(A) study on Pd-Pt Core-Shell catalysts for proton exchange membrane fuel cells

Abstract

In this study, we provide the Pd@Pt binary catalysts which have impressive activity in proton exchange membrane fuel cells (PEMFC) operation condition. Pt monolayer shell was formed on supported Pd core using modified Cu UPD method which is optimized for gram scale mass production of catalysts. Moreover, core shell structure decrease Pt ratio in catalyst, which can make catalyst cost less dependant to Pt. Also modified Cu UPD make core@shell catalyst more than 1g/batch, which can affect to mass production of catalysts and MEA, not only in laboratory level. The uniform Pt shell is essential not only for high durability but also for high activity. We characterized and evaluated core shell catalyst and commercial Pt/C at RDE system. Moreover we evaluated core shell catalysts at single cell system by making MEA with Pd@Pt core@shell catalysts. It has shown higher activity than commercial Pt/C, which can be explained by changes of lattice and electronic structure of the catalysts. Finally, catalysts composition and shape change were observed after accelerated stress test for proving high durability of dealloyed core@shell structure. The dealloyed core@shell catalyst has shown a notable.