Single‐Molecule Nanocatalysis Shows In Situ Deactivation of Pt/C Electrocatalysts during the Hydrogen‐Oxidation Reaction

Abstract By coupling a Pt‐catalyzed fluorogenic reaction with the Pt‐electrocatalyzed hydrogen‐oxidation reaction (HOR), we combine single‐molecule fluorescence microscopy with traditional electrochemical methods to study the real‐time deactivation kinetics of a Pt/C electrocatalyst at single‐particle level during electrocatalytic hydrogen‐oxidation reaction. The decay of the catalytic performance of Pt/C could be mainly attributed to the electrocatalysis‐induced etching or dissolution of Pt nanoparticles. Spontaneous regeneration of activity and incubation period of the Pt electrocatalyst were also observed at single‐particle level. All these new insights are practically useful for the understanding and rational design of highly efficient electrocatalysts for application in fuel cells.