Insight into the selective oxidation mechanism of glycerol to 1,3‐dihydroxyacetoneoverAuCu–ZnOinterface

Abstract

AbstractDirectional regulation of polyol oxidation selectivity by constructing active sites with specific structure is a critical yet challenging problem. Herein, the specific Au‐based catalyst with efficient Au–Cu–ZnO interfacial active sites was successfully designed to promote selective oxidation of glycerol to 1,3‐dihydroxyacetone under mild conditions. X‐ray absorption spectroscopy revealed that the increased electron transfer between Au and Cu increases the content of Au+, resulting in the higher catalytic activity (turnover frequency: 402.5 h−1). Meanwhile, small AuCu alloy nanoparticles (ca., 2.7 nm) could be inserted into the ZnO lattice with the formation of Au(Cu)–O–Zn linkages, resulting in the enrichment of interfacial oxygen vacancies. These interfacial oxygen vacancies induce the activation and adsorption of the secondary hydroxyl group of glycerol on the interfacial active sites, improving the selectivity of 1,3‐dihydroxyacetone (83.4%). Furthermore,in situFourier transform infrared, structure‐dependent kinetics and density functional theory calculation demonstrated that Au–Cu–ZnO interfacial active sites could enhance the participation of OH* and oxygen vacancies in activating the OH and CH bonds, respectively, promoting the improvement of the catalytic performance. The outcome of this work offers new insights for the rational design of high effective catalyst for the selective oxidation of polyol.