Deciphering the Metal–Support Interaction of Au/ZnO Catalyst Induced by H2 and O2 Pretreatment

Abstract Metal–support interaction (MSI) provides great possibilities to tune the activity, selectivity, and stability of heterogeneous catalysts. Herein, the Au/ZnO catalyst is prepared by commercial ZnO and chloroauric acid, and the structure evolution of the catalyst pretreated by H 2 and O 2 gas at varied temperature is investigated to provide mechanistic insights of MSI. It is found that the H 2 treatment at 300 °C and above can induce the formation of both the ZnO x overlayer and bulk Au–Zn alloy. In contrast, the O 2 treatment can form the ZnO x overlayer at 500 °C and above without the formation of Au–Zn alloy. It is also revealed that the ZnO x overlayer is dynamically stable (permeable), which can provide access for reactant molecules during the reaction process. And, the Au–Zn alloy can recover to Au and ZnO under the CO oxidation reaction condition, which can be deemed as a re‐activation process that endows H 2 ‐treated samples with the superior activity and stability.