Breaking the linear correlations for enhanced electrochemical nitrogen reduction by carbon-encapsulated mixed-valence Fe_(7)(PO_(4))_(6)  

作　　者：Lehui Ma Fanfan Xu Linlin Zhang Zhongfen Nie Kai Xia Mingxia Guo Mingzhu Li Xin Ding 

机构地区：[1]College of Chemistry and Chemical Engineering,Qingdao University,Qingdao 266071,Shandong,China

出　　处：《Journal of Energy Chemistry》2022年第8期182-187,I0006,共7页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China(21908120 and 22109078);the Youth Innovation Team Project of Shandong Provincial Education Department(2019KJC023)。

摘　　要：Electrochemical nitrogen reduction(NRR)is deemed as a consummate answer for the traditional Haber–Bosch technology.Breaking the linear correlations between adsorption and transition-state energies of intermediates is vital to improve the kinetics of ammonia synthesis and obtain a less energy-intensive process.Herein,carbon-encapsulated mixed-valence Fe_(7)(PO_(4))_(6) was prepared and applied as an electrocatalyst for high-efficiency NRR.A dramatic faradaic efficiency(FE)of 36.93%and an NH_(3) production rate of 13.1μg h^(-1) mg_(cat)^(-1) were obtained at-0.3 V versus RHE,superior to nearly all Fe-based catalysts.Experiments and DFT calculations revealed that the superior performance was ascribed to the synergistic effect of mixed-valence iron pair,which braked the linear correlations to improve the kinetics of ammonia from collaborative hydrogenation and*NH_(3) separation.This work proves the feasibility of mixedvalence catalysts for nitrogen reduction and thus opening a new avenue towards artificial nitrogenfixation catalysts.

关 键 词：N2 reduction reaction(NRR) MIXED-VALENCE Linear correlations Nitrogen fixation N_(2)activation 

分 类 号：TQ113.26[化学工程—无机化工] TQ426