J. Phys. IV France 7 (1997) C2-955-C2-956
Characterization of Carbon Supported Pt/Ru Alloy Particles Using EXAFS SpectroscopyK.I. Pandya1, E.B. Anderson2, D.E. Sayers1 and W.E. O'Grady3
1 Department of Physics, North Carolina State University, Raleigh, NC 27695, U.S.A
2 PSI Technology Company, 20 New England Business Center, Andover, MA 01810, U.S.A.
3 Code 6170, Naval Research Laboratory, Washington, DC 20375, U.S.A.
Pt/Ru alloys are used for electrooxidation of methanol in direct methanol fuel cells. Their catalytic activity strongly depends upon the structure and composition of the alloy particles. We have investigated the structure of Pt/Ru alloy particles supported on high surface area carbon for three different compositions, namely Pt:Ru,8.5:1.5,1:1 and 1.5:8.5. The samples were prepared by impregnating the carbon with salt solutions of the two metals followed by reduction to the alloy. The total metal loading was 10 wt%. The PtL3 and Ru K EXAFS experiments were carried out at LN2 temperature on beamline X11A of NSLS. The data were analyzed to get consistent structural parameters from both the Pt and Ru EXAFS. The results show that the metals are completely alloyed and the average Pt-Ru distance is 2.70 Å. Difficulties which arose in the data analysis will be discussed.
© EDP Sciences 1997