kinetics of ethylene glycol electrooxidation on the noble metal-based nano-catalysts

A comparative electrooxidation of eg in the alkaline solution was investigated over pt, pd and au nanoparticle-modified carbon-ceramic electrode. the kinetic parameters of eg oxidation, i.e., tafel slope and activation energy (e a), were determined on the modified electrodes. the lowest e a value of 8.9 kj mol−1 was calculated on pt|cce. in continuation, the reaction orders with respect to the eg and naoh concentrations on pd|cce were found to be 0.4–0.2 and 0.6, respectively. an adsorption equilibrium constant (b) of 22.36 m−1 and the adsorption gibbs energy change (δg°) of −7.7 kj mol−1 were obtained on pd|cce. the chronopotentiometry (cp) and chronoamperometry (ca) results showed that pd|cce and then au|cce have better performance stability than pt|cce for eg electrooxidation. additionally, the electrochemical impedance spectroscopy (eis) suggested faster electron-transfer kinetics on pt than that on the pd and au electrocatalysts.