Using spontaneous deposition of ruthenium or electrolysis from ruthenium containing media, ruthenium-covered platinum single crystal electrodes were prepared, and were employed as catalysts for electrooxidation of methanol. The experiments were carried out using electrochemical techniques and electron spectroscopies of surface science. As before, structure/function measurements indicate that the Pt(111)/Ru electrode is the most effective catalyst. We show that at a typical potential of interest to methanol fuel cell technology (ca. 0.3 V vs. RHE), methanol oxidation reaction occurs at the surface which is covered by the chemisorbed CO at high coverage. In order to investigate temperature effects, we have constructed several Arrhenius plots for all Pt(hkl)/Ru surfaces investigated, and tabulated the apparent activation energies from the plots. The data indicate that the electrode surface structure is the controlling factor in these activation energies, as well as in the Tafel slopes (see also: W. Chrzanowski, A. Wieckowski, Langmuir, 14 (1998) 1967). Mechanisms involved in the studied heterogeneous reactions on the complex, bimetallic surfaces are discussed in extenso, albeit still on the qualitative level, while a more quantitative treatment is under development. With further efforts, this project may contribute to the design of small particle, fuel cell catalysts having activity superior to those that are considered presently for utilization in the direct oxidation methanol fuel cell.