LAUSR

Scanning electrochemical microscopy (SECM) is a “non-contact” scanning probe technique capable of providing chemical and/or topographic information about surfaces immersed in a solution. It is a powerful in situ and operando tool for obtaining insights into electrocatalytic rates and mechanisms. Herein, examples are given on how SECM can be used to characterize (1) hydrogen oxidation reaction electrocatalysts for fuel-cell applications, (2) oxygen evolution reaction electrocatalysts for water splitting applications, and (3) electrochemical CO2-reducing catalysts. We also report a new operando method of SECM in which we can separate electrochemical reduction of CO2 to CO in aqueous media from parasitic hydrogen evolution as a function of applied potential. Understanding hydrogen evolution suppression is a major challenge in the intelligent design of CO2-reducing electrocatalysts. Via this multireactional SECM technique, we observed the optimal potential window for electrochemically reducing CO2 to CO with ...