A pulse electrochemical deposition method to prepare membrane electrode assemblies with ultra-low anode Pt loadings through in situ construction of active core–shell nanoparticles on an electrode

Abstract

Ultra-low Pt loading membrane electrode assemblies (ULP MEAs) are prepared through in situ construction of core–shell Ir@Pt nanoparticles (Ir/Vulcan XC-72R as the core) on the surface of an electrode via a pulse electrochemical deposition (PED) approach. The core material is coated on a membrane with a conventional catalyst-coated membrane process prior to the deposition of the shell metal (Pt in this case). The ULP MEAs are characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The effects of a number of preparation parameters on cell performance are investigated in detail. The performance of the ULP MEA, in which the anode loadings of Pt and metals are ∼0.012 mg cm−2 and 0.044 mg cm−2(0.012 mg cm−2 Pt + 0.032 mg cm−2 Ir) respectively, is found to be competitive with that of an MEA prepared with an anode Pt loading of 0.1 mg cm−2 (commercial Pt/C catalyst from Johnson Matthey), manifesting the solid advantage of this in situ PED method.