HYDRODESULFURIZATION OF THIOPHENE BY TRANSITION-METAL SULFIDES - A MOLECULAR-ORBITAL TOPOLOGY STUDY

Transition metal sulphides have the ability to catalyze the hydrodesul phurization (HDS) process of thiophene and related compounds in the pr esence of hydrogen. We present the results of scattered-wave calculati ons on model catalyst clusters and catalyst-thiophene complexes, which indicate that ppi bonding, between the sulphur atoms in the catalyst and the sulphur and carbon atoms in the thiophene ring, is responsible for binding the thiophene molecule to the catalyst in the initial sta ges of the HDS process.