Lu Zhiwei, Gong Weiming, Chen Jinpeng, Guo Peng, Zhang Yingxian, Zhang Lan, Yan Minglei, Wu Chun, Sun Mengmeng, Su Gehong, Wang Wei, Wang Yanying, Ye Jianshan, Zhu Wenxin, Wang Jianlong, Rao Hanbing
College of Science, Sichuan Agricultural University, Xin Kang Road, Ya'an, Yucheng, 625014, P.R. China.
College of Water Conservancy and Hydropower Engineering, Sichuan Agricultural University, Xin Kang Road, Ya'an, Yucheng, 625014, P.R. China.
Small Methods. 2025 Apr;9(4):e2401278. doi: 10.1002/smtd.202401278. Epub 2024 Oct 8.
Efficient, stable, and low-cost oxygen reduction catalysts are the key to the large-scale application of metal-air batteries. Herein, high-dispersive FeO nanoparticles (NPs) with abundant oxygen vacancies uniformly are anchored on lignin-derived metal-nitrogen-carbon (M-N-C) hierarchical porous nanosheets as efficient oxygen reduction reaction (ORR) catalysts (FeO/M-N-C, M═Cu, Mn, W, Mo) based on a general and economical KCl molten salt-assisted method. The combination of Fe with the highly electronegative O induces charge redistribution through the Fe-O-M structure, thereby reducing the adsorption energy of oxygen-containing substances. The coupling effect of FeO NPs with M-N-C expedites the catalytic activity toward ORR by promoting proton generation on FeO and transfer to M-N-C. Experimental and theoretical calculation further revealed the remarkable electronic structure evolution of the metal site during the ORR process, where the emission density and local magnetic moment of the metal atoms change continuously throughout their reaction. The unique layered porous structure and highly active M-N sites resulted in the excellent ORR activity of FeO/Cu-N-C with the onset potential of 0.977 V, which is superior to Pt/C. This study offers a feasible strategy for the preparation of non-noble metal catalysts and provides a new comprehension of the catalytic mechanism of M-N-C catalysts.
高效、稳定且低成本的氧还原催化剂是金属空气电池大规模应用的关键。在此，基于一种通用且经济的氯化钾熔盐辅助方法，具有丰富氧空位的高分散性FeO纳米颗粒（NPs）均匀地锚定在木质素衍生的金属氮碳（M-N-C）分级多孔纳米片上，作为高效氧还原反应（ORR）催化剂（FeO/M-N-C，M = Cu、Mn、W、Mo）。Fe与电负性高的O的结合通过Fe-O-M结构诱导电荷重新分布，从而降低含氧化合物的吸附能。FeO NPs与M-N-C的耦合效应通过促进FeO上质子的产生并转移到M-N-C来加快对ORR的催化活性。实验和理论计算进一步揭示了ORR过程中金属位点显著的电子结构演变，其中金属原子的发射密度和局部磁矩在整个反应过程中持续变化。独特的层状多孔结构和高活性的M-N位点导致FeO/Cu-N-C具有优异的ORR活性，起始电位为0.977 V，优于Pt/C。本研究为非贵金属催化剂的制备提供了一种可行策略，并对M-N-C催化剂的催化机理提供了新的理解。
