Monday, 29 May 2017: 10:30
Grand Salon B - Section 7 (Hilton New Orleans Riverside)
Polymer electrolyte membrane fuel cells (PEMFCs) are the most attractive power source for vehicles with zero CO2 emission, low weight and volume, high power density, and high efficiency. However, high cost and low durability of PEMFCs have prevented the highly efficient technologies from being fully implemented and commercialized, mainly due to the use of noble platinum catalyst in the electrodes. To reduce the Pt usage, platinum and nickel (Pt-Ni) alloy catalysts with controlled shapes have been developed over the past years. In particular, PtNi octahedral catalysts exhibited significant enhancement of ORR performance with well-extended (111) facet. Here, we report metal-doped PtNi octahedral nanoparticles on carbon support (M-PtNi/C) for oxygen reduction reaction (ORR) in PEMFCs. M-PtNi/C catalysts showed high mass activity compared with commercial Pt/C and undoped octahedral PtNi/C catalysts. The M-PtNi/C catalysts not only showed remarkable enhancement in an initial ORR performance, but also exhibited a great stability in a voltage-cycling test with keeping the initial Ni concentration in the nanoparticles. They maintained the initial octahedral shape after the durability test, while the PtNi/C catalyst lost its initial octahedral shape and the Ni atoms in the PtNi/C catalyst were dissolved during the first a few cycles. These results demonstrate that M-PtNi/C catalysts can be utilized as a new active and durable ORR catalyst for PEMFCs.