The effects of temperature and the concentrations of NaBH(4), NaBO(2) and NaOH on the rate of NaBH(4) hydrolysis over carbon-supported ruthenium catalyst were investigated using isothermal rate data extracted from non-isothermal reactions. It was shown that the hydrolysis was a zero-order reaction with respect to the concentration of NaBH(4) and the reaction rate decreased with the increase in OH(-) concentration. A rate expression was then derived to correlate the hydrolysis rate with the temperature and NaOH concentration. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.