Nitrogen-doped graphene-like carbon from bio-waste as efficient low-cost electrocatalyst for fuel cell application

The development of metal-free carbon-based catalysts for alkaline fuel cells has been the subject of current interest, because of the low cost and improving fuel cell efficiency. Particularly, nitrogen-doped carbon shows prominent results. Here, we show an oxygen reduction reaction (ORR) activity of nitrogen-doped graphene-like carbon materials (N-GLC) prepared by heating bagasse-derived carbon and melamine in a 1:15 ratio. The N-GLC catalyst displays excellent electro-catalytic activity towards the ORR with an onset potential of 0.92 V vs. reversible hydrogen electrode (RHE) in alkaline media (0.1 M KOH). Moreover, the half-wave (E_1/2) potential 0.83 V is almost the same compared to Pt-C (40 wt%) catalyst and the diffusion limiting current of 4 mA cm^-2. The rotating ring disc experiment showed a four-electron pathway (n = 3.65) with the moderate peroxide (HO^-2) yield. Due to its promising ORR activity and long-term electrochemical stability, N-GLC catalyst is used in alkaline anion exchange membrane fuel cell (AEMFC) as a single cell, about 6 mW cm^- peak power density was achieved at the load current density of ~20 mA cm^-. So the N-GLC can be a cheap alternative ORR catalyst for AEMFC applications. (author)