Cu-supported nano-ZrZnOx as a highly active inverse catalyst for low temperature methanol synthesis from CO2 hydrogenation

Abstract

Hydrogenation of CO₂ into methanol at low-temperature on Cu-based catalysts is of great significance, but remains challenging to enhance activity. In this paper, we report an inverse catalyst constructed with nano-ZrZnO_x supported on Cu particles with outstanding methanol synthesis performance at 220 ℃, two times higher than that of commercial Cu/ZnO/Al₂O₃ catalysts under the same conditions. Detailed structure characterization and performance evaluation demonstrate that the ZrZnO_x mixed oxide serves as the most active oxide-metal interface site for CO₂ hydrogenation. The ZrZnO_x/Cu inverse catalyst increases the weak and medium CO₂ adsorption sites which are further demonstrated responsible to the methanol productivity. In situ DRIFTs studies reveal that the inverse interface accelerates the reduction of asymmetric formate intermediates and prevents the generation of CO. The combination of enhanced CO₂ activation capability and accelerated hydrogenation rate of intermediates over the ZrZnO_x/Cu inverse catalyst probably contribute to the remarkable methanol synthesis performance from CO₂.