Synergistically enhanced single-atomic site Fe by Fe3C@C for boosted oxygen reduction in neutral electrolyte. (June 2021)

• Record Type: Journal Article
• Authors: Wei, Xiaoqian; Song, Shaojia; Wu, Nannan; Luo, Xin; Zheng, Lirong; Jiao, Lei; Wang, Hengjia; Fang, Qie; Hu, Liuyong; Gu, Wenling; Song, Weiyu; Zhu, Chengzhou
• Is Part Of: Nano energy. Volume 84(2021)
• Publication Date: 2021-06
• Subjects: Single-atomic sites -- Synergistic effects -- Oxygen reduction reaction -- Neutral electrolytes -- Zinc-air batteries; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2021.105840
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Developing single-atomic site (SAS) catalysts for oxygen reduction reaction (ORR) with superior activities in the renewable-energy initiatives is critical but remains challenging. Herein, exceptional SAS Fe boosted by adjacent graphene-encapsulated Fe3 C nanocrystals (Fe3 C@C-Fe SAS) is constructed for ORR. Because of the strong synergistic effects between SAS Fe and Fe3 C@C nanocrystals, Fe3 C@C-Fe SAS shows robust ORR performance in the neutral electrolyte with the onset potential of 0.99 V and negligible activity loss after 30 k cycles of an accelerated durability test, much better than that of Pt/C catalyst. Notably, the integrated zinc-air battery in the neutral system exhibits an outstanding peak power density of 74.8 mW/cm 2 and durability over 100 h, representing a state-of-the-art PGM-free ORR catalyst. More importantly, the density functional theory (DFT) calculations shed light on that the introduction of Fe3 C@C nanocrystals is favorable for the activation of O2 molecules and desorption of OH* on the Fe SAS, resulting in accelerated reaction kinetics and promising ORR activity. Given the explicit structure-performance relationships for Fe3 C@C-Fe SAS, this work provides a new strategy for the design of more advanced energy-based electrocatalysts. Graphical Abstract: ga1 Highlights: Fe3 C@C enhanced single-atomic site Fe catalyst (Fe3 C@C-Fe SAS) is fabricated. The optimized Fe3 C@C-Fe SAS manifests outstanding ORR performance at neutral conditions. The introduction of Fe3 C@C is verified to optimize the adsorption/desorption of intermediates on Fe SAS.