Highly selective CuO-ZnO@Cu-MOR catalysts prepared by ultrafast solid processing for carbon dioxide hydrogenation to methanol

Abstract

The conversion of CO₂ into methanol has emerged as a promising strategy for addressing climate change and optimizing the utilization of carbon resources. Conventional synthesis methods for Cu-based catalysts, such as co-precipitation, necessitate the consumption of substantial amounts of solvent and meticulous control over preparation conditions, while also being susceptible to deactivation by water during hydrogenation. Therefore, it is crucial to develop a catalyst that can be readily synthesized and exhibits outstanding performance and durability. In this study, we present an ultrafast (only 20 min), solid-phase grinding approach to fabricate CuO-ZnO@Cu-MOR catalysts for CO₂ hydrogenation to methanol. The resulting catalysts were comprehensively characterized using XRD, XPS, H₂-TPR, NH₃-TPD, SEM, HRTEM, and In-situ-FTIR techniques. Notably, the CuO-ZnO@Cu-MOR catalysts with a distinctive capsule-like structure displayed a high catalytic performance for CO₂ hydrogenation. The byproducts of methane and water produced by the CO₂ hydrogenation process were able to be further converted to methanol through Cu-MOR, leading to a significant enhancement of the methanol selectivity (95.6 %) and CO₂ conversion (22.8 %). Moreover, a long-term test lasting 300 h demonstrated constant catalytic performances and superior durability.