The Pt-catalyzed carbon nanotubes (CNT(Pt)) synthesized in powder form manifests extremely durable Pt catalytic properties. Compared with traditional Pt nanoparticle catalysts. CNT(Pt) exhibits abnormally increased cyclic voltammerty peak areas versus time. This experimental observation not reported previously is explained by the increased catalytic surface areas resulting from newly created crystalline Pt nanoparticles and nanosheets outside carbon nanotubes during repeated potential cycles. CNT(Pt) can initiate a new phase of the research taking an advantage of combined effects of various properties of CNTs (for example, hydrogen-storage capability) and Pt (for example, high catalytic activity). (C) 2012 Elsevier B.V. All rights reserved.