Methane oxidation reactions on MoO3(100):: A theoretical study

A molecular orbital study of methane oxidation reactions on the (100) surface of MoO3 is made. The adsorption energy for the molecular species or fragments has been computed using a methodology based on the atom superposition and electron delocalization molecular orbital (ASED-MO) theory. Calculations were performed using a bulk superimposable Mo30O107-34 cluster model. Different sequences and sites for H abstraction from methane were explored on layers exposing molybdenum or oxygen atoms. The oxygen coordination and the geometric arrangements for the adsorbed species were analyzed. The process appears to be endothermic. The formation of oxygenated products such as formaldehyde, CO and CO2 is also addressed. Our results are in good agreement with recent literature reports, showing that total oxidation of methane is difficult to achieve. (C) 1998 Elsevier Science B.V.