Abstract
Constructing highly efficient and cost-effective catalysts for neutral oxygen reduction reaction (ORR) remains extremely challenging due to the sluggish reaction kinetics resulting from the low ionic conductivity and limited OH− concentration in the neutral electrolytes. Herein, we intentionally integrate the atomic Fe-N4 sites and Fe nanoclusters on N-doped multimodally porous carbon (FeSA+NC@NMPC) to achieve coherent optimization of rapid oxygen-containing intermediate conversions and fast water dissociation to provide abundant protons for boosting neutral ORR performance. As expected, the FeSA+NC@NMPC exhibits an excellent half-wave potential of 0.76 V in 0.1 M phosphate buffer solutions, outperforming that of commercial Pt/C (0.73 V). Theoretical calculations reveal the synergistic effect between atomic Fe-N4 sites and Fe nanoclusters, in which the former possess stable O2 adsorption and rapid intermediate conversion, while the latter facilitates fast water dissociation to supply protons for accelerating the proton-coupled electron transfer process. Moreover, the FeSA+NC@NMPC-based neutral zinc-air batteries afford a high open-circuit potential of 1.42 V and outstanding cycling stability at 5 mA cm−2 for 100 h. This work utilizes the advantages of both single sites and clusters of Fe to provide an in-depth understanding of the neutral ORR mechanism and advances the development of related energy storage and conversion technologies.
Original language | English |
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Article number | 146065 |
Journal | Chemical Engineering Journal |
Volume | 475 |
DOIs | |
Publication status | Published - 1 Nov 2023 |
Keywords
- Fe single atomic sites
- Neutral Zinc-air batteries
- Oxygen reduction reaction
- Synergistic effect
- Water dissociation
ASJC Scopus subject areas
- General Chemistry
- Environmental Chemistry
- General Chemical Engineering
- Industrial and Manufacturing Engineering