Support Effect in High Activity Gold Catalysts for CO Oxidation

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• 作者：Massimiliano Comotti ; Wen-Cui Li ; Bernd Spliethoff ; and Ferdi Sch&uuml ; th
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：January 25, 2006
• 年：2006
• 卷：128
• 期：3
• 页码：917 - 924
• 全文大小：882K
• 年卷期：v.128,no.3(January 25, 2006)
• ISSN：1520-5126

文摘

In this work, we present a detailed study concerning the evaluation of the metal-supportinteraction in high activity gold catalysts for CO oxidation. Using the colloidal deposition method, modelcatalysts were prepared, which allow the isolation of the effect of the support on the catalytic activity.Prefabricated gold particles were thus deposited on different support materials. Since the deposition processdid not change the particle sizes of the gold particles, only the influence of the support could be studied.TiO₂, Al₂O₃, ZrO₂, and ZnO were used as support materials. Catalytic tests and high resolution transmissionelectron microscopy clearly show that the support contributes to the activity. However, our results are notin line with the distinction between active and passive supports based on the semiconducting properties ofthe oxidic material. The most active catalysts were obtained with TiO₂ and Al₂O₃, while ZnO and ZrO₂gave substantially less active catalysts. Furthermore, the effect of other important parameters on the catalyticactivity (i.e., particles size distribution, calcination temperature, and aging time for a Au/TiO₂ catalyst) hasalso been studied. Using this preparation route, the catalysts show high-temperature stability, size dependentactivity, and a very good long-term stability.