Stability of bismuth adlayers on Pt(111) electrodes in the presence of adsorbed organic compounds

The interactions of bismuth adlayers with adsorbed organic compounds on Pt(111) surfaces have been examined using voltammetric techniques. Evidence is provided that adsorbed CO affects bismuth adatoms giving rise to different adsorption states. After CO stripping, a potential excursion to negative potentials allows the surface diffusion of bismuth adatoms to take place in order to attain their most stable state on the Pt(111) surface. A similar effect on the bismuth adlayer is also carried out by tetrahydroxy-p-benzoquinone, an organic compound that exhibits a completely different behavior from that observed for CO adspecies on Pt(111) electrodes. (C) 1998 Elsevier Science S.A. All rights reserved.