LAUSR

Abstract Selective electrochemical oxidation of acetaldehyde in aqueous alkaline ethanol solutions on the silver-containing electrodeshas been presented. Several types of silver-containing electrode were used: the smooth silver disk electrode, rough silver electrode and the glassy carbon electrode modified with the silver-polypyrrole composite ink. Silver-polypyrrole (Ag-PPy) composite was synthesized via single-step chemical oxidation with the use of diluted aqueous solutions of silver nitrate and pyrrole in molar ratio 1:50. It has been shown that acetaldehyde is oxidized selectively on silver in the presence of ethanol in alkaline solutions. The influence of various factors (pH, the presence of molecular oxygen, ethanol and acetate anions, surface area extension and polypyrrole presence) on the aldehyde electrooxidation process has been studied. It was shown that for the silver-polypyrrole composites the aldehyde electrooxidation peak potential is shifted to negative direction in comparison with the silver electrode. However, the sensitivity of the silver-polypyrrolecomposite modified electrode is lower than for smooth or rough silver electrode. The addition of nitrate anions in alkaline solution permits to increase the peak currents for Ag-PPy modified electrode.