Ternary Ni–Co–Fe oxides based on Prussian blue analog for efficient photothermal catalytic CO2 reduction to CO and CH4

Photothermal catalytic CO2 reduction is an attractive way to alleviate the current energy crisis, but it is important to prepare catalysts with efficient catalytic capacity. In this work, Prussian blue analogs were firstly prepared, and then calcined to obtain porous transition metal (Ni, Co, Fe) oxides (TMOs). The metal composition of catalysts has great influences on their structures and catalytic properties. Among them, NCF-TMO catalyst shows excellent photothermal catalytic performance, and can produce 2.9 mmol g-1 h-1 CO and 1.6 mmol g-1 h-1 mmol CH4 at low CO2 and H2 concentrations. For the NCF-TMO, its superior catalytic performance mainly benefitted from two reasons: (1) The construction of heterojunction between NiO, Co3O4 and Fe2O3, which promotes the efficient dynamic processes of charge carriers; (2) The formation of abundant surface reactive active sites facilitates the efficient conversion of CO2 molecules. This study offers a bright direction for the resource utilization of CO2.