AuPd Nanoalloy-Decorated TS-1 Zeolite Photocatalyst for Highly Selective Methane-to-Methanol Oxidation at Low Temperature

The direct oxidation of methane to methanol at room temperature is a highly sought-after but challenging reaction due to methane’s inert C−H bond and methanol overoxidation. Conventional approaches often require high temperature and pressure or special oxidants. Here, we report an AuxPdy/TS-1 composite photocatalyst with tunable Au/Pd ratios that achieves highly selective methane-to-methanol conversion at near-room temperature using water as the oxidant. An optimized Au0.1Pd0.05/TS-1 photocatalyst exhibits an activity of 64.7 mmol gAuPd−1 h−1 and a turnover frequency of 19.1 h-1 with 100% methanol selectivity under simulated solar light. This performance arises from the efficient electron-hole generation by encapsulated nanoalloy AuPd clusters, generating ·OH and ·CH3 radicals for methane activation and water oxidation, as evidenced by in situ EPR and DRIFT spectroscopy. DFT calculations show that Au sites preferentially mediate the formation of methanol via surface-bound *CH3 and *OH intermediates. Alloy-induced Pd→Au charge redistribution modulates CH4/H2O activation energetics and weakens methanol binding. This study demonstrates an efficient and mild route for highly selective methane utilization under mild conditions.