Interface-confined triangular FeO_x nanoclusters on Pt(111)

Under the oxidizing condition, the cheap metal component of bimetallic catalysts often segregates to the surface and forms oxide nanoclusters (NCs) supported on the metal surface, which exhibit unique structures and catalytic properties drastically different from the corresponding bulk materials. Here, density functional theory calculations are employed to describe the atomic and electronic structures of a series of triangular FeO_x NCs confined on Pt(111) with the size ranging from ∼0.3 nm to ∼2.2 nm, which behave differently from the FeO film reported previously. The lattice of supported FeO_x NCs on Pt(111) is found to vary not only with the NC size but also with the Fe/O ratio or the edge termination. Owing to a strong FeO_x-Pt interaction, the heterogeneous distribution of local atomic and electronic structures of Fe across the FeO_x NC is observed, though most of Fe atoms are positioned at the threefold hollow site of Pt(111). Our study not only sheds light on the catalytically active sites of supported FeO_x NCs but also provides guidance for the design of highly active and stable oxide nanocatalysts under reactive environment.