Ni/SiO2 catalysts with Ni content up to 50 wt.% were prepared by depositing nickel hydroxides in a sol-gel-derived wet silica gel, where nickel hydroxides were produced by the increase in pH due to the decomposition of urea. The Ni dispersion in the resulting catalysts is relatively high, and increases monotonically with increasing Ni content up to 40 wt.%. The Ni/SiO2 catalysts have large volume and large-sized mesopores at <= 20 wt.% Ni-loading, and have high thermal stability. In the CO2-reforming of methane, the catalytic activity proportionally increases with increasing Ni content at reaction temperatures between 500 and 900 degrees C. High and steady catalytic activity is achieved when we use the Ni/SiO2 catalysts with Ni content of 20 wt.% under the reaction conditions of high space-time velocity and high temperature. (c) 2005 Elsevier B.V. All rights reserved.