Nitrogen-Doping Effects on PtRu/C Anodes: Fundamental Study

Much research has been done on nitrogen doping of the anode and cathode catalyst carbon supports for PEM DMFC fuel cells due to its positive effect on both the methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR). The effect of the nitrogen doping has been obfuscated due the fact that past studies have been done on complex carbon powders, which by themselves have an effect on MOR and ORR. To separate the effects of complex carbons from nitrogen-doped carbon on MOR, diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) on nitrogen doped highly ordered pyrolytic graphite (HOPG) was performed. DRIFTS of CO oxidation over unmodified HOPG, Ar-bombarded HOPG with PtRu nanoparticles (Ar-HOPG-PtRu), and N-doped HOPG with PtRu nanoparticles (N-HOPG-PtRu) showed a redshift in the adsorbed CO stretching peak over N-HOPG-PtRu (2169 cm ^-1) in comparison to Ar-HOPG-PtRu and unmodified HOPG (2173 cm ^-1). N-HOPG-PtRu was also shown to oxidize CO more quickly than Ar-HOPG-PtRu or unmodified HOPG.