Thin films of Co-B prepared by pulsed laser deposition as efficient catalysts in hydrogen producing reactions

Hydrogen generation by catalytic hydrolysis of sodium borohydride (NaBH4) is studied by using Co-B-based thin film catalyst synthesized by pulsed laser deposition (PLD) technique. Co-B nanoparticles, produced in the catalyst film after the laser ablation process, act as active centers producing significantly higher Hz generation rate than Co-B bulk powder. Surface morphology was studied by using scanning electron microscopy and compositional analysis was established by using X-photoelectron and infrared spectroscopies. Films were deposited at different PLD set-up parameters in order to understand the possible role of size and density of the nanoparticles in the catalytic process. Cobalt has been found here to act as an efficient catalyst only when alloyed with boron which partially prevents cobalt oxidation. In particular we report that when used as suitable thin films, Co-B produces H-2 with a maximum generation rate of about 3300 ml/min per gram of catalyst. (C) 2007 Elsevier B.V. All rights reserved.