An innovative catalyst of nickel-palladium alloy nanocrystals embedded nitrogen-doped graphene for efficient oxygen reduction reaction

A novel hybrid based on non-precious metal catalysts embedded into nitrogen doped graphene nanosheets was developed for oxygen reduction reaction (ORR) by pyrolyzing a mixture of Ni, Pd salts, nitrogen source, and graphene oxide. Scanning electron microscopy, transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy analyses indicated the binary NiPd nanoparticles good dispersed on nitrogen-doped graphene sheet (NiPd NPs/N-GR) under a unique core-shell nanostructure with high interaction, thereby creating massive catalytic sites and boosting the activity towards ORR in alkaline medium. The electrochemical measurements showed the onset and half-wave potential of the NiPd NPs/N-GR were +0.961 and +0.82 V, respectively, indicating a comparable catalytic behavior to a commercial Pt/C product (20 wt%). In addition, such catalyst also exhibited superior stability and methanol tolerance ability to Pt/C. The achieved superiorities of the NiPd NPs/N-GR imply that this material is potential to replace Pt-based catalysts in for ORR applications. (C) 2019 Elsevier B.V. All rights reserved.