Resolution of Electronic and Structural Factors Underlying Oxygen-Evolving Performance in Amorphous Cobalt Oxide Catalysts
| Autor: | Sarah R. Soltau, Hacksung Kim, Gihan Kwon, David M. Tiede, David J. Mandia, Alex B. F. Martinson, Hoyoung Jang, Jungho Kim, Anil U. Mane, Jun-Sik Lee, Lisa M. Utschig |
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| Rok vydání: | 2018 |
| Předmět: |
X-ray absorption spectroscopy
Oxygen evolution chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Amorphous solid symbols.namesake chemistry.chemical_compound Crystallography Colloid and Surface Chemistry chemistry Octahedron symbols 0210 nano-technology Raman spectroscopy Cobalt oxide Cobalt Cobalt phosphate |
| Zdroj: | Journal of the American Chemical Society. 140:10710-10720 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.8b02719 |
| Popis: | Non-noble-metal, thin-film oxides are widely investigated as promising catalysts for oxygen evolution reactions (OER). Amorphous cobalt oxide films electrochemically formed in the presence of borate (CoBi) and phosphate (CoPi) share a common cobaltate domain building block, but differ significantly in OER performance that derives from different electron-proton charge transport properties. Here, we use a combination of L edge synchrotron X-ray absorption (XAS), resonant X-ray emission (RXES), resonant inelastic X-ray scattering (RIXS), resonant Raman (RR) scattering, and high-energy X-ray pair distribution function (PDF) analyses that identify electronic and structural factors correlated to the charge transport differences for CoPi and CoBi. The analyses show that CoBi is composed primarily of cobalt in octahedral coordination, whereas CoPi contains approximately 17% tetrahedral Co(II), with the remainder in octahedral coordination. Oxygen-mediated 4 p-3 d hybridization through Co-O-Co bonding was detected by RXES and the intersite dd excitation was observed by RIXS in CoBi, but not in CoPi. RR shows that CoBi resembles a disordered layered LiCoO |
| Databáze: | OpenAIRE |
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