Papers by Author: Young Whan Cho

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 NaAlH4 by reducing the dehydrogenation temperature and improving the dehydrogenation kinetics. Although the catalytic effect of Ti5Si3 is not better than that of TiCl3, the Ti5Si3 catalyst has an advantage over TiCl3 in terms of hydrogen capacity by releasing more hydrogen than TiCl3 during dehydrogenation. NaAlH4 catalyzed with Ti5Si3 shows reversible hydrogen storage by being hydrogenated at moderate conditions, although the hydrogenation kinetics is rather slow.

Abstract: The hydrogenation characteristics and embrittlement behavior of Ti50Zr(50-x)Cux alloys (x=25,33,40) are reported. The hydrogenation kinetics decreased with increasing Zr-content. Though the Ti50Zr25Cu25 alloy showed the slowest kinetics, it absorbed large amount of hydrogen (~2.4 wt.%) and exhibited the best resistance against hydrogen embrittlement. The excellent characteristics of Ti- Zr-Cu alloys in hydrogen environment indicated that they are promising materials in future for energy applications.