Catalytic effect of Ti5Si3 on dehydrogenation of NaAlH4

Abstract

Fine Ti5Si3 powder has been synthesized from a mixture of elemental Ti and Si powders using a mechanochemical method. It shows a good catalytic effect on NaAIH(4) by reducing the dehydrogenation temperature and improving the dehydrogenation kinetics. Although the catalytic effect of Ti5Si3 is not better than that of TiCI3, the Ti5Si3 catalyst has an advantage over TiCI3 in terms of hydrogen capacity by releasing more hydrogen than TiCI3 during dehydrogenation. NaAIH(4) catalyzed with Ti5Si3 shows reversible hydrogen storage by being hydrogenated at moderate conditions, although the hydrogenation kinetics is rather slow.