Optimizing CO₂ Hydrogenation to DME through Tailored Interfacial Interactions: Weakening Synergy in CuZnZr and Al-Modified SBA-15 Catalysts

The direct dimethyl ether (DME) synthesis reaction via CO₂ hydrogenation typically requires a bifunctional catalyst that effectively combines a methanol synthesis catalyst with a methanol dehydration catalyst, but the effect of the relationship between the two catalysts on the catalytic performance has not been as well studied. In this study, we developed a CuZnZr/Al–S(10)-PG bifunctional catalyst physically mixed with Al-modified SBA-15 and the traditional CuZnZr catalyst for the hydrogenation of CO₂ to DME. A pivotal discovery is that the modulation of interaction intensity between these two constituents significantly influences the electronic configuration of each component. Through X-ray photoelectron spectroscopy characterization and methanol dehydration experiments, it was confirmed that diminishing the synergistic interplay between CuZnZr and Al-modified SBA-15, which regulated the electronic structure of the Cu–Zn interface and enhanced the Cu–Zn interfacial interaction, played a crucial role in enhancing the catalyst’s performance in CO₂ hydrogenation to DME. This finding contests established beliefs about the necessity of strong synergistic interactions in such systems and provides new insights for designing rational bifunctional catalysts.