Abstract: | Research on the underpotential deposition of H (upd H) and anion adsorption on Pt( 100) in 0.5 M aqueous H2SO4 solution by cyclic voltammetry (CV) indicates that the overall adsorption/desorption charge density is affected strongly by variation of the temperature T, and that it decreases by about 1/3 when T is raised from 293 to 328 K. The sharp peak at 0.375 V vs. RHE assigned to the anion adsorption decreases its potential, current density and charge density. The CV feature assigned to the upd H, a wide shoulder overlapping the sharp peak, also decreases with T augmentation, but the decline of its charge density is less pronounced. The results indicate that the Hupd and anion surface coverages, θHAN and θAN respectively are strongly temperature-dependent. This behavior may be assigned to lateral repulsive interactions. |