Novel composites of porous SiO2-LP and SiO2-HP supports are synthesized by the silica–polyethylene glycol monooleyl ether surfactant self-assembly method to obtain a large surface area. Cobalt is immobilized in the supports by incipient wetness impregnation. A stable and active Co/SiO2 catalyst is examined using FE-SEM, BET and XRD. Further, the catalyst is tested for catalytic hydrolysis of alkaline sodium borohydride (NaBH4) solution: the rate of hydrogen generation is found to increase with increasing cobalt loading of the Co/SiO2 catalyst. The hydrogen generation rates increase dramatically when the temperature is increased from 17 to 40 °C. The highest hydrogen generation rates of Co/SiO2 catalyst are obtained at 2513 mL min− 1 g− 1 in 20 mL of 5 wt.% NaBH4 solution containing 5 wt.% NaOH at 40 °C.