不同分子筛负载镍催化剂的正辛烷异构化和芳构化性能

选用SAPO-11，USY，ZSP-3三种分子筛为载体，浸渍镍制备催化剂；采用BET、XRD、程序升温氨脱附（NH3-TPD）以及吡啶吸附-脱附红外光谱法对催化剂进行表征。以正辛烷为模型化合物，在临氢的条件下，考察催化剂的异构化及芳构化性能。结果表明：Ni/SAPO-11具有最好的异构化选择性和较好的芳构化选择性，但转化率最低； Ni/ZSP-3虽然具有最高的转化率和芳构化选择性，但其异构化选择性最低；Ni/USY的选择性和转化率均介于两者之间，但芳构化选择性最差。稀土改性可以调节ZSP-3分子筛为载体的催化剂表面酸中心分布，提高异构化和芳构化选择性。

ISOMERIZATION AND AROMATIZATION OF n-OCTANE OVER VARIOUS MOLECULAR SIEVES SUPPORTED NICKEL CATALYATS

Nickel supported catalysts were prepared by impregnating nickel on SAPO-11,USY and ZSP-3 molecular sieves.BET,XRD,NH3-TPR and pyridine adsorption-desorption FT-IR were used to characterize the prepared catalysts.The hydroisomerization and hydroaromatization performance of these catalysts were evaluated with a micro-reactor using n-octane as model compound.Test results indicated that among the three catalysts,Ni/SAPO-11 showed the highest isomerization selectivity and good aromatization selectivity,but its conversion was the lowest;Ni/ZSP-3 showed the highest conversion and aromatization selectivity,yet its isomerization selectivity was the lowest;Ni/USY showed moderate isomerization selectivity and conversion,however,its aromatization selectivity was poor.Using ZSP-3 molecular sieve modified by rare earth cations as support,the surface acid center distributions of catalyst were altered,resulting in an enhancement of catalyst selectivity to isomerization and aromatization.