Synthesis gas production from dry reforming of methane over Ni/Al2O3 stabilized by ZrO2

The effect of zirconia as a promoter and catalyst preparation method for Ni/Al2O3 on catalyst activity and coke inhibition was investigated for the reforming of CH4 by CO2. The performance of the promoted catalyst prepared by co-impregnation and sequential impregnation methods with different loadings of ZrO2 was compared. The addition of ZrO2 greatly improved the stability of Ni/Al2O3 catalyst in terms of coke inhibition by enhancing the dissociation of oxygen intermediates, which then react with carbonaceous species formed over the metal. The rate of catalyst deactivation due to coke deposition for the sequential impregnated catalyst was lower compared to the co-impregnated catalyst at the same promoter loading. For the co-impregnated catalyst, ZrO2 loading did not substantially affect the catalyst stability, while the low promoter loading in sequentially impregnated catalyst was much more stable than the high loading. The 7% ZrO2 loaded in Ni/Al2O3 by sequential impregnation yielded the most stable catalyst for a dry reforming reaction. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.