Thermodynamics of the formation of surface PtO stripes on Pt(111) in the absence of subsurface oxygen
This paper examines the thermodynamics of PtO 2 stripes formed as intermediates of Pt(111) surface oxidation as a function of the degree of dilation parallel to the stripes, using density functional theory and atomistic thermodynamics. Internal energy calculations predict 7/8 and 8/9 stripe structur...
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| Published in | Physical chemistry chemical physics : PCCP Vol. 22; no. 19; pp. 1634 - 164 |
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| Main Authors | , , , |
| Format | Journal Article |
| Language | English |
| Published |
20.05.2020
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| Online Access | Get full text |
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| Summary: | This paper examines the thermodynamics of PtO
2
stripes formed as intermediates of Pt(111) surface oxidation as a function of the degree of dilation parallel to the stripes, using density functional theory and atomistic thermodynamics. Internal energy calculations predict 7/8 and 8/9 stripe structures to dominate at standard temperature and pressure, which contain 7 or 8 elevated PtO
2
units per 8 or 9 supporting surface Pt atoms, respectively. Moreover, we found a thermodynamic optimum with respect to mean in-stripe Pt-Pt spacing close to that of α-PtO
2
. Vibrational zero point energies, including bulk layer contributions, make a small but significant contribution to the stripe free energies, leading to the 6/7 stripe being most stable, although the 7/8 structure is still close in free energy. These findings correspond closely to experimental observations, providing insight into the driving force for oxide stripe formation and structure as the initial intermediate of platinum surface oxidation, and aiding our understanding of platinum catalysts and surface roughening under oxidative conditions.
This paper examines the thermodynamics of PtO
2
stripes formed as intermediates of Pt(111) surface oxidation as a function of the degree of dilation parallel to the stripes, using density functional theory and atomistic thermodynamics. |
|---|---|
| Bibliography: | 33 Electronic supplementary information (ESI) available: Thermodynamics of stripe formation and free molecules, computational details of DFT calculations and stripe geometries, DFT formation energies and corrections for free molecules, surface and stripe vibrational analysis including bulk modes, formation energies of PtO 2 structures under standard conditions, and stripe formation energies with respect to Pt binding energies. All calculations are performed at 300 K, and simulations were performed using the PBE exchange-correlation functional through VASP. All structural images were rendered using VESTA. See DOI 10.1039/c9cp05107d |
| ISSN: | 1463-9076 1463-9084 |
| DOI: | 10.1039/c9cp05107d |