title: Uniform Fe3O4/Nitrogen-Doped Mesoporous Carbon Spheres Derived from Ferric Citrate-Bonded Melamine Resin as an Efficient Synergistic Catalyst for Oxygen Reduction.
abstract: Developing a facile strategy to synthesize an efficient and inexpensive catalyst for the oxygen reduction reaction (ORR) is critical to the commercialization of many sustainable energy storage and conversion techniques. Herein, a novel and convenient strategy was presented to prepare Fe3O4embedded into nitrogen-doped mesoporous carbon spheres (Fe3O4/N-MCS) by the polycondensation between methylolmelamines and ammonium ferric citrate (AFC) and subsequent pyrolysis process. In particular, the polycondensation reaction was completely finished within a very short time (6.5 min), and the iron contents can be adjusted and had a great influence on the microstructure. Moreover, the Fe3O4/N-MCS can be used as a robust catalyst for the ORR in alkaline media, and the catalyst with the iron content of 3.35 wt % exhibited excellent electrochemical performance in terms of more positive onset potential (E0= 1.036 V vs RHE) and half-wave potential (E1/2= 0.861 V) and much better methanol tolerance and long-term durability, in comparison with that of 20% Pt/C. The remarkable performance was ascribed to the characteristics of large specific surface area, mesoporous structure, high contents of pyridinic N and graphitic N, as well as strong electronic interaction between Fe3O4and protective N-doped graphitic layers.
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Gui
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Asif
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Zhengyun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Junwu
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology , Wuhan, 430074, P.R. China.
authors.forename: Hongfang
authors.identifier: http://orcid.org/0000-0002-9180-6629
authors.initials: H
authors.lastname: Liu
keywords: ammonium ferric citrate; iron oxides; mesoporous structure; nitrogen-doped carbon matrices; oxygen reduction reaction