Xu Hui-Min, Yue Kai-Hang, Song Lian-Jie, Zhang Hong-Cheng, Zhu Hong-Rui, Zhang Zhi-Jie, Li Gao-Ren
College of Materials Science and Engineering, Sichuan University, Chengdu, 610065.
CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 585 Heshuo Road, Shanghai, 200050, China.
Angew Chem Int Ed Engl. 2024 Dec 16;63(51):e202412025. doi: 10.1002/anie.202412025. Epub 2024 Oct 25.
Zinc-air batteries (ZABs) have the advantages of high energy density and rich zinc raw materials. It is a low-cost, green and sustainable energy storage device. At present, one of the key technologies that hinder the large-scale application of ZABs is the design and fabrication oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) bifunctional catalysts with excellent performance, especially the non-platinum-based catalysts. Here N-doped carbon-coated Fe-based selenium oxide catalyst FeO(SeO)/FeC@NC with high performance has been fabricated by a one-step pyrolysis and then the electrochemical oxidization. The experimental results confirmed that the existence of Fe-O-Se bonds in FeO(SeO) crystal phase of FeO(SeO)/FeC@NC, and the Fe-O-Se bonds could obviously enhance ORR and OER catalytic performance of FeO(SeO)/FeC@NC. Density functional theoretical calculations (DFT) confirmed that the FeO(SeO) in FeO(SeO)/FeC@NC had a higher d-band center of Fe atom and a lower p-orbital coupling degree with its own lattice O atom than FeO, which leads to Fe site of FeO(SeO) being more likely to adsorb external oxygen intermediates. The Fe-O-Se bonds in FeO(SeO) results in the modification of coordination environment of Fe atoms and optimizes the adsorption energy of Fe site for oxygen intermediates. Compared with FeO/FeC@NC, the FeO(SeO)/FeC@NC showed the obvious enhancements of ORR/OER catalytic activities with a half-wave potential of 0.91 V for ORR in 0.1 M KOH electrolyte and a low overpotential of 345 mV for OER at 10 mA cm in a 1.0 M KOH electrolyte. The peak power density and specific capacity of FeO(SeO)/FeC@NC-based ZABs are higher than those of Pt/C+RuO-ZABs. The above results demonstrate that the asymmetrical Fe-O-Se bonds in FeO(SeO) plays a key role in improving the bifunctional catalytic activities of ORR/OER for ZABs.
锌空气电池（ZABs）具有能量密度高和锌原材料丰富的优点。它是一种低成本、绿色且可持续的储能装置。目前，阻碍ZABs大规模应用的关键技术之一是设计和制备具有优异性能的析氧反应（OER）和氧还原反应（ORR）双功能催化剂，尤其是非铂基催化剂。在此，通过一步热解然后进行电化学氧化制备了具有高性能的氮掺杂碳包覆铁基氧化硒催化剂FeO(SeO)/FeC@NC。实验结果证实了FeO(SeO)/FeC@NC的FeO(SeO)晶相中存在Fe-O-Se键，且该键可显著增强FeO(SeO)/FeC@NC的ORR和OER催化性能。密度泛函理论计算（DFT）证实，FeO(SeO)/FeC@NC中的FeO(SeO)比FeO具有更高的Fe原子d带中心以及与自身晶格O原子更低的p轨道耦合度，这使得FeO(SeO)的Fe位点更易吸附外部氧中间体。FeO(SeO)中的Fe-O-Se键导致Fe原子配位环境的改变，并优化了Fe位点对氧中间体的吸附能。与FeO/FeC@NC相比，FeO(SeO)/FeC@NC在0.1 M KOH电解液中ORR的半波电位为0.91 V，在1.0 M KOH电解液中10 mA cm时OER的低过电位为345 mV，显示出ORR/OER催化活性的明显增强。基于FeO(SeO)/FeC@NC的ZABs的峰值功率密度和比容量高于Pt/C+RuO-ZABs。上述结果表明，FeO(SeO)中不对称的Fe-O-Se键在提高ZABs的ORR/OER双功能催化活性中起关键作用。
