Proton exchange membrane fuel cells (PEMFC) are considered as a promising renewable energy source for a future hydrogen energy society. However, highly active and durable catalysts are required for the PEMFCs because of their high overpotential at the cathode and exposure under the harsh acidic condition for oxygen reduction reaction (ORR). Since the finding of the superior activity of Pt3Ni(111) for ORR, the many of octahedral PtNi nanoparticles have been reported and evaluated. However, their milligram-scale synthesis method and poor stability were obstacles for the commercialization of PEMFCs. In our study, we focus on gram-scale production of octahedral PtNi nanoparticles with Pt overlayers (PtNi@Pt), resulting in enhanced electrocatalytic activity and stability. Such PtNi@Pt nanoparticles show high mass activity (1.24 A mg-1Pt ) at 0.9 V (vs RHE), compared to commercial Pt/C (0.22 A mg-1Pt). Single-cell performance also showed enhanced current density of 3.1 A cm−2 at 0.6 V in O2 flow while the commercial Pt/C had the value of 2.5 A cm−2. After 30,000 cycles of the accelerated degradation test (ADT), the PtNi@Pt still showed better performance than the commercial Pt/C in a single-cell system. The Pt layers deposition could enhance the catalytic performance and stability of octahedral PtNi nanoparticles.

Gram-scale production of active and stable octahedral PtNi@Pt nanoparticles for proton exchange membrane fuel cell

256th National Meeting (2018)

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