Abstract

SIERRA GALLEGO, Germán; BATIOT-DUPEYRAT, Catherine; BARRAULT, Joël  and  MONDRAGON, Fanor. Hydrogen and carbon nanotubes production by methane decomposition over Ni°/La₂O₃ obtainedfrom LaNiO_3-δ erovskite. Rev.fac.ing.univ. Antioquia [online]. 2008, n.44, pp. 07-19. ISSN 0120-6230.

LaNiO₃ perovskite, both reduced and non-reduced, was evaluated in the decomposition of methane at 600°C and 700°C. The Ni°/La₂O₃ obtained by reduction of LaNiO₃ showed the largest methane decomposition activity and also the highest yield of hydrogen and carbon nanotubes (CNTs): 18 LH₂ /(gcat h) and 2.2 g CNT/(g cat h), respectively. To our knowledge, these figures are among the highest values reported in the scientific literature. When non-reduced perovskite was used, the conversions and yields of CNTs were about 4 times lower than those with reduced catalyst. Multi walled carbon nanotubes were characterized by X-ray diffraction, surface area, transmission electron microscopy (TEM), scanning electron microscopy, thermogravimetric analysis, and Raman spectroscopy. TEM micrographs showed that the CNTs were multi-walled, with inner diameters ranging from 5 to 16 nm, external diameters up to about 40 nm, and several microns in length.

Keywords : Methane decomposition; CNTs; hydrogen production; perovskites.