Title

Lifting the Pt{100} Surface Reconstruction Through Oxygen Adsorption: A DFT Analysis

Document Type

Article

Subject Area(s)

Engineering, Chemical Engineering, Catalysis and Reaction Engineering, Membrane Science

Abstract

The adsorption of atomic oxygen on unreconstructed Pt{100}-(1×1)" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">Pt{100}-(1×1)Pt{100}-(1×1) and reconstructedPt{100}-(5×1)" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">Pt{100}-(5×1)Pt{100}-(5×1) 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 (5×1)" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">(5×1)(5×1) is more stable than the unreconstructed (1×1)" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">(1×1)(1×1) phase at zero oxygen coverage. However, oxygen absorption on the Pt{100}-(5×1)" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">Pt{100}-(5×1)Pt{100}-(5×1) 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 (1×1)" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">(1×1)(1×1)surfaces. These results have ramifications for understanding the full Pt{100}(1×1)→Pt{100}" role="presentation" style="box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative;">Pt{100}(1×1)→Pt{100}Pt{100}(1×1)→Pt{100}-hex-R0.7° surface phase transition.