PNNL

Abstract

Electro-catalysis has various important applications especially fuel cells. As a key element in electro-catalysis, the surface chemistry of electro-catalysts may strongly influence the catalytic activity and reaction mechanism, the fundamental understanding of which would provide guidance for designing high-efficiency catalysts. Herein, we utilized our recently developed in situ liquid SIMS approach to investigate the electro-catalytic oxidation of ethanol on gold surfaces in alkaline environments involved in direct alcohol fuel cells. Formation of adsorbed hydroxide intermediates on the gold surfaces upon electro-oxidation was molecularly witnessed under operando conditions, the evolution of which was revealed to govern the electro-catalytic processes. Moreover, the hydroxide intermediates as active sites participated in the reaction through transferring nucleophilic hydroxyl groups into the adjacent ethanol molecules. This work brings new light into electro-catalytic research and will facilitate the improvement of catalytic systems on the basis of surface chemistry-catalytic performance relationship.