Cobalt chloride (CoCl(2)) is one of the most reactive catalysts in the hydrolysis of sodium borohydride (NaBH(4)). The present study reports hydrogen release results for NaBH(4)(-) CoCl(2) systems, both solids having been mixed together via a 'solvent' route Actually, the 'solvent' route using tetrahydrofuran (THF), compared to the mechanical mixing ('mortar' route), improves the CoCl(2) reactivity in terms of catalyst activation time, hydrogen generation rate (HGR) and total conversion. SEM and XRD observations suggest that the 'THF' route favors the ex-situ reduction of Co(2+) to an active cobalt phase Other metal (cobalt or ruthenium) salts are also reported. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.