Reaction Mechanism of the Low-Temperature Water-Gas Shift Reaction on Au/TiO2 Catalysts
Reaction Mechanism of the Low-Temperature Water-Gas Shift Reaction on Au/TiO2 Catalysts
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DOI：
10.1021/acs.jpcc.7b02400
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发表时间：
2017-06-08
影响因子：
3.7
通讯作者：
Takeda, Seiji
中科院分区：
文献类型：
--
作者：
Sun, Keju;Kohyama, Masanori;Takeda, Seiji
通过密度泛函理论计算和微观动力学研究，深入探讨了Au/TiO 2催化剂上低温水煤气变换反应的氧化还原和缔合机理。对于氧化还原机制，我们已经观察到，在TiO 2表面上的金簇和额外的氧空位的存在下是至关重要的WGS反应，特别是对于H-2，释放的过程。对于通过中间物种的缔合机理，在WGS反应中很难产生COOH。HCOO可能生成，而HCOO应该是副反应的产物，因为H-2释放困难。结果表明，Au/TiO 2催化剂上的WGS反应可用氧化还原机理来解释。目前的理解的机制应该打开一扇新的大门，催化剂设计在WGS反应。
The redox and associative mechanisms for the low temperature water gas shift (WGS) reaction on Au/TiO2 catalysts are thoroughly examined by density functional theory calculations and microkinetic studies. For the redox mechanism, we have observed that the presence of a gold cluster and extra oxygen vacancies on a TiO2 surface is vital for the WGS reaction, especially for the process of H-2, release. For the associative mechanism via intermediate species, it is very hard for COOH to be generated in the WGS reaction. HCOO could be generated, while HCOO should only be a product of side reactions because of the difficulty in H-2 release. The present results indicate that the WGS reaction on Au/TiO2 catalysts can be well explained by the redox mechanism. The present understanding of the mechanism should open a new door for catalyst design in WGS reactions.