在表面的特定场所一氧化碳的速度解析动力学
Jannis Neugebohren1, Dmitriy Borodin1, Hinrich W Hahn1
1Institute for Physical Chemistry, University of Goettingen, Göttingen, Germany.
Nature
|June 15, 2018
概括
这项研究揭示了等催化剂的不同活性部位如何协作. 研究人员使用一种新方法绘制了反应速率, 显示在低温下占主导地位, 在高温下占主导地位.
科学领域:
- 表面科学和异质催化.
- 化学动力学和反应机制
- 纳米粒子和材料科学.
背景情况:
- 催化剂通过稳定活性部位的过渡状态来加速反应.
- 对于具有多个同时活跃位点的催化剂,机理理解是具有挑战性的.
- 一氧化碳对的氧化是一种研究得很好的,但在机理上复杂的异质反应.
研究的目的:
- 开发和应用一种在不同活性点同时测量反应速率的方法.
- 阐明在二氧化碳氧化过程中表面的阶梯边缘与梯田的机械贡献.
- 为理解和设计改进的异质催化剂提供框架.
主要方法:
- 使用分子束进行受控的反应物引入.
- 使用切片离子成像绘制产品分子速度向量.
- 应用速度解析的动力学来区分和量化特定活跃点的速度.
主要成果:
- 在不同活性部位同时测量反应速率.
- 绘制了白金阶梯边缘和露台场所的一氧化碳的氧化率.
- 确定了两种不同的反应道:在低温下占主导地位,而高温时占主导地位.
结论:
- 开发的速度解析动力学方法可以同时测量多个活性位点的速度.
- 通过区分特定站点的贡献,可以提高对异质反应的机制理解.
- 这种方法广泛适用于设计更高效的催化剂.
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