Determination of the Activation Energy for Hydride Decomposition Using a Sieverts-Type Apparatus and the Kissinger Equation

We developed a method to determine the activation energy for hydride decomposition using a Sieverts-type apparatus and the Kissinger equation, not using thermal analysis methods. The quantity of hydrogen released from the sample and the temperature of the reactor were first measured as a function of time at different heating rates (phi) in a Sieverts-type apparatus. The dehydriding rates were calculated according to time and the temperature T-m (at which the dehydriding rate was the highest). phi and T-m were then applied to the Kissinger equation. The dehydriding rate of Mg-5Ni samples obeyed a first-order law, and the Kissinger equation could thus be used to determine the activation energy. On a heating rate of 3 K/min, the decomposition rate of hydride was the highest at 590.0 K. From a plot of ln (phi/T-m(2)) versus 1/T-m, the obtained activation energy for hydride decomposition was 174 kJ/mole.

Automated summary

We developed a method to determine the activation energy for hydride decomposition using a Sieverts-type apparatus and the Kissinger equation. The dehydriding rates were calculated based on measurements of hydrogen released and reactor temperature, and the Kissinger equation was applied to determine the activation energy.