Recent advances in scanning electrochemical microscopy for probing the sites in electrocatalysts

Abstract

In electrochemical reactions, the study of catalyst activity is becoming increasingly extensive. The insights into the active sites of catalysts have been providing ideas for efficiently designing highly active and selective catalysts. Therefore, powerful in-situ characterization tools can provide strong evidence and persuasive power for electrochemical process. Scanning electrochemical microscope (SECM) has gained increasing attention as a powerful analytical tool for characterizing catalytic activity in electrochemical process. In this review, we summarized the application methods of SECM in electrochemical reactions such as hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR), nitrate reduction reaction (NitRR). We also briefly introduced the common operation modes of SECM. The recent progress of SECM in probing the reaction sites, reaction kinetics and charge transfer of electrocatalysts is reviewed. Finally, we discuss the challenges and prospects of SECM in characterizing the activity of electrocatalysts. This paper provides a reference for readers on SECM experimental method and theoretical analysis.