在Pd上进行乙烯化的双地下 (2H') 机制
Nicholas Golio1, Andrew J Gellman1,2
1Department of Chemical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213, United States.
概括
一个新的双地下 (2H') 机制准确地模拟了 (Pd) 表面的乙烯化. 这种包含地下的模型与实验数据保持一致,并改善了对催化反应的理解.
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:
- 霍里乌蒂-波兰尼框架是表面反应的一个关键模型.
- 现有的模型,如兰格穆尔-欣舍尔伍德有局限性,特别是对于H2-D2交换.
- 地表 (H) 在激活的表面反应中起作用.
研究的目的:
- 开发一种微动力学模型,用于Pd上的乙烯化,其中包括地下.
- 扩大Horiuti-Polanyi框架,使用双层地下 (2H) 机制.
- 在Pd.上对乙烯化实验数据验证2H机制.
主要方法:
- 开发了一个基于Horiuti-Polanyi框架的微动力学模型.
- 纳入了双地下 (2H) 机制,以计算地下.
- 模型预测与实验结果对AgxPd1-x组合扩散合金膜 (CSAF) 上的乙烯化进行了比较.
主要成果:
- 2H机制准确地预测了乙烯化 (0.69 ± 0.18) 在H2中的反应顺序.
- 估计有效化速率常数 (k_eff) 在10^10到10^14mol/m^2/sec之间.
- 确定乙烯吸附能量大约为10kJ/mol.
结论:
- 双地表 (2H) 机制提供了一个准确的表征乙烯化在Pd.
- 考虑到地下对于精确建模基于的催化剂的表面反应至关重要.
- 2H机制为理解复杂的催化过程提供了一个更强大的框架.
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