title: Fe-Cluster Pushing Electrons to N-Doped Graphitic Layers with Fe3C(Fe) Hybrid Nanostructure to Enhance O2Reduction Catalysis of Zn-Air Batteries.
abstract: Non-noble metal catalysts with catalytic activity toward oxygen reduction reaction (ORR) comparable or even superior to that of Pt/C are extremely important for the wide application of metal-air batteries and fuel cells. Here, we develop a simple and controllable strategy to synthesize Fe-cluster embedded in Fe3C nanoparticles (designated as Fe3C(Fe)) encased in nitrogen-doped graphitic layers (NDGLs) with graphitic shells as a novel hybrid nanostructure as an effective ORR catalyst by directly pyrolyzing a mixture of Prussian blue (PB) and glucose. The pyrolysis temperature was found to be the key parameter for obtaining a stable Fe3C(Fe)@NDGL core-shell nanostructure with an optimized content of nitrogen. The optimized Fe3C(Fe)@NDGL catalyst showed high catalytic performance of ORR comparable to that of the Pt/C (20 wt %) catalyst and better stability than that of the Pt/C catalyst in alkaline electrolyte. According to the experimental results and first principle calculation, the high activity of the Fe3C(Fe)@NDGL catalyst can be ascribed to the synergistic effect of an adequate content of nitrogen doping in graphitic carbon shells and Fe-cluster pushing electrons to NDGL. A zinc-air battery utilizing the Fe3C(Fe)@NDGL catalyst demonstrated a maximum power density of 186 mW cm-2, which is slightly higher than that of a zinc-air battery utilizing the commercial Pt/C catalyst (167 mW cm-2), mostly because of the large surface area of the N-doped graphitic carbon shells. Theoretical calculation verified that O2molecules can spontaneously adsorb on both pristine and nitrogen doped graphene surfaces and then quickly diffuse to the catalytically active nitrogen sites. Our catalyst can potentially become a promising replacement for Pt catalysts in metal-air batteries and fuel cells.
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Hu
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Mouyi
authors.initials: M
authors.lastname: Weng
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Tan
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Tian
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Joseph
authors.initials: J
authors.lastname: Amine
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Zheng
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Haibiao
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
authors.forename: Feng
authors.identifier: http://orcid.org/0000-0002-8216-1339
authors.initials: F
authors.lastname: Pan
keywords: Fe3C(Fe) cluster; N-doped graphitic layers; Oxygen reduction reaction (ORR); Synergistic effect; Zn−air batteries