FTIR measurements of charge displacement adsorption of CO, on poly- and single crystal (100) of Cu electrodes

CO is reversibly adsorbed on a Cu electrode with simultaneous charge transf er, as observed by voltammetric measurements. In-situ FTIR measurements wer e conducted with a Cu(100) electrode in a phosphate buffer solution (pH 6.8 ) and a polycrystalline Cu electrode in a carbonate buffer solution (pH 10. 3). With increase of the negative potential, the infrared absorption band o f anions (phosphate anion and CO32-) diminishes at the potential of the cha rge transfer, whereas that of the adsorbed CO increases. Specifically adsor bed anions will remain still on the electrode surface below the potential o f zero charge (prc) to some extent. The apparent charge transfer is observe d at a potential below the pzc, where CO is adsorbed, displacing specifical ly adsorbed anions. (C) 1998 Elsevier Science Ltd. All rights reserved.