title: Triangular trinuclear metal-N4 complexes with high electrocatalytic activity for oxygen reduction.
abstract: A new class of macrocyclic metal-N(4) complexes [MN(4)](n) (M = Co and Fe) were designed and synthesized based on a triangular ligand. Their unique triangular trinuclear structure provides a high density of active sites and facilitates the reduction of dioxygen via a four-electron pathway. Among them, a [CoN(4)](3)/C catalyst (20 wt %) exhibits high catalytic activity and long-time stability for the oxygen reduction reaction (ORR) in alkaline conditions, superior to the commercial Pt/C catalyst. Such structurally well-defined [MN(4)](n) complexes provide a platform for a new generation of nonprecious metal catalysts (NPMCs) for fuel cell applications.
authors.affiliation: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Ruili
authors.initials: R
authors.lastname: Liu
authors.forename: Christian
authors.initials: C
authors.lastname: von Malotki
authors.forename: Lena
authors.initials: L
authors.lastname: Arnold
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Koshino
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Higashimura
authors.forename: Martin
authors.initials: M
authors.lastname: Baumgarten
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen