View article

The oxidation of formic acid at single crystal Pt (111) and Pt (100) electrodes in aqueous sulphuric acid was investigated using in-situ IR spectroscopy. The strongly adsorbed poisoning species, CO_ads, was formed more slowly and to a lesser extent on the (111) surface. Correlation between the voltammetry and the spectra led to the assignment of broad bands near 1750 cm⁻¹ to absorption by reactive intermediates, probably (COOH)_ads. A detailed reaction scheme consistent with the electrochemical and spectroelectrochemical data and featuring linked, parallel pathways involving adsorbed poison and adsorbed reactive intermediate, is presented.