Influence of Oxygen Addition on the Reaction of Propane Catalytic Dehydrogenation to Propylene over Modified Pt-Based Catalysts

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• 作者：Changlin Yu ; Qingjie Ge ; Hengyong Xu ; Wenzhao Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2007
• 出版时间：December 5, 2007
• 年：2007
• 卷：46
• 期：25
• 页码：8722 - 8728
• 全文大小：131K
• 年卷期：v.46,no.25(December 5, 2007)
• ISSN：1520-5045

文摘

The influences of oxygen addition to catalytic dehydrogenation system on the structure and the dehydrogenationperformance of Pt-based catalysts were investigated. The results showed that a small amount of oxygen additioninto the reaction system could greatly improve the catalytic performance of Pt-Sn/Ce--Al₂O₃ catalyst althoughit evidently decreased the catalytic stability of Pt/-Al₂O₃, Pt-Sn/-Al₂O₃, and Pt/Ce--Al₂O₃ catalysts. Theaddition of a small amount of oxygen can decrease the pressure of hydrogen, eliminate coke, and providepartial heat for catalytic dehydrogenation reaction. Hydrogen chemisorption results indicated that steam couldreduce the interactions between metal and support, thus promoting the sintering of platinum particles. Thatadverse effect of steam on the structure on Pt-Sn/Ce--Al₂O₃ was moderate, but it was serious on otherPt-based catalysts due to low-stability platinum particles. Both the promoting effect of Ce on the propaneconversion and the inhibiting effect of Sn on the CO_x formation could be simultaneously achieved during thereaction over Pt-Sn/ Ce--Al₂O₃ catalyst. At 546 C, a 50% yield of propylene improvement was obtaineddue to the small oxygen addition.