F改性Hβ对Mo-Ni/F-Hβ催化剂的FCC汽油硫转移反应催化性能的影响

Effect of modification to Hβ with F on the performance of Mo-Ni/F-Hβ catalyst in the sulfur transfer reactions of FCC gasoline

通过添加不同含量的F对Hβ分子筛进行改性,制备Mo-Ni/F-Hβ催化剂,采用N2吸附-脱附、NH3-TPD、XRD、Py-FTIR和SEM等方法对该催化剂进行了表征,研究了F改性对该Mo-Ni/F-Hβ催化剂在FCC汽油中硫醇醚化和噻吩烷基化等硫转移反应中催化性能的影响。结果表明,以0.5%含量F修饰的β分子筛制备的催化剂对硫醚化反应和噻吩烷基化反应具有明显的促进作用,并能提高对二烯烃选择性加氢的选择性。F的引入可增强Hβ分子筛的中强酸量,降低强酸量,并提高了L/B酸中心比例,这些变化对催化性能改善起到重要作用。

Hβ zeolite was modified with different contents of F to prepare the Mo-Ni/F-Hβ catalysts. The Mo-Ni/F-Hβ catalysts were characterized by nitrogen physisorption, NH3-TPD, XRD, Py-FTIR and SEM;the effect of modification to Hβ with F on the catalytic performance of Mo-Ni/F-Hβ in the sulfur transfer reactions such as etherification of mercaptan and alkylation of thiophene in FCC gasoline was then investigated. The results indicate that the Mo-Ni/F-Hβ catalyst prepared with 0.5% F-modified Hβ zeolite can promote the thioetherification and thiophene alkylation reactions and improve the selectivity of dienes hydrogenation. The introduction of F can enhance the medium strong acid content of Hβ zeolite, reduce the strong acid content, and increase the ratio of L/B acid sites, all these may contribute to improving the catalytic performance of Mo-Ni/F-Hβ in the sulfur transfer reactions of FCC gasoline.