Propane dehydrogenation over supported Pt and Pt-Sn catalysts: Catalyst preparation, characterization, and activity measurements
Propane dehydrogenation over supported Pt and Pt-Sn catalysts: Catalyst preparation, characterization, and activity measurements
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DOI：
10.1006/jcat.1996.0001
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发表时间：
1996-01-01
影响因子：
7.3
通讯作者：
Blekkan, EA
中科院分区：
文献类型：
--
作者：
Barias, OA;Holmen, A;Blekkan, EA
以SiO_2和γ-Al_2O_3为载体，采用浸渍法制备了Pt和Pt-Sn催化剂，并对其进行了程序升温还原（TPR）、氢化学吸附、程序升温脱附（TPD）和丙烷脱氢反应的研究。在没有促进剂的情况下，Pt在两种载体上显示出相同的初始比活性，但由于焦化而迅速失活。Sn作为促进剂的效果取决于载体。在γ-Al 2 O3上，锡与载体相互作用，并稳定在氧化态>0。结果是Pt分散度的增加和催化活性的稳定性的改善，而在脱氢中的初始比活性没有任何变化。在SiO2上，Sn更容易被还原，并且可能形成合金。这导致Pt分散度的类似增加和催化稳定性的改善，但也导致比活性的强烈降低。在两种载体上的催化稳定性的变化被氢吸附性能的急剧变化所掩盖，如从还原后的TPD曲线所看到的。(C)出版社：Academic Press，Inc.
Pt and Pt-Sn catalysts supported on SiO2 and gamma-Al2O3 and prepared by impregnation have been studied by temperature-programmed reduction (TPR), hydrogen chemisorption, temperature-programmed desorption (TPD), and catalytic dehydrogenation of propane. Without the promoter Pt shows the same initial specific activity on both supports, but deactivates rapidly due to coking. The effect of Sn as a promoter depends on the support. On gamma-Al2O3 tin interacts with the support and is stabilized in an oxidation state >0. The result is an increase in Pt dispersion and an improved stability of the catalytic activity without any change in the initial specific activity in dehydrogenation. On SiO2 the Sn is more readily reduced, and alloy formation is possible. This leads to a similar increase in Pt dispersion and improved catalytic stability, but also to a strong reduction in the specific activity. The change in catalytic stability on both supports is paralleled by a dramatic change in the hydrogen adsorption properties, as seen from the TPD profiles after reduction. (C) 1996 Academic Press, Inc.