DFT studies on the interaction of PtxRuyMz (M = Fe, Ni, Cu, Mo, Sn, x + y + z = 4, x ≥ 1, y ≥ 1) alloy clusters with O2

Abstract

The reaction mechanism of O2 dissociation on PtxRuyMz (M = Fe, Ni, Cu, Mo, Sn, x + y + z = 4, x ≥ 1, y ≥ 1) alloy catalysts have been investigated with density functional theory calculations in this work. For bare alloy clusters, bimetallic clusters are more stable than the ternary alloy clusters. The geometries of the PtxRuyMz–O2 system, O–O bond stretching frequency and electronic-structure details have been investigated. The energies of O2 adsorption on PtRu clusters are slightly higher than those on PtxRuyMz clusters, and the more charge transfer to O2 from the metal cluster, the higher O2 the adsorption energy obtains. The reaction barriers show that the catalytic performance of trimetallic clusters are better than those of bimetallic clusters, and Pt2RuM clusters exhibit superior catalytic activity for O2 dissociation. The different performance of these alloy clusters for O2 dissociation is scrutinised with aid of molecular orbital and natural bond orbital population analysis.