Solar-energy-driven photothermal catalytic C–C coupling from CO2 reduction over WO3–

Solar-energy-driven catalytic CO2 reduction for the production of value-added carbon-based materials and chemical raw materials has attracted great interest to alleviate the global climate change and energy crisis. The production of multicarbon (C2) products through CO2 reduction is extremely attractive, however, the yield and selectivity of C2 products remain low because of the low reaction temperature required and the low photoelectron density of the substrate. Here, we introduce WO3–x, which contains oxygen vacancies and exhibits an excellent photothermal conversion efficiency, to improve the generation of C2 products (C2H4 and C2H6) under simulated sunlight (UV-Vis-IR) irradiation. WO3–x produced 5.30 and 0.93 μmol·g–1 C2H4 and C2H6, respectively, after 4 h, with a selectivity exceeding 34%. In situ Fourier transform infrared spectra and theoretical calculations showed that the oxygen vacancies enhanced the water activation and hydrogenation of adsorbed CO for the formation of C2 products via C–C coupling from CH2/CH3 intermediates. The findings of this study could assist in the design of highly active solar-energy-driven catalysts to produce C–C coupling products through CO2 reduction.