一氧化碳在有序的Pt{11}/Sn表面合金上的电氧化
Brian E Hayden1, Michael E Rendall, Oliver South
1Department of Chemistry, The University of Southampton, Southampton SO17 1BJ, U.K. beh@soton.ac.uk
Journal of the American Chemical Society
|June 19, 2003
概括
-锡合金催化剂通过双功能机制增强CO电氧化. 锡激活水,在特定的电位上促进CO氧化,这对于耐碳的燃料电池催化剂至关重要.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
背景情况:
- 一氧化碳 (CO) 的电氧化对于燃料电池至关重要.
- 基催化剂是必不可少的,但容易受到CO中毒.
- 将与锡 (Pt-Sn) 合金为提供了潜在的CO耐受性.
研究的目的:
- 在模型-锡合金表面上研究CO的电氧化.
- 阐明锡在促进CO氧化中的作用.
- 了解Pt-Sn催化剂中CO耐受性的机制.
主要方法:
- 准备具有定义结构的模型 Pt(111)/Sn 表面.
- 现场电化学测量 (循环电压测量,剥离电压测量).
- 现场光辐射光谱检测表面状态.
主要成果:
- 确定了与Sn位点上氧化物吸附/脱附相关的表面氧化还原对.
- 锡原子在金属和氧化状态之间切换,与氧化还原对相关.
- 二氧化碳的电氧化发生在与Sn位点上的氧化物吸附相吻合的电位,表明一种双功能机制.
结论:
- 锡通过水激活显著促进CO电氧化.
- Pt-Sn合金结构稳定且有效应对0.5V以下的CO氧化 (RHE).
- 这些发现对于开发用于燃料电池的耐氧化碳基阳极催化剂至关重要.
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