Determination of the potential of zero charge of Pt/CO electrodes using an impinging jet system

Abstract

In this manuscript, the potential of zero charge (pzc) of platinum single-crystal electrodes has been determined using the impinging jet system and recording the transient associated with the interphase formation. Initially, the Pt(111), Pt(110), and Pt(100) electrodes covered with CO were used. To demonstrate the validity of the procedure, the values obtained for the pzc of these electrodes were compared with those previously reported in the literature and also with those expected from work function changes. An excellent agreement has been found. After that, the values for the pzc of the stepped surfaces having (111) terraces and (110) steps were determined. For these surfaces, the pzc initially diminishes as the step density increases, in accordance with the expected diminution of the work function due to the Smoluchowski effect on the step site. However, for the shorter terraces, the pzc value increases with the step density, probably because of step dipole-dipole coupling due to the presence of a CO layer on the electrode.