Resumen

ALDANA, José; CALAFAT, Álvaro  y  SANCHEZ, Nora. Efecto del precursor de níquel en la desactivación de catalizadores de Ni/SiO₂ durante la descomposición termocatalítica de metano a 823 K. Rev. Téc. Ing. Univ. Zulia [online]. 2012, vol.35, n.1, pp.001-003. ISSN 0254-0770.

The effect of the nickel precursor [Ni(NO₃)₂ or Ni(O₂C₂H₃)₂] on deactivation of Ni/SiO₂ catalysts for thermo catalytic decomposition (TCD) of methane at 823 K has been investigated. TCD of methane was studied by the thermogravimetric method, monitoring the mass change of the catalyst due to carbon deposition. The samples were characterized by X-ray diffraction and temperature programmed reduction. The catalysts prepared from Ni(O₂C₂H₃)₂ showed a better performance in TCD of methane compared with those prepared from Ni(NO₃)₂, due to the lower catalyst deactivation constant showed. Ni metal particles tended to disperse during the reaction on the catalysts prepared from Ni(NO₃)₂, while those tended to sinter when catalysts were prepared using Ni(O₂C₂H₃)₂. The capability of the catalytic system to maintain a suitable metal particle size for methane decomposition was related to the metal-support interaction, which was stronger on the catalysts prepared from Ni(O₂C₂H₃)₂. It is suggested that the occurrence of fragmentary dispersion or atomic erosion were the main reason for the rapid deactivation of catalysts prepared from Ni(NO₃)₂.

Palabras clave : methane decomposition; Ni/SiO₂ catalyst; nickel acetate; catalyst deactivation; metal particle size.