Highly active and durable oxygen reduction reaction(ORR)catalysts with sufficient activity and stability of Pt are beneficial for the commercialization of proton exchange membrane fuel cells.Here we report an effectiv...Highly active and durable oxygen reduction reaction(ORR)catalysts with sufficient activity and stability of Pt are beneficial for the commercialization of proton exchange membrane fuel cells.Here we report an effective approach to prepare a composite catalyst comprising of ordered L1_(2)-Pt_(3)Fe intermetallic nanoparticles interact with single atom Fe-N_(x)-C_(y)active sites.The addition of Fe and the confinement effect of hierarchical porous structure limit the growth of intermetallic particle size(around2.5 nm).The ligand effect of the electron transfer from Fe to Pt and the synergistic interaction between L1_(2)-Pt_(3)Fe and Fe-N_(x)-C_(y)work together to reduce oxygen intermediates adsorption and improve kinetics process.Experimentally,the L1_(2)-Pt_(3)Fe/C_(Fe-N-C)catalyst shows high mass activity and specific activity at 1.010 A/mg_(Pt)and 1.166 mA/cm^(2),respectively,which are 5.8 and 5.1 times higher than those of commercial Pt/C(0.174 A/mg_(Pt)and 0.230mA/cm^(2)).Thanks to the more stable L1_(2)structure,L1_(2)-Pt_(3)Fe/C_(Fe-N-C)exhibits better durability(14mV E_(1/2)loss of L1_(2)-Pt_(3)Fe/C_(Fe-N-C)and 33 mV E_(1/2)loss of commercial Pt/C)after 30,000 cycles accelerated stress tests.The strategy to design and prepare small particle Pt-based intermetallic alloys coordinated with M-N-C active sites provides a new direction to obtain low-cost and easily prepared effective ORR catalysts.展开更多
基金supported by the National Science and Technology Major Project(No.2017YFB0102900)National Natural Science Foundation of China(Nos.21633008,21673221 and U1601211)Jilin Province Science and Technology Development Program(Nos.20200201001JC,20190201270JC and 20180101030JC)。
文摘Highly active and durable oxygen reduction reaction(ORR)catalysts with sufficient activity and stability of Pt are beneficial for the commercialization of proton exchange membrane fuel cells.Here we report an effective approach to prepare a composite catalyst comprising of ordered L1_(2)-Pt_(3)Fe intermetallic nanoparticles interact with single atom Fe-N_(x)-C_(y)active sites.The addition of Fe and the confinement effect of hierarchical porous structure limit the growth of intermetallic particle size(around2.5 nm).The ligand effect of the electron transfer from Fe to Pt and the synergistic interaction between L1_(2)-Pt_(3)Fe and Fe-N_(x)-C_(y)work together to reduce oxygen intermediates adsorption and improve kinetics process.Experimentally,the L1_(2)-Pt_(3)Fe/C_(Fe-N-C)catalyst shows high mass activity and specific activity at 1.010 A/mg_(Pt)and 1.166 mA/cm^(2),respectively,which are 5.8 and 5.1 times higher than those of commercial Pt/C(0.174 A/mg_(Pt)and 0.230mA/cm^(2)).Thanks to the more stable L1_(2)structure,L1_(2)-Pt_(3)Fe/C_(Fe-N-C)exhibits better durability(14mV E_(1/2)loss of L1_(2)-Pt_(3)Fe/C_(Fe-N-C)and 33 mV E_(1/2)loss of commercial Pt/C)after 30,000 cycles accelerated stress tests.The strategy to design and prepare small particle Pt-based intermetallic alloys coordinated with M-N-C active sites provides a new direction to obtain low-cost and easily prepared effective ORR catalysts.
