Ni_2P/TiO_2-SiO_2催化剂的制备、表征及其加氢脱氮反应性能评价

PREPARATION,CHARACTERIZATION AND HYDRODENITROGENATION ACTIVITY OF Ni_2P/TiO_2-SiO_2CATALYST

采用溶胶-凝胶法制备了不同Ti?Si比的TiO2-SiO2复合载体,其负载的磷化镍催化剂采用等体积浸渍法和H2原位还原法制备,以喹啉为模型化合物,考察了活性组分负载量、Ni?P比、Ti?Si比对催化剂加氢脱氮性能的影响。采用N2吸附、XRD、TPR、NH3-TPD和FT-IR等技术对载体和催化剂进行了表征。结果表明:溶胶-凝胶法制成的复合载体具有较大的比表面积,其负载的磷化镍催化剂具有较好的可还原性,Ni?P摩尔比小于1.0时,还原后所形成的物相为Ni2P;当Ti?Si摩尔比为1?2、Ni?P摩尔比为1.0、Ni-P负载量(w)为25%时,Ni2P?TiO2-SiO2催化剂具有最佳的加氢脱氮效果。

TiO2-SiO2 composite support was prepared by sol-gel method,and the supported nickel phosphide catalysts,Ni2 P/TiO2-SiO2 ,were prepared by incipient wetness impregnation and in situ H 2 reduction method. The samples were characterized by N2 adsorption-desorption,XRD,TPR,NH 3-TPD and FT-IR. Their hydrodenitrogenation （HDN）performance was evaluated in a continuous-flow fixed-bed reactor using quinoline as a model molecule to investigate the effect of the active component loading, Ni/P molar ratio and Ti/Si molar ratio. The results show that TiO2-SiO2 composite support has a larger specific surface area. The Ni2 P/TiO2-SiO2 catalyst precursor has a better reducibility,which helps the formation of Ni2 P phase. Ni2 P phase appears for the Ni2 P/TiO2-SiO2 catalyst at n（Ni）/n（P）≤1.0. The optimal HDN activity occurs for the Ni2 P/TiO2-SiO2 with Ti/Si molar ratio of 1/2,Ni/P molar ratio of 1.0 and the loading of （NiO＋P2 O5 ）of 25%.