NH3BH3 as an internal hydrogen source for high pressure experiments

Aminoborane NH3BH3 is proposed as an appropriate material to produce hydrogen in the high-pressure cells designed for the synthesis of hydrides in sizeable amounts at pressures of a few GPa and elevated temperatures. Aminoborane is a non-hydroscopic material and it does not noticeably react with air that permits assembling the high-pressure cells under ambient conditions without any precautions. If heated to 300 degrees C at any pressure from 0.6 to 9 GPa, aminoborane decomposes to H-2 gas and chemically inert amorphous BN and does not further absorb the liberated hydrogen. Experiments using NH3BH3 and AIH(3) alternatively as the internal hydrogen source gave coinciding isotherms of hydrogen solubility in rhodium at 600 degrees C and pressures up to 9 GPa therefore demonstrating that the partial pressure of impurities (if any) in the H-2 gas generated by NH3BH3 is well below the accuracy +/- 0.3 GPa of determination of the total gas pressure. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.