DESCOMPOSICIÓN DE METANO CON CATALIZADORES DE Ni, Fe, PROMOVIDOS CON Pd Y SOPORTADOS EN CARBÓN

Abstract

Hydrogen production plays an important role in hydrocarbon desulfurization, methanol and ammonia production, oils and fats acids hydrogenation and other industrial application. However, in the near future its principal application will be as fuel in proton-exchanged membrane fuel cells. Despite the best route to produce pure H2 would be via renewable energy resources, those methods are still too expensive. For this reason, at the beginning of hydrogen production it has to be produced by fossil fuels. This work is focused to hydrogen production by methane catalytic decomposition with Ni-, Fe- carbon supported, as well as Ni-Pd and Fe-Pd supported in commercial activated carbon. The catalysts were synthesized by incipient impregnation and photoassisted methods. The characterization was carried out by X-ray diffraction, temperature programmed reduction (RTP), UV-Vis spectroscopy, Raman spectroscopy (ER), X-ray photoelectronic spectroscopy (XPS), Mössbauer spectroscopy (MS) and transmission electronic microscopy (TEM). The catalysts were tested in a fix bed reactor at atmospheric pressure with temperatures in the range of 500-620 °C. The effluent gas mix was analyzed with a gas chromatograph on line. Ni, Fe catalysts showed good dispersion on carbon support with particle size of 10 nm for nickel catalyst (15 wt%). The surface composition of the catalysts was determinate by XPS was found Ni, NiO and Fe, FeO, Fe2O3, Fe3O4 phases for Ni, Fe catalysts, respectively. Iron catalyst shown better activity than Ni catalysts in methane catalytic decomposition. The nickel catalysts synthesized by impregnation method were more active than catalysts by photodeposition method; this could be possible by encapsulation of active particles in the latter catalysts. Ni-Pd catalyst synthesized by impregnation method shown the best results in methane catalytic decomposition with a conversion value of 12% at 620 °C, because the good dispersion and the small particle size in the catalyst.