In-situ synthesis of interfacial In-O-Mn lewis acid-base pairs for low-temperature photothermal CO₂ hydrogenation to methanol.

Abstract

CO₂ hydrogenation into methanol suffers from a huge obstacle of low methanol yield due to the leverage effect of CO₂ conversion and methanol selectivity. Here, we report an In₂O₃-MnCO₃ catalyst consisting of In₂O₃ covalently linked to MnCO₃ for efficiently photothermal CO₂ hydrogenation into methanol. Covalent linkage, the O atoms of In₂O₃ occupy the oxygen vacancies of MnCO₃, enables the formation of In-O-Mn Lewis acid-base pairs at the In₂O₃-MnCO₃ interface. Both light irradiations and heatings improve the electron excitations and transfers from In to O, promoting CO₂ activation and methanol production. The In₂O₃-MnCO₃ containing 30 mol.% In achieves 67.5% methanol selectivity and 13.5% CO₂ conversion at 150 °C, 4.0 MPa, and 14400 mL·h^-1·g^-1 with a high stability for at least 500 h on stream. This study provides a serial In-Mn catalyst design and understanding of the molecular-level structure-mediated photothermal catalytic hydrogenation.