Nitrogen-self-doped carbon with a porous graphene-like structure as a highly efficient catalyst for oxygen reduction

Abstract

A non-noble metal nitrogen (N)-doped carbon catalyst, with a porous graphene-like structure, is prepared by pyrolyzing polyaniline with addition of urea. Herein, urea not only serves as a N source similar to polyaniline by incorporating N atoms into the carbon matrix, but plays a key role in forming the porous graphene-like structured carbon nanosheet. The electrochemical characterization shows that the prepared catalyst with a unique graphene-like structure exhibits an oxygen reduction reaction (ORR) activity that outperforms that of the commercial Pt/C catalyst in alkaline media, its half-wave potential nearly 30 mV more positive than Pt/C, and both superior stability and fuel (methanol and CO) tolerance to Pt/C. Significantly, such a catalyst also exhibits a good ORR activity which is comparable to Pt/C, as well as a higher stability than Pt/C in acidic media.