In this study, cobalt boride (Co-B) catalysts were prepared on different carbon supports for hydrogen generation from alkaline sodium borohydride (NaBH 4 ). As carbon support, four different types of activated carbon, namely IRH3, Acticarbone3S, GAC250, and AC35, were used. Including 10%, 15%, and 20% weight loadings of Co-B catalysts, they were synthesized with the mentioned activated carbon supports.A variety of techniques, namely inductively coupled plasma optical emission spectrometer, X-ray diffraction, and N 2 adsorpsion-desorption (Brunauer-Emmett-Teller method) analysis were applied for detecting the particles' morphology as well as textural, structural, and other physical properties of materials. The study revealed that crystallinity, porous characteristics, and pore size distribution of activated carbons had very strong effects on Co-B formation on the surface. The hydrogen generation rate increased by increasing Co-B loading. AC35 and GAC250 types of activated carbon supports were more effective than IRH3 and Acticarbone3S counterparts in hydrogen generation from NaBH 4 , which was associated with their morphological structures. K E Y W O R D Sactivated carbon, hydrogen generation, hydrolysis, porous materials, sodium borohydride Int J Chem Kinet. 2018;50:839-845.