International Journal of Hydrogen Energy, Vol.41, No.41, 18484-18493, 2016
Ni/CeO2-Al2O3 catalysts for methane thermo-catalytic decomposition to COx-free H-2 production
The effect of ceria addition to alumina on the catalytic performance of the active NiO particle has been investigated during methane decomposition to CO/CO2 free H-2 production. The CeO2-Al2O3 supports with different CeO2 loading were prepared by co-precipitation and loaded with 50 wt% Ni by incipit wetness impregnation method. The catalysts were characterized by XRD, HRTEM, BET, TPR and Raman spectroscopy. The results revealed that the catalytic activity was strongly depended on the ceria content in the catalyst. The highest. methane decomposition to H-2 was achieved over the Ni/Ce-25-Al-75 catalyst. TEM images illustrated that, various kinds of carbon nano-structured materials were obtained on the catalyst surface according to the Ce content. Carbon nanofiber (CNF) and graphene films (GF) were formed on the surface of Al2O3 , Ni/Ce-25-Al-75 , Ce-50-Al-30 and Ce-75-Al-25 supported Ni catalysts. While only multi-walled carbon nanotubes (MWCNT) was obtained on Ni/Ce catalyst. The formation of Ni-O-Ce solid solution induced highly dispersed Ni particles with relatively small sizes, leading to the growth of filamentous carbon. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.