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 COadsare 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.