Redispersion of Gold Supported on Oxides

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• 作者：Jacinto S谩 ; Sarah Frances Rebecca Taylor ; Helen Daly ; Alexandre Goguet ; Ramchandra Tiruvalam ; Qian He ; Christopher J. Kiely ; Graham J. Hutchings ; Christopher Hardacre
• 刊名：ACS Catalysis
• 出版年：2012
• 出版时间：April 6, 2012
• 年：2012
• 卷：2
• 期：4
• 页码：552-560
• 全文大小：513K
• 年卷期：v.2,no.4(April 6, 2012)
• ISSN：2155-5435

文摘

Although many gold heterogeneous catalysts have been shown to exhibit significant activity and high selectivity for a wide range of reactions in both the liquid and gas phases, they are prone to irreversible deactivation. This is often associated with sintering or loss of the interaction of the gold with the support. Herein, we report on the use of methyl iodide as a method of dispersing gold nanoparticles supported on silica, titania, and alumina supports. In the case of titania- and alumina-based catalysts, the gold was transformed from nanometer particles into small clusters and some atomically dispersed gold. In contrast, although there was a drop in the gold particle size on the silica support following CH₃I treatment, the size remained in the submicrometer range. The structural changes were correlated with changes in the selectivity and activity for ethanol dehydration and benzyl alcohol oxidation. From these observations, it is clear that this treatment provides a method by which deactivated gold catalysts can be reactivated via redispersion of the gold.

Keywords:

gold; redispersion; methyl iodide; oxides; dehydration; oxidation