Deactivation of Ru Catalysts under Catalytic CO Oxidation by Formation of Bulk Ru Oxide Probed with Ambient Pressure XPS
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- 作者：Kamran Qadir ; Sun Mi Kim ; Hyungtak Seo ; Bongjin S. Mun ; Funda Aksoy Akgul ; Zhi Liu ; Jeong Young Park
- 刊名：The Journal of Physical Chemistry C
- 出版年：2013
- 出版时间：June 27, 2013
- 年：2013
- 卷：117
- 期：25
- 页码：13108-13113
- 全文大小：316K
- 年卷期：v.117,no.25(June 27, 2013)
- ISSN：1932-7455
文摘
The surface science approach of using model catalysts in conjunction with the development of in situ spectroscopic tools, such as ambient pressure X-ray photoelectron spectroscopy (AP-XPS), offers a synergistic strategy for obtaining a substantially better understanding of deactivation phenomena. In this study, we investigated the nature of Ru oxides on a Ru polycrystalline film under oxidizing, reducing, and catalytic CO oxidation reaction conditions. Thus, bulk Ru oxide was easily formed on such Ru catalysts, the growth of which was dependent on reaction temperature. Once formed, such an oxide is irreversible and cannot be completely removed even under reducing conditions at elevated temperatures (200 掳C). Our reaction studies showed substantial deactivation of the Ru film during catalytic CO oxidation, and its activity could be partially recovered after reduction pretreatment. Such continuous deactivation of a Ru film is correlated with irreversibly formed bulk Ru oxide, as shown by AP-XPS. Such in situ spectroscopic evidence of the transition of oxides to a catalytically inactive state can enable more effective design of catalysts with less deactivation.