Kinetic models of surface explosions
Kinetic models of surface explosions
复制标题
表面爆炸的动力学模型
DOI：
10.1088/0953-8984/7/32/005
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
M. Bowker
中科院分区：
文献类型：
--
作者：
R. Sharpe;M. Bowker
通过对一些可能的动力学模型进行数学建模，并检验与广泛的实验数据的拟合质量，探索了单晶表面‘爆炸’的动力学。二阶自催化一直是以前首选的模型。然而，这个模型是不一致的，因为它假设吸附物质在表面上是随机分布的，而孤岛现象却是已知的在许多‘爆炸性’吸附体系中发生的。事实上，人们发现有必要假设启动点附近的高局部覆盖率(实际上独立于全球覆盖率)才能很好地符合数据。因此，需要一种新的方法来考虑相邻吸附体之间的相互作用的影响。利用简单的假设，建立了一个圆形岛屿模型，该模型考虑了异步启动的影响和岛屿合并导致的成品率降低。这被发现能够产生与由二阶模型获得的数据一样好的对爆炸性的解吸数据的拟合。
The kinetics of surface 'explosions' on single-crystal surfaces has been explored by mathematical modelling of a number of possible kinetic models and examining the quality of fit to a wide range of experimental data. Second-order autocatalysis has been the previously preferred model. However, this model is inconsistent since it assumes a random distribution of adsorbates on the surface and yet islanding is known to occur in a number of 'explosive' adsorbate systems. Indeed, it is found to be necessary to assume a high local coverage (practically independent of the global coverage) near initiation sites to fit the data well. Hence, a new approach that takes into account the effect of interactions between neighbouring adsorbates is required. A circular island model is developed which incorporates the effects of asynchronous initiation and the reduced yield caused by island merging using simple assumptions. This is found to be capable of producing fits to 'explosive' desorption data as good as those obtained by the second-order model.