Insight into the Selective Oxidation Mechanism of Glycerol to 1,3-Dihydroxyacetone Over Aucu/Zno Catalyst with Abundant Interfacial Oxygen Vacancies

Directional regulation of polyol oxidation selectivity by constructing active sites with specific structure is a critical yet challenging problem. Herein, we successfully designed efficient Au-Cu-ZnO interfacial sites to promote selective oxidation of glycerol (GLY) to 1,3-dihydroxyacetone (DHA) under mild conditions. X-ray absorption spectroscopy revealed that the electron transfer between Au and Cu reduces the electron cloud density of Au, improving the oxidation activity of GLY (turnover frequency: 402.5 h -1 ). Meanwhile, during the thermal treatment process, small AuCu alloy nanoparticles (c.a. 2.7 nm) could be inserted into the ZnO lattice with the formation of Au(Cu)-O-Zn linkages, resulting in the enrichment of oxygen vacancy defects (Vo). The interfacial oxygen vacancies could induce the adsorption of the secondary hydroxyl group of GLY, leading to an unprecedented DHA selectivity (83.4%). Furthermore, in situ fourier transform infrared, structure-dependent kinetics and density functional theory calculation demonstrated that the Au-Cu-ZnO interfacial active site could enhance the participation of oxygen-activated species O* in activating the C-H and O-H bonds, resulting in the improvement of catalytic performance of GLY oxidation to DHA. The outcome of this work offers new insights for the high-efficiency Au-based catalyst to promote the oxidation reaction path of GLY caused by the introduction of Cu