title: Fe-N-Doped Carbon Capsules with Outstanding Electrochemical Performance and Stability for the Oxygen Reduction Reaction in Both Acid and Alkaline Conditions.
abstract: High surface area N-doped mesoporous carbon capsules with iron traces exhibit outstanding electrocatalytic activity for the oxygen reduction reaction in both alkaline and acidic media. In alkaline conditions, they exhibit more positive onset (0.94 V vs RHE) and half-wave potentials (0.83 V vs RHE) than commercial Pt/C, while in acidic media the onset potential is comparable to that of commercial Pt/C with a peroxide yield lower than 10%. The Fe-N-doped carbon catalyst combines high catalytic activity with remarkable performance stability (3500 cycles between 0.6 and 1.0 V vs RHE), which stems from the fact that iron is coordinated to nitrogen. Additionally, the newly developed electrocatalyst is unaffected by the methanol crossover effect in both acid and basic media, contrary to commercial Pt/C. The excellent catalytic behavior of the Fe-N-doped carbon, even in the more relevant acid medium, is attributable to the combination of chemical functions (N-pyridinic, N-quaternary, and Fe-N coordination sites) and structural properties (large surface area, open mesoporous structure, and short diffusion paths), which guarantees a large number of highly active and fully accessible catalytic sites and rapid mass-transfer kinetics. Thus, this catalyst represents an important step forward toward replacing Pt catalysts with cheaper alternatives. In this regard, an alkaline anion exchange membrane fuel cell was assembled with Fe-N-doped mesoporous carbon capsules as the cathode catalyst to provide current and power densities matching those of a commercial Pt/C, which indicates the practical applicability of the Fe-N-carbon catalyst.
authors.affiliation: Instituto Nacional del Carbón (CSIC) , P.O. Box 73, Oviedo 33080, Spain.
authors.forename: Guillermo A
authors.initials: GA
authors.lastname: Ferrero
authors.forename: Kathrin
authors.initials: K
authors.lastname: Preuss
authors.forename: Adam
authors.initials: A
authors.lastname: Marinovic
authors.affiliation: Department of Chemistry, University College London , WC1H 0AJ London, U.K.
authors.forename: Ana Belen
authors.initials: AB
authors.lastname: Jorge
authors.affiliation: Department of Chemical Engineering, University College London , WC1E 7JE London, U.K.
authors.forename: Noramalina
authors.initials: N
authors.lastname: Mansor
authors.affiliation: Department of Chemical Engineering, University College London , WC1E 7JE London, U.K.
authors.forename: Dan J L
authors.initials: DJ
authors.lastname: Brett
authors.affiliation: Instituto Nacional del Carbón (CSIC) , P.O. Box 73, Oviedo 33080, Spain.
authors.forename: Antonio B
authors.initials: AB
authors.lastname: Fuertes
authors.affiliation: Instituto Nacional del Carbón (CSIC) , P.O. Box 73, Oviedo 33080, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Sevilla
authors.forename: Maria-Magdalena
authors.initials: MM
authors.lastname: Titirici
keywords: capsule; carbon nanomaterial; nitrogen-doping; non-noble metal catalysts; oxygen reduction reaction