1Doping-Mediated Metal-Support Interaction Promotion toward Light-Assisted Methanol Production over Cu/ZnO/Al2O3

Many studies have demonstrated the feasibility of utilizing light-mediated electronic perturbations to regulate or promote the thermal catalytic conversion of CO2 to methanol. However, such studies are usually performed on pre-designed thermal catalysts with little regard to properties which govern the light-driven process. Herein, we investigate the promoting effect of two dopants with different intrinsic properties on metal-support interaction and catalytic performance. The promoting effects of Mg and La are assessed during thermal and light-assisted methanol synthesis over the Cu/ZnO/Al2O3 (CZA) catalyst. Photoenhancement factor increased from 138% (CZA) to 146 and 164%, respectively, for Mg- and La-doped catalysts. Enriched interfacial oxygen vacancies are tentatively determined as the predominant factor which channels the photogenerated electrons to the adsorbed formate species at the interface. X-ray photoelectron spectroscopy and temperature-programmed H-2 reduction analyses also suggest a defect-mediated improvement in the Cu-ZnO interaction in the presence of both dopants. In addition, the La-doped catalyst enhanced methanol selectivity by modulating the adsorption states of intermediates, as shown by density functional theory and in situ diffuse reflectance infrared Fourier transform spectroscopy studies. This work illustrates the potential of improving light-driven processes by boosting the metal-support interfacial interaction.