Anodic Oxidation Enabled Cation Leaching for Promoting Surface Reconstruction in Water Oxidation.
Yan Duan1,2, Jun Yan Lee1, Shibo Xi3
1School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Angewandte Chemie (International Ed. in English)
|December 29, 2020
Summary
Controlled anodic leaching of chromium in cobalt chromium oxide (CoCr2O4) transforms inactive spinel into a highly active oxygen evolution reaction (OER) catalyst. This method intentionally modifies catalyst surfaces for improved water electrolysis efficiency.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Rational catalyst design is crucial for efficient water electrolysis.
- Understanding cation leaching and surface reconstruction is key for active electrocatalysts.
- Controlled surface modification strategies are underexplored.
Purpose of the Study:
- To report controllable anodic leaching of Cr in CoCr2O4.
- To transform inactive spinel CoCr2O4 into a highly active oxygen evolution reaction (OER) catalyst.
- To investigate the mechanism of surface reconstruction.
Main Methods:
- Activation of pristine CoCr2O4 at high anodic potential.
- Analysis of surface chemistry changes.
- Electrochemical performance testing for OER.
Main Results:
- Controllable anodic leaching of Cr was achieved.
- Inactive spinel CoCr2O4 transformed into a highly active OER catalyst.
- Surface defects, oxygen vacancies, and reconstruction into active Co oxyhydroxides were observed.
Conclusions:
- Controlled anodic potential is important for modifying electrocatalyst surface chemistry.
- A novel mechanism involving cation configuration evolution via non-concerted proton-electron transfer was proposed.
- This approach enables the rational design of efficient OER catalysts.
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