Probing the Dynamic Structure and Chemical State of Au Nanocatalysts during the Electrochemical Oxidation of 2-Propanol

A size-dependent trend was observed for the electrochemical total oxidation of 2-propanol to CO2 over Au nanoparticles (NPs), with increasing activity (increased current density and lower overpotential) for decreasing NP size. Furthermore, an enhanced stability against poisoning by the unreacted acetone intermediate was also obtained for NPs smaller than ∼2 nm. Operando X-ray absorption fine structure (XAFS) measurements provided insight into the dynamic evolution of the NP structure and chemical state under reaction conditions, shedding light on the nature of the most catalytically active species and catalyst deactivation phenomena via chemically driven sintering.