杂原子ZSM-12型分子筛的酸性及其催化性能的研究

STUDIES ON ACIDIC AND CATALYTIC PROPERTIES OF HETERO-ATOM ZSM-12 ZEOLITES

用TPD法研究了不同杂原子含量的氢型Fe-Si-ZSM-12和B-Si-ZSM-12型分子筛的表面酸性,观察到杂原子含量和表面酸性之间的关系.此两种分子筛的表面酸性都比Al-Si-ZSM-12型分子筛弱,酸性强弱的顺序为:Al-Si-ZSM-12>>Fe-Si-ZSM-12>B-Si-ZSM-12.还考察了这两种杂原子分子筛对苯和乙醇烷基化的催化活性,两者的活性都低于Al-Si-ZSM-12,但有相对较高的乙醇脱水活性.

The TPD have been used to study the surface acidity of H-B-Si-ZSM-12 and H-Fe-Si-ZSM-12 zeolite catalysts. It is shown that the surface acidity is related to the SiO_2/B_2O_3 or SiO_2/Fe_2O_3 ratio. The surface acidities of these two hetero-atom zeolites are weaker than that of Al-Si-ZSM-12 with an order as H-Al-Si-ZSM-12>>H-Fe-Si-ZSM-12>H-B-Si-ZSM-12. The catalytic activity of H-B-Si-ZSM-12 and H-Fe-Si-ZSM-12 catalysts on the alkylation of benzene with ethanol have been investigated, showing that both catalysts are less active than Al-Si-ZSM-12, but relatively more active on ethanol dehydration.