Dehydrogenation of Propane over Silica-Supported Platinum-Tin Catalysts Prepared by Direct Reduction: Effects of Tin/Platinum Ratio and Reduction Temperature
Dehydrogenation of Propane over Silica-Supported Platinum-Tin Catalysts Prepared by Direct Reduction: Effects of Tin/Platinum Ratio and Reduction Temperature
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DOI：
10.1002/cctc.201402306
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发表时间：
2014-09-01
期刊：
影响因子：
4.5
通讯作者：
Tanaka, Tsunehiro
中科院分区：
文献类型：
--
作者：
Deng, Lidan;Miura, Hiroki;Tanaka, Tsunehiro
采用直接还原法制备了一系列不同Sn/Pt原子比（1/3-3）的Pt-Sn/SiO2催化剂，并进行了丙烷脱氢制丙烯的测试。通过 XRD、TEM、CO 吸附、X 射线光电子能谱和 X 射线吸收精细结构分析进行的结构表征表明，无论 Sn/Pt 比例或还原温度如何，Pt-Sn/SiO2 催化剂都具有高度分散的 Pt-Sn 合金核和富锡表面。高分散的SnO2与Pt-Sn合金颗粒共存，部分Pt-Sn合金表面被SnO2覆盖。在所制备的催化剂中，由Pt3Sn合金和少量Pt-Sn合金组成的1Pt1Sn/SiO2_1073K（Sn/Pt比=1，在1073K还原）表现出最高的活性。相反，如果Sn/Pt比大于1和/或还原温度为1273K，则主要观察到Pt-Sn合金并且Pt-Sn/SiO2催化剂表现出低活性。
A series of Pt-Sn/SiO2 catalysts with different Sn/Pt atomic ratios (1/3-3) were prepared by a direct reduction method and tested for the dehydrogenation of propane to propylene. Structural characterization by XRD, TEM, CO adsorption, X-ray photoelectron spectroscopy, and X-ray absorption fine structure analysis revealed that the Pt-Sn/SiO2 catalysts possessed a highly dispersed Pt-Sn alloy core with a Sn-rich surface regardless of the Sn/Pt ratio or reduction temperature. Highly dispersed SnO2 coexisted with the Pt-Sn alloy particles, and part of the Pt-Sn alloy surface was covered with SnO2. Among the catalysts prepared, 1Pt1Sn/SiO2_1073K (Sn/Pt ratio=1, reduced at 1073K), composed of Pt3Sn alloy with a small fraction of Pt-Sn alloy, exhibited the highest activity. In contrast, if the Sn/Pt ratio was larger than 1 and/or the reduction temperature was 1273K, Pt-Sn alloy was observed mainly and the Pt-Sn/SiO2 catalysts showed low activity.