Ni/SiO2 catalysts with bimodal pore structure were prepared by the sol-gel method of silicon tetraethoxide and nickel nitrate in the presence of poly(ethylene oxide) (PEO) and urea. The presence of PEO was effective to induce phase separation during the sol-gel process, and through-macropores interconnected three-dimensionally were formed by fixing transitional structure of the phase separation. After gelation, the as-prepared wet gel was aged at 80 degrees C for decomposition of urea in order to increase pH of the solution within the gel. This pH increase led both the ripening of silica gel network through dissolution-reprecipitation and homogeneous deposition of nickel hydroxide. As a result, Ni could be dispersed highly in the silica network. In addition to the high dispersion of Ni, thus prepared Ni/SiO2 has typical bimodal pore structure with size-controllable macropores and mesopores. The bimodal porous Ni/SiO2 also had high thermal stability and showed steady catalytic activity in CO2-reforming of methane at 700 degrees C. (C) 2006 Elsevier Inc. All rights reserved.