Non-oxidative propane dehydrogenation over Pt-Zn-containing zeolites
Non-oxidative propane dehydrogenation over Pt-Zn-containing zeolites
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DOI：
10.1016/j.apcata.2006.03.028
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发表时间：
2006-06-07
影响因子：
5.5
通讯作者：
Weitkamp, Jens
中科院分区：
文献类型：
--
作者：
De Cola, Patrizia Laura;Glaeser, Roger;Weitkamp, Jens
从沸石Na-ZSM-5（MFI）、Na-ZSM-11（MEL）、Na-Beta（β-沸石）、Na-丝光沸石（莫尔）、K-L（LTL）和Na-Y（FAU）开始，将锌含量为0.6 - 13.4重量%的含Pt-Zn催化剂和0.5重量%的铂含量制备了锌通过浸渍或水性离子交换引入，铂通过随后用H2 PtCl 6浸渍引入。采用化学分析（AES/ICP）、X射线衍射（XRD）、吸附吡啶红外光谱（FT IR）、氮气吸附和程序升温还原（TPR）等方法对催化剂进行了表征。在n（Si）/n（Al）比>= 26的沸石的水溶液离子交换之后，催化剂中的锌含量高于由它们的离子交换容量所预期的。这种与锌的过度交换被解释为氧化锌物种的形成。在丙烷的非氧化脱氢中在555 ℃下测试含Pt-Zn沸石。在10元环沸石Na-ZSM-5和Na-ZSM-11上发生芳构化反应，而在12元环沸石Na-Beta、Na-丝光沸石、K-L和Na-Y上主要发生丙烷脱氢反应。用于并入锌的不同程序并不显著影响具有较低n（Si）/n（Al）比（= 8.7和锌含量接近2.5wt.%）的大孔沸石的催化行为。在0.5Pt/2. 6 Zn-Beta沸石上，观察到丙烷脱氢为丙烯的接近热力学平衡的稳定转化率（X-Pr约为29%，T = 555 ℃和p = 0.1MPa）持续至少63小时。该沸石上的丙烯选择性> 90%。(c)2006 Elsevier B. V.保留所有权利。
Starting from the zeolites Na-ZSM-5 (MFI), Na-ZSM-11 (MEL), Na-Beta (*BEA), Na-mordenite (MOR), K-L (LTL) and Na-Y (FAU), Pt-Zn-containing catalysts with a zinc content between 0.6 and 13.4 wt.% and a platinum content of 0.5 wt.% were prepared. Zinc was introduced by impregnation or aqueous ion exchange, platinum by subsequent impregnation with H2PtCl6. The catalysts were characterized by chemical analysis (AES/ICP), X-ray diffraction (XRD), FT IR spectroscopy of adsorbed pyridine, nitrogen adsorption and temperature-programmed reduction (TPR). After the aqueous ion exchange of the zeolites with n(Si)/n(Al)-ratios >= 26, the zinc content in the catalysts was higher than that expected from their ion exchange capacity. This over-exchange with zinc was explained by the formation of oxidic zinc species. The Pt-Zn-containing zeolites were tested in the non-oxidative dehydrogenation of propane at 555 degrees C. Aromatization occurred over the 10-membered-ring zeolites Na-ZSM-5 and Na-ZSM-11, whereas propane dehydrogenation was the major reaction over the 12-membered-ring zeolites Na-Beta, Na-mordenite, K-L and Na-Y. The different procedures used for the incorporation of zinc did not significantly affect the catalytic behavior of the large-pore zeolites with lower n(si)/n(Al)-ratios ( = 8.7 and zinc contents close to 2.5 wt.%. Over the zeolite 0.5Pt/2.6Zn-Beta, a stable conversion close to the thermodynamic equilibrium for the dehydrogenation of propane to propene (X-Pr approximate to 29%, T = 555 degrees C and p = 0.1 MPa) was observed for at least 63 It time-on-stream. The propene selectivity over this zeolite was > 90%. (c) 2006 Elsevier B.V. All rights reserved.