Oxygen reduction reaction mechanism on a phosporus-doped pyrolyzed graphitic Fe/N/C catalyst
The oxygen reduction reaction (ORR) mechanism on the active sites of a phosphorus-doped pyrolyzed Fe/N/C catalyst is examined by using density functional theory based calculations. The introduction of the phosphorus dopant creates three initial possible active sites for the ORR i.e. , FeN 4 , C-N an...
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Published in | New journal of chemistry Vol. 43; no. 28; pp. 1148 - 11418 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
15.07.2019
|
Subjects | |
Online Access | Get full text |
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Summary: | The oxygen reduction reaction (ORR) mechanism on the active sites of a phosphorus-doped pyrolyzed Fe/N/C catalyst is examined by using density functional theory based calculations. The introduction of the phosphorus dopant creates three initial possible active sites for the ORR
i.e.
, FeN
4
, C-N and P-doped sites. In the presence of O
2
, the P-doped sites become passivated while the rest of the catalyst sites are still functional. The ORR profile for the associative mechanism (the O
2
molecule is reduced from its molecular form) on the FeN
4
site is practically unaffected by the presence of the neighboring P&z.dbd;O site. However, the ORR profile for the dissociative mechanism (the O
2
molecule is reduced from its dissociated form) on the FeN
4
site is significantly improved as compared to that on the undoped Fe/N/C catalyst system. This phenomenon is mainly induced by the distortion of C-C networks due to the presence of the neighboring FeN
4
and P&z.dbd;O sites, which leads to the stabilization of the *OH adsorption state on the C atoms next to the FeN
4
site.
The interaction between neighbouring FeN
4
and P
subs
sites of a P-doped pyrolyzed Fe/N/C catalyst promotes four-electron reduction through associative and dissociative mechanisms. |
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Bibliography: | 10.1039/c9nj02118c Electronic supplementary information (ESI) available. See DOI |
ISSN: | 1144-0546 1369-9261 |
DOI: | 10.1039/c9nj02118c |