| Literature DB >> 33372346 |
Yan Duan1,2, Jun Yan Lee1, Shibo Xi3, Yuanmiao Sun1, Jingjie Ge1, Samuel Jun Hoong Ong1,4, Yubo Chen1,5, Shuo Dou6, Fanxu Meng1,4, Caozheng Diao3, Adrian C Fisher5,7, Xin Wang6, Günther G Scherer8, Alexis Grimaud9,10, Zhichuan J Xu1,2,4,5.
Abstract
A rational design for oxygen evolution reaction (OER) catalysts is pivotal to the overall efficiency of water electrolysis. Much work has been devoted to understanding cation leaching and surface reconstruction of very active electrocatalysts, but little on intentionally promoting the surface in a controlled fashion. We now report controllable anodic leaching of Cr in CoCr2 O4 by activating the pristine material at high potential, which enables the transformation of inactive spinel CoCr2 O4 into a highly active catalyst. The depletion of Cr and consumption of lattice oxygen facilitate surface defects and oxygen vacancies, exposing Co species to reconstruct into active Co oxyhydroxides differ from CoOOH. A novel mechanism with the evolution of tetrahedrally coordinated surface cation into octahedral configuration via non-concerted proton-electron transfer is proposed. This work shows the importance of controlled anodic potential in modifying the surface chemistry of electrocatalysts.Entities:
Keywords: Co-based materials; OER; controllable leaching; site occupancy; surface reconstruction
Year: 2020 PMID： 33372346 DOI： 10.1002/anie.202015060
Source DB: PubMed Journal: Angew Chem Int Ed Engl ISSN： 1433-7851 Impact factor: 15.336