摘要
质子交换膜燃料电池(PEMFC)中使用的高成本铂族金属(PGM)催化剂阻碍了其广泛应用.尽管使用低铂负载量的燃料电池可以很大程度克服这一挑战,但是电池的高电流密度性能将因此严重降低.为了克服这一两难困境,我们报道了超细铂钴纳米线(PtCoNWs)作为超低铂负载和高性能膜电极组件(MEA)阴极催化剂的开发.PtCoNWs在MEA中的氧还原反应(ORR)展现出1.06±0.14 Amg_(Pt)^(-1)的破纪录的高质量活性(MA),因此获得了5.14 W_(rate)mg_(Pt)^(-1)的极佳的铂利用率.在30,000次方波加速稳定性测试(AST)后,PtCoNW保持了0.45 Amg_(Pt)^(-1)的可观的终止寿命(EOL)质量活性,仍高于美国能源部2020年催化剂寿命开始(BOL)目标.原位X射线吸收光谱(XAS)研究表明,PtCoNWs中的高度合金化稳定了超细结构,并可能有助于PEMFC中的高ORR活性和功率密度性能.
The high cost of platinum(Pt)-group metal(PGM)-based catalysts used in proton-exchange membrane fuel cells(PEMFCs)poses a critical roadblock to their widespread adoption.Although using low PGM loading PEMFCs can largely address this challenge,high current density performance will be severely compromised consequently.To overcome this dilemma,we report the development of ultrathin platinum-cobalt nanowires(PtCoNWs)as the cathode catalysts for ultralow Pt loading and high-performance membrane electrode assembly(MEA).The Pt Co NWs delivered a record-high mass activity(MA)of 1.06±0.14 A mg_(Pt)^(-1) of Pt-alloy catalysts towards oxygen reduction reaction(ORR)in MEA,yielding an impressive total Pt utilization of 5.14 W_(rate)mg_(Pt)^(-1).The PtCoNWs retained a respectable endof-life MA of 0.45 Amg_(Pt)^(-1) after the 30,000 cycles square-wave accelerated stability test,which is still above the Department of Energy 2020 beginning-of-life target for catalysts.In-situ Xray absorption spectroscopy studies suggest that the high degree of alloying in the Pt Co NWs stabilizes the ultrathin structure and may contribute to the high ORR activity and power density performance in PEMFC.
作者
黄进
彭博思
Thomas Stracensky
刘泽延
张翱
徐明杰
刘洋
赵紫鹏
段镶锋
贾晴鹰
黄昱
Jin Huang;Bosi Peng;Thomas Stracensky;Zeyan Liu;Ao Zhang;Mingjie Xu;Yang Liu;Zipeng Zhao;Xiangfeng Duan;Qingying Jia;Yu Huang(Department of Materials Science and Engineering,University of California,Los Angeles,CA 90095,USA;Department of Chemistry and Biochemistry,University of California,Los Angeles,CA 90095,USA;Department of Chemistry and Chemical Biology,Northeastern University,Boston,MA 02115,USA;Irvine Materials Research Institute,University of California,Irvine,CA 92697,USA;Department of Materials Science,University of California,Irvine,CA 92697,USA;California NanoSystems Institute,University of California,Los Angeles,CA 90095,USA)
基金
support from the Office of Naval Research(N000141812155)
support from the National Science Foundation(DMREF 1437263)
supported in part by the National Science Foundation through the UC Irvine Materials Research Science and Engineering Center(DMR-2011967)。
