Hydrotreating on mixed vanadium-nickel sulphides - A study of the synergetic effect

The preparations of pure and mixed vanadium-nickel sulphides were carried o ut by the homogeneous precipitation method (under inert atmosphere). Thioph ene HDS, pyridine HDN, toluene hydrogenation and vanadyl porphyrin HDP, wer e carried out as catalytic tests. The catalysts were also characterized by XPS, TPR, BET surface area and XRD. These solids, after sulphidation proced ure, exhibit a synergetic effect, the importance of which depends on the hy drotreating reaction. The product distributions obtained in the thiophene h ydrodesulphurization and the pyridine hydrodenitrogenation and the activity observed for toluene hydrogenation suggest that the synergy is mainly rela ted to the hydrogenation step. The cause of this synergy could tentatively be assigned to an electronic transfer between the two metallic components i n the mixed sulphides. (C)2000 Elsevier Science B.V. All rights reserved.