Synthesis of Dimethyl Ether from CO2 and H2 Using a Cu-Fe-Zr/HZSM-5 Catalyst System

The CuO-Fe2O3-ZrO2/HZSM-5 bifunctional catalyst was prepared and used for the direct synthesis of dimethyl ether (DME) from CO2 and H-2. The results revealed that doping the CuO-Fe2O3 catalyst with ZrO2 might increase the specific surface area and change the chemical combination state of CuO by decreasing the outer-shell electron density of Cu via an obvious change in the interaction between CuO and Fe2O3. Addition of ZrO2 to the catalyst strongly affects the hydrocarbon selectivity. When using the CuO-Fe2O3-ZrO2/HZSM-5 bifunctional catalyst system, both the conversion of CO2 and the yield of DME were much higher than those obtained using CuO-Fe2O3/HZSM-5 as catalysts. Reactions carried out at 260 degrees C and 3.0 MPa with a gaseous hourly space velocity of 1500 mL center dot g(cat)(-l)center dot h(-1) using CuO-Fe2O3-ZrO2/HZSM-5 with 1.0 wt % ZrO2 as the hydrogenation catalyst provided a 28.4% conversion of CO2 with 64.5% selectivity for DME.