| Cobalt supported on N-enriched hierarchical porous carbon polyhedron derived from ZIF-8 as an effective ORR electrocatalyst in acidic medium |
| کد مقاله : 1022-CNF |
| نویسندگان: |
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Maryam Jafari *1، Mohammad Javad Parnian2، Hussein Gharibi1 1دانشگاه تربیت مدرس 2The university of calgery |
| چکیده مقاله: |
| Sluggish oxygen reduction reaction has been a challenge in energy conversion and storage systems [1,2]. On the other hand, issues like a high price, scarce reserve, and poor durability of Pt-based catalysts have encouraged researchers to substitute these common fuel cell catalysts with nonprecious metal catalysts (NPMCs), especially metal-nitrogen-carbon composites. These nitrogen-enriched porous carbon composites have recently attracted much attention due to their excellent features [3,4]. The critical point is that exploring non-noble-metal catalysts for replacing high-cost significant metal catalysts can be a considerable challenge. Recently, many reports have focused on pyrolyzed carbon materials obtained from MOFs, especially zeolite imidazole frameworks (ZIFs), as one of the subclasses of MOFs. This material contains imidazole linkers containing carbon, nitrogen atoms, and M+2 ions (M=Zn, Co, etc.) like ZIF-8. First, a feature that makes these templates more applicable is their high surface area [5]. Second, the obtained carbon from the pyrolysis is active, unlike the traditional carbon support like Black Pearl and Kejten Black, etc. The reason behind the selection of ZIF-8 is that the boiling point of Zn atoms is low (mp: 420 ̊C, bp: 907 ̊C). Hence it can evaporate away at high temperatures over 800 ̊C. Therefore a porous carbon with a high specific surface area is generated. Moreover, high in-situ nitrogen doping into the carbonaceous framework through thermal treatment makes a uniform dispersion of Nx-C active sites throughout the framework. Herein, a simple two-step method is used to synthesize transition metal catalysts (Co) supported on N-doped porous carbon polyhedron (NC). Finally, the catalytic performance of the synthesized catalyst is compared for ORR in acidic media. In this work, it was clearly illustrated when homogeneous dispersion of Co nanoparticles on N-doped supported derived from ZIF-8 was obtained, the electrocatalyst activity was improved. The reduction peak appeared at 0.525 VRHE and Eonst=0.747 VRHE in 0.1 M HClO4 compared to Co-free support (0.453 VRHE and 0.651 VRHE, respectively). Hence, it can be concluded that the synergic effect between high-nitrogen doped carbon support and transition metal nanoparticles is the critical point in good ORR performance of as-prepared Co/NC catalyst. |
| کلیدواژه ها: |
| Zeolitic Imidazolium Framework (ZIF-8), Nonprecious metal catalysts (NPMCs), Co nanoparticles, Oxygen reduction reaction |
| وضعیت : چکیده برای ارائه به صورت پوستر پذیرفته شده است |