NiCo alloy nanoparticles encapsulated in N-doped 3D porous carbon as efficient electrocatalysts for oxygen reduction reaction

A series of N-doped three dimensional porous carbons loaded with NiCo alloy nanoparticles ([email protected]) have been successfully fabricated by a template-assisted in-situ pyrolysis strategy and the ORR activities of different-concentration alloy supported N-doped carbons are systematically investigated. The optimized sample exhibits a positive half-wave potential of 0.78 V (vs. RHE), a high diffusion-limited current density (5.120 mA cm−2), and a high durability over 92%, which is superior to the Pt/C. The excellent activity and stability are mainly due to synergistic effect between carbon matrix and NiCo alloy. The N-doped porous carbon support with high surface area and good conductivity not only provides more active sites but also promotes electron transport and mass transfer process. Furthermore, the unique core-shelled structure [email protected] can effectively avoid the dissolution and corrosion of alloy particles and the surface peeling of particles during the catalyze reaction, which is beneficial to improving the activity and stability.