Modulating the electronic spin state by constructing dual-metal atomic pairs for activating the dynamic site of oxygen reduction reaction
Shenghua Ye, Shuhua Xie, Yaqi Lei, Xiuyuan Yang, Jing Hu, Lirong Zheng, Zhida Chen, Yonghuan Fu, Xiangzhong Ren, Yongliang Li, Xiaoping Ouyang, Qianling Zhang, Jianhong Liu, Xueliang Sun
Abstract
In this study, dual-metal atomic pairs of manganese (Mn)-iron (Fe) binuclear sites (BNSs) with two conjoint MnN4 and FeN4 moieties (MnFeN8) anchored onto a graphite-like structure (GLS) (Mn-Fe BNSs/GLS) were constructed. The binuclear MnFeN8 structure was verified experimentally and theoretically. Magnetic measurements and Gaussian calculations reveal that this unique Mn-Fe BNSs exhibit strong short-range electronic interaction between Mn and Fe sites, which decouples two paired d electrons in Fe sites, thereby transforming Fe sites from an intermediate to a high spin state. The optimal electronic configuration of Fe sites and their binuclear structure facilitate an oxygen reduction reaction (ORR) thermodynamically and dynamically, respectively, endowing Mn-Fe BNSs with improved ORR performance.