煤焦油富含芳烃的特点使其具有制备高性能喷气燃料的可行性，且芳烃中稠环芳烃类化合物的加氢饱和产物——环烷烃（如全氢菲）可显著增强喷气燃料的热安定性，而该过程实现的关键在于制备高性能加氢饱和催化剂。针对菲加氢饱和反应中的吸附问题，基于Ni2P的特殊电子结构，以强化芳烃吸附为目标，采用溶胶凝胶法制备了复合氧化物Al2O3-TiO2载体，使用次磷酸盐歧化法制备了系列Ni2P/Al2O3-TiO2菲加氢饱和催化剂，探究了载体中掺入不同含量TiO2对Ni2P催化剂几何结构、电子结构和菲加氢饱和性能的影响。结果表明：反应温度320 ℃、压力5 MPa、重时空速52 h-1时，与Ni2P/Al2O3相比，TiO2掺杂量为15%时催化剂的菲转化率维持在95%左右，全氢菲选择性由49%增至68%，且转换频率由0.3 s-1提升至0.7 s-1。进一步分析掺杂后催化剂的几何结构和活性组分的电子结构发现，TiO2掺入Al2O3载体后，可向活性组分Ni2P传递适量电子，使得Ni2P中Ni处于适宜的缺电子状态，提高了Ni2P/Al2O3-TiO2催化剂对菲及中间产物的吸附能力；同时，TiO2掺杂有利于形成小粒径Ni2P，TiO2掺杂量为15%时，催化剂中Ni2P粒径最小（4.3 nm），可为加氢反应提供更多的活性位点，使该催化剂具有较强的菲加氢饱和能力。

The characteristics of coal tar rich in aromatic hydrocarbons give it the feasibility of preparing high-performance jet fuels,and the hydrogenation saturated products of fused-ring aromatic compounds (such as perhydrophenanthrene) can significantly enhance the thermal stability of jet fuels. The key point to realize this process is to prepare high performance hydrogenation saturation catalyst. In view of the adsorption problems in the saturation reaction of phenanthrene hydrogenation,based on the special electronic structure of Ni2P,in order to strengthen aromatics adsorption as the goal,the composite oxide carrier Al2O3-TiO2 was prepared by sol-gel method,and a series of Ni2P/Al2O3-TiO2-phenanthrene hydrogenation saturation catalyst were prepared by the hypophosphite decomposition method. The effects of different content of TiO2 on the geometrical structure,electronic structure and phenanthrene hydrogenation saturation of Ni2P catalyst were investigated. The results show that when the reaction temperature is 320 ℃,the reaction pressure is 5 MPa,and the WHSV is 52 h-1),contrast with Ni2P/Al2O3 catalyst,the conversion of phenanthrene do not changed (95%),while the selectivity of perhydrophenanthrene over Ni2P/Al2O3-TiO2 (15% TiO2)）is increased from 49% to 68%. Meanwhile,the turnover frequency was also improved from 0.3 s-1 to 0.7 s-1. The geometric structure and electronic structure of the catalysts were analyzed,and it is found that TiO2 can deliver the appropriate amount of electrons to the Ni in Ni2P catalyst,and so that Ni in Ni2P is in a suitable electron deficient state,which will enhance the adsorption capacity of Ni2P/Al2O3-TiO2 catalyst for phenanthrene and intermediate products. Moreover,the doping of TiO2 is beneficial to the formation of Ni2P with smaller particle size. When TiO2 doping amount is 15%,Ni2P has the smallest particle size (4.3 nm) in the catalyst,which can provide more active sites for hydrogenation reaction and make the catalyst have strong phenanthrene hydrogenation saturation capacity.

0 引言

1 试验

   1.1 催化剂制备

   1.2 Ni2P/Al2O3-TiO2催化剂的表征

   1.3 菲加氢催化剂活性评价

2 结果与讨论

   2.1 不同TiO2掺杂量催化剂的菲加氢活性评价

   2.2 Ni2P-xTi催化剂结构表征

3 结论