Wang Liping, Xiao Jin, Mao Qiuyun, Cai Chao, Zhong Qifan, Liu Changxu, Liu Min
School of Metallurgy and Environment, Central South University, Changsha 410083, China.
School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Center of Low-Carbon Nonferrous Metallurgy, Central South University, Changsha 410083, China.
J Colloid Interface Sci. 2025 Feb;679(Pt B):588-599. doi: 10.1016/j.jcis.2024.10.122. Epub 2024 Oct 24.
Constructing efficient electrocatalysts for the oxygen reduction reaction (ORR) is crucial for the commercialization of metal-air batteries. Iron oxide-based catalysts exhibit promising potential for ORR. However, addressing the issue of inferior catalytic performance is essential, and a comprehensive understanding of the catalytic mechanism of iron oxide-based catalysts is also lacking. In this study, we present FeO nanoparticles encapsulated in N-doped graphitic carbon layers (NGC) hosted by hierarchically porous carbon (FeO@NGC), achieved through a facile dual melt-salt template strategy. The encapsulation of FeO nanoparticles protects them from corrosion and exfoliation, endowing the catalysts with superior stability. Density functional theory (DFT) calculations discover that the electronic interaction between FeO nanoparticles and N-doped graphitic carbon layers induces directional interfacial electron transfer, which effectively modulates the surface electronic structure to improve the binding ability to O, weaken the OO bond, and optimize the adsorption of intermediates, thus boosting the intrinsic activity. DFT unveils that the C atoms nearest to graphitic-N in NGC are active sites. Finally, the synergistic effects of FeO nanoparticles and NGC result in outstanding ORR performance and superior stability and methanol tolerance of FeO@NGC, with a half-wave potential of 0.89 V, surpassing that of Pt/C by 50 mV. FeO@NGC also shows better performance than Pt/C when used as the air-electrode catalyst in zinc-air battery.
构建用于氧还原反应（ORR）的高效电催化剂对于金属空气电池的商业化至关重要。基于氧化铁的催化剂在ORR方面展现出了广阔的潜力。然而，解决催化性能较差的问题至关重要，并且目前还缺乏对基于氧化铁的催化剂催化机理的全面理解。在本研究中，我们通过一种简便的双熔盐模板策略制备了包裹在由分级多孔碳（FeO@NGC）负载的氮掺杂石墨碳层（NGC）中的FeO纳米颗粒。FeO纳米颗粒的包裹保护它们免受腐蚀和剥落，赋予催化剂优异的稳定性。密度泛函理论（DFT）计算发现，FeO纳米颗粒与氮掺杂石墨碳层之间的电子相互作用诱导了定向界面电子转移，这有效地调节了表面电子结构，提高了对O的结合能力，削弱了OO键，并优化了中间体的吸附，从而提高了本征活性。DFT揭示，NGC中最靠近石墨氮的C原子是活性位点。最后，FeO纳米颗粒和NGC的协同效应导致FeO@NGC具有出色的ORR性能、优异的稳定性和甲醇耐受性，半波电位为0.89 V，比Pt/C高出50 mV。当用作锌空气电池的空气电极催化剂时，FeO@NGC也表现出比Pt/C更好的性能。
