Neutron-scattering and volumetric study of hydrogen adsorbed and absorbed on Raney palladium

Abstract

The adsorption and absorption of hydrogen on Raney palladium has been studied by inelastic neutron scattering and by volumetry. At low hydrogen pressure (2 mbar) several species are observed by neutron scattering: hydrogen adsorbed on a three-coordinated site, subsurface species and also the α- and β-hydrides. At higher hydrogen pressures (400 mbar) the intensity is dominated by scattering from the α- and β-hydrides. The ease of hydride formation on Raney palladium at low hydrogen pressure is accounted for by the residual aluminium, which acts as an alloy component. On the other hand, the solubility decreases at high hydrogen pressure, compared with pure palladium.