Phosphorus-doped iron-nitrogen-carbon catalyst with pentacoordinated single atom sites for efficient oxygen reduction  

作　　者：Lili Fan Xiaofei Wei Xuting Li Zhanning Liu Mengfei Li Shuo Liu Zixi Kang Fangna Dai Xiaoqing Lu Daofeng Sun 

机构地区：[1]School of Materials Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China [2]College of Science,China University of Petroleum(East China),Qingdao 266580,China

出　　处：《Nano Research》2023年第2期1810-1819,共10页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21875285,22171288,and 22005340);the Key Research and Development Projects of Shandong Province(No.2019JZZY010331);the Natural Science Foundation of Shandong Province(No.ZR2020MB017).

摘　　要：Single-atomic Fe-N4 is the well-acknowledged active site in iron-nitrogen-carbon(Fe-N-C)material for oxygen reduction reaction(ORR).The adjusting of the electronic distribution of Fe-N4 is promising for further enhancing the performance of the Fe-N-C catalyst.Herein,a phosphorus(P)-doped Fe-N-C catalyst with penta-coordinated single atom sites(FeNPC)is reported for efficient oxygen reduction.Fe K-edge X-ray absorption spectroscopy(XAS)verifies the coordination environment of single Fe atom,while density functional theory(DFT)calculations reveal that the penta-coordination and neighboring doped P atoms can simultaneously change the electronic distribution of Fe-N_(4)and its adsorption strength of key intermediates,reducing the reactionfree energy of the potential-limiting step.Electrochemical tests validate the remarkable intrinsic ORR activity of FeNPC in alkaline media(a half-wave potential(E_(1/2))of 0.904 V vs.reversible hydrogen electrode(RHE)and limited current density(JL)of 6.23 mA·cm^(−2))and an enhanced ORR performance in neutral(E_(1/2)=0.751 V,J_(L)=5.27 mA·cm^(−2))and acidic media(E_(1/2)=0.735 V,JL=5.82 mA·cm^(−2))with excellent stability,highlighting the benefits of optimizing the local environment of singleatomic Fe-N4.

关 键 词：Fe-N-C Fe-N4 penta-coordination oxygen reduction reaction P-DOPING 

分 类 号：O64[理学—物理化学]