Self-restoring of the active surface in the hydrogen sponge laNi5

Abstract

Photoemission studies combined with measurements of the magnetic susceptibility show that La segregates to the surface of LaNi5 in the presence of O2 or H2O, and the Ni precipitations are formed during hydrogenation. This represents a self-restoring mechanism of the active surface, since the highly reactive La removes the oxygen and keeps the Ni metallic. Dissociative adsorption of H2 may then occur at the Ni atoms. © 1978 The American Physical Society.