title: Mesoporous NiCo2O4Nanoplates on Three-Dimensional Graphene Foam as an Efficient Electrocatalyst for the Oxygen Reduction Reaction.
abstract: Catalysts for the oxygen reduction reaction (ORR) are highly important in fuel cells and metal-air batteries. Cheap ORR catalysts with ultrahigh electrochemical activity, selectivity, and stability are extremely desirable but still remain challenging. Herein, mesoporous NiCo2O4nanoplate (NP) arrays on three-dimensional (3D) graphene foam are shown to be a highly economical ORR catalyst. This mesoporous mixed-valence oxide can provide more electrocatalytic active sites with increased accessible surface area. In addition, graphene-foam-supported NiCo2O4NP arrays have a 3D hierarchical porous structure, which is of great benefit to ion diffusion and electron transfer. As a result, the mesoporous NiCo2O4NP arrays/graphene foam catalyst exhibits outstanding ORR performance with the four-electron reduction of O2to H2O in alkaline media. Furthermore, the mesoporous catalyst shows enhanced electrocatalytic activity with a half-wave potential of 0.86 V vs RHE and better stability compared with a commercial Pt/C catalyst.
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan 030001, China.
authors.forename: Xili
authors.initials: X
authors.lastname: Tong
authors.affiliation: Analytical Instrumentation Center, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan 030001, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan 030001, China.
authors.forename: Congxiu
authors.initials: C
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, and Department of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan 030001, China.
authors.forename: Xiang-Yun
authors.initials: XY
authors.lastname: Guo
keywords: NiCo2O4; electrocatalysis; graphene foam; mesoporous structure; oxygen reduction reaction