Ability of hydrogen storage CeNi Ga and MgNi alloys to hydrogenate acetylene.

Abstract

Hydrogen storage properties and reactivity for hydrogenation of acetylene in a series of CeNi Ga ( = 0, 0.5, 0.75, 1, 1.25, 1.5) alloys and MgNi were determined and compared. The structure of CeNi (CaCu type) was maintained up to CeNiGa when Ni was replaced by Ga. The replacement facilitated hydrogenation absorption by creating larger interstitial spaces through expansion of the lattice, allowing CeNiGa to absorb the greatest proportion of hydrogen atoms among the alloys under the same conditions. The results showed that the absorbed hydrogen in CeNiGa improved reactivity. In contrast, MgNi formed a hydride upon hydrogenation of acetylene and thus possessed much lower activity. The difference of the activity of absorbed hydrogen between CeNi Ga and MgNi was confirmed from transient response tests under reaction gases alternately containing He and H.