Polypyrrole-assisted oxygen electrocatalysis on perovskite oxides
| Autor: | Myeong-Hee Lee, Hyun-Kon Song, Ho-Il Ji, Sihyuk Choi, Hadi Tavassol, Chanseok Kim, Se Hun Joo, Yuju Jeon, Sang Kyu Kwak, Dong-Gyu Lee, Su Hwan Kim, Guntae Kim |
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| Rok vydání: | 2017 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Inorganic chemistry Oxide Oxygen evolution chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Polypyrrole Electrocatalyst 01 natural sciences Pollution Nitrogen Oxygen 0104 chemical sciences Catalysis chemistry.chemical_compound Nuclear Energy and Engineering chemistry Environmental Chemistry 0210 nano-technology Perovskite (structure) |
| Zdroj: | Energy & Environmental Science. 10:523-527 |
| ISSN: | 1754-5706 1754-5692 |
| Popis: | Nitrogen-containing electrocatalysts, such as metal–nitrogen–carbon (M–N–C) composites and nitrogen-doped carbons, are known to exhibit high activities for an oxygen reduction reaction (ORR). Moreover, even if the mechanism by which nitrogen improves the activities is not completely understood, a strong electronic interaction between nitrogen and active sites has been found in these composites. Herein, we demonstrate a case in which nitrogen improves the electroactivity, but in the absence of a strong interaction with other components. The overpotentials of the ORR and oxygen evolution reaction (OER) on perovskite oxide catalysts were significantly reduced simply by mixing the catalyst particles with polypyrrole/carbon composites (pPy/C). Any strong interactions between pPy (a nitrogen-containing compound) and active sites of the catalysts are not confirmed. A scenario based on the sequential task allocation between pPy and oxide catalysts for the ORR was proposed: (1) molecular oxygen is incorporated into pPy as a form of superoxide (pPy^+O2^−), (2) the superoxide is transferred to the active sites of perovskite catalysts, and (3) the superoxide is completely reduced along the 4e ORR process. |
| Databáze: | OpenAIRE |
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