Bioinspired Proton–Electron Dual Channels for Selective Photocatalytic Oxidation of Methane to Methanol

Abstract

Photocatalytic methane conversion holds great promise for upgrading this abundant feedstock under ambient conditions, yet the selective partial oxidation of methane to methanol remains challenging. In triphasic aerobic photocatalysis, inefficient interfacial supply and transfer of protons and electrons restrict methanol production and promote overoxidation. Herein, we design bioinspired proton–electron dual-channels on the photocatalyst through surface modification with trimesic acid and palladium. The optimized catalyst achieves a remarkable methanol production rate of ∼5.15 mmol g–1 h–1 with a selectivity of nearly 95.0% in liquid-phase products. Multimodal spectroscopic characterizations and theoretical calculations reveal that the interfacial channels facilitate proton-coupled electron transfer and favor the selective generation of •OH radicals, which directly couple with in situ produced •CH3 intermediates to form methanol. Concurrently, this architecture expedites the reduction of the CH3OOH intermediate to methanol, efficiently suppressing its further oxidation. This work offers fresh perspectives on precise interfacial regulation of proton-coupled electron transfer, and provides a versatile blueprint for future heterogeneous photocatalyst design in methane upgrading.