Effects of Alumina Thickness on CO Oxidation Activity over Pd20/Alumina/Re(0001): Correlated Effects of Alumina Electronic Properties and Pd20 Geometry on Activity

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• 作者：Matthew D. Kane ; F. Sloan Roberts ; Scott L. Anderson
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：January 22, 2015
• 年：2015
• 卷：119
• 期：3
• 页码：1359-1375
• 全文大小：756K
• ISSN：1932-7455

文摘

The CO oxidation activity of size-selected Pd₂₀ clusters deposited on alumina films grown on Re(0001) is shown to depend strongly on the film thickness in the 0 to 10 nm range. For the reaction conditions of these experiments, binding and activation of O₂ is shown to be the limiting process, which can be varied by a factor of 2 by tuning the alumina film thickness, due to effects on both the electronic structure of the alumina film and the morphology of the supported Pd clusters. The alumina films are shown to be doped with Re atoms diffusing from the Re(0001) substrate, leading to a strong dependence of the surface electronic properties on alumina thickness, which in turn, results in the observed thickness-dependent activity of the Pd₂₀.