Synergistic effect of Co0 with Cu11In9 intermetallic compound enhancing catalytic performance of CO2 hydrogenation to methanol

Abstract

CO₂ hydrogenation to methanol is a critical technology for hydrogen energy conversion and a promising approach to mitigate the energy crisis and greenhouse effect. However, developing highly selective catalysts remains a major challenge for its practical application. Herein, we synthesize an efficient CoCuInO-r catalyst with Cu₁₁In₉ and Co⁰ dual sites on In₂O₃ via a sol-gel method. The Cu₁₁In₉ intermetallic compound enhances H₂ adsorption capacity and strength, and increases oxygen vacancy concentration on the catalyst surface, thereby improving CO₂ activation and hydrogenation efficiency. Meanwhile, Co⁰ suppresses the desorption of the ∗CO species, facilitating its further hydrogenation to methanol. In-situ DRIFTS experiments indicate that the CO₂ hydrogenation to methanol over CoCuInO-r follows the formate pathway. Compared with CuInO-r (containing Cu₁₁In₉ on In₂O₃), CoCuInO-r exhibits a ∼20% increase in methanol selectivity and a 2-fold higher methanol space-time yield, reaching 7.68 mmol·g⁻¹·h⁻¹ at 300 °C and 4 MPa.