摘要
对比考察了Ｐｔ／ＫＬ沸石，Ｐｔ／Ａｌ２Ｏ３和载铂铝交联蒙脱土（Ｐｔ／Ａｌ－ＣＬＭ）催化剂对不同碳原子数烷烃的芳构化特性．脉冲微反的评价结果表明：Ｐｔ／Ａｌ－ＣＬＭ比Ｐｔ／Ａｌ２Ｏ３和Ｐｔ／ＫＬ具有较高的转化ｎ－Ｃ８，ｎ－Ｃ９为其对应芳烃的选择性，在转化ｎ－Ｃ８时，产物中的间、对位二甲苯收率很高，而转化ｎ－Ｃ９时有高的正丙苯收率．采用１２９Ｘｅ－ＮＭＲ、ＸＲＤ和孔分布测定考察了Ｐｔ／Ａｌ－ＣＬＭ和Ｐｔ／ＫＬ、Ｐｔ／Ａｌ２Ｏ３之间孔结构的差异．结果表明：由于ｎ－Ｃ８，ｎ－Ｃ９在反应过程中其过渡态的极限尺寸与Ｐｔ／Ａｌ－ＣＬＭ０．９ｎｍ左右的层间域相匹配，因而它对ｎ－Ｃ８，ｎ－Ｃ９具有择形芳构化作用．
ompared with Pt/KL zeolite and Pt/Al2O3 catalyst, the activity of platinum containing cross-linking montmorillonite (Pt/Al-CLM ) for aromatization of n-paraffins with different carbon atoms (n-C6, n-C7, n-C8, n-C9, n-C10) was researched. The measured results by pulse reactor showed that Pt/AI-CLM exhibited higher capacity for selective conversion of n-C8 and n-C9 to their correspondent aromatics as compared with Pt/KL and Pt/Al2O3.For the conversion of n-C8, the high yield of mand p- xylenes was obtained, and for the conversion of n-C9 the n-propylbenzene was the main product.129Xe-NMR, XRD and pore distribution measurement were used to investigate the porou structure variance between Pt/AI-CLM, Pt/Al2()3 and Pt/KL. The results showed that the interlayer space>0.9nm of Pt/Al-CLM had the shape selective effect on aromatization of n-C8 and n-C9. The shape selective aromatization character maybe due to the approximate 0.9 um interlayer space of Pt/Al-CLM that corresponding with the size of cyclic transient structure of n-C8 and n-C9 during reaction process.
关键词
铝交联蒙脱土
烷烃
芳构化
载铂
latinum
montmorillonite
n-paraffin
aromatization
shape selectivity
