An in-situ Moessbauer study on the formation and stability of the Fe-Mo-S phase in carbon-supported iron molybdenum sulfide HDS catalysts

The transition of an oxidic FeMo/ C precursor i n to the actual active sul fide catalyst is studied by means of in-situ Mossbauer spectroscopy. It is found that the composition of the sulfided catalyst is influenced by t he sulfidation method applied. A correlation between the spectral contribution of a mixed Fe-Mo sulfide (Fe-Mo- 5 ) phase and the activity for thiophene HDS is demonstrated.