Enhanced Catalytic Performance for Dimethyl Ether Synthesis from Syngas with the Addition of Zr or Ga on a Cu-ZnO-Al2O3/γ-Al2O3 Bifunctional Catalyst

Direct Synthesis of dimethyl ether (DME) from synthesis gas was investigated oil bifunctional catalysts, containing Cu-ZnO-Al2O3 promoted with Zr or Ga on gamma-Al2O3 as a methanol dehydration catalyst. In Comparison to an unpromoted bifunctional catalyst, promoted catalysts with Zr of Ga showed a higher catalytic performance and stability. The facile reducibility of copper particles with high dispersion and an appropriate acidity and electronic state of copper species are mainly responsible for the superior catalytic performance with the help of structural promoting effects of Ga or Zr components on Cu-ZnO-Al2O3. The high formation rate of methanol by CO hydrogenation on the Zr-promoted Cu-ZnO-Al2O3 and the dehydration rate of methanol to DME on the modified acidic sites of gamma-Al2O3 are mainly responsible for the superior catalytic activity and stability.