二氧化碳加氢直接合成二甲醚催化剂的研究 Ⅰ. 沉淀剂对催化剂结构和性能的影响

A series of CuO-ZnO-Al2O3/HZSM-5 composed catalysts were prepared with different precipitation agents, such as aqueous solution of ammonia, sodium hydroxide, sodium oxalate and sodium carbonate. Their catalytic performance for hydrogenation of CO2 was evaluated. The physical-chemical properties of the catalysts were also studied by means of H2-TPR, XRD, BET, CO2-TPD and H2-TPD. The result showed that precipitation agents had obvious effect on the activity, structure of crystal phases, reduction property, as well as absorption properties to CO2 and H2 of catalyst. There existed two kinds of adsorption center on the catalyst. Their activity and selectivity were in close relationship with the adsorption property. The mechanism of CO2 hydrogenated directly to methanol and DME were proposed based on the study.