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This content will become publicly available on October 16, 2018

Title: Experimental Proof of the Bifunctional Mechanism for the Hydrogen Oxidation in Alkaline Media

Realization of the hydrogen economy relies on effective hydrogen production, storage, and utilization. The slow kinetics of hydrogen evolution and oxidation reaction (HER/HOR) in alkaline media limits many practical applications involving hydrogen generation and utilization, and how to overcome this fundamental limitation remains debatable. Here we present a kinetic study of the HOR on representative catalytic systems in alkaline media. Electrochemical measurements show that the HOR rate of Pt-Ru/C and Ru/C systems is decoupled to their hydrogen binding energy (HBE), challenging the current prevailing HBE mechanism. The alternative bifunctional mechanism is verified by combined electrochemical and in situ spectroscopic data, which provide convincing evidence for the presence of hydroxy groups on surface Ru sites in the HOR potential region and its key role in promoting the rate-determining Volmer step. The conclusion presents important references for design and selection of HOR catalysts.
Authors:
ORCiD logo [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1] ;  [3] ; ORCiD logo [1]
  1. Northeastern Univ., Boston, MA (United States). Dept. of Chemistry and Chemical Biology
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
  3. Shanghai Jiao Tong Univ. (China). Shanghai Electrochemical Energy Devices Research Center and Dept. of Chemical Engineering
Publication Date:
Report Number(s):
BNL-203460-2018-JAAM
Journal ID: ISSN 1433-7851
Grant/Contract Number:
SC0012704; AC02‐76SF00515; 21676165; 21336003
Type:
Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 56; Journal Issue: 49; Journal ID: ISSN 1433-7851
Publisher:
Wiley
Research Org:
Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II); SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Advanced Research Projects Agency - Energy (ARPA-E); National Natural Science Foundation of China (NNSFC)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 08 HYDROGEN; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; alloys; electrocatalysis; electrochemistry; reaction mechanisms; supported catalysts
OSTI Identifier:
1433947