催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (11): 970-974.

• 研究论文 • 上一篇    下一篇

载体组成对负载型PtSn/ZSM-5催化剂上丙烷脱氢反应性能的影响

邱安定,李恩霞,范以宁   

  1. 南京大学化学化工学院, 介观化学教育部重点实验室, 江苏省纳米技术重点实验室, 江苏南京 210093
  • 收稿日期:2007-11-25 出版日期:2007-11-25 发布日期:2011-10-13

Effect of Support Composition on Catalytic Performance of PtSn/ZSM-5 Catalyst for Propane Dehydrogenation

QIU Anding, LI Enxia, FAN Yining*   

  1. Key Laboratory of Mesoscopic Chemistry of Education Ministry, Jiangsu Provincial Laboratory for Nanotechnology, College of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu, China
  • Received:2007-11-25 Online:2007-11-25 Published:2011-10-13

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摘要： 用微型催化反应装置结合吡啶吸附的红外光谱、NH3-程序升温脱附、热重、H2化学吸附和程序升温还原等物理化学手段研究了载体组成对负载型PtSn/ZSM-5催化剂上丙烷脱氢反应性能的影响. 结果表明,负载型PtSn/ZSM-5催化剂对丙烷脱氢的催化性能与载体组成密切相关. 随着ZSM-5载体中SiO2/Al2O3比的增加,催化剂表面的酸中心总量和强酸中心量逐渐减少. 当SiO2/Al2O3摩尔比从45增至108时,催化剂对丙烷脱氢反应的催化活性提高,并且催化剂的积炭量下降. 当SiO2/Al2O3摩尔比增至304时, Sn组分与载体ZSM-5之间的相互作用减弱,经H2还原后催化剂中Sn0物种所占的比例增加,导致催化剂H2化学吸附量和丙烷脱氢反应活性下降.

关键词: 铂, 锡, ZSM-5分子筛, 负载型催化剂, 丙烷, 脱氢, 丙烯

Abstract: The effect of ZSM-5 composition on catalytic performance of the supported PtSn/ZSM-5 catalyst for propane dehydrogenation was studied using a microreactor combined with infrared spectroscopy of adsorbed pyridine, temperature-programmed desorption of NH3, thermogravimetry, H2 chemisorption, and temperature-programmed reduction. The results showed that the ZSM-5 composition exerted great influence on the catalytic performance of PtSn/ZSM-5 for propane dehydrogenation. With the increase of SiO2/Al2O3 molar ratio in theZSM-5support, the numbers of both total and stronger acidic sites decreased. When the SiO2/Al2O3 molar ratio in the ZSM-5 support increased from 45 to 108, the catalytic activity increased, and the amount of coke formed on the catalyst surface decreased. When the SiO2/Al2O3 molar ratio in the ZSM-5 support was higher than 304, the interaction of Sn species with the ZSM-5 support became weaker, and the ratio of Sn0 species in the catalyst increased after reduction in H2, resulting in the decrease of H2 uptake and catalytic activity of the PtSn/ZSM-5 catalyst for propane dehydrogenation.

Key words: platinum, tin, ZSM-5 zeolite, supported catalyst, propane, dehydrogenation, propylene