Tailoring first coordination sphere of dual-metal atom sites boosts oxygen reduction and evolution activities

• Main Authors: Wang, Zhe, Xu, Ruojie, Ye, Qitong, Jin, Xiaoyan, Lu, Zhe, Yang, Zhenbei, Wang, Yong, Yan, Tao, Liu, Yipu, Pan, Zhijuan, Hwang, Seong-Ju, Fan, Hong Jin
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2024
• Subjects: Physics; Boron introduction; Dual-atom catalysts
• Online Access: https://hdl.handle.net/10356/174713
• Institution: Nanyang Technological University

It is important to tune the coordination configuration of dual-atom catalyst (DAC), especially in the first coordination sphere, to render high intrinsic catalytic activities for oxygen reduction/evolution reactions (ORR/OER). Herein, a type of atomically dispersed and boron-coordinated DAC structure, namely, FeN4B-NiN4B dual sites, is reported. In this structure, the incorporation of boron into the first coordination sphere of FeN4/NiN4 atomic sites regulates its geometry and electronic structure by forming “Fe-B-N” and “Ni-B-N” bridges. The FeN4B-NiN4B DAC exhibits much enhanced ORR and OER property compared to the FeN4-NiN4 counterparts. Density functional theory calculations reveal that the boron-induced charge transfer and asymmetric charge distributions of the central Fe/Ni atoms optimize the adsorption and desorption behavior of the ORR/OER intermediates and reduce the activation energy for the potential-determining step. Zinc-air batteries employing the FeN4B-NiN4B cathode exhibit a high maximum power density (236.9 mW cm−2) and stable cyclability up to 1100 h. The result illustrates the pivotal role of the first-coordination sphere of DACs in tuning the electrochemical energy conversion and storage activities.