Photothermal CO2 methanation offers a clean and sustainable solution to store intermittent renewable energy as synthetic CH4. However, its high reaction temperature and low space-time yield hinder its industrial application. Here we report an Au/Ce0.95Ru0.05O2 solid-solution catalyst exhibiting a remarkable photothermal CO2 methanation activity approaching the thermal catalysis limit under visible–near-infrared light irradiation without external heating. Localized surface-plasmon-induced hot-electron injection created abundant oxygen vacancies near the dispersed ruthenium sites, accelerating CO2 methanation. An approximately 6- to 8-fold increase in the pre-exponential factor was evidenced using Arrhenius plot analysis under visible–near-infrared light irradiation. Using a flow reactor, a photothermal CH4 production rate of (473,{mathrm{mmol}},{mathrm{g}}_{mathrm{cat}}^{-1},{mathrm{h}}^{-1}) was obtained at a gas hourly space velocity of (80,000,{mathrm{ml}},{mathrm{g}}_{mathrm{cat}}^{-1},{mathrm{h}}^{-1}) with ~100% CH4 selectivity, ~75% single-pass CO2 conversion and excellent durability. Our study offers insights into plasmonic-steered photochemistry, which may open opportunities for the high-yielding synthesis of carbon-based chemicals using solar energy.
Light-driven CO2 methanation over Au-grafted Ce0.95Ru0.05O2 solid-solution catalysts with activities approaching the thermodynamic limit
