Hydrogen generation from solid-state pellets of sodium borohydride with cobalt boride catalysts has been studied. The nature of the reducing agent (NaBH4, NH3 BH3) and the catalyst precursor (CoCl2 center dot 6H(2)O, Co3O4) was shown to have a substantial influence on the rate of hydrogen evolution. The effect of pH on the activity of the catalysts added to the solid-state pellets of sodium borohydride was estimated. It was found that the cobalt catalysts formed under the action of sodium borohydride undergo strong changes in an alkali medium due to boron leaching from cobalt boride and formation of low active Co-0 and Co(OH)(2). (C) 2014 Elsevier B.V. All rights reserved.