Building Atomic Scale and Dense FeâN4 Edge Sites of Highly Efficient FeâNâC Oxygen Reduction Catalysts Using a Sacrificial Bimetallic Pyrolysis Strategy.
Small
; 19(48): e2304750, 2023 Nov.
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| MEDLINE
| ID: mdl-37537155
ABSTRACT
Replacing high-cost and scarce platinum (Pt) with transition metal and nitrogen co-doped carbon (M/N/C, M = Fe, Co, Mn, and so on) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells has largely been impeded by the unsatisfactory ORR activity of M/N/C due to the low site utilization and inferior intrinsic activity of the MâN4 active center. Here, these limits are overcome by using a sacrificial bimetallic pyrolysis strategy to synthesize FeâNâC catalyst by implanting the Cd ions in the backbone of ZIF-8, leading to exposure of inaccessible FeN4 edge sites (that is, increasing active site density (SD)) and high fast mass transport at the catalyst layer of cathode. As a result, the final obtained Fe(Cd)âNâC catalyst has an active site density of 33.01 µmol g-1 (with 33.01% site utilization) over 5.8 times higher than that of FeâNâC catalyst. Specially, the optimal catalyst delivers a high ORR performance with a half-wave potential of 0.837 (vs RHE) in a 0.1 m HClO4 electrolyte, which surpasses most of Fe-based catalysts.
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01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Small
Asunto de la revista:
ENGENHARIA BIOMEDICA
Año:
2023
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Article