Regulating electrocatalytic properties of oxygen reduction reaction via strong coupling effects between Co-NC sites and intermetallic Pt3Co

Abstract

Developing the Pt-based intermetallic nanoparticles could accelerate the sluggish kinetic of oxygen reduction reaction, while it remains a great challenge to explore efficient synthesis strategies enhancing thermal stabilities and electrocatalytic properties. This work employed the metal-support coupling strategy to construct the Pt3Co/CoNC hierarchical nanostructure, where the well-dispersed atomically ordered Pt3Co nanoparticles were anchored on the Co-NC sites. Physical structure analysis combined with density functional theory calculations demonstrated the strong coupling effect between Pt and surrounding Co-NC sites, which could weaken the activation energy to break O-O bonds and enhance the intrinsic activity and stability of Pt. Hence, the Pt3Co/CoNC exhibited the optimized ORR activities with the half-wave potentials of 0.97 V in KOH solution and displayed the peak power density of 187 mW cm−2 as the cathode of Zn-air battery. This metal-support coupling strategy can be further generalized and improved to synthesize other Pt-based catalysts with efficient electrocatalytic properties.