Microkinetic Simulation of Temperature-Programmed Desorption

详细信息    查看全文

• 作者：Chia-Ching Wang ; Jyun-Yi Wu ; Jyh-Chiang Jiang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：March 28, 2013
• 年：2013
• 卷：117
• 期：12
• 页码：6136-6142
• 全文大小：393K
• 年卷期：v.117,no.12(March 28, 2013)
• ISSN：1932-7455

文摘

The temperature-programmed desorption (TPD) spectra were simulated by combining density functional theory (DFT) calculations and microkinetic modeling. In the microkinetic analyses, all kinetic and thermodynamic parameters were obtained from DFT calculations to minimize artificial assumptions. For the case study, the desorptions of NH₃ and H₂O from the RuO₂(110) surface were simulated. The coverage-dependent desorption energies were introduced into the microkinetic model because different adsorbates on the surface will exhibit different desorption behaviors. In addition, temperature-dependent pre-exponential factors were applied to the desorption rate equations. The calculated pre-exponential factors are ranged from 10¹⁴ to 10¹⁷ s^鈥?, which are greatly larger than 10¹³ s^鈥?, a generally accepted empirical value for desorption processes. The desorption temperatures obtained from microkinetic simulations consist with experimental results, and the simulated TPD patterns are also similar to the experimental observations.