Electrochemical Reduction and Consumption of 4-Phenyl-3-buten-2-one

When benzylideneacetone (BDA), a commonly used brightener in the zinc plating process, is added to a solution containing Zn2+ ions in aqueous 0.5 M KCl and 0.1 M H-3 BO3, the zinc electroreduction potential shifts towards negative values by about 0.24 V to -1.28 V vs. SCE. Two stages are observed during the reduction of Zn2+ to zinc at -1.28 V in the presence of BDA. Besides Zn2+ reduction, the BDA, itself, is reduced in two steps at the mercury electrode. The BDA is reduced at a potential of -1.12 V versus saturated calomel electrode (SCE) for the first step, the formation of 4-phenyl-2-butanone and at -1.32 V vs. SCE for the second step, the formation of 4-phenyl-2-butanol. It was found that, Zn2+ ions do not form complexes with BDA in the substrate's concentrations used in the present study. The mineralization of the solution, which is the loss of organic compounds from solution, occurs during BDA electrolysis and is due to the rapid decomposition of BDA. The mineralization obtained after 60 minutes with current density of 0.015 A per square centimeter results in 16% loss of carbon content. (C) 2014 Elsevier Ltd. All rights reserved.