Nano-mediated uniform ternary Cu-Co-Ni-based nitrogen-doped carbon nanotubes with synergistic reactivity for high-performance oxygen reduction

Here, we report nano-mediated Cu-Co-Ni-based nitrogen-doped carbon nanotubes (N-CNTs/T-CCN) by hydrothermal and procedural calcination strategy. The nitrogen-doped carbon nanotubes (N-CNTs) show more average diameter and the N-CNTs are uniformly modified with ternary Cu-Co-Ni-based nanoparticles (T-CCN). The hybrid exhibits excellent ORR catalytic activity. The onset potential (E-onset) and half-wave potential (E-1/2) are 0.96 V and 0.87 V (versus reversible hydrogen electrode, RHE) in 0.1 M KOH. Most importantly, compared to 20% Pt/C, N-CNTs/T-CCN catalyst displays better methanol tolerance and higher stability. The H2O2 yield of the N-CNTs/T-CCN is less than 7.5% and the electron-transfer number (n) is about 3.9. High ORR performance may be related to the synergistic enhancement effect. The N-CNTs supply good electrical conductivity and allow large numbers of active sites to efficiently participate; the T-CCN can improve the local work function of the N-CNTs by synergistic electronic interaction and promote O-2 adsorption; the stability of embedded T-CCN can be greatly improved, mainly due to the weakness of Ostwald effect. All these advantages make the hybrid a promising ORR catalyst.

Automated summary

A nano-mediated Cu-Co-Ni-based nitrogen-doped carbon nanotube catalyst was synthesized by hydrothermal and procedural calcination methods, demonstrating excellent methanol tolerance and stability, with the synergistic enhancement effect playing a key role in improving catalytic performance.