High-density Au-OV synergistic sites boost tandem photocatalysis for CO2 hydrogenation to CH3OH

Abstract

The production of renewable methanol (CH₃OH) via the photocatalytic hydrogenation of CO₂ is an ideal method to ameliorate energy shortages and mitigate CO₂ emissions: however, the highly selective synthesis of methanol at atmospheric pressure remains challenging owing to the competing reverse water-gas shift (RWGS) reaction. Herein, we present a novel approach for the synthesis of CH₃OH via photocatalytic CO₂ hydrogenation using a catalyst featuring highly dispersed Au nanoparticles loaded on oxygen vacancy (O_V)-rich molybdenum dioxide (MoO₂), resulting in a remarkable selectivity of 43.78%. The active sites in the Au/MoO₂ catalyst are high-density Au-oxygen vacancies, which synergistically promote the tandem methanol synthesis via an initial RWGS reaction and subsequent CO hydrogenation. This work provides comprehensive insights into the design of metal-vacancy synergistic sites for the highly selective photocatalytic hydrogenation of CO₂ to CH₃OH.