Mechanistic insights into the atmosphere-dependent strong metal-support interactions of Au/ZnO catalysts for oxidative esterification

Strong metal-support interactions (SMSI) are pivotal for constructing interfacial active sites, yet its precise regulation remains a formidable challenge. Here, we report a facile strategy to modulate the atmosphere-dependent SMSI in Au/ZnO catalysts by strictly regulating the oxygen partial pressure during thermal treatment. We reveal that the encapsulation degree of Au particles exhibits a volcano-shaped dependence on oxygen partial pressure, which drives electron transfer from Au to the support to create abundant interfacial oxygen vacancies (Au–O V –Zn). For the oxidative esterification of methacrolein, mechanistic investigations reveal that these interfacial defects constitute frustrated Lewis acid–base pairs to promote the formation of hemiacetal intermediates, and simultaneously serve as active sites for oxygen activation. The activated lattice oxygen migrates to the Au surface and generate active Au–O species that effectively overcome the kinetic barrier of the rate-determining β-H elimination. Driven by this interfacial synergy, the catalyst exhibiting the most pronounced SMSI achieves state-of-the-art performance with an MMA yield of 91.8%. These findings provide a new strategy for the design of high-performance catalysts via interfacial defect engineering.