Integrating photochemical and photothermal effects for selective oxidative coupling of methane into C2+ hydrocarbons with multiple active sites

The direct photocatalytic oxidation of methane to value-added chemicals has garnered considerable interest in recent years. However, achieving high productivity while maintaining high selectivity at an appreciable methane conversion rate remains a formidable challenge. Here, we present photochemically-triggered and photothermally-enhanced oxidative coupling of methane to multi-carbon C 2+ alkanes over an Au and CeO 2 nanoparticle-decorated ZnO photocatalyst, which exhibits a record-breaking C 2+ production rate of 17,260 μmol g −1 h −1 with ~90% C 2+ selectivity under wide-spectrum light irradiation without a secondary source of heating. Comprehensive characterizations and computational studies reveal that CH 4 activation is a photochemical reaction initiated by ultraviolet light-excited ZnO, and the introduction of CeO 2 substantially enhances the activation of CH 4 and O 2 due to the cooperative interaction between Au and CeO 2 . Concurrently, Au nanoparticles capture visible and near-infrared light to generate localized heating, which greatly promotes the subsequent desorption of produced methyl radical for C–C coupling prior to undergoing further undesired overoxidation.