Xu Hao, Xiao Lihui, Yang Peixia, Lu Xiangyu, Liu Lilai, Wang Dan, Zhang Jinqiu, An Maozhong
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 150001 Harbin, China.
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 150001 Harbin, China.
J Colloid Interface Sci. 2023 May 15;638:242-251. doi: 10.1016/j.jcis.2023.01.140. Epub 2023 Jan 31.
Zeolitic imidazole framework (ZIF)-derived iron-nitrogen-carbon (FeNC) materials are expected to be high-efficiency catalysts for oxygen reduction reaction (ORR). However, increasing the density of active sites while avoiding metal accumulation still faces significant challenges. Herein, solvent environment engineering is used to synthesize the FeNC containing dense Fe-N moieties by adjusting the solvent during the ZIF precursor synthesis process. Compared with methanol and water/methanol, the aqueous media can provide a more moderate Fe content for the ZIF precursor, which facilitates the construction of high-density Fe-N sites and prevent the appearance of iron-based nanoparticles during pyrolysis. Therefore, the FeNC(C) nanocubes synthesized in an aqueous media have the highest single atom Fe loading (0.6 at%) among the prepared samples, which presents excellent oxygen reduction properties and durability under alkaline and acidic conditions. The advantage of FeNC(C) is proven in Zn-air batteries, with outstanding performance and long-term stability.
沸石咪唑框架（ZIF）衍生的铁氮碳（FeNC）材料有望成为氧还原反应（ORR）的高效催化剂。然而，在增加活性位点密度的同时避免金属积累仍然面临重大挑战。在此，通过在ZIF前驱体合成过程中调节溶剂，利用溶剂环境工程合成了含有密集Fe-N部分的FeNC。与甲醇和水/甲醇相比，水性介质可为ZIF前驱体提供更适中的铁含量，这有利于构建高密度的Fe-N位点，并防止在热解过程中出现铁基纳米颗粒。因此，在水性介质中合成的FeNC（C）纳米立方体在制备的样品中具有最高的单原子铁负载量（0.6 at%），在碱性和酸性条件下均表现出优异的氧还原性能和耐久性。FeNC（C）的优势在锌空气电池中得到了验证，具有出色的性能和长期稳定性。
