Hydrogen oxidation on ordered intermetallic phases of platinum and tin – A combined experimental and theoretical study

Hydrogen oxidation on the surfaces of the intermetallic compounds Pt3Sn, PtSn and PtSn2 has been studied by the rotating disc electrode technique. Pt3Sn and PtSn were found to be good catalysts, about as good as Pt, while PtSn2 was inactive over the investigated range of potentials. Underpotential deposition of hydrogen is observed only on Pt3Sn. These results are explained by theoretical calculations based on a theory developed within our own group, and by density functional theory.

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► The intermetallic compounds Pt3Sn, PtSn and PtSn2 are interesting potential catalysts for several reactions.
► Experimentally we have found that hydrogen oxidation occurs on Pt3Sn and PtSn with about the same speed as on pure platinum, while PtSn2 shows no activity at low overpotentials.
► Only Pt3Sn adsorbs hydrogen before the onset potential for hydrogen evolution.
► These findings are explained by a theory developed in our group.