Research on the performance of photothermal catalytic CO2 hydrogenation to methanol using lanthanum- modified copper calcium titanate

Abstract

Perovskite oxide catalysts of copper calcium titanate with lanthanum (La) substituting for calcium sites were prepared by the sol-gel method, and their performance in the photothermal CO₂ hydrogenation to methanol was experimentally investigated. Techniques such as XRD, SEM, CO₂-TPD, H₂-TPR, XPS, UV-Vis DRS, and EIS were employed to evaluate the advantages of La substitution for the copper calcium titanate catalysts. The results showed that after an appropriate amount of La substitution, the catalyst achieved a methanol space-time yield of 5.788 mmol/(g·h) under 0.8 MPa and 250 ℃ with illumination, which represents a significant improvement in catalytic performance compared to the unsubstituted catalyst. This enhancement is attributed to the promotion of oxygen vacancy formation by La substitution, which enhances the photothermal response efficiency of the catalyst and, consequently, its catalytic activity.