Computational study of the adsorption of molecular hydrogen on PdAg, PdAu, PtAg, and PtAu dimers

摘要

The adsorption and dissociation of the H2 molecule on the PdAg, PdAu, PtAg, and PtAu heteronuclear dimers, both isolated and deposited on carbon, were investigated by means of density functional theory. It was found that the Pd and Pt ends of the isolated dimers adsorb H2 more exoenergetically than the Ag and Au ends. The dimers were also deposited on a carbon support and it turned out that they prefer to adsorb on the support by their Pd and Pt ends rather than by the Ag and Au ends. The adsorption of H2 on the carbon-supported dimers is somewhat less exoenergetic than that on the isolated dimers but, after the dissociation of H2, the binding of the H atoms to the dimers remains stronger in the presence of the support.