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Engineering Energy Level of FeN4 Sites via Dual-Atom Site Construction Toward Efficient Oxygen Reduction
Small ( IF 13.0 ) Pub Date : 2022-12-29 , DOI: 10.1002/smll.202205283
Zhaoyan Luo 1 , Xianliang Li 1 , Tingyi Zhou 1 , Yi Guan 2 , Jing Luo 2 , Lei Zhang 1 , Xueliang Sun 2 , Chuanxin He 1 , Qianling Zhang 1 , Yongliang Li 1 , Xiangzhong Ren 1
Affiliation  

Single-atom catalysts based on metal–N4 moieties and embedded in a graphite matrix (defined as MNC) are promising for oxygen reduction reaction (ORR). However, the performance of MNC catalysts is still far from satisfactory due to their imperfect adsorption energy to oxygen species. Herein, single-atom FeNC is leveraged as a model system and report an adjacent Ru-N4 moiety modulation effect to optimize the catalyst's electronic configuration and ORR performance. Theoretical simulations and physical characterizations reveal that the incorporation of Ru-N4 sites as the modulator can alter the d-band electronic energy of Fe center to weaken the FeO binding affinity, thus resulting in the lower adsorption energy of ORR intermediates at Fe sites. Thanks to the synergetic effects of neighboring Fe and Ru single-atom pairs, the FeN4/RuN4 catalyst exhibits a half-wave potential of 0.958 V and negligible activity degradation after 10 000 cycles in 0.1 m KOH. Metal–air batteries using this catalyst in the cathode side exhibit a high power density of 219.5 mW cm−2 and excellent cycling stability for over 2370 h, outperforming the state-of-the-art catalysts.

中文翻译:

通过双原子位点构造实现 FeN4 位点的工程能级以实现高效氧还原

基于金属-N 4部分并嵌入石墨基质(定义为 M N C)的单原子催化剂有望用于氧还原反应 (ORR)。然而,由于MNC催化剂对氧物种的吸附能不完善,其性能仍不能令人满意。在此,单原子 Fe N C 被用作模型系统并报告相邻的 Ru-N 4部分调制效应以优化催化剂的电子配置和 ORR 性能。理论模拟和物理表征表明,Ru-N 4的掺入作为调节剂的位点可以改变Fe中心的d带电子能量以削弱FeO结合亲和力,从而导致ORR中间体在Fe位点的吸附能较低。由于相邻的 Fe 和 Ru 单原子对的协同作用,FeN 4 /RuN 4催化剂在 0.1 m KOH中循环 10 000 次后表现出 0.958 V 的半波电位和可忽略的活性下降 。在阴极侧使用这种催化剂的金属-空气电池表现出 219.5 mW cm -2的高功率密度和超过 2370 小时的出色循环稳定性,优于最先进的催化剂。
更新日期:2022-12-29
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