Analysis of the electrochemical performance of MoNi-CeO2 cermet as anode material for solid oxide fuel cell. Part I. H2, CH4 and H2/CH4 mixtures as fuels

This paper investigates the catalytic activity and the electrochemical performance of bimetallic formulation combining Mo and Ni with CeO2 (MoNi-Ce) in relation its potential use as anode material for SOFC. The catalytic properties were evaluated for methane partial oxidation as function of temperature and the carbon deposition on the anode surface was analysed by TG-MS. A conversion of 12.8% was reached for partial methane oxidation at 850 degrees C as well as a high coke resistance. The electrochemical performance was studied in a single cell with La0.58Sr0.4Fe0.8Co0.2O3-delta (LSCF) as cathode, La0.9Sr0.1-Ga0.8Mg0.2O2.85 (LSGM) as electrolyte and MoNi-Ce as anode. A thin buffer layer of La0.4Ce0.6O4-delta (LCD) between anode and electrolyte was used to avoid possible interfacial reactions. The cell was tested in different humidified fuels (H-2, CH4 and H-2/CH4 mixtures) and static air at 750, 800 and 850 degrees C. The electrochemical behaviour was evaluated by current voltage curves, impedance spectroscopy and load demand. Stability tests were also performed in pure CH4 at each studied temperature in order to assess degradation of the electrochemical cell performance. No significant performance degradation was detected in all studied fuels even pure methane, which suggests that MoNi-Ce is a suitable anode material for direct methane SOFC. (C) 2013 Elsevier B.V. All rights reserved.