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DOE OSTI · 1694362

Stable Surface Terminations of a Perovskite Oxyhydride from First-Principles

Wang, Kristen·Fung, Victor·Wu, Zili·Jiang, De-en
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Abstract

Successful synthesis of some perovskite oxyhydrides and their unique catalytic properties have recently attracted researchers’ attention. However, their surface structure remains unclear. Here we identify stable surface terminations of a prototypical perovskite oxyhydride, BaTiO 2.5 H 0.5 , under catalytically relevant temperatures and pressures by using first-principles thermodynamics based on density functional theory. Five low-index facets, including (100), (010), (210), (011), and (211), and their various terminations for a total of 47 different surfaces have been examined for relative stability at different temperatures (700, 500, 300 K) and gas environments (10 –15 ≤ P O2 ≤ 1 atm, 10–15 ≤ PH2 ≤ 100 atm). The most stable ones are found to be (010)-Ba 2 O 2 , (210)-Ti 2 O 2 , and (211)-Ba 2 O 4 H surface terminations. These polar surfaces are stabilized by charge compensation. This work provides important insights into the stable surfaces of perovskite oxyhydrides for future studies of their catalytic properties.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYAnionsLayersPerovskitesStabilitySurface structures

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Wang, Kristen, Fung, Victor, Wu, Zili, Jiang, De-en. 2020-07-27. Stable Surface Terminations of a Perovskite Oxyhydride from First-Principles. https://doi.org/10.1021/acs.jpcc.0c03956

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