Hydrolytic cleavage of ammonia-borane complex for hydrogen production

A new process for generating hydrogen via near room temperature hydrolysis of AB complex using small amounts of platinum group metal catalyst has been studied. Using in situ B-11 NMR spectroscopy, the overall rate of K2Cl6Pt catalyzed hydrolysis of AB complex was calculated to be third-order. The pre-exponential factor (A) and the activation energy (E-a) of Arrhenius equation, In k = In A - E(a)lRT, were determined to be: A = 1.6 x 10(11) L mol(-1) s(-1) and E-a = 86.6 kJ mol(-1) for temperature range of (25-35 degrees C). X-ray photoelectron spectroscopy of the residue suggested that the platinum salt was reduced from Pt4+ to P-t0 within the course of the reaction and X-ray diffraction analysis pattern for the residue showed crystallized single-phase boric acid. (C) 2007 Published by Elsevier B.V