Connected Pt-Co Catalysts Possessing Chemically Ordered Structures for Improved Oxygen Reduction Performances

摘要

Polymer electrolyte fuel cells(PEFCs)are promising technol-ogy for transportation and stationary applications,owing to their high energy conversion efficiency and clean emissions.However,a sluggish oxygen reduction reaction(ORR)rate and the low durability of conventional catalysts in PEFCs limit the wider commercialization.To address these issues,our group has developed a carbon-free,connected plati-num-iron(Pt-Fe)na-noparticle catalyst with porous hollow capsule structure(Fig.1).This catalyst exhibits an enhanced ORR activity(9 times higher than a commercial Pt/C)as well as excellent durability against start-stop operations,due to the carbon-free structure.[1] However,during the load cycle operation,iron is dissolved from the catalyst,leading to the loss of ORR activi-ty.In addition,iron ions cause Fenton reaction,which gener-ates OH radicals,leading to the degradation of polymer elec-trolytes.Therefore,in this work,we developed a new carbon-free and iron free catalyst,connected platinum-cobalt(Pt-Co)with chemically ordered structures.And the effect of ordered structures on their ORR performances was discussed.