title: Well-Defined ZIF-Derived Fe-N Codoped Carbon Nanoframes as Efficient Oxygen Reduction Catalysts.
abstract: A series of ZIF-derived Fe-N codoped carbon materials with a well-defined morphology, high surface area, tunable sizes and porous nanoframe structure was successfully prepared by synthesizing Fe-doped ZIF-8 through the assembly of Zn2+ions with 2-methylimidazole in the presence of iron(III) acetylacetonate, followed by pyrolysis at a high temperature and in an Ar atmosphere. The prepared optimum catalyst materials exhibited excellent activity for the oxygen reduction reaction (ORR) and outstanding durability in both acidic and alkaline solutions. We found that Fe doping during the ZIF-8 synthesis stage was crucial to achieve the materials' well-defined morphology, tunable size, good particle dispersion, and high performance. XPS revealed that Fe doping greatly enhanced the fractions of graphitic-N and pyridinic-N and decreased the fraction of oxidized-N. We suggest that the porosity and high surface area of the nanoframe structure originated from the metal-organic frameworks, the high dispersion of Fe in the nanoframe, and the enhanced proportions of active N species, all of which were responsible for the materials' significantly enhanced ORR performance.
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Yijie
authors.initials: Y
authors.lastname: Deng
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Guanghua
authors.initials: G
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Kailing
authors.initials: K
authors.lastname: Sun
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Xiudong
authors.initials: X
authors.lastname: Shi
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Long
authors.initials: L
authors.lastname: Zheng
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Li
authors.affiliation: The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology , Guangzhou 510641, China.
authors.forename: Shijun
authors.identifier: http://orcid.org/0000-0003-2481-0377
authors.initials: S
authors.lastname: Liao
keywords: ZIF-8; carbon nanoframes; fuel cell; high dispersion; oxygen reduction