ADSORPTION AND ELECTROOXIDATION OF CARBON-MONOXIDE ON PLATINIZED PLATINUM AT LOW ANODIC POTENTIALS

Variations in the current (at E-r = const) and open circuit potential are measured upon bringing CO in contact with a Pt/Pt electrode in 0.5 M H2SO4 at E-r = 0.2-0.6 V. Chemisorption of CO is found to be accomp anied by changes in the structure of the electrical double layer and b y oxidation of CO. The chemisorption process affects adsorption of hyd rogen and oxygen more strongly than that of ions. Polarization curves for electrooxidation of CO in acidic solutions are recorded at various pH. At low E-r, the process is assumed to involve the activated compl ex [CO + (H2O)(n)](ads) and to be limited by a chemical stage (possibl y, dehydration of the reaction complex), rather than by electron trans fer.