Effects of platinum nano electrodeposits on corrosion of carbon substrate

The electrodes for the experiments were prepared by electrodepositing Pt on a carbon substrate. In the cyclic voltammograms of the carbon electrodes with and without Pt nano electrodeposits, the total anodic current including the currents from the oxygen evolution reaction and carbon corrosion increased abruptly above a critical potential. The oxidation overpotential of the carbon electrodes with Pt nano electrodeposits was lower than that of the bare carbon electrode. This phenomenon was more prominent at 75 °C than at 25 °C. In the potentiostatic experiments, the current transients and corresponding power spectral density (PSD) increased with increasing applied potential to the electrodes. Furthermore, the current transients for the carbon electrodes with Pt nano electrodeposits were much higher than those for the bare carbon electrode. This suggests that the corrosion of the carbon substrate can be accelerated by the Pt nano electrodeposits.

► The density of pulsed electrodeposited Pt nano particles reached a maximum and then decreased slightly, whereas the diameter of the deposits increased with time. ► The carbon corrosion was severed in the electrodes with Pt nano electrodeposits compared with that in the bare electrode, indicating the accelerated carbon corrosion due to the catalytic activity of the electrodeposited Pt. ► The model for the corrosion of the carbon substrate by Pt nano electrodeposits was proposed.