High metal content Pt-Ru alloy catalysts (80 and 90 wt.%) with various carbons were prepared by the colloidal method without increasing particle size. As increasing the specific areas Of Supporting materials, catalysts exhibited homogeneous dispersions. The 90 wt.% Pt-Ru/Ketjen Black showed the best performance as the anode catalyst in unit cell and the 80 wt.% Pt-Ru/Ketjen Black in electrochemical experiments. This difference comes from types of electrolytes, i.e. liquid and solid. (c) 2006 Elsevier Ltd. All rights reserved.