多级孔ZSM-5分子筛的加氢脱硫性能

Hydrodesulfurization performance of hierarchical ZSM-5 zeolites

以四头聚季铵盐为模板合成的多级孔ZSM-5分子筛为载体、Pd为金属组分制备新型介孔分子筛基Pd催化剂,考察其对4,6-二甲基二苯并噻吩的加氢脱硫活性,并与其他催化剂进行对比。结果表明,与常规ZSM-5分子筛基Pd催化剂和γ-Al2O3基Pd催化剂相比,以多级孔ZSM-5分子筛为载体制备的Pd催化剂表现出更高的加氢脱硫活性。该催化剂同时具有介孔和B酸中心,为4,6-二甲基二苯并噻吩的异构化和脱硫反应提供了更多的活性中心,使其能够发生甲基异构化反应,生成3,6-二甲基二苯并噻吩后进行氢解脱硫。

Pd catalysts with hierarchical ZSM-5 zeolites prepared from multi-head group quaternary ammonium surfactants templates as supports were prepared and tested in hydrodesulfurization(HDS)of 4,6-dimethyldibenzothiophene(4,6-DM-DBT).Reaction results showed that compared with conventional ZSM-5-based Pd catalyst andγ-Al2O3-based Pd catalyst,Pd catalysts with hierarchical porous ZSM-5 zeolites as support showed higher HDS activity.Mesopores and B acid centers in the as-prepared catalysts provided more active sites for HDS and isomerizaiton of 4,6-DM-DBT.4,6-DM-DBT was converted to 3,6-dimethyldibenzothiophene by methyl isomerization and then desulfurized by hydrogenation.