Fabrication and surface characterization of a novel approach for membrane electrode assembly using Nafion/PPy electrochemically coated with copper, nickel and silver

A novel approach is developed for the preparation of a membrane electrode assembly with low methanol crossover, designed for application in direct methanol fuel cells. This method involves a two-step process starting with the modification of a Nafion membrane through chemical oxidative polymerization of pyrrole, using FeCl₃ as an oxidant. Subsequently, galvanostatic electrodeposition of several metals (copper, nickel and silver) was performed on the previously prepared composite membrane (polypyrrole–Nafion). Scanning electron microscopy was conducted to examine the growth evolution, morphology and distribution of the deposited polypyrrole and metals. Additionally, X-ray photoelectron analysis enabled for the identification of elemental composition and chemical states within the coating to confirm the growth evolution, morphology and oxide phases present in the coatings, as well as their structural characteristics. © 2024 Society of Chemical Industry.