Unlocking a Dual‐Channel Pathway in CO₂ Hydrogenation to Methanol over Single‐Site Zirconium on Amorphous Silica

Abstract

Converting CO₂ into methanol on a large scale is of great significance in the sustainable methanol economy. Zirconia species are considered to be an essential support in Cu-based catalysts due to their excellent properties for CO₂ adsorption and activation. However, the evolution of Zr species during the reaction and the effect of their structure on the reaction pathways remain unclear. Herein, single-site Zr species in an amorphous SiO₂ matrix are created by enhancing the Zr-Si interaction in Cu/ZrO₂ -SiO₂ catalysts. In situ X-ray absorption spectroscopy (XAS) reveals that the coordination environment of single-site Zr is sensitive to the atmosphere and reaction conditions. We demonstrate that the CO₂ adsorption occurs preferably on the interface of Cu and single-site Zr rather than on ZrO₂ nanoparticles. Methanol synthesis in reverse water-gas-shift (RWGS)+CO-hydro pathway is verified only over single-dispersed Zr sites, whereas the ordinary formate pathway occurs on ZrO₂ nanoparticles. Thus, it expands a non-competitive parallel pathway as a supplement to the dominant formate pathway, resulting in the enhancement of Cu activity sixfold and twofold based on Cu/SiO₂ and Cu/ZrO₂ catalysts, respectively. The establishment of this dual-channel pathway by single-site Zr species in this work opens new horizons for understanding the role of atomically dispersed oxides in catalysis science.