Adsorption of water at the SrO surface of ruthenates
Autor: | Bernhard Stöger, Ulrike Diebold, Wernfried Mayr-Schmölzer, Daniel Halwidl, Florian Mittendorfer, Michael Schmid, Josef Redinger, Jin Peng, David Fobes, Gareth S. Parkinson, Jiri Pavelec, Zhiqiang Mao |
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Jazyk: | angličtina |
Rok vydání: | 2018 |
Předmět: |
Materials science
Oxide FOS: Physical sciences 02 engineering and technology Activation energy 010402 general chemistry 01 natural sciences Article chemistry.chemical_compound Adsorption X-ray photoelectron spectroscopy Monolayer Molecule General Materials Science Perovskite (structure) Condensed Matter - Materials Science Mechanical Engineering Materials Science (cond-mat.mtrl-sci) General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Crystallography chemistry Mechanics of Materials Density functional theory 0210 nano-technology |
Zdroj: | Nature materials |
Popis: | Although perovskite oxides hold promise in applications ranging from solid oxide fuel cells to catalysts, their surface chemistry is poorly understood at the molecular level. Here we follow the formation of the first monolayer of water at the (001) surfaces of Sr$_{n+1}$Ru$_n$O$_{3n+1}$ ($n$ = 1, 2) using low-temperature scanning tunnelling microscopy, X-ray photoelectron spectroscopy, and density functional theory. These layered perovskites cleave between neighbouring SrO planes, yielding almost ideal, rocksalt-like surfaces. An adsorbed monomer dissociates and forms a pair of hydroxide ions. The OH stemming from the original molecule stays trapped at Sr-Sr bridge positions, circling the surface OH with a measured activation energy of 187 $\pm$ 10 meV. At higher coverage, dimers of dissociated water assemble into one-dimensional chains and form a percolating network where water adsorbs molecularly in the gaps. Our work shows the limitations of applying surface chemistry concepts derived for binary rocksalt oxides to perovskites. |
Databáze: | OpenAIRE |
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