Effect of power ultrasound on the electrochemical platinum vertical bar HCOOH interface

The effect of ultrasound (f = 20 kHz) on the electrochemical behavior of a platinum electrode was investigated in aqueous media. A study of HCOOH oxid ation on platinum showed that low-intensity ultrasound (on the order of I-u s = 2 W cm(-2)) increases the potential oxidation zone and the current inte nsity. The catalytic activity of freshly reduced platinum was also observed to increase significantly under the effect of ultrasound, depending on the upper potential investigated during platinum oxidation. Monitoring the pot ential during electrolysis of formic acid at an imposed current with a plat inum electrode under ultrasound showed oscillating reactions characteristic of passivation/depassivation phenomena on the platinum electrode. (C) 2001 Elsevier Science B.V. All rights reserved.