Abstract
Catalyst activity and stability for CO2 reforming of CH4 depends specifically upon the support and the active metal. A side reaction of dry reforming of methane is the decomposition to carbon that covers the Ni particles causing catalyst deactivation. Hence, an appropriate combination of Ni with support is needed to allow for long term stable operation. In this paper, CO2 reforming of CH4 is studied by investigating the effect of addition of TiO2-P.25 separately to gamma-Al2O3 and alpha-Al2O3 supports used for nickel based catalyst. The reforming reactions are performed using (CO2:CH4) feed ratio of 1:1 and reaction temperature range of 500-800 degrees C. Both fresh and used catalysts are characterized by SEM and TGA techniques. It is found when alpha-Al2O3 support is modified with 20 wt% TiO2-P25, the catalyst activity and stability is enhanced. The conversion rates of CH4 and CO2 without and with 20 wt% TiO2-P25. respectively, are changed from 72.3% to 76.7% and 73.3% to 81.2%, respectively, and, most importantly, carbon formation is reduced from 28.1 to 12.8, respectively. However, when gamma-Al2O3 support is modified with TiO2-P25, the catalyst activity is enhanced with simultaneous increase in carbon formation. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.