Regeneration of copper catalysts mediated by molybdenum-based oxides

Cu catalysts, known for their unparalleled catalytic capabilities due to their unique electronic structure, have faced inherent challenges in maintaining long-term effectiveness under harsh hydrogenation conditions. Here, we demonstrate a molybdenum-mediated redispersion behavior of Cu under high-temperature oxidation conditions. The oxidized Cu nanoparticles with rich metal-support interfaces tend to dissolve into the MoO3 support upon heating to 600 degrees C, which facilitates the subsequent regeneration in a reducing atmosphere. A similar redispersion phenomenon is observed for Cu nanoparticles supported on ZnO-modified MoO3. The modification of ZnO significantly improves the performance of the Cu catalyst for CO2 hydrogenation to methanol, with the high activity being well maintained after four repeated oxidation-reduction cycles. In situ spectroscopic and theoretical analyses suggest that the interaction involved in the formation of the copper molybdate-like compound is the driving force for the redispersion of Cu. This method is applicable to various Mo-based oxide supports, offering a practical strategy for the regeneration of sintered Cu particles in hydrogenation applications. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.