Screening effects in surface infrared spectra of CO adsorbed on electrodes: application to isothermal desorption measurements Original Research Article

Infrared spectra of CO adsorbed on platinum electrodes were examined for effects of dielectric screening. Screening of the incident infrared radiation field by the adlayer polarization typically results in non-linear relationships between adsorbed CO vibrational band intensities and CO surface coverages. It is shown that the solvent in the electrochemical environment can reduce the strong Beer’s law deviations observed for adsorbed CO in vacuum by maintaining the adlayer polarizability more constant with changes in CO surface coverage. The screening analysis was applied to correct adsorbed CO infrared peak absorbances in measurements of rate constants for CO desorption from electrodes.