Anodos eletrocatalíticos para reforma interna de etanol em pilhas a combustível de óxido sólido

Abstract

Using the Pechini route, NiO and CGO powders were synthesized for the production and optimization of electrode and electrolyte suspensions of solid oxide fuel cell (SOFC). Aiming at the internal reform of ethanol in the SOFC anode, molybdenum oxides (MoO2) catalysts were tested in circular flat (50 mm diameter and ~ 0.4 mm thick) SOFC cells consisting of a cathodic layer, 2 electrolytic layers and 2 anodic layers. The physical chemistry characterization of the materials was performed using BET, X-ray diffraction and scanning electron microscopy techniques. Theelectrochemical performance of the SOFC cell was evaluated by electrochemical impedance spectroscopy and linear voltammetry. The complete SOFC cell in the presence of the MoO2-based catalyst showed low polarization strength of 0.51 ohm.cm-2, current density of 0,98 A.cm-2 and maximum power density of 404 mW cm-2, using as fuel a mixture of 33% (v / v) ethanol in water fed directly into the anode at 740 ° C. The results with the cell without the catalyst using hydrogen as fuel were;polarization resistance 0.88 ohm.cm-2, current density 0.65 A.cm-2 maximum power density 334 mW cm-2. The results point to a good electrochemical performance and a promising catalytic activity of MoO2 for direct ethanol reform. Performance can be improved by optimizing film thickness and molybdenum concentration in the anode.