Analysis of the Active Au Species on Au/伪-Fe₂O₃ Catalyst

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• 作者：Wei Jiying ; ^{weijiying@tsinghua.edu.cn} ; Zhang Zhenzhong ; Zhang Lan ; Meng Bifang ; Jiang Feng
• 关键词：Au/伪-Fe2O3 ; carbon monoxide oxidation ; active Au species ; deactivation
• 刊名：Rare Metal Materials and Engineering
• 出版年：2012
• 期刊代码：P57_18755372
• 类别：et
• 出版时间：March, 2012
• 卷：41
• 期：3
• 页码：377-382
• 文件大小：609 K

摘要

Au/伪-Fe₂O₃ catalysts for CO oxidation were prepared by chemical coprecipitation at different pH values, and the as-prepared samples were calcined or UV (位=254 nm) irradiated, respectively. The structure was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N₂ adsorption and desorption analysis (BET) and temperature programmed reduction (H₂-TPR), and the active Au species on the catalysts was investigated. The results show that Au³⁺, Au^未+ (0=未=1) and Au⁰ coexist on the surface of Au/伪-Fe₂O₃ catalysts treated at 110 掳C, and their activity order is Au³⁺> Au^未+> Au⁰. The sample prepared at pH=8 shows the best catalytic performance since it has more Au³⁺ species and high specific surface area. High temperature calcination can cause serious deactivation due to the reduction of Au³⁺ and Au^未+ species, together with the decrease of the specific surface area of 伪-Fe₂O₃. UV irradiation can also cause the reduction of oxidative Au species and the growth of Au particle.