Verification of the rate-controlling step in the dehydriding reaction of Mg2Ni hydride

The effects of hydrogen pressure and temperature on the dehydration reaction of Mg2Ni hydride were studied. Under relatively high hydrogen pressures, the slow nucleation of the solid solution caused an incubation period at the beginning of the reaction. The dehydration reaction of the hydride progressed with the nucleation and growth mechanism. The rate-controlling step in the reaction was the mass transport of hydrogen molecules through pores, interparticle channel or cracks.