Abstract
| Original language | English |
|---|---|
| Journal | Science Bulletin |
| Volume | 63 |
| Issue number | 1 |
| Pages (from-to) | 24-30 |
| ISSN | 0309-7552 |
| DOIs | |
| Publication status | Published - 2018 |
Keywords
- Encapsulated Fe catalysts
- Oxygen reduction reaction
- Ion poisoning
- Active sites
- NPMCs
Cite this
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Electrochemical probing into the active sites of graphitic-layer encapsulated iron oxygen reduction reaction electrocatalysts. / Zhong, Lijie; Jensen, Jens Oluf; Cleemann, Lars Nilausen; Pan, Chao; Li, Qingfeng.
In: Science Bulletin, Vol. 63, No. 1, 2018, p. 24-30.Research output: Contribution to journal › Journal article › Research › peer-review
TY - JOUR
T1 - Electrochemical probing into the active sites of graphitic-layer encapsulated iron oxygen reduction reaction electrocatalysts
AU - Zhong, Lijie
AU - Jensen, Jens Oluf
AU - Cleemann, Lars Nilausen
AU - Pan, Chao
AU - Li, Qingfeng
PY - 2018
Y1 - 2018
N2 - The graphitic-layer encapsulated iron-containing nanoparticles (G@Fe) have been proposed as a potential type of active and stable non-precious metal electrocatalysts (NPMCs) for the oxygen reduction reaction (ORR). However, the contribution of the encapsulated components to the ORR activity is still unclear compared with the well-recognized surface coordinated FeNx/C structure. Using the strong complexing effect of the iron component with anions, cyanide (CN−) in alkaline and thiocyanate (SCN−) in acidic media, the metal containing active sites are electrochemically probed. Three representative catalysts are chosen for a comparison including the as-prepared encapsulated G@Fe, commercial Fe/N/C catalyst with iron–nitrogen coordinated surface functionalities and molecular iron phthalocyanine (FePc) containing well-defined structures and compositions. It was found that all samples showed significant shifts of half-wave potentials indicating that surface Fe coordinated sites in all cases. The G@Fe catalyst showed the weakest poisoning effect (the lowest shifts of half-wave potential) compared to the Fe/N/C and FePc catalysts in both electrolytes. These results could be explained that the encapsulated iron components influence the FeNx/C and/or NxC surface functionality.
AB - The graphitic-layer encapsulated iron-containing nanoparticles (G@Fe) have been proposed as a potential type of active and stable non-precious metal electrocatalysts (NPMCs) for the oxygen reduction reaction (ORR). However, the contribution of the encapsulated components to the ORR activity is still unclear compared with the well-recognized surface coordinated FeNx/C structure. Using the strong complexing effect of the iron component with anions, cyanide (CN−) in alkaline and thiocyanate (SCN−) in acidic media, the metal containing active sites are electrochemically probed. Three representative catalysts are chosen for a comparison including the as-prepared encapsulated G@Fe, commercial Fe/N/C catalyst with iron–nitrogen coordinated surface functionalities and molecular iron phthalocyanine (FePc) containing well-defined structures and compositions. It was found that all samples showed significant shifts of half-wave potentials indicating that surface Fe coordinated sites in all cases. The G@Fe catalyst showed the weakest poisoning effect (the lowest shifts of half-wave potential) compared to the Fe/N/C and FePc catalysts in both electrolytes. These results could be explained that the encapsulated iron components influence the FeNx/C and/or NxC surface functionality.
KW - Encapsulated Fe catalysts
KW - Oxygen reduction reaction
KW - Ion poisoning
KW - Active sites
KW - NPMCs
U2 - 10.1016/j.scib.2017.11.017
DO - 10.1016/j.scib.2017.11.017
M3 - Journal article
VL - 63
SP - 24
EP - 30
JO - Science Bulletin
JF - Science Bulletin
SN - 0309-7552
IS - 1
ER -