Selective light absorber-assisted single nickel atom catalysts for ambient sunlight-driven CO2 methanation

Abstract

Ambient sunlight-driven CO₂ methanation cannot be realized due to the temperature being less than 80 °C upon irradiation with dispersed solar energy. In this work, a selective light absorber was used to construct a photothermal system to generate a high temperature (up to 288 °C) under weak solar irradiation (1 kW m^-2), and this temperature is three times higher than that in traditional photothermal catalysis systems. Moreover, ultrathin amorphous Y₂O₃ nanosheets with confined single nickel atoms (SA Ni/Y₂O₃) were synthesized, and they exhibited superior CO₂ methanation activity. As a result, 80% CO₂ conversion efficiency and a CH₄ production rate of 7.5 L m^-2 h^-1 were achieved through SA Ni/Y₂O₃ under solar irradiation (from 0.52 to 0.7 kW m^-2) when assisted by a selective light absorber, demonstrating that this system can serve as a platform for directly harnessing dispersed solar energy to convert CO₂ to valuable chemicals.