NH的动力学3 Pt上的溶解和扩散:对奥斯瓦尔德过程的影响
Dmitriy Borodin1,2, Igor Rahinov3, Oihana Galparsoro4,5
1Institute for Physical Chemistry, Georg-August University of Goettingen, Tammannstraße 6, 37077 Goettingen, Germany.
Journal of the American Chemical Society
|October 21, 2021
概括
精确的氨 (NH3) 脱吸测量显示,对的表面反应建模具有关键性的自由度. 这有助于更好地理解奥斯瓦尔德过程和氨结合能.
科学领域:
- 表面科学
- 化学运动学
- 催化剂
背景情况:
- 表面的氨 (NH3) 脱吸动力学对于理解像奥斯瓦尔德过程这样的催化过程至关重要.
- 现有的模型通常使用简化的分区函数,可能会限制准确性.
研究的目的:
- 准确地测量Pt{11}和Pt{332}表面的NH3脱吸率.
- 确定吸附和扩散的基本速率常数.
- 完善表面反应的理论模型.
主要方法:
- 时间解析的脱吸测量.
- 过渡状态理论模型.
- 结合自由度分区函数的开发.
主要成果:
- 确定了Pt{111}上NH3脱吸和扩散的准确速率常数.
- 配对的自由度分区函数准确地重现了实验数据.
- 确定了NH3与Pt111的结合能量 (1.13±0.02 eV) 和扩散屏障 (0.71±0.04 eV).
- 在Pt上,NH3显示了阶梯站点与露台站点之间的绑定能量偏好 (0.23 ± 0.03 eV).
结论:
- 传统的分区函数模型不足以描述NH3脱吸.
- 需要采用结合自由度的精细理论方法.
- 这些发现挑战了12%的规则,并解释了当前奥斯瓦尔德过程模型的局限性,表明平均场动力学并不总是适用.
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