a material's structure and functionality is an important step in the process, such that viable polymorphs for a given chemical composition need to be identified. Machine-learning-based surrogate models have the potential to accelerate the search for polymorphs that target specific applications. Herein, we report a readily generalizable active-learning (AL) accelerated algorithm for identification of electrochemically stable iridium oxide polymorphs of IrO2 and IrO3. The search is coupled to a subsequent analysis of the electrochemical stability of the discovered structures for the acidic oxygen evolution reaction (OER). Structural candidates are generated by identifying all 956 structurally unique AB2 and AB3 prototypes in existing materials databases (more than 38000). Next, using an active learning approach, we find 196 IrO2 polymorphs within the thermodynamic amorphous synthesizability limit and reaffirm the global stability of the rutile structure. We find 75 synthesizable IrO3 polymorphs and report a previously unknown FeF3-type structure as the most stable, termed α-IrO3. To test the algorithms performance, we compare to a random search of the candidate space and report at least a 2-fold increase in the rate of discovery. Additionally, the AL approach can acquire the most stable polymorphs of IrO2 and IrO3 with fewer than 30 density functional theory optimizations. Analysis of the structural properties of the discovered polymorphs reveals that octahedral local coordination environments are preferred for nearly all low-energy structures. Subsequent Pourbaix Ir-H2O analysis shows that α-IrO3 is the globally stable solid phase under acidic OER conditions and supersedes the stability of rutile IrO2. Calculation of theoretical OER surface activities reveal ideal weaker binding of the OER intermediates on α-IrO3 than on any other considered iridium oxide. We emphasize that the proposed AL algorithm can be easily generalized to search for any binary metal oxide structure with a defined stoichiometry.
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- 2020
9. Systematic Investigation of Iridium-Based Bimetallic Thin Film Catalysts for the Oxygen Evolution Reaction in Acidic Media
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Strickler, Alaina L, Flores, Raul A, King, Laurie A, Nørskov, Jens K, Bajdich, Michal, and Jaramillo, Thomas F
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oxygen evolution reaction ,electrocatalysis ,acidic media ,Cr doping ,volcano plot ,theoretical overpotential ,electrochemical characterization ,density functional theory ,Chemical Sciences ,Engineering ,Nanoscience & Nanotechnology - Abstract
Multimetallic Ir-based systems offer significant opportunities for enhanced oxygen evolution electrocatalysis by modifying the electronic and geometric properties of the active catalyst. Herein, a systematic investigation of bimetallic Ir-based thin films was performed to identify activity and stability trends across material systems for the oxygen evolution reaction (OER) in acidic media. Electron beam evaporation was used to co-deposit metallic films of Ir, IrSn2, IrCr, IrTi, and IrNi. The electrocatalytic activity of the electrochemically oxidized alloys was found to increase in the following order: IrTi < IrSn2 < Ir ∼ IrNi < IrCr. The IrCr system demonstrates two times the catalytic activity of Ir at 1.65 V versus RHE. Density functional theory calculations suggest that this enhancement is due to Cr active sites that have improved oxygen binding energetics compared to those of pure Ir oxide. This work identifies IrCr as a promising new catalyst system that facilitates reduced precious metal loadings for acid-based OER catalysis.
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- 2019
10. Highly selective oxygen reduction to hydrogen peroxide on transition metal single atom coordination.
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Jiang, Kun, Back, Seoin, Akey, Austin J, Xia, Chuan, Hu, Yongfeng, Liang, Wentao, Schaak, Diane, Stavitski, Eli, Nørskov, Jens K, Siahrostami, Samira, and Wang, Haotian
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MD Multidisciplinary - Abstract
Shifting electrochemical oxygen reduction towards 2e- pathway to hydrogen peroxide (H2O2), instead of the traditional 4e- to water, becomes increasingly important as a green method for H2O2 generation. Here, through a flexible control of oxygen reduction pathways on different transition metal single atom coordination in carbon nanotube, we discovered Fe-C-O as an efficient H2O2 catalyst, with an unprecedented onset of 0.822 V versus reversible hydrogen electrode in 0.1 M KOH to deliver 0.1 mA cm-2 H2O2 current, and a high H2O2 selectivity of above 95% in both alkaline and neutral pH. A wide range tuning of 2e-/4e- ORR pathways was achieved via different metal centers or neighboring metalloid coordination. Density functional theory calculations indicate that the Fe-C-O motifs, in a sharp contrast to the well-known Fe-C-N for 4e-, are responsible for the H2O2 pathway. This iron single atom catalyst demonstrated an effective water disinfection as a representative application.
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- 2019
11. Challenges in Modeling Electrochemical Reaction Energetics with Polarizable Continuum Models
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Gauthier, Joseph A, Ringe, Stefan, Dickens, Colin F, Garza, Alejandro J, Bell, Alexis T, Head-Gordon, Martin, Nørskov, Jens K, and Chan, Karen
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Chemical Sciences ,Physical Chemistry ,Theoretical and Computational Chemistry ,Affordable and Clean Energy ,density functional theory ,catalysis ,electrocatalysis ,electrochemistry ,solvation ,Inorganic Chemistry ,Organic Chemistry ,Chemical Engineering ,Industrial biotechnology ,Organic chemistry ,Physical chemistry - Abstract
A major challenge in the modeling of electrochemical phenomena is the accurate description of the interface between an electrolyte and a charged conductor. Polarizable continuum models (PCM) have been gaining popularity because they offer a computationally inexpensive method of modeling the electrolyte. In this Perspective, we discuss challenges from using one such model which treats the ions using a linearized Poisson-Boltzmann (LPB) distribution. From a physical perspective, this model places charge unphysically close to the surface and adsorbates, and it includes excessively steep ramping of the dielectric constant from the surface to the bulk solvent. Both of these issues can be somewhat mitigated by adjusting parameters built into the model, but in doing so, the resultant capacitance deviates from experimental values. Likewise, hybrid explicit-implicit approaches to the solvent may offer a more realistic description of hydrogen bonding and solvation to reaction intermediates, but the corresponding capacitances also deviate from experimental values. These deviations highlight the need for a careful adjustment of parameters in order to reproduce not only solvation energies but also other physical properties of solid-liquid interfaces. Continuum approaches alone also necessarily do not capture local variations in the electric field from cations at the interface, which can affect the energetics of intermediates with substantial dipoles or polarizability. Finally, since the double-layer charge can be varied continuously, LPB/PCM models provide a way to determine electrochemical barriers at constant potential. However, double-layer charging and the atomic motion associated with reaction events occur on significantly different timescales. We suggest that more detailed approaches, such as the modified Poisson-Boltzmann model and/or the addition of a Stern layer, may be able to mitigate some but not all of the challenges discussed.
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- 2019
12. Electrosynthesis of ammonia with high selectivity and high rates via engineering of the solid-electrolyte interphase
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Li, Shaofeng, Zhou, Yuanyuan, Li, Katja, Saccoccio, Mattia, Sažinas, Rokas, Andersen, Suzanne Z., Pedersen, Jakob B., Fu, Xianbiao, Shadravan, Vahid, Chakraborty, Debasish, Kibsgaard, Jakob, Vesborg, Peter C.K., Nørskov, Jens K., and Chorkendorff, Ib
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- 2022
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13. A spin promotion effect in catalytic ammonia synthesis
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Cao, Ang, Bukas, Vanessa J., Shadravan, Vahid, Wang, Zhenbin, Li, Hao, Kibsgaard, Jakob, Chorkendorff, Ib, and Nørskov, Jens K.
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- 2022
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14. Acid anion electrolyte effects on platinum for oxygen and hydrogen electrocatalysis
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Kamat, Gaurav Ashish, Zamora Zeledón, José A., Gunasooriya, G. T. Kasun Kalhara, Dull, Samuel M., Perryman, Joseph T., Nørskov, Jens K., Stevens, Michaela Burke, and Jaramillo, Thomas F.
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- 2022
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15. CO Methanation over Ni-Fe Alloy Catalysts: An Inverse Design Problem.
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Wenqiang Yang, Zhenbin Wang, and Nørskov, Jens K.
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- 2024
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16. Monitoring oxygen production on mass-selected iridium–tantalum oxide electrocatalysts
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Zheng, Ya-Rong, Vernieres, Jerome, Wang, Zhenbin, Zhang, Ke, Hochfilzer, Degenhart, Krempl, Kevin, Liao, Ting-Wei, Presel, Francesco, Altantzis, Thomas, Fatermans, Jarmo, Scott, Soren Bertelsen, Secher, Niklas Mørch, Moon, Choongman, Liu, Pei, Bals, Sara, Van Aert, Sandra, Cao, Ang, Anand, Megha, Nørskov, Jens K., Kibsgaard, Jakob, and Chorkendorff, Ib
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- 2022
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17. A new tool to assess Clinical Diversity In Meta‐analyses (CDIM) of interventions
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Barbateskovic, Marija, Koster, Thijs M., Eck, Ruben J., Maagaard, Mathias, Afshari, Arash, Blokzijl, Fredrike, Cronhjort, Maria, Dieperink, Willem, Fabritius, Maria L., Feinberg, Josh, French, Craig, Gareb, Barzi, Geisler, Anja, Granholm, Anders, Hiemstra, Bart, Hu, Ruixue, Imberger, Georgina, Jensen, Bente T., Jonsson, Andreas B., Karam, Oliver, Kong, De Zhao, Korang, Steven K., Koster, Geert, Lai, Baoyong, Liang, Ning, Lundstrøm, Lars H., Marker, Søren, Meyhoff, Tine S., Nielsen, Emil E., Nørskov, Anders K., Munch, Marie W., Risom, Emilie C., Rygård, Sofie L., Safi, Sanam, Sethi, Naqash, Sjövall, Fredrik, Lauridsen, Susanne V., van Bakelen, Nico, Volbeda, Meint, van der Horst, Iwan C.C., Gluud, Christian, Perner, Anders, Møller, Morten H., Keus, Eric, and Wetterslev, Jørn
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- 2021
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18. Electrochemical Activation of CO2 through Atomic Ordering Transformations of AuCu Nanoparticles
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Kim, Dohyung, Xie, Chenlu, Becknell, Nigel, Yu, Yi, Karamad, Mohammadreza, Chan, Karen, Crumlin, Ethan J, Nørskov, Jens K, and Yang, Peidong
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Engineering ,Chemical Sciences ,Nanotechnology ,Bioengineering ,Affordable and Clean Energy ,General Chemistry ,Chemical sciences - Abstract
Precise control of elemental configurations within multimetallic nanoparticles (NPs) could enable access to functional nanomaterials with significant performance benefits. This can be achieved down to the atomic level by the disorder-to-order transformation of individual NPs. Here, by systematically controlling the ordering degree, we show that the atomic ordering transformation, applied to AuCu NPs, activates them to perform as selective electrocatalysts for CO2 reduction. In contrast to the disordered alloy NP, which is catalytically active for hydrogen evolution, ordered AuCu NPs selectively converted CO2 to CO at faradaic efficiency reaching 80%. CO formation could be achieved with a reduction in overpotential of ∼200 mV, and catalytic turnover was enhanced by 3.2-fold. In comparison to those obtained with a pure gold catalyst, mass activities could be improved as well. Atomic-level structural investigations revealed three atomic gold layers over the intermetallic core to be sufficient for enhanced catalytic behavior, which is further supported by DFT analysis.
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- 2017
19. Understanding trends in C-H bond activation in heterogeneous catalysis.
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Latimer, Allegra A, Kulkarni, Ambarish R, Aljama, Hassan, Montoya, Joseph H, Yoo, Jong Suk, Tsai, Charlie, Abild-Pedersen, Frank, Studt, Felix, and Nørskov, Jens K
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Nanoscience & Nanotechnology - Abstract
While the search for catalysts capable of directly converting methane to higher value commodity chemicals and liquid fuels has been active for over a century, a viable industrial process for selective methane activation has yet to be developed. Electronic structure calculations are playing an increasingly relevant role in this search, but large-scale materials screening efforts are hindered by computationally expensive transition state barrier calculations. The purpose of the present letter is twofold. First, we show that, for the wide range of catalysts that proceed via a radical intermediate, a unifying framework for predicting C-H activation barriers using a single universal descriptor can be established. Second, we combine this scaling approach with a thermodynamic analysis of active site formation to provide a map of methane activation rates. Our model successfully rationalizes the available empirical data and lays the foundation for future catalyst design strategies that transcend different catalyst classes.
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- 2017
20. Analysis of the limitations in the oxygen reduction activity of transition metal oxide surfaces
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Li, Hao, Kelly, Sara, Guevarra, Dan, Wang, Zhenbin, Wang, Yu, Haber, Joel A., Anand, Megha, Gunasooriya, G. T. Kasun Kalhara, Abraham, Christina Susan, Vijay, Sudarshan, Gregoire, John M., and Nørskov, Jens K.
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- 2021
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21. Combined Dexamethasone and Dexmedetomidine as Adjuncts to Popliteal and Saphenous Nerve Blocks in Patients Undergoing Surgery of the Foot or Ankle:A Randomized, Blinded, Placebo-controlled Clinical Trial
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Maagaard, Mathias, Funder, Kamilia S., Schou, Nikolaj K., Penny, Jeannette, Toquer, Peter, Laigaard, Jens, Stormholt, Emma R., Nørskov, Anders K., Jæger, Pia, Andersen, Jakob H., Mathiesen, Ole, Maagaard, Mathias, Funder, Kamilia S., Schou, Nikolaj K., Penny, Jeannette, Toquer, Peter, Laigaard, Jens, Stormholt, Emma R., Nørskov, Anders K., Jæger, Pia, Andersen, Jakob H., and Mathiesen, Ole
- Abstract
Background Both dexamethasone and dexmedetomidine increase the duration of analgesia of peripheral nerve blocks. The authors hypothesized that combined intravenous dexamethasone and intravenous dexmedetomidine would result in a greater duration of analgesia when compared with intravenous dexamethasone alone and placebo. Methods The authors randomly allocated participants undergoing surgery of the foot or ankle under general anesthesia and with a combined popliteal (sciatic) and saphenous nerve block to a combination of 12 mg dexamethasone and 1 µg/kg dexmedetomidine, 12 mg dexamethasone, or placebo (saline). The primary outcome was the duration of analgesia measured as the time from block performance until the first sensation of pain in the surgical area as reported by the participant. The authors predefined a 33% difference in the duration of analgesia as clinically relevant. Results A total of 120 participants from two centers were randomized and 119 analyzed for the primary outcome. The median [interquartile range] duration of analgesia was 1,572 min [1,259 to 1,715] with combined dexamethasone and dexmedetomidine, 1,400 min [1,133 to 1,750] with dexamethasone alone, and 870 min [748 to 1,138] with placebo. Compared with placebo, the duration was greater with combined dexamethasone and dexmedetomidine (difference, 564 min; 98.33% CI, 301 to 794; P < 0.001) and with dexamethasone (difference, 489 min; 98.33% CI, 265 to 706; P < 0.001). The prolongations exceeded the authors’ predefined clinically relevant difference. The duration was similar when combined dexamethasone and dexmedetomidine was compared with dexamethasone alone (difference, 61 min; 98.33% CI, –222 to 331; P = 0.614). Conclusions Dexamethasone with or without dexmedetomidine increased the duration of analgesia in patients undergoing surgery of the foot or ankle with a popliteal (sciatic) and saphenous nerve block. Combined dexamethasone and dexmedetomi, BACKGROUND: Both dexamethasone and dexmedetomidine increase the duration of analgesia of peripheral nerve blocks. The authors hypothesized that combined intravenous dexamethasone and intravenous dexmedetomidine would result in a greater duration of analgesia when compared with intravenous dexamethasone alone and placebo. METHODS: The authors randomly allocated participants undergoing surgery of the foot or ankle under general anesthesia and with a combined popliteal (sciatic) and saphenous nerve block to a combination of 12 mg dexamethasone and 1 µg/kg dexmedetomidine, 12 mg dexamethasone, or placebo (saline). The primary outcome was the duration of analgesia measured as the time from block performance until the first sensation of pain in the surgical area as reported by the participant. The authors predefined a 33% difference in the duration of analgesia as clinically relevant. RESULTS: A total of 120 participants from two centers were randomized and 119 analyzed for the primary outcome. The median [interquartile range] duration of analgesia was 1,572 min [1,259 to 1,715] with combined dexamethasone and dexmedetomidine, 1,400 min [1,133 to 1,750] with dexamethasone alone, and 870 min [748 to 1,138] with placebo. Compared with placebo, the duration was greater with combined dexamethasone and dexmedetomidine (difference, 564 min; 98.33% CI, 301 to 794; P < 0.001) and with dexamethasone (difference, 489 min; 98.33% CI, 265 to 706; P < 0.001). The prolongations exceeded the authors' predefined clinically relevant difference. The duration was similar when combined dexamethasone and dexmedetomidine was compared with dexamethasone alone (difference, 61 min; 98.33% CI, -222 to 331; P = 0.614). CONCLUSIONS: Dexamethasone with or without dexmedetomidine increased the duration of analgesia in patients undergoing surgery of the foot or ankle with a popliteal (sciatic) and saphenous nerve block. Combined dexamethasone and dexmedetomidine did not increase the duration o
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- 2024
22. Peripheral nerve blocks for closed reduction of distal radius fractures—A protocol for a systematic review
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Pisljagic, Sanja, Temberg, Jens L., Steensbæk, Mathias T., Yousef, Sina, Maagaard, Mathias, Chafranska, Lana, Lange, Kai H.W., Rothe, Christian, Lundstrøm, Lars H., Nørskov, Anders K., Pisljagic, Sanja, Temberg, Jens L., Steensbæk, Mathias T., Yousef, Sina, Maagaard, Mathias, Chafranska, Lana, Lange, Kai H.W., Rothe, Christian, Lundstrøm, Lars H., and Nørskov, Anders K.
- Abstract
Background Current methods of anaesthesia used for closed reduction of distal radial fractures may be insufficient for pain relief and muscle relaxation, potentially compromising reduction quality and patient satisfaction. Peripheral nerve blocks have already been implemented for surgery of wrist fractures and may provide optimal conditions for closed reduction due to complete motor and sensory blockade of the involved nerves. However, existing literature on peripheral nerve blocks for closed reduction is sparse, and no updated systematic review or meta-analysis exists. Aims This protocol is developed according to the PRISMA-P statement. The systematic review and meta-analysis aim to consolidate the literature regarding the effect and harm of peripheral nerve blocks compared with other anaesthesia modalities for closed reduction of distal radius fractures in adults. Methods The two primary outcomes are the proportion of participants needing surgery after closed reduction and pain during closed reduction. We will only include randomised clinical trials. Two review authors will each independently screen literature, extract data, and assess risk of bias with Risk of Bias 2 Tool. Meta-analysis will be carried out with Rstudio. We will also perform a Trial Sequential Analysis. The certainty of evidence will be judged using GRADE guidelines. Discussion We will use up-to-date methodology when conducting the systematic review outlined in this protocol. The results may guide clinicians in their decision-making regarding the use of anaesthesia for closed reduction of distal radius fractures in adults., Background: Current methods of anaesthesia used for closed reduction of distal radial fractures may be insufficient for pain relief and muscle relaxation, potentially compromising reduction quality and patient satisfaction. Peripheral nerve blocks have already been implemented for surgery of wrist fractures and may provide optimal conditions for closed reduction due to complete motor and sensory blockade of the involved nerves. However, existing literature on peripheral nerve blocks for closed reduction is sparse, and no updated systematic review or meta-analysis exists. Aims: This protocol is developed according to the PRISMA-P statement. The systematic review and meta-analysis aim to consolidate the literature regarding the effect and harm of peripheral nerve blocks compared with other anaesthesia modalities for closed reduction of distal radius fractures in adults. Methods: The two primary outcomes are the proportion of participants needing surgery after closed reduction and pain during closed reduction. We will only include randomised clinical trials. Two review authors will each independently screen literature, extract data, and assess risk of bias with Risk of Bias 2 Tool. Meta-analysis will be carried out with Rstudio. We will also perform a Trial Sequential Analysis. The certainty of evidence will be judged using GRADE guidelines. Discussion: We will use up-to-date methodology when conducting the systematic review outlined in this protocol. The results may guide clinicians in their decision-making regarding the use of anaesthesia for closed reduction of distal radius fractures in adults.
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- 2024
23. Mixing short- and long-acting local anaesthetics in peripheral nerve blocks:Protocol for a systematic review and meta-analysis
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Temberg, Jens L., Pisljagic, Sanja, Steensbæk, Mathias T., Yousef, Sina, Chafranska, Lana, Lange, Kai H.W., Rothe, Christian, Nørskov, Anders K., Maagaard, Mathias, Lundstrøm, Lars H., Temberg, Jens L., Pisljagic, Sanja, Steensbæk, Mathias T., Yousef, Sina, Chafranska, Lana, Lange, Kai H.W., Rothe, Christian, Nørskov, Anders K., Maagaard, Mathias, and Lundstrøm, Lars H.
- Abstract
Introduction This protocol describes a systematic review and meta-analysis to evaluate the clinical effects of mixing short- and long-acting local anaesthetics in peripheral nerve blocks. Clinicians often combine short- and long-acting local anaesthetics to achieve a briefer onset time. However, this may come with a prize, namely a shorter total duration of the block, which is of clinical importance. Objective This systematic review aims to strengthen the knowledge of the clinical effects associated with this practice. The primary outcome is the duration of block analgesia. Secondary outcomes are block onset time, sensory and motor block duration. Exploratory outcomes are postoperative pain scores, cumulative 24-h opioid consumption and the prevalence of serious adverse events. Methods We will conduct a meta-analysis of the extracted data, and the risk of bias for each study will be evaluated. We will perform a Trial Sequential Analysis, subgroup, and sensitivity analyses and assess the overall risk of publication bias. Finally, we will evaluate the review using the GRADE principles., Introduction: This protocol describes a systematic review and meta-analysis to evaluate the clinical effects of mixing short- and long-acting local anaesthetics in peripheral nerve blocks. Clinicians often combine short- and long-acting local anaesthetics to achieve a briefer onset time. However, this may come with a prize, namely a shorter total duration of the block, which is of clinical importance. Objective: This systematic review aims to strengthen the knowledge of the clinical effects associated with this practice. The primary outcome is the duration of block analgesia. Secondary outcomes are block onset time, sensory and motor block duration. Exploratory outcomes are postoperative pain scores, cumulative 24-h opioid consumption and the prevalence of serious adverse events. Methods: We will conduct a meta-analysis of the extracted data, and the risk of bias for each study will be evaluated. We will perform a Trial Sequential Analysis, subgroup, and sensitivity analyses and assess the overall risk of publication bias. Finally, we will evaluate the review using the GRADE principles.
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- 2024
24. New challenges in oxygen reduction catalysis: a consortium retrospective to inform future research
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Stevens, Michaela Burke, Anand, Megha, Kreider, Melissa E., Price, Eliza K., Zeledón, José Zamara, Wang, Liang, Peng, Jiayu, Li, Hao, Gregoire, John M., Hummelshøj, Jens, Jaramillo, Thomas F., Jia, Hongfei, Nørskov, Jens K., Roman-Leshkov, Yuriy, Shao-Horn, Yang, Storey, Brian D., Suram, Santosh K., Torrisi, Steven B., Montoya, Joseph H., Stevens, Michaela Burke, Anand, Megha, Kreider, Melissa E., Price, Eliza K., Zeledón, José Zamara, Wang, Liang, Peng, Jiayu, Li, Hao, Gregoire, John M., Hummelshøj, Jens, Jaramillo, Thomas F., Jia, Hongfei, Nørskov, Jens K., Roman-Leshkov, Yuriy, Shao-Horn, Yang, Storey, Brian D., Suram, Santosh K., Torrisi, Steven B., and Montoya, Joseph H.
- Abstract
In this perspective, we highlight results of a research consortium devoted to advancing understanding of oxygen reduction reaction (ORR) catalysis as a means to inform fuel cell science. We demonstrate how targeted collaborations between different institutions from academic, national lab, and industry backgrounds and different scientific disciplines like theory, experiment, and characterization can yield unique insights into fuel cell catalysts. We comment on such insights into material designs for platinum-group-metal alloys, transition metal oxides, and non-traditional materials including metal–organic frameworks; systems that have served as the foundational building blocks for our consortium. We also motivate a renewed focus on catalyst durability in light of emerging technological requirements and paths forward in understanding in situ and operando electrochemical stability. Finally, we describe new frontiers ORR research can take and how emerging artificial intelligence tools can assist researchers in capturing data, selecting new experiments, and guiding characterization to accelerate the design and discovery of fuel cell catalysts. A main goal of sharing this perspective is to discuss the rationale for our future research plans based on our consortium work. However, we also hope to illustrate both the potential impact of a collaborative strategy with the hopes of inspiring a higher degree of Industry-Academia-National Laboratory collaboration and encourage other centers and consortiums to distill and share their findings in a similar perspective-type article. Together we hope to enable the fuel cell research community to engage in a discussion of strategies for research and accelerated development of catalysts with improved activity and stability.
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- 2024
25. Selective electrochemical generation of hydrogen peroxide from water oxidation
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Viswanathan, Venkatasubramanian, Hansen, Heine A., and Nørskov, Jens K.
- Subjects
Physics - Chemical Physics - Abstract
Water is a life-giving source, fundamental to human existence, yet, over a billion people lack access to clean drinking water. Present techniques for water treatment such as piped, treated water rely on time and resource intensive centralized solutions. In this work, we propose a decentralized device concept that can utilize sunlight to split water into hydrogen and hydrogen peroxide. The hydrogen peroxide can oxidize organics while the hydrogen bubbles out. In enabling this device, we require an electrocatalyst that can oxidize water while suppressing the thermodynamically favored oxygen evolution and form hydrogen peroxide. Using density functional theory calculations, we show that the free energy of adsorbed OH$^*$ can be used as a descriptor to screen for selectivity trends between the 2e$^-$ water oxidation to H$_2$O$_2$ and the 4e$^-$ oxidation to O$_2$. We show that materials that bind oxygen intermediates sufficiently weakly, such as SnO$_2$, can activate hydrogen peroxide evolution. We present a rational design principle for the selectivity in electrochemical water oxidation and identify new material candidates that could perform H$_2$O$_2$ evolution selectively., Comment: 13 pages, 3 figures, 6 pages supporting information
- Published
- 2015
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- View/download PDF
26. Surface Energetics of Alkaline-Earth Metal Oxides: Trends in Stability and Adsorption of Small Molecules
- Author
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Bajdich, Michal, Nørskov, Jens K., and Vojvodic, Aleksandra
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Other Condensed Matter - Abstract
We present a systematic theoretical investigation of the surface properties, stability and reactivity, of rock-salt type alkaline-earth metal oxides including MgO, CaO, SrO, and BaO. The accuracy of commonly used exchange-correlation density functionals (LDA, PBE, RPBE, PBEsol, BEEF-vdW and hybrid HSE) and random-phase approximation (RPA) is evaluated and compared to existing experimental values. Calculated surface energies of the four most stable surface facets under vacuum conditions: the (100) surface, the metal and oxygen terminated octopolar (111), and the (110) surfaces exhibit a monotonic increase in stability from MgO to BaO. On the MgO(100) surface, adsorption of CO, NO, CH4 is characterized by physisorption while H2O chemisorbs, which is in agreement with experimental findings. We further use the on-top metal adsorption of CO and NO molecules to map out the surface energetics of each alkaline-earth metal oxide surface. The considered functionals all qualitatively predict similar adsorption energy trends. The ordering between the adsorption energies on different surface facets can be attributed to differences in the local geometrical surface structure and the electronic structure of the metal constituent of the alkaline-earth metal oxide. The striking observation that CO adsorption strength is weaker than NO adsorption on the (100) terraces as the period of the alkaline-earth metal in the oxide increases, is analyzed in detail in terms of charge redistribution within the {\sigma} and {\pi} channels of adsorbates. Finally, we also present oxygen adsorption and oxygen vacancy formation energies in these oxide systems., Comment: 10 pages, submitted to PRB as regular article
- Published
- 2014
- Full Text
- View/download PDF
27. Characterization of adsorption sites on IrO2via temperature programmed O2 desorption simulations.
- Author
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Ocampo-Restrepo, Vivianne K., Vijay, Sudarshan, Gunasooriya, G. T. Kasun Kalhara, and Nørskov, Jens K.
- Abstract
This study presents simulations of temperature-programmed desorption (TPD) profiles using desorption energy data from density functional theory (DFT) calculations. We apply this method to investigate the desorption of oxygen (O
2 ) from IrO2 (110) to gain insight into the kinetics of oxygen coupling and desorption, important elementary steps in the oxygen evolution reaction (OER). Initially, we confirm the thermodynamically stable adsorption site for oxygen in the pristine IrO2 (110) as IrCUS , even with a high oxygen coverage. We successfully simulate TPD for O2 desorption, achieving good agreement with experimental TPD data for different initial oxygen exposures when including more than one adsorption site. We identify a new adsorption site, related to the formation of steps on IrO2 (110)(IrCUS-step-0.5 ), that is essential for reproducing the experimental TPD. Our findings suggest that the observed TPD peaks are the result of different adsorption sites on the surface, rather than solely a lateral interactions effect. This work provides insight into the behavior of oxygen adsorption on IrO2 , with implications for understanding surface reactivity and catalytic processes involving this material. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
28. Mixing short‐ and long‐acting local anaesthetics in peripheral nerve blocks: Protocol for a systematic review and meta‐analysis
- Author
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Temberg, Jens L., primary, Pisljagic, Sanja, additional, Steensbæk, Mathias T., additional, Yousef, Sina, additional, Chafranska, Lana, additional, Lange, Kai H. W., additional, Rothe, Christian, additional, Nørskov, Anders K., additional, Maagaard, Mathias, additional, and Lundstrøm, Lars H., additional
- Published
- 2023
- Full Text
- View/download PDF
29. Insights into carbon nanotube nucleation: Cap formation governed by catalyst interfacial step flow
- Author
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Rao, Rahul, Sharma, Renu, Abild-Pedersen, Frank, Nørskov, Jens K., and Harutyunyan, Avetik R.
- Subjects
Condensed Matter - Materials Science - Abstract
In order to accommodate an increasing demand for carbon nanotubes (CNTs) with desirable characteristics one has to understand the origin of helicity of their structures. Here, through in situ microscopy we demonstrate that the nucleation of a carbon nanotube is initiated by the formation of the carbon cap. Nucleation begins with the formation of a graphene embryo that is bound between opposite step-edges on the nickel catalyst surface. The embryo grows larger as the step-edges migrate along the surface, leading to the formation of a curved carbon cap when the steps flow across the edges of adjacent facets. Further motion of the steps away from the catalyst tip with attached rims of the carbon cap generates the wall of the nanotube. Density Functional Theory calculations bring further insight into the process, showing that step flow occurs by surface self diffusion of the nickel atoms via a step-edge attachment-detachment mechanism. Since the fact that cap forms first in the sequence of stages involved in nanotube growth, we suggest that it originates the helicity of the nanotube. Therefore, the angular distribution of catalyst facets could be exploited as a new parameter for controlling the curvature of the cap and, presumably, the helicity of the nanotube., Comment: 4 figures
- Published
- 2014
30. Tuning the electronic structure of Ag-Pd alloys to enhance performance for alkaline oxygen reduction
- Author
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Zamora Zeledón, José A., Stevens, Michaela Burke, Gunasooriya, G. T. Kasun Kalhara, Gallo, Alessandro, Landers, Alan T., Kreider, Melissa E., Hahn, Christopher, Nørskov, Jens K., and Jaramillo, Thomas F.
- Published
- 2021
- Full Text
- View/download PDF
31. The Challenge of CO Hydrogenation to Methanol: Fundamental Limitations Imposed by Linear Scaling Relations
- Author
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Elnabawy, Ahmed O., Schumann, Julia, Bothra, Pallavi, Cao, Ang, and Nørskov, Jens K.
- Published
- 2020
- Full Text
- View/download PDF
32. Identification of Highly Active Fe Sites in (Ni,Fe)OOH for Electrocatalytic Water Splitting
- Author
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Friebel, Daniel, Louie, Mary W, Bajdich, Michal, Sanwald, Kai E, Cai, Yun, Wise, Anna M, Cheng, Mu-Jeng, Sokaras, Dimosthenis, Weng, Tsu-Chien, Alonso-Mori, Roberto, Davis, Ryan C, Bargar, John R, Nørskov, Jens K, Nilsson, Anders, and Bell, Alexis T
- Subjects
Engineering ,Materials Engineering ,Chemical Sciences ,Affordable and Clean Energy ,General Chemistry ,Chemical sciences - Abstract
Highly active catalysts for the oxygen evolution reaction (OER) are required for the development of photoelectrochemical devices that generate hydrogen efficiently from water using solar energy. Here, we identify the origin of a 500-fold OER activity enhancement that can be achieved with mixed (Ni,Fe)oxyhydroxides (Ni(1-x)Fe(x)OOH) over their pure Ni and Fe parent compounds, resulting in one of the most active currently known OER catalysts in alkaline electrolyte. Operando X-ray absorption spectroscopy (XAS) using high energy resolution fluorescence detection (HERFD) reveals that Fe(3+) in Ni(1-x)Fe(x)OOH occupies octahedral sites with unusually short Fe-O bond distances, induced by edge-sharing with surrounding [NiO6] octahedra. Using computational methods, we establish that this structural motif results in near optimal adsorption energies of OER intermediates and low overpotentials at Fe sites. By contrast, Ni sites in Ni(1-x)Fe(x)OOH are not active sites for the oxidation of water.
- Published
- 2015
33. First principles micro-kinetic model of catalytic non-oxidative dehydrogenation of ethane over close-packed metallic facets
- Author
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Hansen, Martin Hangaard, Nørskov, Jens K., and Bligaard, Thomas
- Published
- 2019
- Full Text
- View/download PDF
34. A theoretical explanation of the effect of oxygen poisoning on industrial Haber-Bosch catalysts
- Author
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Rohr, Brian A., Singh, Aayush R., and Nørskov, Jens K.
- Published
- 2019
- Full Text
- View/download PDF
35. Ab initio van der Waals interactions in simulations of water alter structure from mainly tetrahedral to high-density-like
- Author
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Møgelhøj, Andreas, Kelkkanen, André, Wikfeldt, K. Thor, Schiøtz, Jakob, Mortensen, Jens Jørgen, Pettersson, Lars G. M., Lundqvist, Bengt I., Jacobsen, Karsten W., Nilsson, Anders, and Nørskov, Jens K.
- Subjects
Condensed Matter - Materials Science ,Physics - Chemical Physics ,Physics - Computational Physics - Abstract
The structure of liquid water at ambient conditions is studied in ab initio molecular dynamics simulations using van der Waals (vdW) density-functional theory, i.e. using the new exchange-correlation functionals optPBE-vdW and vdW-DF2. Inclusion of the more isotropic vdW interactions counteracts highly directional hydrogen-bonds, which are enhanced by standard functionals. This brings about a softening of the microscopic structure of water, as seen from the broadening of angular distribution functions and, in particular, from the much lower and broader first peak in the oxygen-oxygen pair-correlation function (PCF), indicating loss of structure in the outer solvation shells. In combination with softer non-local correlation terms, as in the new parameterization of vdW-DF, inclusion of vdW interactions is shown to shift the balance of resulting structures from open tetrahedral to more close-packed. The resulting O-O PCF shows some resemblance with experiment for high-density water (A. K. Soper and M. A. Ricci, Phys. Rev. Lett., 84:2881, 2000), but not directly with experiment for ambient water. However, an O-O PCF consisting of a linear combination of 70% from vdW-DF2 and 30% from experiment on low-density liquid water reproduces near-quantitatively the experimental O-O PCF for ambient water, indicating consistency with a two-liquid model with fluctuations between high- and low-density regions.
- Published
- 2011
36. Trends in Metal Oxide Stability for Nanorods, Nanotubes, and Surfaces
- Author
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Mowbray, D. J., Martinez, J. I., Calle-Vallejo, F., Rossmeisl, J., Thygesen, K. S., Jacobsen, K. W., and Norskov, J. K.
- Subjects
Condensed Matter - Materials Science - Abstract
The formation energies of nanostructures play an important role in determining their properties, including the catalytic activity. For the case of 15 different rutile and 8 different perovskite metal oxides, we find that the density functional theory (DFT) calculated formation energies of (2,2) nanorods, (3,3) nanotubes, and the (110) and (100) surfaces may be described semi-quantitatively by the fraction of metal--oxygen bonds broken and the bonding band centers in the bulk metal oxide.
- Published
- 2010
- Full Text
- View/download PDF
37. Spin-mediated promotion of Co catalysts for ammonia synthesis.
- Author
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Ke Zhang, Ang Cao, Wandall, Lau Halkier, Vernieres, Jerome, Kibsgaard, Jakob, Nørskov, Jens K., and Chorkendorff, Ib
- Published
- 2024
- Full Text
- View/download PDF
38. Mixing short‐ and long‐acting local anaesthetics in peripheral nerve blocks: Protocol for a systematic review and meta‐analysis.
- Author
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Temberg, Jens L., Pisljagic, Sanja, Steensbæk, Mathias T., Yousef, Sina, Chafranska, Lana, Lange, Kai H. W., Rothe, Christian, Nørskov, Anders K., Maagaard, Mathias, and Lundstrøm, Lars H.
- Subjects
PERIPHERAL nervous system ,RESEARCH protocols ,ANESTHETICS ,NERVE block ,SEQUENTIAL analysis ,POSTOPERATIVE pain - Abstract
Introduction: This protocol describes a systematic review and meta‐analysis to evaluate the clinical effects of mixing short‐ and long‐acting local anaesthetics in peripheral nerve blocks. Clinicians often combine short‐ and long‐acting local anaesthetics to achieve a briefer onset time. However, this may come with a prize, namely a shorter total duration of the block, which is of clinical importance. Objective: This systematic review aims to strengthen the knowledge of the clinical effects associated with this practice. The primary outcome is the duration of block analgesia. Secondary outcomes are block onset time, sensory and motor block duration. Exploratory outcomes are postoperative pain scores, cumulative 24‐h opioid consumption and the prevalence of serious adverse events. Methods: We will conduct a meta‐analysis of the extracted data, and the risk of bias for each study will be evaluated. We will perform a Trial Sequential Analysis, subgroup, and sensitivity analyses and assess the overall risk of publication bias. Finally, we will evaluate the review using the GRADE principles. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Calcium-mediated nitrogen reduction for electrochemical ammonia synthesis
- Author
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Fu, Xianbiao, primary, Niemann, Valerie A., additional, Zhou, Yuanyuan, additional, Li, Shaofeng, additional, Zhang, Ke, additional, Pedersen, Jakob B., additional, Saccoccio, Mattia, additional, Andersen, Suzanne Z., additional, Enemark-Rasmussen, Kasper, additional, Benedek, Peter, additional, Xu, Aoni, additional, Deissler, Niklas H., additional, Mygind, Jon Bjarke Valbæk, additional, Nielander, Adam C., additional, Kibsgaard, Jakob, additional, Vesborg, Peter C. K., additional, Nørskov, Jens K., additional, Jaramillo, Thomas F., additional, and Chorkendorff, Ib, additional
- Published
- 2023
- Full Text
- View/download PDF
40. Activity and Stability of Single‐ and Di‐atom catalysts for O2 reduction reaction.
- Author
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Karmodak, Naiwrit, primary and Nørskov, Jens K., additional
- Published
- 2023
- Full Text
- View/download PDF
41. Limits to scaling relations between adsorption energies?
- Author
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Vijay, Sudarshan, Kastlunger, Georg, Chan, Karen, and Nørskov, Jens K.
- Subjects
ADSORPTION (Chemistry) ,METALLIC surfaces ,CHEMISORPTION ,ADSORBATES ,TRANSITION metals ,SMALL molecules - Abstract
Linear scaling relations have led to an understanding of trends in catalytic activity and selectivity of many reactions in heterogeneous and electro-catalysis. However, linear scaling between the chemisorption energies of any two small molecule adsorbates is not guaranteed. A prominent example is the lack of scaling between the chemisorption energies of carbon and oxygen on transition metal surfaces. In this work, we show that this lack of scaling originates from different re-normalized adsorbate valence energies of lower-lying oxygen vs higher-lying carbon. We develop a model for chemisorption of small molecule adsorbates within the d-band model by combining a modified form of the Newns–Anderson hybridization energy with an effective orthogonalization term. We develop a general descriptor to a priori determine if two adsorbates are likely to scale with each other. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Bayesian Error Estimation in Density Functional Theory
- Author
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Mortensen, J. J., Kaasbjerg, K., Frederiksen, S. L., Norskov, J. K., Sethna, J. P., and Jacobsen, K. W.
- Subjects
Condensed Matter - Materials Science - Abstract
We present a practical scheme for performing error estimates for Density Functional Theory calculations. The approach which is based on ideas from Bayesian statistics involves creating an ensemble of exchange-correlation functionals by comparing with an experimental database of binding energies for molecules and solids. Fluctuations within the ensemble can then be used to estimate errors relative to experiment on calculated quantities like binding energies, bond lengths, and vibrational frequencies. It is demonstrated that the error bars on energy differences may vary by orders of magnitude for different systems in good agreement with existing experience., Comment: 5 pages, 3 figures
- Published
- 2005
- Full Text
- View/download PDF
43. Pareto-optimal alloys
- Author
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Bligaard, Thomas, Johannesson, Gisli H., Ruban, Andrei V., Skriver, Hans L., Jacobsen, Karsten W., and Norskov, Jens K.
- Subjects
Condensed Matter - Materials Science - Abstract
Large databases that can be used in the search for new materials with specific properties remain an elusive goal in materials science. The search problem is complicated by the fact that the optimal material for a given application is usually a compromise between a number of materials properties and the price. In this letter we present a database consisting of the lattice parameters, bulk moduli, and heats of formation for over 64,000 ordered metallic alloys, which has been established by direct first-principles density-functional-theory calculations. Furthermore, we use a concept from economic theory, the Pareto-optimal set, to determine optimal alloy solutions for the compromise between low compressibility, high stability and price., Comment: 5 pages, 2 figures, To be published in Appl. Phys. Lett
- Published
- 2003
- Full Text
- View/download PDF
44. Theoretical Investigation of the Activity of Cobalt Oxides for the Electrochemical Oxidation of Water
- Author
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Bajdich, Michal, García-Mota, Mónica, Vojvodic, Aleksandra, Nørskov, Jens K, and Bell, Alexis T
- Subjects
Engineering ,Materials Engineering ,Chemical Sciences ,General Chemistry ,Chemical sciences - Abstract
The presence of layered cobalt oxides has been identified experimentally in Co-based anodes under oxygen-evolving conditions. In this work, we report the results of theoretical investigations of the relative stability of layered and spinel bulk phases of Co oxides, as well as the stability of selected surfaces as a function of applied potential and pH. We then study the oxygen evolution reaction (OER) on these surfaces and obtain activity trends at experimentally relevant electro-chemical conditions. Our calculated volume Pourbaix diagram shows that β-CoOOH is the active phase where the OER occurs in alkaline media. We calculate relative surface stabilities and adsorbate coverages of the most stable low-index surfaces of β-CoOOH: (0001), (0112), and (1014). We find that at low applied potentials, the (1014) surface is the most stable, while the (0112) surface is the more stable at higher potentials. Next, we compare the theoretical overpotentials for all three surfaces and find that the (1014) surface is the most active one as characterized by an overpotential of η = 0.48 V. The high activity of the (1014) surface can be attributed to the observation that the resting state of Co in the active site is Co(3+) during the OER, whereas Co is in the Co(4+) state in the less active surfaces. Lastly, we demonstrate that the overpotential of the (1014) surface can be lowered further by surface substitution of Co by Ni. This finding could explain the experimentally observed enhancement in the OER activity of Ni(y)Co(1-y)O(x) thin films with increasing Ni content. All energetics in this work were obtained from density functional theory using the Hubbard-U correction.
- Published
- 2013
45. Predicting Chemical Reaction Barriers with a Machine Learning Model
- Author
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Singh, Aayush R., Rohr, Brian A., Gauthier, Joseph A., and Nørskov, Jens K.
- Published
- 2019
- Full Text
- View/download PDF
46. A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements
- Author
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Andersen, Suzanne Z., Čolić, Viktor, Yang, Sungeun, Schwalbe, Jay A., Nielander, Adam C., McEnaney, Joshua M., Enemark-Rasmussen, Kasper, Baker, Jon G., Singh, Aayush R., Rohr, Brian A., Statt, Michael J., Blair, Sarah J., Mezzavilla, Stefano, Kibsgaard, Jakob, Vesborg, Peter C. K., Cargnello, Matteo, Bent, Stacey F., Jaramillo, Thomas F., Stephens, Ifan E. L., Nørskov, Jens K., and Chorkendorff, Ib
- Published
- 2019
- Full Text
- View/download PDF
47. Theoretical and Experimental Studies of CoGa Catalysts for the Hydrogenation of CO2 to Methanol
- Author
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Singh, Joseph A., Cao, Ang, Schumann, Julia, Wang, Tao, Nørskov, Jens K., Abild-Pedersen, Frank, and Bent, Stacey F.
- Published
- 2018
- Full Text
- View/download PDF
48. Transition-Metal Single Atoms in a Graphene Shell as Active Centers for Highly Efficient Artificial Photosynthesis
- Author
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Jiang, Kun, Siahrostami, Samira, Akey, Austin J., Li, Yanbin, Lu, Zhiyi, Lattimer, Judith, Hu, Yongfeng, Stokes, Chris, Gangishetty, Mahesh, Chen, Guangxu, Zhou, Yawei, Hill, Winfield, Cai, Wen-Bin, Bell, David, Chan, Karen, Nørskov, Jens K., Cui, Yi, and Wang, Haotian
- Published
- 2017
- Full Text
- View/download PDF
49. Ammonia Synthesis from First-Principles Calculations
- Author
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Honkala, K., Hellman, A., Remediakis, I. N., Logadottir, A., Carlsson, A., Dahl, S., Christensen, C. H., and Nørskov, J. K.
- Published
- 2005
50. Combining theory and experiment in electrocatalysis : Insights into materials design
- Author
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Seh, Zhi Wei, Kibsgaard, Jakob, Dickens, Colin F., Chorkendorff, Ib, Nørskov, Jens K., and Jaramillo, Thomas F.
- Published
- 2017
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