Keywords: hydrogen storage, oxyhydrides, anionic vacancies, ceria, nickel oxide, hydrogen reservoirs, aluminium, hydrogen species
Hydrogen species in CeNi1OY and CeAl0.5Ni1OY mixed oxides' catalytic hydrogen reservoirs
The interaction of hydrogen with cerium nickel and aluminium-based mixed oxides (CeNi1OY and CeAl0.5Ni1OY) has been studied by catalytic hydrogenation and Inelastic Neutron Scattering (INS). The mixed oxides are large catalytic hydrogen reservoirs called oxyhydrides and the presence of Al allows increasing hydrogen storage and giving the system better stability, in particular, with increasing temperature. Neutron spectroscopy of the solids studied indicates the coexistence of different hydrogen species that can be assigned to hydride species, hydrogen species in interaction with metallic nickel, as well as hydrogen species from hydroxyl groups. The mobility and reactivity of these hydrogen species have been analysed and discussed.