压力间隙中的时间解析的表面反应动力学
Tzu-En Chien1, Lea Hohmann1, Dan J Harding1
1Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden. djha@kth.se.
Faraday discussions
|May 17, 2024
概括
近环境压力速度图像 (NAP-VMI) 直接测量了Pd上的CO氧化动力学{110}. 一个特定的氧化物结构是高度活跃的,但在更高的氧气压力下,二氧化碳的产生被抑制.
科学领域:
- 表面科学是一门学科.
- 化学动力学 化学动力学
- 催化剂是一种催化剂.
背景情况:
- 在压力间隙中研究催化反应具有挑战性.
- 现有的方法在解决反应动态方面存在局限性.
研究的目的:
- 扩展近环境压力速度图像绘制 (NAP-VMI) 技术用于研究催化反应动力学.
- 在接近环境压力下,研究Pd(110) 表面的CO氧化反应.
主要方法:
- 使用了NAP-VMI与分子束表面散射相结合.
- 在Pd上测量了CO散射和氧化过程的时间和速度解析动力学{110}.
- 在高达1×10−5 mbar的氧气压力下研究的反应.
主要成果:
- 在低O2压力下确定了一个高度活跃的c(2 × 4) 氧化物结构.
- 观察到二氧化碳产品形成的两个反应通道,与不同的二氧化碳结合点相关.
- 确定有效的CO氧化激活能量为1.0 ± 0.13 eV.
- 由于表面结构的变化,在较高的O2压力下,发现CO2的产生被抑制.
结论:
- 在Pd(110) 上的c(2 × 4) 氧化物结构对于活性CO氧化至关重要.
- 表面O原子覆盖和结构影响CO表面寿命和催化活性.
- NAP-VMI是一个强大的工具,用于探测压力间隙中的反应动态.
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