一种TiO2修饰的Pd/Al2O3选择性加氢用催化剂的研究

 研制了一种用TiO2修饰的Pd/Al2O3(Pd/Al2O3-TiO2)选择性加氢催化剂,并采用N2吸附,XRD,SEM,FT-IR,TPD和TPR等手段对催化剂进行了表征,考察了催化剂的催化性能. 结果表明,Pd/Al2O3-TiO2催化剂具有较小的比表面积; 低的表面酸性,且以弱酸中心为主; TiO2在Al2O3表面呈高度分散,并集中于载体到一定的深度; 用含钛溶液浸渍次数以1次为佳. 载体中TiO2的添加使得PdO更易于被还原. 用这种复合氧化物作载体制备的催化剂表现出更高的加氢活性和选择性,优于单纯以Al2O3作载体的催化剂.

Study on TiO2-Modified Pd/Al2O3 Catalyst for Selective Hydrogenation of Pyrolysis Gasoline

The TiO_2-modified Pd/Al_2O_3 (Pd/Al_2O_3-TiO_2) catalyst was prepared by impregnation and characterized by N_2 adsorption, XRD, SEM, FT-IR, TPD and TPR. The catalytic performance of the catalyst for selective hydrogenation of pyrolysis gasoline was studied. All the catalyst samples showed better performance compared with the reference catalyst used in industry. Taking account of convenience and flexibility of preparing Pd/Al_2O_3-TiO_2 catalyst, the suitable modification process should be done just only one time. The Pd/Al_2O_3-TiO_2 catalyst exhibited smaller surface area and lower surface acidity. The titania on alumina was extremely dispersed and concentrated in certain depth in the direction of cross section. The reduction of palladium oxide was more easily with the presence of titania in the Al_2O_3. The catalytic activity and selectivity of Pd/Al_2O_3-TiO_2 catalyst with composite oxide as a support were higher than Pd/Al_2O_3 catalyst with alumina alone as a support.