Highly active nitrogen-doped nanocarbon electrocatalysts for alkaline direct methanol fuel cell

•N-doped nanocarbon cathode catalysts are studied for direct methanol fuel cell.•Pyrolysis in the presence of dicyandiamide is used for N-doping of carbon catalysts.•N-doped nanocarbon catalysts have high electrocatalytic activity for ORR in alkaline media.•N-doped carbon nanotube catalyst shows higher power density compared to Pt/C.

Direct methanol fuel cells are assembled and evaluated using Fumatech FAA3 alkaline anion exchange membrane. Two novel metal-free cathode catalysts are synthesised, investigated and compared with the commercial Pt-based catalyst. In this work nitrogen-doped few-layer graphene/multi-walled carbon nanotube (N-FLG/MWCNT) composite and nitrogen-doped MWCNT (N-MWCNT) catalyst are prepared by pyrolysing the mixture of dicyandiamide (DCDA) and carbon nanomaterials at 800 °C. The resulting cathode catalyst material shows a remarkable electrocatalytic activity for oxygen reduction reaction (ORR) in 0.1 M KOH solution employing the rotating disk electrode (RDE) method. Fuel cell tests are performed by using 1 M methanol as anode and pure oxygen gas cathode feed. The maximum power density obtained with the N-FLG/MWCNT material (0.72 mW cm−2) is similar to that of the Pt/C catalyst (0.72 mW cm−2), whereas the N-MWCNT material shows higher peak power density (0.92 mW cm−2) than the commercial Pt/C catalyst.

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