Density functional theory study of methyl iodide adsorption and dissociation on clean and K-promoted β-Mo2C surfaces

Abstract

We have studied the effect of K on the adsorption and dissociation of methyl iodide on the β-Mo2C(001) surface using density functional theory calculations, and the results were compared with experimental data. The most favorable sites for methyl iodide adsorption are 3-fold sites on both clean and K-promoted surface. The changes in the work function fit our model as the molecule withdraws charge from the surface. The C-I bond weakens when the molecule adsorbs on the surface, and this effect is more noticeable on the K-promoted surface. The dissociation to an I adsorbed atom and a methyl group adsorbed is energetically favorable for both surfaces, but there is a lower activation barrier on the K-doped surface. © 2011 American Chemical Society.