Study on the Relationship Between Catalytic Activity and C-N Structures of a Nitrogen-contained Non-precious Metal Catalyst for Oxygen Reduction Reaction

Abstract

A non-precious metal catalyst (CoMe/C) for oxygen reduction reaction was prepared by a simple procedure using acetylene black, melamine and cobalt chloride as raw materials. The relationship between catalytic activity and C-N structures of CoMe/C was investigated by X-ray photoelectron spectroscopy. Results show that the nitrogen atom exists as Co-N, pyrrolic C-N and pyridinic C-N structures in the CoMe/C catalyst. The Co-N structure has no activity to oxygen reduction reaction. Both pyrrolic and pyridinic C-N structures are the active sites of CoMe/C. The pyrrolic C-N structure is unstable than the pyridinic C-N structure in H 2 SO 4 solution. In heat treating process, the Co(II) ion is reduced to metallic β-cobalt which facilitates the formation of pyrrolic and pyridinic C-N structures to ensure the better activity of CoMe/C catalyst.

Fabrication of a nitrogen-doping carbon-based catalyst towards oxygen reduction reaction using ammonia as a single nitrogen source

“…However, the ORR catalytic activities of CoAmCs obtained at 700 and 800°C deteriorate due to the decomposition of formed active sites at a higher temperature. 18) It has been widely accepted that nitrogen atoms can enter into the graphene nanosheet of carbon black to form different types of C-N structures. Among them, the pyridinic (6-membered ring) and pyrollic (5-membered ring) C-N structures are the active sites Si et al: Fabrication of a nitrogen-doping carbon-based catalyst towards oxygen reduction reaction using ammonia as a single nitrogen source JCS-Japan to ORR.…”