铁对载铂L分子筛催化剂改性研究

STUDY ON REFORMING REACTIONS OVER Fe MODIFIED PtKL ZEOLITE

本工作采用共交换法将铁组元为助剂引入PtKL催化剂内,制成PtFeKL催化剂。在加压连续微反及常压脉冲微反内,比较了该催化剂与PtKL催化剂对正己烷、甲基环戊烷、正戊烷、环己烷及3-甲基戊烷等纯烃的反应性能。同时利用程序升温氢氧滴定(TPT)、M(?)ssbauer谱等物化分析手段进行了表征。实验结果表明,PtFeKL催化剂具有较高的正己烷脱氢环化活性,也具有较高的甲基环戊烷脱氢异构化活性。铁作为助剂引入PtKL催化剂后可改善铂的分散状态,从Mossbauer谱测量中可观察到铁与铂之间存在相互作用,从而减少铂周围的电子密度,对抑制铂的迁移,稳定催化剂的芳构化活性,都有一定的影响。

Fe was introduced into PtKL catalyst as a promoter by co-exchanging method. The catalytic behavior of PtFeKL catalyst was studied with nhexane, methylcyclopentane, n-pentane, cyclohexane and 3-methylpentane in pulse and continuous flow type microreactors. It is shown that PtFeKL catalyst has higher activities for n-hexane dehydrocyclization and methylcyclopentane dehydroisomerization than PtKL catalyst. The catalysts were also charaterized with temperature programmed titration and Mossbauer spectroscopy. Comparing to PtKL catalyst, the dispersion of Pt in PtFeKL catalyst is improved. Mossbauer result shows that there exists interaction between Fe and Pt atoms.