Simple Ways to Obtain Activation Energy for Hydride Decomposition by Applying Data from a Volumetric Method to the Kissinger Equation

Abstract

Thermal analysis methods - such as TGA, DSC analysis, DTA, and TDS analysis - have been used in many reports to determine the activation energy for hydride decomposition. In our preceding work, we showed that the dehydriding rate of Mg-5Ni samples obeyed the first-order law and the Kissinger equation could thus be used to determine the activation energy. In the present work, we used the Mg-5Ni samples after activation. We obtained T_m at different heating rates by finding the temperature at which the ratio of the desorbed hydrogen quantity H_d change to T change, dH_d/dT, was the highest from the desorbed hydrogen quantity H_d versus temperature T curves. T_m’s at different heating rates were also obtained from points of inflection (Φ = dT/dt = 0) in temperature T versus time t curves. The activation energy for hydride decomposition was then calculated by applying T_m’s at different heating rates to the Kissinger equation.