Electrochimica Acta, Vol.229, 253-260, 2017
One-pot synthesis of Pt/CeO2/C catalyst for enhancing the SO2 electrooxidation
SO2 is one of the critical poisoning species to Pt based catalysts of proton exchange membrane fuel cells (PEMFCs). Catalysts suffer severe performance degradation even trace amount of SO2 presenting in the hydrogen or air. To enhance the SO2 electrooxidation of Pt catalyst, we prepared Pt/CeO2/C composite catalysts via a one-pot synthesis method. The CeO2 nanoparticles initially deposited on carbon black, and followed by Pt nanoparticles selectively nucleating on CeO2 surface. The rich Pt-CeO2 interface facilitates the oxygen migration, enhancing SO2 electrooxidation and ORR activity. The catalysts containing 10 and 20 wt.% CeO2 show the best performance, i.e., peak potentials of SO2 electrooxidation are 0.06 and 0.09 V lower than Pt/C, respectively, ORR mass activity is over twofold greater, and area-specific activity is one fourth higher than Pt/C. Oxygen provided by CeO2 reduced the SO2 coverage on Pt surface and changed the dominant adsorbing state of SO2, hence, is vital to the SO2 electrooxidation. Besides, accelerated durability test confirmed that CeO2 could also improve the durability of Pt based catalysts. (C) 2017 Elsevier Ltd. All rights reserved.