Jm. Rojo et al., HYDROGEN ADSORPTION ON RHODIUM PARTICLES SUPPORTED ON STRONTIUM-TITANATE AS FOLLOWED BY H-1-NMR AND MICROCALORIMETRY, Journal of physical chemistry, 98(51), 1994, pp. 13631-13635
Hydrogen adsorption on supported rhodium particles has been studied by
H-1 NMR, volumetry, and microcalorimetry techniques, The amounts of h
ydrogen adsorbed on the metal and support have been evaluated. There i
s a good correlation between the shift of the NMR Line assigned to hyd
rogen adsorbed on the metal and the mean integral heat involved in thi
s adsorption. This permits an estimation of differential shifts corres
ponding to each dose. From analysis of differential NMR shift and diff
erential adsorption heat, it is deduced that the hydrogen-metal intera
ction becomes weaker and less energetic with adsorption. This effect i
s discussed on the basis of the heterogeneity of the adsorption sites
and a modification of the electronic properties at the metal surface.