Catalytic Function of IrO_x in the Two-Step Thermochemical CO₂‑Splitting Reaction at High Temperatures

Splitting CO₂ into CO and O₂ via a two-step thermochemical cycle by utilizing concentrated solar energy is a promising option for CO₂ reduction. Herein, to enhance the solar to fuel energy conversion efficiency, IrO_x as a catalyst is used to increase the fuel production rate of the LaFeO₃-based two-step thermochemical CO₂-splitting reaction. Compared with LaFeO₃, 0.6 atom % IrO_x as a catalyst that loaded on LaFeO₃ can almost double the maximal CO release rate and increase the maximal O₂ evolution rate 0.5 times; when a small amount of IrO_x (2.5 atom %) is doped into the structure of LaFeO₃ through a solution combustion method, the initial CO generation rate can be increased by 5-fold. This work demonstrates that the catalytic function is still necessary in the two-step thermochemical CO₂-splitting reaction even at high temperatures.