PtRu nanoparticles supported on phosphorous-doped carbon as electrocatalysts for methanol electro-oxidation

Abstract

P-doped carbonwas prepared by thermal treatment of commercial carbon Vulcan XC72 with H3PO4 at 800 °C. PtRu nanoparticles were supported on carbon Vulcan XC72 (C) and on P-doped carbon (P-C) using an alcohol reduction process. The obtained materials were characterized by energy-dispersive X-ray spectroscopy, Raman spectroscopy, X-ray diffraction, transmission electron microscopy, and cyclic voltammetry. The performance of the electrocatalyst was evaluated for methanol electro-oxidation. The intensities of D-band and G-band of Raman spectra were different for P-doped carbon and carbon Vulcan XC72. X-ray diffraction of PtRu/C electrocatalyst showed that Pt face-centered cubic phase and Ru amorphous phase coexist in thismaterial, while for PtRu/P-C electrocatalyst, it was observed the presence of PtRu alloy and Ru hexagonal close-packed phases. The use of P-doped carbon as support for PtRu nanoparticles improves the methanol electro-oxidation. This increase of activity could be attributed to a decrease of average nanoparticle sizes and/or more active Pt and Ru species resulting from metal-support interactions.