CHARACTERIZATION AND ACTIVITY OF UNSUPPORTED NI-MO SULFIDE CATALYSTS IN HDN HDS REACTIONS/

Sulfided Ni-Mo catalysts prepared by homogeneous sulfide precipitation (HSP) and impregnated thiosalt decomposition (ITD) methods were used in thiophene HDS, pyridine HDN, and simultaneous HDS/HDN reactions. Al l catalysts were characterized by BET surface area measurement, X-ray diffraction, laser Raman spectroscopy, and X-ray photoelectron spectro scopy. The effect of various reaction parameters such as catalyst comp osition, method of catalyst synthesis, reaction temperature, and react ion pressure on catalytic behavior has been investigated. The inhibiti on/enhancement effects in simultaneous HDS/HDN reactions were also exa mined. The studies conducted over the unsupported catalysts present tr ends very similar to those obtained over the supported catalysts and s uggest the intrinsic nature of active sites to be essentially independ ent of the support.