Preparation and oxygen reduction electroactivity of metal nanoparticles loaded on sheet-like carbon composites

Herein, Co/C-N, Fe/C-N, and Fe-Co/C-N nanocomposites were obtained by the self-template method, and high. temperature pyrolysis of the mixture composed of dicyandiamide, sucrose, and cobalt (ferric) phthalocyanine as nitrogen, carbon, and metal sources respectively. Then a small amount of platinum was deposited on the Co/C-N with better oxygen reduction reaction (ORR) electroactivity by thermal reduction to obtain carbon nanosheet - supported Co-Pt nanoparticles (Co-Pt/C-N). The catalysts were well characterized and tested for ORR. The Co/C-N catalyst displayed the onset potential (E-onset) and half-wave potential (E-1/2) of ORR closed to the Pt/C in an alkaline solution, and it even presented the more positive onset potential and half. wave potential in a neutral solution. For Co-Pt/C-N, its ORR electroactivity in an acidic solution was greatly enhanced compared with the Co/C-N and was comparable to the Pt/C. The excellent ORR electroactivity of the samples is mainly attributed to the 3D structure formed by the carbon nanosheets, uniform distribution of the metal nanoparticles, and abundant pyridine N.

Automated summary

In this study, Co/C-N, Fe/C-N, and Fe-Co/C-N nanocomposites were synthesized using the self-template method and high-temperature pyrolysis. The catalysts showed excellent oxygen reduction reaction (ORR) electroactivity, especially Co-Pt/C-N which exhibited comparable activity to Pt/C in an acidic solution. The remarkable electroactivity of these catalysts can be attributed to the three-dimensional structure formed by carbon nanosheets, uniform distribution of metal nanoparticles, and abundant pyridine N.