Calcined boron–cobalt catalysts, prepared by reduction of cobalt chloride in an aqueous sodium borohydride solution, were applied as components of pelletized solid-state H 2-generating composites based on sodium borohydride. The ferromagnetic catalyst consists of amorphous spherical particles with a mean size of 20 nm, coated with an oxygen-containing shell. A study of the 2 evolution kinetics on adding these formulations into H 2O showed that the heat treatment of the catalyst at 230°С did not affect its performance and the calcination at 500°С and 730°С resulted in a significant decrease in the reaction rate. However, the performance for the catalytic systems studied in hydrolysis of sodium borohydride, calculated per 1 sq cm of the sample surface area, was approximately the same, 0.96 ± 0.12 cu cm of H 2/min. This indicate that the H 2 generation rate in hydrolysis of sodium borohydride correlated with the specific surface area of the catalyst, which is determined by morphological and chemical transformations during calcination.