The behavior of two different catalytic precursors based on iron (FeSO4 . 7H(2)O and Fe2O3) in direct hydroconversion of two coals are studied in this paper. Coal itself was the catalytic support of the dispersed iron sulfide (from iron sulfate); when the catalyst precursor was iron oxide (from red mud), coal and catalyst were directly mixed as powders. The reaction conditions were : 10 MPa (H-2, cold) initial pressure, 30 min, and reaction temperatures of 300, 350, 400, and 425 degrees C, reaching 450 and 500 degrees C for the high-rank coal. The results from Mossbauer spectroscopy demonstrate that pyrite in all the runs, inherent to coal or added as catalyst precursor, is converted into pyrrhotite to a variable extent according to the previous iron distribution and the iron chemical state in the catalyst precursors as well as the CS2 addition. Important chemical and physical transformations of catalysts are observed by XRD and SEM-EDX during the reaction. The catalytic performance seems to be due to the transformation of pyrite into pyrrhotite, to the H2S homogeneous catalysis and, when red mud was the catalytic precursor, to an acid behavior. The red mud exhibited a behavior which deserved particular study for its dependence on composition and acid characteristics.