Temperature effect on the recovery of SO2-Poisoned GC/Nano-Pt electrode towards oxygen reduction

The SO2 poisoning of Pt nanoparticle (n-Pt) modified glassy carbon (GC/n-Pt) electrode and the recovery of its activity for the oxygen reduction reaction (ORR) were studied using cyclic voltammetry at ambient (25 A degrees C) and elevated (70 A degrees C) temperatures. Recovery of the GC/n-Pt electrode by cycling the potential within the ORR range (1.0 to 0.2 V (standard hydrogen electrode)) in 0.1 M H2SO4 was not effective at 25 A degrees C, but at 70 A degrees C the onset potential of the ORR was almost the same as that at the fresh GC/n-Pt electrode. For the two different temperatures used here, the recovery on cycling the potential between 0.4 and 1.7 V was efficient. However, the number of cycles and the amount of charge required for the recovery at 70 A degrees C were the smallest, which is of great interest for the proton exchange membrane fuel cell performance. The recovery using such a wide potential range at 70 A degrees C resulted in an enhancement of the electrocatalytic activity of the GC/n-Pt electrode over a non-poisoned (bare) GC/n-Pt electrode.