Preparation and characterisation of Pt deposition on ion conducting membrane for direct methanol fuel cell electrodes

Abstract

Membrane-electrode assemblies (MEAs) for direct methanol fuel cells (DMFC) have been prepared by depositing platinum on the surface of solid polymer electrolytes (SPE). Chemical and electrochemical depositions were used to achieve good adhesion between platinum particles and the SPE and for reducing the contact resistance. Platinum particle structure and composition were investigated by means of SEM and EDX. Cyclic voltammetry (CV) and methanol oxidation tests were used to determine the electrochemical characteristics of the Pt-SPE electrodes which can be applied in DMFC. Overall the electrodes produced by chemical and electrochemical deposition of Pt onto the membranes are not as active as those produced by hot pressing carbon supported Pt catalyst layers onto the membrane.

Nafion Film-Templated Platinum Electrodes for Oxygen Reduction

“…They argued that deposited particles induced strain in the connecting channels during deposition, allowing them to be larger than the ordinary Nafion pores [13]. However, for the ∼200-nm clusters observed here and by Scott et al [20], it can be hypothesized that Pt deposition, while initiated in the hydrophilic pores of the film, reaches a final growth phase on the top surface of the Nafion. This generates a deposit that is mushroom-shaped in cross section.…”

“…The size of the clusters obviously exceeds the typical hydrated Nafion pore (ion cluster) size of 4 nm. Scott and co-workers reported very similar surface morphology for Pt deposited on Nafion 117 using NaBH 4 for 10 min [20]. Rollins et al obtained 10-15-nm Ag nanoparticles embedded in the structural cavities of Nafion employing also NaBH 4 as reductant [13].…”

Supported Pt and Pt–Ru catalysts prepared by potentiostatic electrodeposition for methanol electrooxidation

“…Electrodeposition in an aqueous solution offers an effective way to deposit platinum and other noble metal catalysts selectively at desired locations in the electrode with both ionic and electronic access [6]. Electrodeposition with pulse current [1,5,7], direct current [8], constant potential or consecutive potential steps [9][10][11][12][13][14][15][16][17][18] and cyclic voltammetry [19,20] have been used to deposit platinum and Pt-Ru bimetallic catalysts onto carbon substrates.…”

Fabrication of Pt-MWNT/Nafion Electrodes by Low-Temperature Decal Transfer Technique for Amperometric Hydrogen Detection

“…[4][5][6] Many attempts have been made to develop a Pt/ Nafion electrode as the key component in amperometric hydrogen sensors since Pt metal has an excellent electrocatalytic activity for hydrogen oxidation and both Pt and Nafion are chemically inert. Various deposition techniques were established to platinize the Nafion surface, including mechanically pressing, 7) vacuum sputtering, 8) electrochemical deposition, 9) and chemical deposition based on a Takenaka-Torikai method 10,11) and an impregnationreduction technique.…”