In-situ ECSTM investigation of H_(2)O_(2)production in cobalt–porphyrin-catalyzed oxygen reduction reaction  

作　　者：Ya-Chen Feng Xiang Wang Zhen-Yu Yi Yu-Qi Wang Hui-Juan Yan Dong Wang 

机构地区：[1]CAS Key Laboratory of Molecular Nanostructure and Nanotechnology,CAS Research/Education Center for Excellence in Molecular Sciences,Beijing National Laboratory for Molecular Science(BNLMS),Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Bejing 100049,China

出　　处：《Science China Chemistry》2023年第1期273-278,共6页中国科学（化学英文版）

基　　金：supported by the National Key R&D Program of China(2021YFA1501002);the National Natural Science Foundation of China(21725306 and 21972147);the Key Research Program of the Chinese Academy of Sciences(XDPB01);the National Postdoctoral Program for Innovative Talents(BX20220307)of the Chinese Postdoctoral Science Foundation。

摘　　要：We report the in-situ investigation of the production of H_(2)O_(2)in 5,10,15,20-tetra(4-methoxyphenyl)-21H,23H-porphyrin cobalt(Ⅱ)(Co TMPP)-catalyzed oxygen reduction reaction(ORR)in neutral electrolytes by electrochemical scanning tunneling microscopy(ECSTM)at the molecular scale.The adsorption of OOH-on active sites can be observed in STM images and is found to be correlated with the pH value of the electrolyte.The thermodynamic parameters of the formation of Co TMPP–OOHcomplex are extracted by the quantitative analysis of the STM images.Two stages of the ORR including the formation of H_(2)O_(2)and further reduction of H_(2)O_(2)at different reduction potentials can be revealed by electrochemical measurements.In-situ ECSTM experiments unambiguously identify the formation of the Co TMPP–OOH-complex as the high contrast species and its reduction and oxidation process.This work provides the direct evidence for understanding the formation and transformation process of H_(2)O_(2)at the molecular scale,which benefits the rational design of the high-efficiency electrocatalysts for ORR and H_(2)O_(2)production.

关 键 词：electrochemical scanning tunnelling microscopy H_(2)O_(2)production cobalt-porphyrin oxygen reduction reaction 

分 类 号：O643.36[理学—物理化学]