Photothermal catalytic activity and mechanism of LaNixCo1−xO3(0 ≦ x ≦ 1) perovskites for CO2 reduction to CH4 and CH3OH with H2O

A series of LaNixCo1−xO3 perovskites were synthesized by sol–gel combustion method, the photothermal catalysis of CO2 and H2O into CH4 and CH3OH was investigated systematically. The crystal structure, surface area, oxygen vacancies, band structures and catalytic performance of LaNixCo1−xO3 perovskites were characterized thoroughly in order to understand the design principle of the material for such a photothermal catalysis of CO2 and H2O. With the change of x value, the best catalytic performance was achieved at x = 0.4 and the accumulated yield of CH4 and CH3OH can reach 678.57, 20.83 μmolg−1 in 6 h, which were 3.4 and 3.8, 1.9 and 2.2 times of that of two end composition, LaCoO3 and LaNiO3 under the same condition. For LaNi0.4Co0.6O3, the surface area reached a maximum concentration of oxygen vacancy while the band gap reached a minimum of 1.42 eV. It is evident that the formation of solid solution between LaMO3 (M = transition metals) compounds can be a general strategy for the new catalyst design.