On the preparation and stability of bimetallic PtMo/C anodes for proton-exchange membrane fuel cells

Synthesis of the bimetallic carbon supported PtMo electrocatalysts via the reductive co-precipitation with either formaldehyde or formic acid as reducing agent is presented. The materials synthesised were characterised with respect to their bulk and surface composition using inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The electrochemical behaviour of the materials was characterised with the help of cyclic voltammetry in sulfuric acid solutions as well as in membrane-electrode assemblies (MEAs). The stability of the electrocatalysts was also investigated. Our experimental results also show that bimetallic PtMo/C catalysts are apparently inherently unstable and suffer from the gradual loss of Mo due to its dissolution into the electrolyte, regardless of whether the components are well-mixed or present in the segregated phases.