Interaction of CH3OH with α-MoO3 finite clusters, a theoretical study

Methanol chemisorption on various faces of molybdenum trioxide are studied by EHT calculations with model clusters. Both energy values and overlap populations show that molecular and dissociative chemisorption can be envisaged. At a distance fixed at 1.75 Å between the surface molybdenum and the methanol oxygen, the stability of the molecular chemisorption complex increases as we pass from the (100) face to the (001) and (010) ones, if the lastmentioned presents an oxygen vacancy before methanol chemisorption. On the (100) and (001) faces containing unsaturated oxygen, dissociative chemisorption leads to states of greater stability than molecular chemisorption. la contrast, if the superficial oxygen involved is saturated, the states obtained are less stable.