O2 adsorbed on Ptn clusters: Structure and optical absorption

The interaction of O-2 with Pt-n and the optical absorption properties of PtnO2 were explored under the framework of density functional theory. The Pt-n (n= 2, 4, 6, 9, 10, 14, 18, 22, and 27) clusters were selected, which were reported as magnetic number Ptn clusters in reference (V. Kumar and Y. Kawazoe, Phys. Rev. B 77(20), 205418 (2008)). The single Pt atom was also considered. The longest O-2 bonds were found for Pt27O2, Pt6O2 and Pt14O2, while PtO2 and Pt2O2 have the shortest O-2 bonds. This result showed that the single Pt atom was not preferred for O-2 activation. The O-2 bond length was closely related to the electron transfer from Pt-n to O-2. The optical absorptions of PtnO2 were investigated with time-dependent density functional theory method. A new term of charge transfer strength was defined to estimate the further electron transfer from Pt-n to O-2 caused by the optical absorption in the visible light range. Our calculations showed that with the increasing n, the further electron transfer from Pt-n to O-2 caused by optical absorption will become very weak. (C) 2018 Author(s).