Analysis of the Vibrational Spectrum of Carbon Monoxide on Platinum Metal Electrodes

摘要

The vibrational frequencies of carbon monoxide adsorbed on a platinum metal electrode are obtained in terms of discrete pairwise interatomic interactions. On the one hand, we show that there is a linear dependence of the shift in frequency with uniform linear changes in the binding energy of carbon and oxygen between the binding energy and the applied electrostatic potential; based on our model, we suggest that the relationship is linear. As a result, we predict a linear dependence of the frequency on electrochemical potential in accord with experiment. On the other hand, we demonstrate that the application of even a relatively large external electric field (of the order of 1,000,000,000 V/m) has only a minimum effect on the vibrational frequency shift. We conclude that the direct effect of the electrostatic field is unlikely to account for the observed spectral shifts.