Hydrogen represents a notable R&D area due to its impact on short and middle term energy business. implementation of the so-called hydrogen economy still faces some technological breakthroughs. The most predominant belongs to storage; its state of the art is mainly focused on solid-state phenomena through physisorption or chemisorption. it has been found that thermal and acid pre-treatments of carbon nanofibres and activated carbon have opposite effects on hydrogen uptake levels. Thermal pre-treatment enhances hydrogen uptake; nonetheless, acid pre-treatment does not favour hydrogen-carbon interactions. Pd modified thermally-acidic pre-treated carbon materials have reversible hydrogen uptakes at the evaluated condition. on the other hand, Ni and Co modified thermally-acidic pre-treated carbon materials certainly uptake hydrogen, but it is not solely released (H(2)O and CH(4) are produced). (c) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved