ULTRASONIC EFFECTS ON ELECTROORGANIC PROCESSES .7. REDUCTION OF BENZALDEHYDES ON ULTRASOUND VIBRATING ELECTRODES

Ultrasound vibrators (titanium stepped horns at 20 kHz) themselves wer e used as cathodes for electroreduction of benzaldehydes in a methanol ic sulfuric acid solution. Three types of vibrating cathode were prepa red by partitioning the surface of the horns with insulating materials : tip-section loop, lateral node and lateral loop cathodes. The curren t efficiency for reduction and product selectivity for the correspondi ng hydrodimeric products were increased with increasing ultrasound osc illating power in different manners on the cathodes. The lateral catho des could exhibit the effect at relatively low ultrasonic powers compa red with the sectional one. In addition, higher efficiency and selecti vity were obtained at the lateral loop cathode than at the node one.