D.-J. Liu
Argonne National Laboratory,
United States
Keywords: low Pt, high durability ORR catalyst
Summary:
At Argonne National Laboratory, we recently developed a new type of ORR catalyst by integrating low loading Pt over transition metal-nitrogen decorated, catalytically active carbon support derived from the zeolitic imidazolate frameworks (ZIF). The new catalyst not only demonstrated excellent platinum mass activity and polarization current density in PEM fuel cell test, but also showed very good durability during fuel cell voltage cycling in the accelerated stress test (AST). Various characterization tools including XPS, XRD, XAS, TEM have identified the new catalyst containing highly strained Pt-Co core-shell NPs over high-density and uniformly distributed Co/N/C and Co@graphene PGM-free active support. DFT calculation found two ORR catalytic routes over Pt and PGM-free active site with a crossover path at the formation of hydrogen peroxide, leading to synergistic catalysis. Our invention was recognized by a US patent and a R&D 100 Award.