Pressure differential scanning calorimetry (PDSC) has been used to study the applicability of six hydrogen absorbing pseudobinary AB(5) and AB(2) alloys for near ambient temperature (10-50 degrees C) and atmospheric pressure (1-10...20 bar) applications. Van't Hoff plots of the materials have been determined From thermal absorption and desorption peak positions at different pressures. The pressure and temperature ranges were 1-70 bar and 20-150 degrees C, respectively.
A large hysteresis effect acid sloping P-C-T plateaux are the most serious problems of MmNi(4.5)Mn(0.45)Zr(0.05) and Zr0.7Ti0.3MnFe. La1-xNdxNi5(x = 0.05-0.1), LmNi(1) (JMC) and Hydralloy C15 (GfE) are all well-suited for the pressure and temperature ranges mentioned above. Zr(Fe0.75Cr0.25)(2) suffers both From hysteresis and sloping P-C-T. plateaux, but it can be used as a hydrogen storage material between an electrolyzer and a fuel cell, especially if the temperature range can be slightly narrowed.