Investigation of Carbon Supported Ru–Pt Nanoparticles for High–Performance Electrocatalytic Oxidation of Methanol

摘要

Platinum-nanoparticle-based catalysts are fascinating and widely used in fuel cells. This study is an attempt to develop low-cost and high performance of carbon supported Ru-Pt nanoparticles (NPs) for direct methanol fuel cells (DMFCs). We have synthesized RuPt/C, Ru@Pt/C, RuPt/MWCNT, and Ru@Pt/MWCNT nanomaterials by a facile two-step reduction method. X-ray diffraction (XRD) shows the f.c.c. Pt and h.c.p. Ru phases and the NPs are under a slight compressed strains. The synthesized NPs obtained small mean sizes (dmean ≤ 3.9 nm) and narrow size distributions (1 – 9 nm). STEM-EDS line scan profiles reveal that architecture of Ru@Pt NPs composes of Ru-core and Pt-rich–Ru alloy shell, while that of RuPt alloy NPs exhibits random arrangement of Ru and Pt atoms. The Ru@Pt/MWCNT possessed the highest methanol oxidation activity with current density (Jf) of 182.4 -2 mA.cm and the lowest electron transfer resistance (Ret) of 606 Ω as compared with the other samples. The outstanding performance of Ru@Pt/MWCNT could be attributed to the high Pt dispersion, the strong synergetic effect of the Ru@Pt NPs (i.e. improving CO poisoning tolerance and enhancing the intrinsic activity of Pt), and the high porosity and electrical conductivity of MWCNT support. Int. J. Electrochem. Sci., Vol. 12, 2017 10188.