Recent progress of Pt-based oxygen reduction reaction catalysts for proton exchange membrane fuel cells

With the increasing consumption of fossil fuels,proton exchange membrane fuel cells(PEMFCs)have attracted considerable attention as green and sustainable energy conversion devices.The slow kinetics of the cathodic oxygen reduction reaction(ORR)has a major impact on the performance of PEMFCs,and although platinum(Pt)can accelerate the reaction rate of the ORR,the scarcity and high cost of Pt resources still limit the development of PEMFCs.Therefore,the development of low-cost high-performance ORR catalysts is essential for the commercial application and development of PEMFCs.This paper reviews the research progress of researchers on Pt-based ORR catalysts in recent years,including Pt/C catalysts,Pt-based alloy catalysts,Pt-based intermetallic compounds,and Pt-based single-atom catalysts(SACs),with a focus on Pt-based alloy catalysts with different nanostructures.We described in detail the difficulties and solutions in the research process of various ORR catalysts and explained the principle of their activity enhancement with density functional theory(DFT).In addition,an outlook on the development of Pt-based catalysts is given,and reducing the amount of Pt used and improving the performance of catalysts are the directions to work on in the coming period.

Precise modification of poly(aryl ether ketone sulfone)proton exchangemembranes with positively charged bismuth oxide clusters for high proton conduction performance

In the field of proton exchange membranes(PEMs),it is still a great challenge to explore new Nafion alternatives,maintaining the high proton conductivity and lowering the cost of practical application.In this work,a series of low sulfonated poly(aryl ether ketone sulfone)(SPAEKS)membranes hybridized by[Bi_(6)O_(5)(OH)_(3)]_(2)(NO_(3))10⋅6H_(2)O(H_(6)Bi_(12)O_(16))have been successfully fabricated.When the doping amount of H6Bi12O16 reaches 5 wt%,the DS15-Bi12-5 showing the best proton conductive ability and mechanical properties.The proton conductivity can achieve 72.8 mS⋅cm−1 at 80℃ and the tensile strength can reach 43.57 MPa.Confirmed by experimental data and activation energy(Ea)calculations,the existence of Bi cluster makes more hydrogen bonds,providing additional proton hopping sites and offers more proton transport vehicles,leading to a high proton conduction performance.This work proved that polyoxometalates(POMs)can replace the role of sulfonate groups in SPAEKS to a certain extent and work out the defects of high sulfonation,making a remarkable contribution to the practical application of low sulfonated SPAEKS.