Encapsulation of metal precursor within ZIFs for bimetallic N-doped carbon electrocatalyst with enhanced oxygen reduction
| Autor: | Congling Li, Jian Li, Rui Liu, Xianxiang Hu, Xia Zhang, Mengchen Wu, Haijun Zhou |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Energy Engineering and Power Technology chemistry.chemical_element Proton exchange membrane fuel cell 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrocatalyst 01 natural sciences 0104 chemical sciences Catalysis Fuel Technology chemistry Chemical engineering Specific surface area Reversible hydrogen electrode 0210 nano-technology Platinum Bimetallic strip Pyrolysis |
| Zdroj: | International Journal of Hydrogen Energy. 43:14701-14709 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2018.05.160 |
| Popis: | High-performance non-precious metal-doped carbon catalysts for oxygen reduction reactions (ORR) are viable candidates in lieu of platinum-based catalysts. It has been universally reported that active Co–N sites combined with Fe–N sites embedded in carbon matrix represent the most promising active sites for ORR process. Benefiting from the cage-encapsulated-precursor pyrolysis strategy, herein, we fabricated a Fe–N and Co–N homogeneously doped carbon framework by one step. TEM demonstrated the ultimate product had well-defined morphology with Fe (0.54 at%), Co (0.31 at%) and N (2.94 at%) uniformly distributed into the carbon skeleton. The N2 absorption-desorption isotherms indicated the MOF-derived catalyst had a high specific surface area of 647.6 m2 g−1 and inherit hierarchical porosity. Significantly, such FeCo–NC catalyst outperformed a current density (5.6 mA cm−2) at 0.70 V (vs reversible hydrogen electrode) 1.18 times higher than that of a commercial 20 wt% Pt/C (5 mA cm−2) catalyst in alkaline medium, and more positive peak potential of 0.63 V than its counterparts. Its high cycling stability and immunity towards methanol crossover in a wide range pH value showed good potential to be used as cathodes in proton exchange membrane fuel cells (PEMFCs) for long term operation. This simple synthesis strategy would to some degree leverage a cage-encapsulated-precursor for tailored utility of active sites for ORR in a porous carbon framework. |
| Databáze: | OpenAIRE |
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