ON THE NATURE OF THE ABSORBATES RESULTING FROM THE CHEMISORPTION OF METHANOL AT A PLATINUM-ELECTRODE IN ACID-MEDIUM - AN EMIRS STUDY

The nature of the adsorbed species formed by chemisorption of aqueous methanol at platinum electrodes has been reexamined, particularly by taking into consideration the EMIRS vibrational spectra obtained below 1050 cm-1, a spectral range not investigated before. Apart from the bands due to adsorbed CO (linearly and bridge or multi-bonded to the surface) which was previously identified and recognized as a poisoning species, several other bands, corresponding to weakly adsorbed species, have been detected. Their interpretation led us to assign them tentatively to methoxy radicals, formate and formyl intermediates. Further structural information has also been obtained. It is suggested that methoxy species are bonded to the metal surface via the oxygen atom and that two types of formate intermediates result, linked by a single or by two oxygen atoms to platinum.