Selective photocatalytic oxidation of methane to methanol by enhancing H2O2 utilization over Au-Pd/In2O3

Hydrogen peroxide (H 2 O 2 ) is widely used as an oxidant for photocatalytic oxidation of methane to value-added chemicals under mild conditions, but suffers from low utilization efficiency. Herein, we propose a comprehensive strategy for the proper amount of hydroxyl radicals (•OH) generation from H 2 O 2 by regulating the Pd/Au molar ratios and the total Au-Pd contents loaded on In 2 O 3 . For the photocatalytic oxidation of methane at ambient temperature, the yield and selectivity of CH 3 OH over the optimized 1.0% AuPd 0.5 /In 2 O 3 catalyst were as high as 2187.0 μmol g −1  h −1 and 94.0% respectively, exceeding most reported literatures. Mechanism investigations revealed that the formation of Au-Pd alloys may contribute to the homolytic cleavage of H 2 O 2 into •OH radicals and improve the selectivity of •OH generation. This work provides some guidance for the delicate design of photocatalysts to manipulate selective H 2 O 2 activation and efficient photocatalytic methane oxidation.