title: Carbon nanotubes/heteroatom-doped carbon core-sheath nanostructures as highly active, metal-free oxygen reduction electrocatalysts for alkaline fuel cells.
abstract: A facile, scalable route to new nanocomposites that are based on carbon nanotubes/heteroatom-doped carbon (CNT/HDC) core-sheath nanostructures is reported. These nanostructures were prepared by the adsorption of heteroatom-containing ionic liquids on the walls of CNTs, followed by carbonization. The design of the CNT/HDC composite allows for combining the electrical conductivity of the CNTs with the catalytic activity of the heteroatom-containing HDC sheath layers. The CNT/HDC nanostructures are highly active electrocatalysts for the oxygen reduction reaction and displayed one of the best performances among heteroatom-doped nanocarbon catalysts in terms of half-wave potential and kinetic current density. The four-electron selectivity and the exchange current density of the CNT/HDC nanostructures are comparable with those of a Pt/C catalyst, and the CNT/HDC composites were superior to Pt/C in terms of long-term durability and poison tolerance. Furthermore, an alkaline fuel cell that employs a CNT/HDC nanostructure as the cathode catalyst shows very high current and power densities, which sheds light on the practical applicability of these new nanocomposites.
authors.affiliation: Department of Chemistry and School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Republic of Korea) http://shjoo.unist.ac.kr/; KIER-UNIST Advanced Center for Energy, UNIST, Ulsan 689-798 (Republic of Korea).
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Sa
authors.forename: Chiyoung
authors.initials: C
authors.lastname: Park
authors.forename: Hu Young
authors.initials: HY
authors.lastname: Jeong
authors.forename: Seok-Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Zonghoon
authors.initials: Z
authors.lastname: Lee
authors.forename: Kyoung Taek
authors.initials: KT
authors.lastname: Kim
authors.forename: Gu-Gon
authors.initials: GG
authors.lastname: Park
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Joo
keywords: carbon nanotubes; electrocatalysts; fuel cells; ionic liquids; oxygen reduction