Ni-Zn supported defective carbon with multi-functional catalytic sites for Baeyer–Villiger reaction using air as oxidant

The development of economic catalysts for aerobic oxidation procedure has attracted extensive attention. In this work, a novel Ni/Zn supported defective carbon with multi-functional catalytic sites was fabricated via a two-step pyrolysis-H₂O₂ treatment. The catalyst was applied to the Baeyer–Villiger (B–V) oxidation using ambient air as a green and safe oxidant. The catalyst with optimal Ni/Zn ratio of (2:1) delivers a high catalytic activity (> 92%) and perfect selectivity (> 99%) for the conversion of a wide range of substituted cyclic-ketones to the corresponding lactones. The characterization results have clarified that the H₂O₂ treatment leads to the formation of active N/O-group on the catalyst surface, which facilitates the adsorption of substrate/intermediate molecules and benefits the reaction. Moreover, the synergistic effect between multi-functional sites results in the buffering/stabilizing of free radicals, enhanced efficiency of oxygen insertion to form lactone. The design principle in this work is believed to shed light on the exploration of all-in-one solid catalyst for diverse oxidative reaction.