磷改性Hβ分子筛对正癸烷异构化反应的催化性能

Catalytic Performance of Hβ Zeolite Modified with Phosphorus for Isomerization of n-Decane

采用XRD ,NH3 TPD和Py IR等研究了磷改性对Hβ分子筛表面酸性质和催化性能的影响 .结果表明 ,少量磷的加入有效地改变了Hβ分子筛的酸量和酸强度的分布 ,使其弱酸量增加 ,强酸量减少 ,B酸中心增加 ,总酸量减少 ;在正癸烷异构化反应中 ,Pt/P Hβ催化剂显著提高了异构化反应的选择性 ,抑制了裂解反应的发生 .当 w(P) =0 75 %和w(Pt) =1 0 %时 ,正癸烷在Pt/P Hβ催化剂上的异构化反应的收率最高 .

The effects of phosphorus modification on the surface acidity and the catalytic performance of Pt/P-Hβ were studied by XRD, NH 3-TPD and Py-IR. The isomerization of n-decane over Pt/P-Hβ with different phosphorus contents was investigated. The addition of an adequate amount of phosphorus to Hβ could effectively change the acid amount and acid strength distribution of Hβ zeolite. The total acid amount and strong acid sites decreased after addition of phosphorus, but the weak acid mount and Brnsted acid sites increased. The optimum balance between metal sites and acid sites was obtained. The results of n-decane isomerization over Pt/P-Hβ showed that the n-decane conversion decreased on Hβ with phosphorus addition, however, the iso-decane selectivity increased. The optimum modification result was obtained over the 1.0%Pt/0.75%P-Hβ catalyst.