Novel Hydrotalcite Composites Membranes for Alkaline Fuel Cells

Abstract

In this work, hydrotalcite (Mg6Al2(CO3)(OH)16•4H2O, HT-CO32-) and an hydrotalcite-like (HT-CO32--OH-) compounds were characterized and used in the fabrication of composite membranes for alkaline fuel cells. HT-CO32--OH- was prepared from commercial hydrotalcite through anion exchange. The materials were characterized by X-Ray Diffraction, Infrared Spectroscopy, CHNS Elemental Analysis, N2 sorption and Dynamic Vapor Sorption. Composite membranes were prepared by casting method using a styrene/ethylene/butylene copolymer as binder. Water up-take and OH- ion conductivity measurements were performed on two independent set of composite membranes. The partial exchange of carbonate by hydroxyl anions increases the water content in the clay gallery. Higher values of water up-take and ion conductivity were measured for the composite membranes containing the HT-CO32--OH- form.