Cyclic-voltammetry characteristics of poly(vinyl pyrrolidone) (PVP) on single-crystal Pt surfaces in aqueous H2SO4

In the present paper we investigated the electrochemical behavior of PVP on polycrystalline and single-crystal Pt electrodes. PVP hampered the characteristic hydrogen UPD and anion adsorption on all investigated surfaces. Several oxidation processes appeared in the anodic sweep with Pt(1 1 1) and Pt(1 0 0) being the most active for the oxidation processes. Repetitive cycling of the PVPads-modified Pt(1 1 1) or Pt(1 0 0) electrodes in PVP-free aqueous H2SO4 solution leads to a continuous suppression of the characteristic hydrogen UPD and anion adsorption as a consequence of PVP oxidation. However no PVP oxidation was observed when cycling the PVPads-modified Pt(1 1 0) electrode in PVP-free aqueous H2SO4 solution.