Sulphur Dioxide Poisoning and Recovery of Platinum Nanoparticles: Effect of Particle Size

摘要

The effect of the size of platinum nanoparticles (nano-Pt) deposited onto glassy carbon (GC) electrode(GCano-Pt) on the SO2 poisoning and recovery is examined. Both hydrogen adsorption and oxygenreduction reaction (ORR) are utilized for the quantification of the extent of poisoning and recovery.Cyclic voltammetry (CV) and scanning electron microscopy (SEM) were used to characterize theGCano-Pt. Two procedures were used in the recovery of the electrodes activity, i.e., the short-range(1.0 to 0.1 V (vs. RHE)) and long-range (0 to1.5 V) recovery. GCano-Pt electrode showed Pt particlesize-dependent poisoning-recovery behavior. For the smallest Pt particle size (20 nm) used in thepresent study the largest extent of the recovery was achieved using either the short-range or long-rangerecovery procedure. The particles of 20 nm showed ~ 83% current recovery after the short-rangerecovery and ~100% after the long-range recovery, while those of the largest particle size (480 nm)used in this investigation showed only 67 and 87% current recovery after short-range and long-rangerecovery, respectively. An attempt to interpret the effects of the nanoparticles size on the poisoningand recovery behavior is introduced. The present experimental framework and analyses may help inthe optimization of the Pt particle size in the ORR and the choice of the recovery approach of SO2poisoning.