Variations in the total charge and the open-circuit potential during the CO adsorption on a platinum electrode in chloride solutions

Transients of the current and open-circuit potential, which occur during adsorption of CO on a Pt/Pt electrode in 1 M HCl and 0.5 M H2SO4 + 0-1 M HCl solutions, are measured. The potential dependences of the total charge in the presence and the absence of a monolayer of Co-ads are constructed. At potentials of the double-layer region (up to the CO oxidation potentials), the integral current transients quantitatively conform to the earlier-developed theoretical notions on the total-charge variations in the case of strong adsorption of neutral species on a hydrogen electrode. The CO chemisorption makes the potential of zero total charge much more positive and leads to the surface recharge. The possibility of a quantitative description of shifts in the open-circuit potential during the CO adsorption is analyzed.