Inelastic neutron scattering study of hydrogen adsorbed on impure palladium black

Abstract

The incoherent inelastic neutron scattering (i.n.s.) spectra of hydrogen strongly chemisorbed on Pd black (Drijfhout, Amsterdam) have been obtained (77 K) without interference from absorbed or type-C adsorbed hydrogen.The spectra were assigned by comparison with the vibrational spectra of transition-metal hydridocarbonyl compounds and from the change in intensity of the i.n.s. bands with surface coverage. Only coverages greater than one monolayer were studied. The data indicate the occupation by H of two-fold bridging and terminal sites, the relative population of the terminal sites increasing at higher hydrogen coverage.