Gold nanoparticles deposited on manganese(III) oxide as novel efficient catalyst for low temperature CO oxidation

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• 作者：Lu-Cun Wang ; Xin-Song Huang ; Qian Liu ; Yong-Mei Liu ; Yong Cao ; He-Yong He ; Kang-Nian Fan ; Ji-Hua Zhuang
• 关键词：Supported gold catalyst ; Manganese(III) oxide ; CO oxidation ; Specific activity ; Support effects
• 刊名：Journal of Catalysis
• 出版年：2008
• 出版时间：1 October 2008
• 年：2008
• 卷：259
• 期：1
• 页码：66-74
• 全文大小：472 K

文摘

Nanostructured α-Mn₂O₃ materials have been employed as supports for anchoring gold nanoparticles, which exhibited high activities for low-temperature CO oxidation in the absence or presence of excess H₂. The specific activity was found to increase with gold loading up to 5 wt % . Comparing the specific rates for CO oxidation (ca. 1.50 mmol_CO g⁻¹_Au s⁻¹ at 25 °C) with the highly active Au catalysts in the current literature confirmed the exceptionally high activity of these new materials. The rate of CO oxidation showed about half-order dependence of CO partial pressure and was nearly independent of O₂ concentration. X-ray photoelectron spectroscopy combined with in situ CO adsorption studies revealed the presence of both metallic and positively charged gold species in the catalyst under reaction conditions. As compared with the coprecipitation-derived Au–MnO_x catalyst, the superior activities of Au/α-Mn₂O₃ have been attributed to its unique redox properties and the facile formation of activated oxygen species on the surface.