Rate limiting steps of the phase transformations in Ti-dopedNaAlH4investigated by isotope exchange

The sorption kinetics of Ti-doped $\mathrm{Na}\mathrm{Al}{\mathrm{H}}_{4}$ has been investigated under the aspect of the replacement of hydrogen by deuterium. For both desorption and absorption, kinetics is found to be slower in the deuterated than in the protonated samples. Comparison of the apparent activation energies and the prefactors indicates that a hydrogen-containing species heavier than H determines the reaction rate.