Abstract
The identification and development of efficient catalysts made of non-precious materials for oxygen reduction reaction (ORR) are essential for the successful operation of a wide range of energy devices. This study provides evidence that earth-abundant nanoparticles of transition metals encapsulated in a nitrogen-doped carbon shell (M@N-C, M=Fe, Co, Ni, Cu or Fe alloys) are promising catalysts in acidic solutions. By density functional theory calculations and experimental validations, we quantitatively propose a method of tuning the ORR activity of M@N-C by controlling the nitrogen-doping level, the thickness of the N-C shells and binary alloying. FeCo@N-C/KB was chosen as the best ORR catalyst because of its onset and half-wave potentials of 0.92 and 0.74 V vs a reversible hydrogen electrode (RHE), respectively, and its excellent durability. Furthermore, FeCo@N-C/KB possesses a high activity for the hydrogen evolution reaction (HER; - 0.24 V vs RHE at - 10 mA cm- 2), thus demonstrating that it is a good bi-functional ORR and HER catalyst in acidic media.
Original language | English |
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Article number | e233 |
Journal | NPG Asia Materials |
Volume | 8 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2016 Sep 23 |
All Science Journal Classification (ASJC) codes
- Modelling and Simulation
- Materials Science(all)
- Condensed Matter Physics