含磷模板和不同硅源对多级孔ZSM-5分子筛结构和催化性能的影响

通过采用不同比例的四丁基氢氧化磷（TBPOH）和四丙基氢氧化铵（TPAOH）混合作为模板剂合成多级孔ZSM-5分子筛，采用XRD，BET，SEM，TEM，NH3-TPD，MAS NMR等方法对分子筛进行物化表征，考察TPAOH和TBPOH的协同作用，期望得到较高结晶度的含P的多级孔ZSM-5。结果表明：以正硅酸乙酯（TEOS）为硅源，在TBPOH和TPAOH物质的量比为1∶1时，合成的多级孔ZSM-5形貌较为规整，由ZSM-5小晶粒堆积而成并呈现出丰富的介孔结构，具有较大的比表面积和孔体积，平均孔径分布于4～10 nm和50～70 nm。相比常规ZSM-5分子筛，合成的多级孔ZSM-5分子筛表现出更强的弱酸性和更多的总酸量。在1，3，5-三异丙苯的裂解反应中，相同转化率下，微孔ZSM-5分子筛表现出较好的苯和二异丙苯的选择性，而多级孔ZSM-5表现出更加优异的丙烯和异丙苯的选择性。

EFFECTS OF PHOSPHORUS TEMPLATE AND SILICON SOURCES ON STRUCTURE AND CATALYTIC PERFORMANCE OF HIERARCHICAL ZSM-5 ZEOLITE

ZSM-5 molecular sieves with hierarchical porous structure were synthesized by using mixture of phosphorus-containing template TBPOH and TPAOH with different proportions, and characterized by XRD，BET，SEM，TEM，NH3-TPD and MAS NMR. The synergistic effect of TPAOH and TBPOH was investigated, by which the phosphorus-containing hier-ZSM-5 with fairly high degree of crystallinity can be obtained. The results showed that the morphology of ZSM-5 is regular and it shows higher specific surface area and pore volume when the molar ratio of TBPOH and TPAOH is 1∶1 with TEOS as the silicon source. The average pore size distributes at 4-10 nm and 50-70 nm. ZSM-5 zeolite rich in mesoporous structure was constituted by accumulation of small grains. Compared with conventional ZSM-5 molecular sieve，hier-ZSM-5 shows greater weak acidity and total amount of acidity. At same conversion of 1，3，5-triisopropylbenzene cracking reaction，the microporous ZSM-5 zeolite shows better selectivity for benzene and diisopropylbenzene，while the hier-ZSM-5 with mesopores shows more excellent selectivity for propylene and cumene.