مرکز منطقه ای اطلاع رساني علوم و فناوري - ELECTROCHEMICAL OXIDATION OF FORMALDEHYDE ON THE PLATINUM ELECTRODE MODIFIED WITH LEAD AND COPPER ADATOMS

Abstract :

Platinum electrodes prepared thermally were modified by lead and copper adatoms electrochemically. The prepared electrodes were characterized by a scanning electron microscope. The micrographs showed that the platinum surface is rough and porous. The electrochemical modification of the platinum surface by copper and lead adatoms is characterized by the presence of clusters of those metals on the platinum surface. The electrochemical measurements made in perchloric acid have shown that the presence of the lead or copper adatoms on the electrode surface decreases the charge linked to the adsorption or desorption of hydrogen atoms. The electrocatalytic performance of the platinum electrode for formaldehyde oxidation was improved with lead adatoms but not with copper adatoms. The result obtained with the platinum electrode modified by lead adatoms was interpreted as a bifunctionnal behaviour of the electrode towards formaldehyde oxidation. For the platinum electrode modified by the copper adatoms, the onset of the formaldehyde oxidation potential is almost similar to that of pure platinum. That was explained either by the inactivity of copper towards formaldehyde oxidation or by the detachment of the copper adatoms from the electrode surface exposing the platinum active sites for the organic compound oxidation.