Oxidation and Surface Segregation Behavior of a Pt-Pd-Rh Alloy Catalyst
Oxidation and Surface Segregation Behavior of a Pt-Pd-Rh Alloy Catalyst
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DOI：
10.1021/jp508144z
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发表时间：
2014-11-13
影响因子：
3.7
通讯作者：
Smith, George D. W.
中科院分区：
文献类型：
--
作者：
Bagot, Paul A. J.;Kruska, Karen;Smith, George D. W.
铂网催化剂广泛用于从氨生产硝酸，其中它们经受结合高温和氧化环境的苛刻操作条件。这些导致金属物质作为挥发性氧化物的显著损失。不同的金属物种在这些环境中如何在基本的原子尺度水平上表现出来还没有很好的理解。在这项工作中，我们研究了PtRhPd纱布在8731273 K温度下氧化的早期阶段。使用先进的实验方法相结合，我们探讨了氧化行为如何强烈影响表面和近表面的纱布微观结构。我们表明，Rh和Pd可以隔离在同一表面的不同区域，并讨论如何将这种原子迁移可以连接到这样的合金的金属损失的机制。
Platinum gauze catalysts are used extensively in the production of nitric acid from ammonia, where they are subject to harsh operating conditions combining elevated temperatures and oxidizing environments. These cause significant loss of metal species as volatile oxides. How different metallic species behave in these environments at a fundamental, atomic-scale level is not well understood. In this work, we study the early stages of oxidation of a PtRhPd gauze at temperatures of 8731273 K. Using a combination of advanced experimental methods, we explore how the oxidation behavior can strongly influence the surface and near-surface gauze microstructure. We show that Rh and Pd can segregate on different areas of the same surface and discuss how such atomic migration can be linked to mechanisms of metal loss from such alloys.