Herein we present a systematic study on the trends in activity of seven novel Pt-lanthanide electrodes (Pt5La, Pt5Ce, Pt5Sm, Pt5Gd, Pt5Tb, Pt5Dy and Pt5Tm). The materials are highly active, presenting a 3 to 6-fold activity enhancement over Pt [3-5], amongst the most active polycrystalline Pt-based catalyst ever reported. Moreover, our recent study showed that PtxGd is highly active in the nanoparticulate form . On the bulk alloys, a Pt overlayer with a thickness of few Pt layers is formed onto the bulk alloys by acid leaching (Fig. 1A) [3-5]. The ORR activity versus the lattice parameter obtained by X-ray diffraction measurements follows a volcano relationship (Fig. 1B). Furthermore, we explain the trends in stability, and present the lattice parameter as a new descriptor that controls both the activity and stability of these materials. Using the lanthanide contraction we demonstrate that the electrocatalytic performance can be engineered by tuning the Pt-Pt distance.
|Journal||Electrochemical Society. Meeting Abstracts (Online)|
|Number of pages||1|
|Publication status||Published - 2015|