A systematic survey of the catalytic effect of up to 10 wt% C-60 carbon buckyballs on the kinetics of hydrogen desorption and subsequent absorption of magnesium hydride has been made. It was found that there was an optimum amount of C-60 additive for the best desorption kinetics as well as an optimum time of ball-milling, improving the desorption kinetics over that of ball-milling alone. A comparison with the additive Nb2O5 under the same conditions indicated that desorption kinetic enhancement was relatively minor. The subsequent absorption kinetics were always poorer than the un-catalysed samples. Crown Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.