Solar Photocatalytic Oxidation of Methane to Methanol with Water over RuOx/ZnO/CeO2 Nanorods

Due to the high stability and chemical inertia of methane, CH4, its selective conversion into value-added organic chemicals under mild conditions has been widely regarded as an important reaction for the chemical industry. Here, we develop a RuOx decorated ZnO/CeO2 photocatalyst for the highly efficient and selective transformation of CH4 into CH3OH under simulated solar light irradiation. The CH3OH generation rate over the optimized RuOx/ZnO/CeO2 composite is 133.54 μmol g–1 h–1 with 97.7% selectivity, which is 20 times higher than that of a ZnO/CeO2 reference system (6.56 μmol g–1 h–1) which only exhibits moderate selectivity (40.5%). We find that the significant boost to the photocatalytic performance is attributable to accelerated interfacial charge separation and a beneficial rise in free hydroxyl radical generation from water oxidation in the presence of RuOx clusters.