PYRIDINE ADSORPTION ON A MOS2 MODELED SURFACE (MO3S8) - A CNDO MOLECULAR-ORBITAL STUDY

Qualitative molecular orbital calculations (CNDO) were carried out for the interaction of a pyridine molecule on a modelled MoS2 surface by a Mo3S8 cluster. Different adsorption modes and adsorption sites were explored. The results show that pi-adsorption is more energetically fa vored than sigma-one. Parallel adsorption produces the activation of C -C and C-N bonds suggesting an irreversible chemisorption with a subse quent fragmentation of the pyridine molecule. A charge transfer from t he pyridine to the MoS2 system occurs after chemisorption mainly in th e pi-adsorption. It is proposed that the sigma-adsorption, which is re sponsible for hydrogenation of the pyridine molecule, results favored after the formation of molecular fragments from pi-adsorption.