A simplified method to determine the coverage dependence of surface diffusion coefficients |
| |
| Affiliation: | 1. University of Tartu, Institute of Physics, Ravila 14C, 50411 Tartu, Estonia;2. University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki, Finland;3. University of Tartu, Institute of Chemistry, Ravila 14A, 50411 Tartu, Estonia;1. Department of Mechanical Engineering Science, Faculty of Engineering and the Built Environment, University of Johannesburg, Auckland, 2006 Johannesburg, South Africa;2. Department of Metallurgy, Faculty of Engineering and the Built Environment, University of Johannesburg, Doornfontein, 2028 Johannesburg, South Africa;1. State Key Laboratory of Multiphase Flow in Power Engineering, Xi''an Jiaotong University, Xi''an 710049, China;2. Xinjin Weihua Institute of Clean Energy Research, Nanhai District, Foshan City, Guangdong Province, China |
| |
| Abstract: | A new method to determine the coverage dependence of surface diffusion coefficients from coverage-gradient experiments is presented. The initial coverage-gradient employed is an evacuated circular region surrounded by a constant coverage. In order to demonstrate this method, Fick's second law equation was numerically solved using coverage-dependent surface diffusion coefficients. An analysis of the results demonstrates that the coverage dependence of the surface diffusion coefficient can be determined using a simple extrapolation procedure. The coverage dependence can be obtained for a wide range of functional forms for the surface diffusion coefficient. The extrapolation procedure requires only that the number of adsorbates that have diffused back into the initially evacuated region be measured as a function of time. This method should be useful in the interpretation of coverage-gradient surface diffusion experiments, especially those performed using laser-induced thermal desorption techniques. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
