Structure‐Dependent Base‐Free Aerobic Oxidation of Benzyl Alcohol over High‐Surface‐Area Mg‐Doped ZnAl2O4 Spinel Supported Gold Nanoparticles

Abstract

A facile and economical strategy to synthesize high surface area Mg-doped ZnAl2 O4 spinels is developed. These materials are employed as catalyst supports to prepare supported gold catalysts for the aerobic oxidation of benzyl alcohol by using molecular oxygen in the absence of additional alkali. The as-fabricated supported Au catalyst with the Mg/(Mg+Zn) molar ratio of 0.15 was found to show good catalytic activity with high benzaldehyde selectivity (>99 %) and a high turnover frequency of 5382 h-1 . The relationship between the surface properties of the supported Au catalysts and their catalytic performances reveals that the high catalytic efficiency is mainly attributable to surface cooperative effects between the abundant basic sites and favorable active Au species, including metallic Au and cationic Auδ+ ions. A possible mechanism for selective oxidation of benzyl alcohol is tentatively proposed. Moreover, the as-fabricated supported Au catalyst could be reused at least four times without significant loss of its catalytic performance. The present finding provides a new route for designing high-performance supported noble or non-noble metal catalysts by using high surface area ZnAl2 O4 -based spinels.