A Pt-free Electrocatalyst Based on Pyrolized Vinazene-Carbon Composite for Oxygen Reduction Reaction

The 2-vinyl-4, 5-dicyanoimidazole (Vinazene) was used as a nitrogen precursor to synthesize a promising non-precious metal (NPM) catalyst for oxygen reduction reaction (ORR). Vinazene together with an iron source was impregnated into a carbon matrix and pyrolyzed at 900 degrees C in N-2 atmosphere. The structure of the resulting Fe-N-C nanocomposite was analyzed by X-ray photoelectron spectroscopy, Raman spectroscopy and X-ray diffraction. Both rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) experiments showed excellent ORR activity for the obtained catalyst with low H2O2 formation (similar to 3.0%) in 0.1 M KOH. The catalyst was found to be rich in mesoporous structure along with high percentage of pyrrolic-N function with surface area of about 673 m(2) g(-1) and pore size of 4.2 nm. In addition to its excellent ORR activity, the catalyst showed remarkable tolerance towards methanol oxidation and demonstrates good stability over 10,000 potential cycles (0.6-1.0V Vs RHE). We believe that this N-rich Vinazene molecule will be beneficial to further development of nitrogen doped carbon electrocatalysts. (C) 2015 Elsevier Ltd. All rights reserved.