Density Functional Theory Study of Methyl Iodide Adsorption and Dissociation on Clean and K-Promoted b-Mo2C Surfaces

M. E. PRONSATO; C. PISTONESI; A. JUAN; A. P. FARKAS; L. BUGYI; F. SOLYMOSI

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Año: 2011 vol. 115 p. 2798 - 2804

1932-7447

We have studied the effect of K on the adsorption and dis sociation of methyl iodide on the b-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.