Quantity of NH3 desorption from the Li-N-H hydrogen storage system examined by Fourier transform infrared spectroscopy

A mixture of LiNH2 and LiH is one of the complex hydride systems for hydrogen storage, and desorbs H-2 with a small amount of NH3 as a contaminant. NH3 impurity in the H-2 stream for polymer electrolyte membrane fuel cells causes poisoning of the cells, which is severe problem for the application. In this work, NH3 and H-2 partial pressures in the desorbed gas from LiH + LiNH2 + l mol% TiCl3 in a closed system were quantitatively estimated by infrared spectroscopy and gas chromatography analysis. H-2 and NH3 were significantly desorbed in the high-temperature range of 300-400 degrees C, and the NH3/H-2 ratio was on the order of 0.1 % in this temperature range. (C) 2007 Elsevier B.V. All rights reserved.