Abstract

CHIRINOS, JEANMELYS; MALDONADO, RAINIER; DIAZ, YRAIDA  and  BRITO, JOAQUÍN L. Evaluación de carburos de Mo, Co-Mo Y Ni-Mo soportados sobre Carbón activado para la Hidrodesulfuración de Tiofeno. Rev. Fac. Ing. UCV [online]. 2005, vol.20, n.4, pp.55-60. ISSN 0798-4065.

Mo, Co-Mo, and Ni-Mo catalytic precursors (20 wt% active phase) supported on microporous activated carbon were synthesized by wet impregnation of ammonium heptamolybdate, nickel nitrate and cobalt sulfate solutions. The oxidic precursors were submitted to a carbiding treatment with a 20% CH4/H2 gas mixture, heating at 5ºC/min up to 700ºC. The resulting solids were characterized by X-Ray Diffaction (XRD), Infrared spectroscopy (FT-IR) and surface area measurements (SSA) from nitrogen physisorption data. XRD results indicated that the Co-Mo/CA catalyst suffered the strongest structural changes. FT-IR showed the signals corresponding to the support and the supported species. SSA of the oxidic samples decreased respect to the support, but increased after the carbiding treatment for the Co-Mo/CA sample. Catalysts were presulfided in situ with CS₂/H₂ mixture and evaluated in thiophene hydrodesulfurization at normal pressure and 350ºC, starting from both oxidic and carbided states. The observed thiophene conversions were similar for oxidic and carbided precursors, only the oxidic Ni-Mo/CA sample showed a higher conversion than the carbided sample.

Keywords : HDS; Catalysts,; Carbides; Oxides; Activated Carbon.