Ti掺杂对Ni2P/SBA-15催化剂加氢脱氮催化性能的影响

采用水热一步合成法制备了SBA 15和Ti SBA 15分子筛,采用等体积浸渍法和H2原位还原法制备了Ni2P/SBA 15和Ni2P/Ti SBA 15催化剂。采用X射线衍射(XRD)、N2吸附脱附(BET)、透射电镜(TEM)、能量色散X射线光谱(EDX)等技术,研究了掺杂Ti原子对SBA 15分子筛及其催化剂形貌和织构性质的影响,并以喹啉为模型化合物,采用微型固定床反应器考察了不同硅/钛摩尔比对催化剂加氢脱氮(HDN)性能的影响。结果表明,Ti的掺杂并没有改变SBA 15高度有序的介孔结构,但改性后载体比表面积略有增大,孔径有所降低;Ni2P/Ti SBA 15中Ti以锐钛矿TiO2和Ti9O17形式存在,而活性组分还原后所形成的物相为Ni2P。Ni2P/Ti SBA 15催化剂的HDN活性均高于Ni2P/SBA 15催化剂,并且不同硅/钛摩尔比的催化剂呈现不同的HDN活性, n(Si)/n(Ti)=25的Ni2P/Ti SBA 15催化剂具有最高的HDN活性。

The Effect of Ti Doping in Ni2P/SBA-15 Catalyst on Its Catalytic Hydrodenitrogenation Performance

The Ti SBA 15 and SBA 15 support were synthesized by hydrothermal synthesis method, and Ni2P/SBA 15 and Ni2P/Ti SBA 15 catalysts were prepared by incipient wetness impregnation and in situ H2 reduction method. The prepared samples were characterized by N2 adsorption desorption, X ray diffraction(XRD), temperature programmed desorption of ammonia(NH3 TPD), Energy dispersive X ray spectrum(EDX) and TEM to investigate the effects of Ti doping on the properties of morphology and texture of the prepared supports and catalysts, and their hydrodenitrogenation(HDN) performances were evaluated in a continuous flow fixed bed reactor by using quinoline as the model compound. The results showed that the Ti doping did not change the highly ordered mesoporous structure of SBA 15, after modification the surface area increased slightly, but the pore radius decreased. The Ti existed in the form of TiO2 and Ti9O17 and the phase of active component after reduction was Ni2P in Ni2P/Ti SBA 15 catalyst. The HDN activity of Ni2P/Ti SBA 15 catalysts was higher than that of Ni2P/SBA 15 catalyst, and Ni2P/Ti SBA 15 with different n(Si)/n(Ti) presented different HDN activity, among which the Ni2P/Ti SBA 15 with n(Si)/n(Ti) of 25 was the best one.