Formation of nanoporous platinum by selective dissolution of Cu from Cu0.75Pt0.25

Abstract

This paper gives results demonstrating the production of nanoporous platinum through the de-alloying of Cu_0.75Pt_0.25alloy in 1 M H₂SO₄. Both field emission scanning electron microscopy and small angle neutron scattering confirm the presence of porosity with a diameter of approximately 3.4 nm. This is the smallest porosity quantitatively reported from a de-alloying process to date. The small size is attributed to the extremely small values of surface diffusivity expected for Pt at room temperature, effectively eliminating room-temperature coarsening processes. The results also show that larger length scales can be achieved through coarsening at elevated temperatures. The ease of production of porous platinum makes it attractive for possible applications, such as high surface area electrodes for biomedical devices or as catalyst materials.