Electrochemical Synthesis of Hydrogen Peroxide Catalyzed by Carbon Nanotubes with Surface Co-NX Sites and Encapsulated Co Nanoparticles

The exploitation of M-NX sites, where M is a transition metal atom, is widely regarded as an effective catalytic strategy to promote the oxygen reduction reaction (ORR). In addition, some studies have shown that transition metal nanoparticles (M NPs) coated with carbon layers can improve the reactivity of ORR and ameliorate the overpotential of the reaction. In this study, we synthesized carbon nanotubes with single-atom Co-NX active sites, Co-NPs outside the tube, and Co-NPs wrapped in the tube by the complexation-pyrolysis synthesis method and explored the role of the particles and Co-NX sites through different pickling steps. The catalyst synthesized with the new stratagem in this study shows outstanding selectivity and also ORR activity. Furthermore, a natural air diffusion electrode fabricated using this material can produce H2O2 at 323 mg L-1 h-1 under neutral conditions without oxygen aeration.

Automated summary

In this study, carbon nanotubes with single-atom Co-NX active sites, Co-NPs outside the tube, and Co-NPs wrapped in the tube were synthesized by the complexation-pyrolysis synthesis method, and the role of particles and Co-NX sites was explored. The catalyst synthesized with the new stratagem showed outstanding selectivity and ORR activity, and a natural air diffusion electrode fabricated using this material could produce H2O2 under neutral conditions without oxygen aeration.