International Journal of Hydrogen Energy, Vol.35, No.22, 12234-12238, 2010
Water consumption during solid state sodium borohydride hydrolysis
In this paper nickel acetate catalyzed sodium borohydride cartridges have been prepared and hydrolyzed with water for hydrogen production Two technological solutions have been tested to increase the overall hydrogen yield namely a porous water diffuser and a hydrophobic membrane The first was used to improve water diffusion inside the hydride while the second to confine water inside the cartridge The generated hydrogen flow showed a very reproducible behavior Hydrogen promptly evolved just after water was pumped into the cartridge After some initial peaks a constant hydrogen flow has been recorded for the whole reaction time The constant flow was related to the presence of the porous diffuser The use of a hydrophobic membrane to confine the water inside the cartridge allowed to increase the overall hydrogen yield about 6 water molecules per mol of hydride were required to complete the reaction The reaction product was identified by XRD as Na(2)B(2)O(4)*8H(2)O The cartridge hydrogen gravimetric content based on water and sodium borohydride weight was as high as 4 64% (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved
Keywords:Hydrogen generator;Sodium borohydride;Solid state hydrolysis;porous diffuser;hydrophobic membrane