Achieving unprecedented photothermal catalytic CO2 methanation performance of Ru doped CeO2 by synergistic tailoring of the light absorption and atomic-scale active sites

Photothermal hydrogenation of CO 2 into high value chemicals is a promising approach for addressing the energy crisis and mitigating CO 2 emissions. However, synergistic tailoring of light absorption and active sites at the atomic level to enhance catalyst performance still remains a challenge. Herein, Ru single atoms doping empowers CeO 2 with two advantageous modifications, inducing abundant of oxygen vacancies and full spectrum (200–2500 nm) responsiveness. Experimental and theoretical calculations verify that the Ru doped CeO 2 (Ru/CeO 2 ) catalyst featuring Ru single atoms and oxygen vacancy active sites, which enables simultaneous H 2 and CO 2 activation, and also reduce the energy barrier in the rate-limiting step of C-O bond cleaving. Meanwhile, the introduction of oxygen defect and Ru doping levels endows the full-spectral light absorption of CeO 2 , thus achieving high-efficiency light-to-thermal conversion. As a result, the optimal Ru/CeO 2 catalyst shows an unprecedented CH 4 yield rate of 123 mmol⋅g −1 ⋅h −1 with near-unity selectivity (˃99%) under light illumination without any external heat source, as well as a good catalytic stability.