DFT study of methanol adsorption and dissociation on β-Mo2C(001)

We have studied the adsorption and dissociation of methanol on beta-Mo2C(001) model surface using density functional theory calculations. We modeled the bulk and the Mo-terminated carbide surface using a four layer slab. Methanol is adsorbed with the OH group pointing towards the surface and the formation of the methoxy specie is energetically favorable after H abstraction. The surface outward dipole moment and adsorption heat computed are in agreement with previous experimental data in chemically analogous systems. The bonding analysis using the crystal orbital overlap population (COOP) curves shows a Mo-Mo weakening upon adsorption and a strong H-Mo interaction after dissociation. (C) 2008 Elsevier B.V. All rights reserved.