Wan Xin, Liu Qingtao, Liu Jieyuan, Liu Shiyuan, Liu Xiaofang, Zheng Lirong, Shang Jiaxiang, Yu Ronghai, Shui Jianglan
School of Materials Science and Engineering, Beihang University, 100191, Beijing, China.
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, China.
Nat Commun. 2022 May 26;13(1):2963. doi: 10.1038/s41467-022-30702-z.
Simultaneously increasing the activity and stability of the single-atom active sites of M-N-C catalysts is critical but remains a great challenge. Here, we report an Fe-N-C catalyst with nitrogen-coordinated iron clusters and closely surrounding Fe-N active sites for oxygen reduction reaction in acidic fuel cells. A strong electronic interaction is built between iron clusters and satellite Fe-N due to unblocked electron transfer pathways and very short interacting distances. The iron clusters optimize the adsorption strength of oxygen reduction intermediates on Fe-N and also shorten the bond amplitude of Fe-N with incoherent vibrations. As a result, both the activity and stability of Fe-N sites are increased by about 60% in terms of turnover frequency and demetalation resistance. This work shows the great potential of strong electronic interactions between multiphase metal species for improvements of single-atom catalysts.
同时提高M-N-C催化剂单原子活性位点的活性和稳定性至关重要，但仍然是一个巨大的挑战。在此，我们报道了一种具有氮配位铁簇和紧密环绕的Fe-N活性位点的Fe-N-C催化剂，用于酸性燃料电池中的氧还原反应。由于电子转移路径畅通且相互作用距离极短，铁簇与卫星Fe-N之间建立了强烈的电子相互作用。铁簇优化了氧还原中间体在Fe-N上的吸附强度，并且通过非相干振动缩短了Fe-N的键幅。结果，就周转频率和抗脱金属性而言，Fe-N位点的活性和稳定性均提高了约60%。这项工作展示了多相金属物种之间的强电子相互作用在改善单原子催化剂方面的巨大潜力。
