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Approaching Theoretical Performances of Electrocatalytic Hydrogen Peroxide Generation by Cobalt-Nitrogen Moieties |
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| Authors: | Runjia Lin Liqun Kang Karolina Lisowska Weiying He Siyu Zhao Shusaku Hayama Graham J Hutchings Dan J L Brett Furio Corà Ivan P Parkin Guanjie He |
| Institution: | 1. Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ UK
Max Planck-Cardiff Centre on the Fundamentals of Heterogeneous Catalysis FUNCAT, Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, UK;2. Department of Inorganic Spectroscopy, Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34–36, 45470 Mülheim an der Ruhr, Germany Department of Chemical Engineering, University College London (UCL), London, WC1E 7JE UK;3. Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ UK;4. Department of Inorganic Spectroscopy, Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34–36, 45470 Mülheim an der Ruhr, Germany University of Göttingen, Institute of Inorganic Chemistry, Tamannstrasse 4, 37077 Göttingen, Germany;5. Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ UK Department of Chemical Engineering, University College London (UCL), London, WC1E 7JE UK;6. Diamond Light Source Ltd, Diamond House, Harwell Campus, Didcot, OX11 0DE UK;7. Max Planck-Cardiff Centre on the Fundamentals of Heterogeneous Catalysis FUNCAT, Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, UK;8. Department of Chemical Engineering, University College London (UCL), London, WC1E 7JE UK |
| Abstract: | Electrocatalytic oxygen reduction reaction (ORR) has been intensively studied for environmentally benign applications. However, insufficient understanding of ORR 2 e−-pathway mechanism at the atomic level inhibits rational design of catalysts with both high activity and selectivity, causing concerns including catalyst degradation due to Fenton reaction or poor efficiency of H2O2 electrosynthesis. Herein we show that the generally accepted ORR electrocatalyst design based on a Sabatier volcano plot argument optimises activity but is unable to account for the 2 e−-pathway selectivity. Through electrochemical and operando spectroscopic studies on a series of CoNx/carbon nanotube hybrids, a construction-driven approach based on an extended “dynamic active site saturation” model that aims to create the maximum number of 2 e− ORR sites by directing the secondary ORR electron transfer towards the 2 e− intermediate is proven to be attainable by manipulating O2 hydrogenation kinetics. |
| Keywords: | Cobalt-Nitrogen Moieties Electrocatalyst Hydrogen Peroxide Oxygen Reduction Reaction |