Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-0165, USA.
J Chem Phys. 2009 Dec 28;131(24):244520. doi: 10.1063/1.3281688.
The adaptive kinetic Monte Carlo method was used to calculate the decomposition dynamics of a methanol molecule on Cu(100) at room temperature over a time scale of minutes. Mechanisms of reaction were found using minimum mode following saddle point searches based on forces and energies from density functional theory. Rates of reaction were calculated with harmonic transition state theory. The dynamics followed a pathway from CH(3)OH, CH(3)O, CH(2)O, HCO, and finally to CO. Our calculations confirm that methanol decomposition starts with breaking the O-H bond followed by breaking C-H bonds in the dehydrogenated intermediates until CO is produced. The bridge site on the Cu(100) surface is the active site for scissoring chemical bonds. Reaction intermediates are mobile on the surface which allows them to find this active reaction site. This study illustrates how the adaptive kinetic Monte Carlo method can model the dynamics of surface chemistry from first principles.
采用自适应动力学蒙特卡罗方法，在分钟时间尺度上计算了甲醇分子在室温下在 Cu(100)上的分解动力学。通过基于密度泛函理论的力和能的最小模式跟随鞍点搜索，找到了反应机制。用谐波过渡态理论计算了反应速率。动力学遵循从 CH(3)OH、CH(3)O、CH(2)O、HCO，最终到 CO 的途径。我们的计算证实，甲醇分解首先从打破 O-H 键开始，然后在脱氢中间体中打破 C-H 键，直到产生 CO。Cu(100)表面的桥位是剪断化学键的活性位。反应中间体在表面上是可移动的，这使得它们能够找到这个活性反应位。这项研究说明了自适应动力学蒙特卡罗方法如何从第一性原理模型化表面化学的动力学。
