Au nanoparticles deposited on the external surfaces of TS-1: Enhanced stability and activity for direct propylene epoxidation with H2 and O2
Au nanoparticles deposited on the external surfaces of TS-1: Enhanced stability and activity for direct propylene epoxidation with H2 and O2
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DOI：
10.1016/j.apcatb.2013.12.041
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发表时间：
2014-05-05
影响因子：
22.1
通讯作者：
Yuan, Weikang
中科院分区：
文献类型：
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作者：
Feng, Xiang;Duan, Xuezhi;Yuan, Weikang
采用沉积-沉淀法制备的Au/TS-1催化剂在丙烯直接环氧化反应中具有良好的应用前景。然而，催化剂通常遭受快速失活。本研究首先将具有开放微孔的煅烧TS-1（TS-1-O）用于负载Au催化剂，然后对不同运行时间下使用过的催化剂进行表征，以了解失活机理。碳质沉积物的堵塞是导致失活的主要原因。因此，我们提出了一个原则的催化剂设计，以提高长期稳定性，通过沉积Au纳米粒子的外表面上的TS-1。为此，使用具有封闭微孔的未煅烧TS-1（TS-1-B）来负载Au催化剂。结果表明，该催化剂不仅具有很好的稳定性，而且在30 h内的PO生成速率为125 g（PO）h（-1）kg（Cat）（-1）。(C)2013爱思唯尔有限公司版权所有。
Au/TS-1 catalysts prepared by deposition-precipitation method are very promising for direct propylene epoxidation with H-2 and O-2. However, the catalysts usually suffer from rapid deactivation. In this work, calcined TS-1 with open micropores (TS-1-O) is first used to support Au catalysts, and then the used catalysts at different time-on-streams are characterized to understand the deactivation mechanism. The micropore blocking by carbonaceous deposits is found to be responsible for the deactivation. We therefore suggest a principle of catalyst design to improve the long term stability by depositing Au nanoparticles on the external surfaces of TS-1. For this purpose, uncalcined TS-1 with blocked micropores (TS-1-B) is used to support Au catalyst. As expected, the designed catalyst is not only very stable because of the elimination of pore blocking and the more accessible active sites, but also highly active with the PO formation rate of 125 g(PO) h(-1) kg(Cat)(-1) for over 30 h. (C) 2013 Elsevier B.V. All rights reserved.