Oxygen-Evolution Reaction by a Palladium Foil in the Presence of Iron
| Autor: | Ivan Kondov, Pavlo Aleshkevych, Nader Akbari, Mohammad Mahdi Najafpour, Matthias Vandichel |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
biology
010405 organic chemistry Chemistry Inorganic chemistry Oxygen evolution Active site chemistry.chemical_element Overpotential 010402 general chemistry Electrochemistry 01 natural sciences 0104 chemical sciences Inorganic Chemistry Vacancy defect biology.protein Density functional theory Physical and Theoretical Chemistry FOIL method Palladium |
| Zdroj: | Inorganic Chemistry. 60:5682-5693 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/acs.inorgchem.0c03746 |
| Popis: | Herein, we investigate the oxygen-evolution reaction (OER) and electrochemistry of a Pd foil in the presence of iron under alkaline conditions (pH ≈ 13). As a source of iron, K2FeO4 is employed, which is soluble under alkaline conditions in contrast to many other Fe salts. Immediately after reacting with the Pd foil, [FeO4]2- causes a significant increase in OER and changes in the electrochemistry of Pd. In the absence of this Fe source and under OER, Pd(IV) is stable, and hole accumulation occurs, while in the presence of Fe this accumulation of stored charges can be used for OER. A Density Functional Theory (DFT) based thermodynamic model suggests an oxygen bridge vacancy as an active site on the surface of PdO2 and an OER overpotential of 0.42 V. A substitution of Pd with Fe at this active site reduces the calculated OER overpotential to 0.35 V. The 70 mV decrease in overpotential is in good agreement with the experimentally measured decrease of 60 mV in the onset potential. In the presence of small amounts of Fe salt, our results point toward the Fe doping of PdO2 rather than extra framework FeOx (Fe(OH)3, FeO(OH), and KFeO2) species on top of PdO2 as the active OER sites. |
| Databáze: | OpenAIRE |
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