Electrodeposition was used to deposit cobalt over polycarbonate membrane (PCM), which was used as stable supported catalyst in hydrolysis of sodium borohydride NaBH(4). We selected PCM as support owing to its lightness, easy handling, stability, and porous structure with nanosized channels. Our primary objective was to obtain a catalytic film resistant to both physical degradation and delamination while H(2) bubbled on its surface. A thin film consisting of mushroom-like cobalt nanoarchitectures were prepared. By SEM, we observed that it is strongly embedded into the PCM thickness, with the anchoring occurring through the channels. This shaped catalyst was mechanically stable and did not show degradation during the reaction. The main results are reported and discussed in details herein. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.