Luo Li, Xu Yan, Wang Dongsheng, Feng Wenhui, Qiu Xiaoqing
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, P. R. China.
Hunan Province Key Laboratory of Applied Environmental Photocatalysis, Changsha University, Changsha 410022, P. R. China.
Inorg Chem. 2022 Feb 21;61(7):3166-3175. doi: 10.1021/acs.inorgchem.1c03573. Epub 2022 Feb 9.
Transition metal-nitrogen-carbon (M-N-C) catalysts (M = Fe, Co, etc.) are the most promising substituents of Pt-based catalysts for oxygen reduction reaction (ORR). However, the insufficient active species in catalysts inevitably hamper their widespread applications. Herein, we report the regulation of the active species in the catalysts of multicomponent N-doped carbon with Fe/FeC nanoparticles by polydopamine (PDA) coating. It is found that the PDA is conducive to increasing the pyridinic, graphitic, and total N content in the carbon matrix. Benefiting from the chelating effects, the PDA further profits the formation of Fe-N structures and the implantation of Fe/FeC nanoparticles in the matrix during the pyrolysis. As expected, the resultant catalysts exhibit over 15 times mass activity toward ORR than nitrogen-doped carbon. Moreover, our developed catalysts show long-term stability as well as high methanol tolerance, which is superior to that of the commercial Pt/C electrode. This work provides a new avenue to explore a wider range of high-performance ORR electrocatalysts by regulating the active species.
过渡金属-氮-碳（M-N-C）催化剂（M = Fe、Co等）是氧还原反应（ORR）中最有前途的铂基催化剂替代物。然而，催化剂中活性物种不足不可避免地阻碍了它们的广泛应用。在此，我们报道了通过聚多巴胺（PDA）包覆对含Fe/FeC纳米颗粒的多组分氮掺杂碳催化剂中的活性物种进行调控。研究发现，PDA有利于提高碳基体中吡啶型氮、石墨型氮和总氮含量。受益于螯合效应，PDA在热解过程中进一步促进了Fe-N结构的形成以及Fe/FeC纳米颗粒在基体中的嵌入。正如预期的那样，所得催化剂对ORR的质量活性比氮掺杂碳高出15倍以上。此外，我们开发的催化剂表现出长期稳定性以及高甲醇耐受性，优于商业Pt/C电极。这项工作为通过调控活性物种探索更广泛的高性能ORR电催化剂提供了一条新途径。
