The present work illustrates the synthesis of an efficient and durable catalyst for electrochemical oxygen reduction reaction (ORR) which is active both in the alkaline and acidic conditions by dispersing few‐layer graphitic carbon coated Co₉S₈ nanoparticles on the nitrogen‐doped carbon (NVC−G) support (Co₉S₈/NVC−G). The size of the Co₉S₈ nanoparticles is nearly 7–8 nm and the particles are found to be dispersed homogeneously on the NVC−G support. The few‐layer graphitic carbon formed on the surface of Co₉S₈ nanoparticles is assisting to accomplish their small size and it also prevents agglomeration of the nanoparticles. The ORR activity of the obtained material was analyzed in both 0.1 M KOH and 0.5 M H₂SO₄ solutions. Co₉S₈/NVC−G displays nearly 70 mV overpotential compared to the state‐of‐the‐art Pt/C in 0.1 M KOH solution. The half‐wave potential (E _1/2) difference of the present system is nearly 75 mV with the commercial Pt/C. Co₉S₈/NVC−G displays promising ORR activity in the acidic conditions as well with nearly 140 mV overpotential compared to its Pt/C counterpart. The system shows about 170 mV lower E _1/2 value with Pt/C. The system shows good stability both in acidic and basic conditions compared to the Pt/C system. Finally, testing of a single cell of a polymer electrolyte membrane fuel cell (PEMFC) was performed by employing Co₉S₈/NVC−G as the cathode catalyst and Nafion‐212 as the proton exchange membrane. The system displays a maximum power density of 245 mW cm⁻² in H₂−O₂ and 115 mW cm⁻² in H₂‐air feeding conditions.

中文翻译：

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Co9S8纳米颗粒负载的氮掺杂碳是在酸性和碱性条件下进行氧还原反应的稳健催化剂

本工作说明了一种用于电化学氧还原反应（ORR）的高效耐用催化剂的合成，该催化剂在碱性和酸性条件下均具有活性，这是通过将少量石墨碳涂层的Co ₉ S ₈纳米颗粒分散在氮掺杂的碳（ NVC-G）支持（Co ₉ S ₈ / NVC-G）。Co ₉ S ₈纳米颗粒的大小接近7–8 nm，并且发现这些颗粒均匀地分散在NVC-G载体上。Co ₉ S ₈表面形成的少层石墨碳纳米颗粒有助于实现其小尺寸，并且还防止了纳米颗粒的团聚。在0.1 M KOH和0.5 MH ₂ SO ₄溶液中分析所得材料的ORR活性。与0.1 M KOH溶液中最新的Pt / C相比，Co ₉ S ₈ / NVC-G显示出近70 mV的超电势。使用商用Pt / C，本系统的半波电势（E _1/2）差接近75 mV。Co ₉ S ₈ / NVC-G在酸性条件下也显示出有希望的ORR活性，并且与Pt / C对应物相比具有近140 mV的超电势。系统显示低约170 mV带有Pt / C的E _1/2值。与Pt / C系统相比，该系统在酸性和碱性条件下均显示出良好的稳定性。最后，通过使用Co ₉ S ₈ / NVC-G作为阴极催化剂和Nafion-212作为质子交换膜，对聚合物电解质膜燃料电池（PEMFC）的单个电池进行了测试。系统在H ₂ -O _2中显示的最大功率密度为245 mW cm ^-2，在H ₂供气条件下显示为115 mW cm ^-2。