Sulfur doped iron-nitrogen-hard carbon nanosheets as efficient and robust noble metal-free catalysts for oxygen reduction reaction in PEMFC  

作　　者：Bin Liu Jiawang Li Bowen Yan Qi Wei Xingyu Wen Huarui Xie Huan He Pei Kang Shen Zhi Qun Tian 

机构地区：[1]Collaborative Innovation Center of Sustainable Energy Materials,School of Physical Science and Technology,Guangxi University,Guangxi Key Laboratory of Electrochemical Energy Materials,State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Nanning 530004,Guangxi,China

出　　处：《Journal of Energy Chemistry》2024年第2期422-433,I0010,共13页能源化学（英文版）

基　　金：finically supported by the National Natural Science Foundation of China(22075055);the Guangxi Science and Technology Project(AB16380030)。

摘　　要：Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).To tackle the issue,herein,a new type of sulfur-doped ironnitrogen-hard carbon(S-Fe-N-HC)nanosheets with high activity and durability in acid media were developed by using a newly synthesized precursor of amide-based polymer with Fe ions based on copolymerizing two monomers of 2,5-thiophene dicarboxylic acid(TDA)as S source and 1,8-diaminonaphthalene(DAN)as N source via an amination reaction.The as-synthesized S-Fe-N-HC features highly dispersed atomic Fe Nxmoieties embedded into rich thiophene-S doped hard carbon nanosheets filled with highly twisted graphite-like microcrystals,which is distinguished from the majority of M-N-C with soft or graphitic carbon structures.These unique characteristics endow S-Fe-N-HC with high ORR activity and outstanding durability in 0.5 M H_(2)SO_(4).Its initial half-wave potential is 0.80 V and the corresponding loss is only 21 m V after 30,000 cycles.Meanwhile,its practical PEMFC performance is a maximum power output of 628.0 mW cm^(-2)and a slight power density loss is 83.0 m W cm^(-2)after 200-cycle practical operation.Additionally,theoretical calculation shows that the activity of Fe Nxmoieties on ORR can be further enhanced by sulfur doping at meta-site near FeN_(4)C.These results evidently demonstrate that the dual effect of hard carbon substrate and S doping derived from the precursor platform of amid-polymers can effectively enhance the activity and durability of Fe-N-C catalysts,providing a new guidance for developing advanced M-N-C catalysts for ORR.

关 键 词：Transition metal-nitrogen-carbon Oxygen reduction reaction Hard carbon Amide based polymer reaction Proton exchange membrane cells 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O643.36[理学—物理化学]