Oxygen Electroreduction on Platinum Nanoparticles Activated Electrodes Deposited onto D-Glucose Derived Carbon Support in 0.1 M KOH

Abstract

Electroreduction of oxygen on the microporous-mesoporous carbon material synthesized from D-(+)-glucose applying hydrothermal carbonization and activated additionally with carbon dioxide method has been studied at the unmodified and Pt-nanoclusters modified electrodes. Electrochemical experiments have been carried out in argon or oxygen saturated 0.1 M KOH solution using the cyclic voltammetry, rotating disk electrode and electrochemical impedance spectroscopy techniques. The carbon material modified with Pt-nanoclusters shows high cathodic current densities up to −67 A m−2 at 3000 rpm. Furthermore, the number of electrons transferred during the oxygen electroreduction is close to four, suggesting that the oxygen reduction reaction on the Pt-nanoclusters modified material could be dominated by a four-electron reduction pathway. The oxygen reduction reaction at unmodified material proceeds through a two-electron reduction pathway within the lower cathodic overpotential region, but changes to a four-electron reduction process within the higher cathodic overpotential region. Compared to the results of the same materials in 0.5 M H2SO4, higher catalytic activity has been determined in the case of 0.1 M KOH aqueous solution.