CuO-ZnO-SiO_2/HZSM-5 Cataly for Dimethyl Ether Synthesis by Hydrogenation of Carbon Dioxide

A series of CuO-ZnO-SiO2/HZSM-5 bifunctional catalysts were prepared using the improved sol-gel methord to study on the hydrogenation of CO2 to DME on one-step.Then some methods,such as the laboratory fixed-bed reaction activity assessment methods,were adopted to discuss the influence of the contents of SiO2 and dehydration components and reaction conditions on the properties of the catalysts.The results indicate that adding the right amount of SiO2 can promote the despersation of CuO and ZnO.The effect is better with the mass of SiO2 3.5%.HZSM-5 plays a role of dehydration and makes gain the better activity of the catalyst when its proportion reachs 10%.The appropriate conditions:the temperature is 240 ℃,the pressure is 4.0 MPa,the airspeed is 1 500～3 500 h -1 and H2/CO2 is 4∶1.