Se/Ru-Au nanocomposites provide enhanced-Electroactivity in direct methanol fuel cells

We have used an impregnation method to prepare Se/Ru-Au nanocomposites from 100-nm Se/Ru core-shell nanoparticles (NPs) and Au NPs (diameters 14, 32, or 56 nm). Au NPs tend to be adsorbed onto Se/Ru core-shell NPs to form Se/Ru-Au nanocomposites. We conducted transmission electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma mass spectrometry to characterize these nanocomposites. Se/Ru-Au nanocomposites have been used to prepare active electrodes in direct methanol fuel cells (DMFCs). Using cyclic voltammetry, we determined mass activities of the bimetallic Se/Ru-Au₁₄, Se/Ru-Au₃₂, and Se/Ru-Au₅₆ toward the oxygen reduction reaction to be 116.3, 73.0, and 87.7 A g^-1, respectively, which are much higher than those of traditional Ru_xSe_y catalysts. Cyclic voltammetry measurements have further revealed that Se/Ru-Au₁₄ electrodes remain highly active over at least 100 cycles. Owing to their ease of large-scale preparation, low cost, high electroactivity, and high stability, the Se/Ru-Au electrodes possess great potential for use in DMFCs.