Yu Ying, Wang Yian, Yang Fei, Feng Dong, Yang Mingyang, Xie Peng-Fei, Zhu Yuanzhi, Shao Minhua, Mei Yi, Li Jin-Cheng
Faculty of Chemical Engineering, Yunnan Provincial Key Laboratory of Energy Saving in Phosphorus Chemical Engineering and New Phosphorus Materials, Kunming University of Science and Technology, Kunming, 650500, China.
Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong, China.
Angew Chem Int Ed Engl. 2025 Jan 15;64(3):e202415691. doi: 10.1002/anie.202415691. Epub 2024 Nov 27.
Zeolitic-imidazolate frameworks (ZIFs) are among the most efficient precursors for the synthesis of atomically dispersed Fe-N/C materials, which are promising catalysts for enhancing the performance of Zn-air batteries (ZABs) and proton exchange fuel cells (PEMFCs). However, existing ZIF-derived Fe-N/C electrocatalysts mostly consist of microporous materials, leading to insufficient mass transport and inadequate battery/cell performance. In this study, we synthesize an atomically dispersed meso/microporous Fe-N/C material with curved Fe-N active sites, denoted as FeSA-N/TC, through the pyrolysis of hemin-modified ZIF films on ZnO nanorods, obtained from the self-assembly reaction between Zn from ZnO hydrolysis and 2-methylimidazole. Density functional theory calculations demonstrate that the curved Fe-N active sites can weaken the intermediate adsorptions, resulting in lower free energy barriers and enhanced performance during oxygen reduction reaction (ORR). Specifically, FeSA-N/TC exhibits exceptional ORR performance with half-wave potentials of 0.925 V in alkaline media and 0.825 V in acidic media. When used as the cathodic catalyst in PEMFCs and ZABs, FeSA-N/TC achieves high peak power densities (H-O PEMFC: 1100 mW cm; H-Air PEMFC: 715 mW cm; liquid-state ZAB: 228 mW cm; solid-state ZAB: 112 mW cm), demonstrating its feasibility and efficiency in practical applications.
沸石咪唑酯骨架材料（ZIFs）是合成原子分散型Fe-N/C材料最有效的前驱体之一，这类材料有望成为提升锌空气电池（ZABs）和质子交换燃料电池（PEMFCs）性能的催化剂。然而，现有的ZIF衍生Fe-N/C电催化剂大多由微孔材料组成，导致传质不足以及电池/燃料电池性能欠佳。在本研究中，我们通过对在ZnO纳米棒上的血红素修饰ZIF薄膜进行热解，合成了一种具有弯曲Fe-N活性位点的原子分散型介孔/微孔Fe-N/C材料，记为FeSA-N/TC，该ZIF薄膜由ZnO水解产生的Zn与2-甲基咪唑之间的自组装反应得到。密度泛函理论计算表明，弯曲的Fe-N活性位点能够减弱中间体吸附，从而降低自由能垒并提高氧还原反应（ORR）过程中的性能。具体而言，FeSA-N/TC在碱性介质中半波电位为0.925 V，在酸性介质中为0.825 V，展现出优异的ORR性能。当用作PEMFCs和ZABs的阴极催化剂时，FeSA-N/TC实现了高的峰值功率密度（氢-氧PEMFC：1100 mW cm；氢-空气PEMFC：715 mW cm；液态ZAB：228 mW cm；固态ZAB：112 mW cm），证明了其在实际应用中的可行性和效率。
