Concave PtCo nanooctahedra with high-energy {110} facets for the oxygen reduction reaction

Cost-effective electrocatalysts for the oxygen reduction reaction (ORR) play significant roles in fuel cells and metal–air batteries. Herein, novel PtCo concave nanooctahedra (CNO) with high-energy {110} facets are successfully fabricated by a facile one-pot hydrothermal synthetic approach. Iminodiacetic acid (IDA) plays a crucial role as a structure-guiding agent in regulating the morphology of the PtCo CNO due to its strong chelation with metal ions through the two carboxyl groups and imino group. Benefiting from their unique concave structure and alloy effects, the obtained PtCo CNO exhibit excellent electrochemical activity and stability for the ORR relative to pure Pt nanoparticles (NPs) and commercial Pt black catalysts in alkaline media.