INTERACTION OF THIOPHENE WITH A MOLYBDENUM-DISULFIDE CATALYST - AN INELASTIC NEUTRON-SCATTERING STUDY

The inelastic neutron scattering (INS) spectra of thiophene adsorbed o n MoS2/alumina catalysts are compared with the spectrum of free thioph ene. Changes in the vibrational modes of thiophene due to interaction of thiophene with the catalyst are observed. On the sulfided not-reduc ed catalyst out-of-plane C-H motions of thiophene are modified. On the reduced catalyst in-plane motions of alpha-H's are also modified. Evi dently the thiophene molecules lie flat on the sulfided catalyst and, in addition on the reduced catalyst, bind to the exposed molybdenum ce ntre through ring sulfur with consequent modification of the alpha-H m otions.