Urchin-Shaped Hollow Iron-Nitrogen-Doped Carbon Microspheres as High-Performance Electrocatalysts for Oxygen Reduction. Issue 4 (1st January 2017)

• Record Type: Journal Article
• Authors: Park, Min Jung; Kwon, S. Joon; Park, Hyun S.; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Nam, Suk Woo; Kim, Jin Young
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 4(2017)
• Page Start: F224
• Page End: F228
• Publication Date: 2017-01-01
• Subjects: Electrocatalyst -- Oxygen reduction -- PEMFC; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0291704jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Oxygen reduction reaction (ORR) kinetics are enhanced in alkaline media. Hence, alternative non-platinum (Pt)-group metal electrocatalysts have been investigated extensively in this medium to compete with Pt in terms of performance and durability. Among various non-Pt catalysts, one of the most popular class of electrocatalysts is iron- and nitrogen-doped carbon-based (Fe–N–C) by the high electrocatalytic activity and selectivity in ORR. However, the inherent catalytic reactivity of such non-Pt electrocatalysts remains inferior to that of state-of-the-art Pt electrocatalysts. Here, we explore the ORR of hollow and urchin-like, three-dimensional (3D) nanostructured Fe–N–Cs prepared via polymerization-induced self-assembly of aniline followed by carbonization. The resulting Fe–N–Cs consist of a hollow microsphere framework coupled with nanorod bundles, and exhibit large surface areas (874 m 2 g −1 ), hierarchical cavities, and excellent electrical conductivities (0.63 Scm −1 ) as electrodes. They are of particular interest as oxygen reduction electrocatalyst for proton exchange membrane fuel cells (PEMFCs). These unique features, which enhance electrocatalytic efficiency, are attributed to efficient mass- and electro-transport ORR kinetics. Electrochemical experiments reveal improved onset (ca. 1.04 V) and half-wave potentials (ca. 0.9 V), which is comparable to those of commercial Pt electrocatalysts. The 3D hierarchical porous network with high interdigitation of well-dispersed nanorod building blocks is thought to be key to facilitating the ORR reaction.