Electrochemical oxidation of ethanol on thin coating of platinum based material on nickel support

Abstract

For the development of cost effective direct alcohol fuel cells, the key point for anodic oxidation of ethanol is the search for a cheaper electrocatalyst which can effectively increase the current density and decrease the anodic overvoltage. In this respect, thin deposits of platinum and co-deposits of platinum and ruthenium on Ni- support from different baths,

have been studied taking 1<i>M </i>ethanol in 1<i>M </i>NaOH solution. Polarization and chronopotenti ometric studies indicate the intrinsic superiority of Ni/Pt-Ru electrodes over Ni/Pt and Ni electrodes, but the overall electrocatalytic activity of the coated electrodes follows the order: Ni/Pt (PVA) > Ni/Pt > Ni/Pt-Ru(PVA) > Ni/Pt -Ru > Ni, (where PVA is polyvinyl alcohol). An increase in the roughness factor due to smaller size (150nm ) of deposit of Pt than co-deposit of Pt and Ru under the experimemal deposition condition may be the cause of the above mentioned order. Steady state polarization, cyclic voltammetry, chromopotentiometry and SEM images have been used to correlate the catalytic activity of such electrodes with the characteristics of the deposits and surface morphology.