A simultaneous voltammetric and uv-visible reflectance spectroscopic investigation of the adsorption of carbon monoxide on a platinum electrode in aqueous solution

Abstract

The adsorption of carbon monoxide, CO, on a smooth platinum electrode has been studied by in situ UV-visible reflectance spectroscopy. Two kinds of adsorbed CO species are detected, depending on both the electrode potential and the degree of coverage. The interpretation of the relative reflectivity changes with respect to the coverage in CO ads species leads to the conclusion that bridge bonded CO is adsorbed first at low coverage, whilst linearly bonded CO predominates at high coverage. Furthermore the change of reflectivity due to the adsorption of the linearly bonded species is twice as great as for the adsorption of the bridge bonded species, which is in accordance with the number of electrons per site, eps, involved.