Catalytic reduction of SO by CO over AuPt(CO) and AuPt(CO) clusters: a first-principles study.

The catalytic properties of the magic gold-platinum bimetallic clusters (AuPt and AuPt) for the reduction of SO by CO, without or with preadsorbing CO molecules, are firstly investigated using density functional theory calculations. We find that the catalytic activities improve effectively with the preadsorption of CO onto the catalysts and that the catalytic activities of AuPt(CO) are better than those of AuPt(CO) as more CO molecules are adsorbed onto the catalysts. During the reaction process, the AuPt(CO) clusters always keep two-dimensional morphologies except for when n = 5 and the AuPt(CO) clusters have three-dimensional geometries except for when n = 0. The most stable adsorption site for SO molecules on the catalysts is the site of preadsorbing the next CO molecule on the corresponding catalysts. The largest activation energy (E) is related to the metal 5d (M-5d) band center and the charge transfer (C) as well as the bond length (R) between COS and the catalyst contribute to the desorption energy (E) of COS corporately. We propose that AuPt(CO) is a cost-effective gold-platinum bimetallic catalyst for the reduction of SO by CO.