In-situ exsolved ultrafine Ni nanoparticles from CeZrNiO2 solid solution for efficient photothermal catalytic CO2 reduction by CH4

CO2 reduction by CH4 (CRM) to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas. Herein, the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO2 solid solution (Ni@CZNO) was synthesized by the sol-gel method. High yield of H2 and CO (58.0 and 69.8 mmol min−1 g−1) and excellent durability (50 h) were achieved by photothermal catalytic CRM merely under focused light irradiation. Structural characterization and DFT calculations reveal that CZNO has rich oxygen vacancies that can adsorb and activate CO2 to produce reactive oxygen species. Oxygen species are transferred to ultrafine Ni nanoparticles through the rich Ni-CZNO interface to accelerate carbon oxidation, thereby maintaining the excellent catalytic stability of the catalyst. Moreover, the experimental results reveal that light irradiation can not only enhance the photothermal catalytic CRM activity through photothermal conversion and molecular activation, but also improve the stability by increasing the concentration of oxygen vacancies and inhibiting CO disproportionation.