This paper presents the synthesis and characterization of NiO-Al2O3-SiO2 catalysts prepared by co-precipitation method and the catalytic activities estimated for the production of H-2 by CH4 decomposition. The physico-chemical characteristics are evaluated by XRD analysis, TPR and O-2 pulse chemisorption, XPS, CHNS, SEM/EDAX, TEM and BET-surface areas of fresh and used forms of catalysts. XRD studies revealed the presence of hydrotalcite-like precursors in oven dried form and produced dispersed NiO species upon calcination in static air at 450 degrees C. The catalyst compositions for NiO-Al2O3-SiO2 System. are optimized based on various parameters such as varying Ni loadings, change in Al/Si ratios, precipitation at different pH and finally choice of precursors on CH4 decomposition activities. Based on the results it is concluded that the composition of NiO-Al2O3-SiO2 and preparation conditions played a key role in the decomposition of CH4. The optimized compositions are established for the production of H-2 that can be utilized in fuel cell applications. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.