Highly active metal-free nitrogen-containing carbon catalysts for oxygen reduction synthesized by thermal treatment of polypyridine-carbon black mixtures

A straight-forward method for the synthesis of metal-free catalysts for oxygen reduction by thermal treatment of a mixture of poly(3,5-pyridine) with carbon black in helium is reported. The catalyst was characterized by X-ray diffraction and photoelectron spectroscopy, cyclic voltammetry and rotating disk electrode measurements. The new catalyst exhibited remarkable activity similar to Pt-based catalysts in alkaline media.

Research highlights
► A method for synthesis of a metal-free catalyst for oxygen reduction was developed.
► The method involves pyrolysis of a mixture of polypyridine with Vulcan carbon.
► A polymer to carbon ratio of 2:5, pyrolyzed at 800 °C yielded the most active catalyst.
► The catalyst exhibits remarkable activity comparable to platinum based catalysts.