The adaptive kinetic Monte Carlo method was used to calculate the dynamics of methanol decomposition on Cu(100) at room temperature over a time scale of minutes. Mechanisms of reaction were found using min-mode following saddle point searches based upon forces and energies from density functional theory. Rates of reaction were calculated with harmonic transition state theory. The dynamics followed a pathway from CH3-OH, CH3-O, CH2-O, CH-O and finally C-O. 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.
Revised: April 7, 2011 |
Published: December 31, 2009
Citation
Xu L., D. Mei, and G.A. Henkelman. 2009.Adaptive kinetic Monte Carlo simulation of methanol decomposition on Cu(100).Journal of Chemical Physics 131, no. 24:Art. No. 244520.PNNL-SA-67380.doi:10.1063/1.3281688