Catalytic Reduction of NO2 with Hydrogen on Pt Field Emitter Tips: Kinetic Instabilities on the Nanoscale

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• 作者：J.-S. McEwen ; P. Gaspard ; Y. De Decker ; C. Barroo ; T. Visart de Bocarm ; N. Kruse
• 刊名：Langmuir
• 出版年：2010
• 出版时间：November 2, 2010
• 年：2010
• 卷：26
• 期：21
• 页码：16381-16391
• 全文大小：1197K
• 年卷期：v.26,no.21(November 2, 2010)
• ISSN：1520-5827

文摘

The catalytic reduction of NO₂ with hydrogen on a Pt field emitter tip is investigated using both field electron microscopy (FEM) and field ion microscopy (FIM). A rich variety of nonlinear behavior and unusually high catalytic activity around the {012} facets are observed. Our FEM investigations reveal that the correlation function exhibits damped oscillations with a decaying envelope, showing that molecular noise will influence the dynamics of the oscillations. The dependence of the oscillatory period on the P_H2/P_NO2 pressure ratios is analyzed. Similar patterns are reported under FIM conditions. Corresponding density functional theory (DFT) calculations for the adsorption of NO₂ on Pt{012} in the presence of an external electric field are performed in order to gain an atomistic understanding of the underlying nonlinear phenomena.