物理化学学报 >> 2008, Vol. 24 >> Issue (07): 1297-1301.doi: 10.3866/PKU.WHXB20080730

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PtSn/Al2O3/MCM-41催化剂的丙烷脱氢催化性能

黄丽华; 杨利利; 许波连; 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, 南京 210093
  • 收稿日期:2008-01-25 修回日期:2008-04-08 发布日期:2008-07-04
  • 通讯作者: 范以宁 E-mail:ynfan@nju.edu.cn

Catalytic Properties of PtSn/Al2O3/MCM-41 Catalysts for Propane Dehydrogenation

HUANG Li-Hua; YANG Li-Li; XU Bo-Lian; FAN Yi-Ning   

  1. Jiangsu Provincial Key Laboratory of Nanotechnology, Key Laboratory of Mesoscopic Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
  • Received:2008-01-25 Revised:2008-04-08 Published:2008-07-04
  • Contact: FAN Yi-Ning E-mail:ynfan@nju.edu.cn

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摘要： 用微型催化反应装置评价, 并结合X射线粉末衍射(XRD)、表面积和孔结构测试、程序升温还原(TPR)、氢化学吸附和热重分析等方法研究了负载型PtSn/γ-Al2O3, PtSn/MCM-41和PtSn/Al2O3/MCM-41催化剂的丙烷脱氢反应催化性能. 发现PtSn/Al2O3/MCM-41催化剂具有较PtSn/MCM-41催化剂高的丙烷脱氢反应活性和较PtSn/γ-Al2O3催化剂高的反应稳定性. 实验结果表明, 纯硅MCM-41载体表面的锡物种因与载体相互作用较弱故易被还原, 导致铂金属分散度和催化剂的丙烷脱氢活性较低. 用Al2O3修饰MCM-41可以增强Sn物种与Al2O3/MCM-41载体之间的相互作用, 提高PtSn/Al2O3/MCM-41催化剂铂金属分散度和丙烷脱氢催化活性. 并且, 积炭后的PtSn/Al2O3/MCM-41催化剂具有较高的铂金属表面裸露度, 故具有较高的丙烷脱氢反应稳定性. PtSn/Al2O3/MCM-41催化剂优良的丙烷脱氢催化性能可能不仅与Sn-载体Al2O3/MCM-41较强的相互作用有关, 而且与Al2O3/MCM-41载体的介孔结构有关.

关键词: Pt, Sn, MCM-41, Al2O3, 丙烷脱氢

Abstract: The catalytic properties of PtSn/γ-Al2O3, PtSn/MCM-41 and PtSn/Al2O3/MCM-41 catalysts for propane dehydrogenation were studied using microreactor tests combined with X-ray diffraction (XRD), BET surface area and pore structure measurements, temperature-programmed reduction (TPR), H2-chemisorption and thermogravimetric (TG) analysis. It was shown that the PtSn catalysts supported on Al2O3-modified MCM-41 (Al2O3/MCM-41) exhibited higher activity than the PtSn/MCM-41 catalyst, and higher catalytic stability than the conventional PtSn/γ-Al2O3 catalyst for propane dehydrogenation. The characterization results of the catalysts revealed that on the surface of pure MCM-41, the dispersed Sn species were easier to be reduced to metallic state due to weak interaction of Sn with MCM-41 support, resulting in lower Pt dispersity and thus lower catalytic activity. In contrast, modifying the surface of MCM-41 by alumina could enhance the interaction between Sn and Al2O3/MCM-41 support, and increase Pt dispersity and catalytic activity for propane dehydrogenation. Moreover, the PtSn/Al2O3/MCM-41 catalysts had larger bare fraction of Pt surface after coke deposition, leading to their higher catalytic stability than the PtSn/γ-Al2O3 catalyst. It is suggested that the unique catalytic properties of PtSn/Al2O3/MCM-41 catalysts are correlated not only to the strong interaction of Sn with Al2O3/MCM-41support but also to the mesoporous structure of the Al2O3/MCM-41 support.

Key words: Pt, Sn, MCM-41, Al2O3, Propane dehydrogenation

MSC2000: 

  • O643