Lifting the Pt{100} surface reconstruction through oxygen adsorption:A density functional theory analysis

摘要

The adsorption of atomic oxygen on unreconstructed Pt{100}-(1 X 1) and reconstructed Pt{100}-(5X1) was modeled using density-functional theory in an attempt to understand the relative stability of the unreconstructed phase as a function of oxygen coverage.Our calculations showed that at zero temperature the (5X1) is more stable than the unreconstructed (1 X 1) phase at zero oxygen coverage.However,oxygen absorption on the Pt{100}-(5X1) phase removed the reconstruction,reversing the phase stability.Using thermochemical analysis,we show desorption of oxygen corresponding to a temperature near 730 K,consistent with experimentally observed desorption peaks for oxygen covered (1X1) surfaces.These results have ramifications for understanding the full Pt{100}(1X l)->Pt{100}-hex-R0.7~° surface phase transition.