Pt Electrodes Modified by Ruthenium A Study in Tolerance

5 M HiSQ). Ruthenium packii dnisity was 0.22, 0.23. 036v 0.40, respectively. (AS Waszczuk eiat Cc iyright 2001 by Academic Press) 

In order to try to better understand the mechanism of enhanced CO tolerance, we undertook a C NMR investigation of chemisorbed CO on these Ru modified electrode surfaces. C NMR spectra recorded in a 14.1 T magnetic field showed the presence of two broad peaks for 

Double-Gauasian Deconvolution ofNMR Data and the Corresponding T, Data. 

The first term is the standard Korringa contribution in which T is the absolute temperature and a is the Korringa constant, obtained from the straight line fit at T 200 K. The second term accounts for surface 

From the EC-NMR data, we conclude that diffusion of CO on Pt/Ru islands is fast and that the exchange between these two different 

In order to try to better understand the mechanism of enhanced CO tolerance, we undertook a C NMR investigation of chemisorbed CO 

6 kHz and 5.7, 4.9, and 5.1 kcal/mol, for Pt/Ru-14, Pt/Ru-35, and Pl/Ru-52, respectively. For comparison, the activation energy for CO diffusion on pure Pt under the same electrochemical conditions has been previously determined to be 7.8 kcal/mol. Clearly, the presence of Ru substantially enhances surface diffusion for the CO molecules on Pt/Ru sites, but for the Pt sites, the effects are very small. Thus, COs bound to Ru are more mobile than those adsorbed on Pt and 

---