| Autor: |
Peng, Xiong, Omasta, Travis J., Magliocca, Emanuele, Wang, Lianqin, Varcoe, John R., Mustain, William E. |
| Předmět: |
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| Zdroj: |
Angewandte Chemie International Edition; 1/21/2019, Vol. 58 Issue 4, p1046-1051, 6p |
| Abstrakt: |
Efficient and durable nonprecious metal electrocatalysts for the oxygen reduction (ORR) are highly desirable for several electrochemical devices, including anion exchange membrane fuel cells (AEMFCs). Here, a 2D planar electrocatalyst with CoOx embedded in nitrogen‐doped graphitic carbon (N‐C‐CoOx) was created through the direct pyrolysis of a metal–organic complex with a NaCl template. The N‐C‐CoOx catalyst showed high ORR activity, indicated by excellent half‐wave (0.84 V vs. RHE) and onset (1.01 V vs. RHE) potentials. This high intrinsic activity was also observed in operating AEMFCs where the kinetic current was 100 mA cm−2 at 0.85 V. When paired with a radiation‐grafted ETFE powder ionomer, the N‐C‐CoOx AEMFC cathode was able to achieve extremely high peak power density (1.05 W cm−2) and mass transport limited current (3 A cm−2) for a precious metal free electrode. The N‐C‐CoOx cathode also showed good stability over 100 hours of operation with a voltage decay of only 15 % at 600 mA cm−2 under H2/air (CO2‐free) reacting gas feeds. The N‐C‐CoOx cathode catalyst was also paired with a very low loading PtRu/C anode catalyst, to create AEMFCs with a total PGM loading of only 0.10 mgPt‐Ru cm−2 capable of achieving 7.4 W mg−1PGM as well as supporting a current of 0.7 A cm−2 at 0.6 V with H2/air (CO2 free)—creating a cell that was able to meet the 2019 U.S. Department of Energy initial performance target of 0.6 V at 0.6 A cm−2 under H2/air with a PGM loading <0.125 mg cm−2 with AEMFCs for the first time. A planar electrocatalyst with CoOx embedded in nitrogen‐doped graphitic carbon (N‐C‐CoOx) was created through the direct pyrolysis of a metal–organic complex. The N‐C‐CoOx catalyst shows high oxygen reduction activity, indicated by excellent half‐wave (0.84 V vs. RHE) and onset (1.01 V vs. RHE) potentials. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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