Infrared Studies of the Promoting Role of Water on the Reactivity of Pt/FeOx Catalyst in Low-Temperature Oxidation of Carbon Monoxide

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• 作者：Suying Li ; Mingjun Jia ; Jun Gao ; Ping Wu ; Menglong Yang ; Shaohua Huang ; Xiaowei Dou ; Ying Yang ; Wenxiang Zhang
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：February 5, 2015
• 年：2015
• 卷：119
• 期：5
• 页码：2483-2490
• 全文大小：364K
• ISSN：1932-7455

文摘

For the purpose of revealing the promoting role of water on the reactivity of the supported Pt/FeO_x catalyst in the low-temperature oxidation of CO, in situ diffuse reflectance infrared Fourier transform (DRIFT) spectra were conducted to study the adsorption properties of CO under various conditions. In the case of without water (CO + O₂), CO could be preferentially adsorbed on the active Pt sites, and then strongly adsorbed on the Fe³⁺ sites, which might considerably inhibit the ability for O₂ activation, and result in the decrease of reactivity of Pt/FeO_x for low-temperature oxidation of CO. For the CO oxidation under wet condition (CO + O₂ + H₂O), coadsorption of water and oxygen was observed, which could form surface oxygen/hydroxyls species, and significantly inhibit the adsorption of CO on the Fe³⁺ sites, thus avoiding the deep reduction of the active Fe³⁺ sites located at the boundaries between FeO_x and Pt nanoparticles. In this case, the catalytic redox cycle in the active Fe³⁺ sites (mainly for O₂ activation) could be easily achieved by the addition of H₂O, which finally results in the significant improvement of the activity and stability of the Pt/FeO_x catalyst in low-temperature oxidation of CO.