PYRIDINE INTERACTION WITH A PARTIALLY HYDROGENATED MOS2 MODELED SURFACE - A MOLECULAR-ORBITAL STUDY

Chemisorption of pyridine on a partially hydrogenated surface of MoS2 was modelled by the interaction of a pyridine molecule with a Mo3S8H2 cluster. Calculation of total energies, bond orders, diatomic energies , charge transferences and interatomic orbital overlaps was performed by the CNDO/UHF method. Results show a net charge transfer from the py ridine molecule to the Mo adsorption center. The interaction of pi-ads orbed pyridine with chemisorbed hydrogen bridged on Mo-Mo positions le ads to a partial hydrogenation of the nitrogen compound. A mechanism o f pyridine hydrogenation is proposed based on the fact that Mo adsorpt ion centers (vacancies) are pivotal for hydrogen atoms transfer. These results suggest a regioselective hydrogenation.