稀土改性CuO-ZnO-ZrO_2/SAPO-34分子筛催化CO_2加氢合成低碳烯烃

Synthesis of Light Olefins from CO_2 Hydrogenation Catalyzed over Rare Earths Modified CuO-ZnO-ZrO_2/SAPO-34

采用共沉淀法分别制备了Y_2O_3,La_2O_3和Ce O_2改性的Cu O-Zn O-Zr O_2,表征结果表明,稀土改性的Cu O-Zn O-Zr O_2分散性良好,比表面积增大.将稀土改性的Cu O-Zn O-Zr O_2与SAPO-34分子筛机械混合用于催化CO_2加氢一步法合成了低碳烯烃,在反应温度400℃,压力3 MPa,空速为1800 m L·g^(-1)_(cat)·h^(-1),氢碳体积比为3∶1,Ce O_2改性Cu O-Zn O-Zr O_2与SAPO-34质量比为1∶1,催化剂用量为1.0 g时,CO_2的单程转化率为54.6%,低碳烯烃的选择性和产率分别为51.1%和27.9%.

Y_2O_3,La_2O_3 and Ce_2O_3modified Cu O-Zn O-Zr O_2 catalysts were prepared by co-precipitation method. The samples were characterized by X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）,transmission electron microscopy（ TEM）,Brunauer-Emmett-Teller（ BET）,temperature programmed reduction（ TPR） and thermogravimetry（ TG）. Rare earth metals modified Cu O-Zn O-Zr O_2 catalyst have good dispersion and higher specific surface area. The activity of biofunctional prepared by mechanical mixing of modified Cu O-Zn O-Zr O_2 with SAPO-34 for the hydrogenation of carbon dioxide to light olefins was investigated. Under the conditions of reaction temperature of 400 ℃, pressure of 3. 0 MPa, space velocity（ SV） of 1800 m L·g-1_（cat）·h-1,CO_2/H_2（ volume ratio） of 1 ∶ 3,mass ratio of Ce-Cu O-Zn O-Zr O_2/SAPO-34 to 1 ∶ 1 and the quality of multiple catalyst of 1. 0 g,the conversion of CO_2 could reach to 54. 6%,with a light olefins selectivity and yield of 51. 1% and 27. 9%,respectively.