In – Cu binary oxides catalyst for CO2 hydrogenation

Hydrogenation reactions are a crucial catalytic process for valorizing CO2 waste, with possible products including methanol and formic acid. Methanol is produced through thermal catalysis, while formate is generated via electrocatalysis. To enhance methanol production in thermal catalysis, this work explores In-Cu binary oxide catalysts. Literature suggests that In2O3-based catalysts exhibit high selectivity towards methanol, whereas the industrial standard Cu/ZnO/Al2O3 catalyst shows higher CO2 conversion but lower methanol selectivity. A combination of In-Cu oxide catalysts aims to improve catalytic performance. Additionally, these catalysts were tested for formate production through electrocatalysis. In-Cu binary oxide catalysts were synthesized via gel-oxalate coprecipitation, varying the atomic ratios of In and Cu. They were characterized using techniques such as ICP-MS, N2 physisorption, XRD, H2-TPR, CO2-TPD, SEM, and TEM. To assess thermo-catalytic performance, the catalysts were tested in a fixed-bed reactor under specific conditions (20 NL/g-cat/h, 2.1 MPa, H2/CO2/N2 molar ratio of 15/5/1) at temperatures between 200-300°C. A 20-hour stability test was conducted on each sample to investigate deactivation phenomena. The spent catalysts were characterized to explain the catalytic results.