Zhao Haiyan, Chen Li, Ni Nan, Lv Yang, Wang Hezhen, Zhang Jia, Li Zhiwen, Liu Yu, Geng Yubo, Xie Yan, Wang Li
Liaoning Key Laboratory of Plasma Technology, School of Physics and Materials Engineering, Dalian Minzu University, 18 Liaohe West Road, Dalian 116600, China.
Shanghai Key Laboratory of Molecular & Process Engineering, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
Molecules. 2023 Aug 4;28(15):5885. doi: 10.3390/molecules28155885.
There is an urgent need to design and synthesize non-noble metal electrocatalysts (NNMEs) for the replacement of platinum-based electrocatalysts to enhance the sluggish oxygen reduction reaction (ORR) for Zn-air batteries and fuel cells. Herein, Fe-N,S-C materials were fabricated through two steps: first, reprecipitating hemin by adjusting the pH and, then, decorating it with melamine and cysteine in the presence of Zn. The resulting Fe-N,S-C-950 (Zn) was prepared after pyrolysis at 950 °C. Using this method, abundant iron-based active species with good dispersion were obtained. The fabrication of more micropores in Fe-N,S-C-950 (Zn) plays a positive role in the improvement of ORR activity. On comparison, Fe-N,S-C-950 (Zn) outperforms Fe-N,S-C-950 and Fe-N-C-950 (Zn) with respect to the ORR due to its larger specific surface area, porous structure, multiple iron-based active sites and N- and S-doped C. Fe-N,S-C-950 (Zn) achieves outstanding ORR performances, including a half-wave potential (E) of 0.844 V and 0.715 V versus a reversible hydrogen electrode (RHE) in 0.1 M KOH and 0.1 M HClO solution, respectively. In addition, Fe-N,S-C-950 (Zn) shows an outstanding Zn-air battery performance with an open-circuit voltage (OCV) of 1.450 V and a peak power density of 121.9 mW cm, which is higher than that of 20 wt% Pt/C. As a result, the as-prepared electrocatalyst in this work shows the development of the Zn-assisted strategy combined with the assembly of porphyrins as NNMEs for the enhancement of the ORR in both alkaline and acidic solutions.
迫切需要设计和合成非贵金属电催化剂（NNMEs）来替代铂基电催化剂，以改善锌空气电池和燃料电池中缓慢的氧还原反应（ORR）。在此，通过两步制备了Fe-N,S-C材料：首先，通过调节pH值使血红素再沉淀，然后在锌存在的情况下用三聚氰胺和半胱氨酸对其进行修饰。在950℃热解后得到了Fe-N,S-C-950（Zn）。采用这种方法，获得了分散良好的大量铁基活性物种。在Fe-N,S-C-950（Zn）中形成更多的微孔对ORR活性的提高起到了积极作用。相比之下，Fe-N,S-C-950（Zn）在ORR方面优于Fe-N,S-C-950和Fe-N-C-950（Zn），因为它具有更大的比表面积、多孔结构、多个铁基活性位点以及N和S掺杂的碳。Fe-N,S-C-950（Zn）实现了出色的ORR性能，在0.1M KOH和0.1M HClO溶液中，相对于可逆氢电极（RHE）的半波电位（E）分别为0.844V和0.715V。此外，Fe-N,S-C-950（Zn）表现出出色的锌空气电池性能，开路电压（OCV）为1.450V，峰值功率密度为121.9mW/cm²，高于20wt% Pt/C。因此，这项工作中制备的电催化剂展示了锌辅助策略与卟啉组装相结合作为NNMEs在碱性和酸性溶液中增强ORR的发展。
