Efficient charge transfer channel over in-situ photo-thermo-induced Cu-ZnO for H2 production from methanol steam reforming

The intrinsic photon and thermal effects originated surface structure reconstruction of heterogenous photo-thermo-catalysis are prevalent and closely associated with their catalytic performance. Current efforts mainly focus on improving the catalyst synthesis details for structure modification. Herein, we propose a photo-thermo-induced in-situ strategy to manipulate the surface structure evolution of the catalyst by controlling the light irradiance under the operating MSR reaction. Exposing the precursor of Cu/ZnO/Al2O3 catalyst to an operating MSR condition at 15 × kW m−2 (1 × sun = 1 kW−2) irradiance is found to form steady-state Cu-ZnOx interface sites by the light-intensified reduction of CuO to metallic Cu and strong metal–support interaction (SMSI). Such Cu-ZnOx interface sites achieve an excellent H2 production rate of 1.12 mol g−1h−1 with the corresponding solar-to-hydrogen conversion efficiency of 5.3%, exceeding previously reported photocatalysts and thermocatalysts. Experimental results and theory suggest that Cu-ZnOx not only enhances the carrier dynamics but also reduces the lower interfacial barrier for rate-determining steps of dehydrogenation of CH3O* and dissociation of H2O, which may stem from the special charger transfer channel, promoting hot carriers from Cu into water molecules along the ZnOx and subsequently resulting in the formation of electron-deficient Cu to benefited methanol activation. This work brought us to the exciting technology of high-efficient solar-to-hydrogen conversion, and it could adjust the electronic structure of the heterojunction catalyst; it is foreseeable that this photo-induced modulation strategy can be extended to other applications.