Hydroxyapatite-supported palladium(0) nanoclusters as effective and reusable catalyst for hydrogen generation from the hydrolysis of ammonia-borane

Herein we report the preparation, characterization and catalytic use of hydroxyapatite-supported palladium(0) nanoclusters in the hydrolysis of ammonia-borane. Palladium(0) nanoclusters were formed in situ from the reduction of palladium(II) ion exchanged hydroxyapatite during the hydrolysis of ammonia-borane and supported on hydroxyapatite. The hydroxyapatite-supported palladium(0) nanoclusters are stable enough to be isolated as solid materials and characterized by using a combination of advanced analytical techniques. They are isolable, redispersible and reusable as an active catalyst in the hydrolysis of ammonia-borane even at low concentration and temperature. They provide a maximum hydrogen generation rate of similar to 1425 mL H-2 min(-1) (g Pd)(-1) and 12300 turnovers in the hydrolysis of ammonia-borane at 25 +/- 0.1 degrees C before deactivation. The work reported here also includes the full experimental details for the collection of a wealth of kinetic data to determine the activation energy (E-a = 54.8 +/- 2.2 kj/mol) and the effect of catalyst concentration on the rate for the catalytic hydrolysis of ammonia-borane. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.