DFT studies on the interaction of Pt_xRu_yM_z (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 Pt_xRu_yM_z (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 Pt_xRu_yM_z–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 Pt_xRu_yM_z 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.

Keywords:

• O₂ dissociation
• ternary alloy clusters
• catalysis

Additional information

Funding

This research was financially supported by National Natural Science Foundation of China [grant number 51277188] and the sharing of Chongqing University's large-scale equipment.