(544ev) Direct Synthesis of Dimethyl Ether By CO2 Hydrogenation over a High Active CuO/ZnO/ZrO2/Al2O3 and HZSM-5 Bifunctional Catalyst

A series of CuO/ZnO/ZrO₂/Al₂O₃ with different atomic ratios of Zr/Al were synthesized by co-precipitation method. The structural properties such as BET surface, Cu surface area and Cu dispersion, particle size distribution of catalysts were comprehensively characterized and the effects of zirconium loading on catalyst properties were determined. The prepared catalysts showed a very high surface area and Cu dispersion. These results indicates that the presence of zirconium in catalyst can enhance the formation of porous structure in catalyst thereby improve the BET surface area and Cu dispersion. Bifunctional catalysts prepared by physically mixing CuO/ZnO/ZrO₂/Al₂O₃ with HZSM-5 were tested to direct synthesize dimethyl ether (DME) by CO₂ hydrogenation reaction. The reaction conditions such as reaction temperature and pressure were investigated and the optimum reaction conditions were determined. The effects of zirconium loading on DME synthesis were also evaluated. The highest DME yield was obtained over 18.3% with the CO₂ conversion of 26.5% and DME selectivity of 69.2% at the optimum reaction condition.