abstract
The electrocatalytic activity of composite anodes, consisting of micron-scale sized Pt particles and nanocrystalline Ce0.8Gd0.2O2-delta(CGO) prepared by the cellulose-precursor technique, was evaluated for the oxidation of dry methane in a solid oxide fuel cell (SOFC) with zirconia-based electrolyte at 1173 K. Increasing current density above 100 mA/cm(2) and the corresponding decrease of CH4/O-2 ratio down to 2-3 suppressed carbon formation, but decreased CO/CO2 molar ratio in the product mixture to 0.3-0.9. The methane conversion rate was found to increase linearly with current, suggesting an increasing role of total CH4 oxidation by oxygen electrochemically supplied onto the anode surface. The results show that, although ceria-based anode components are well known to improve SOFC performance, their presence leads to high CO2 selectivity and thus seems inappropriate for the generation of synthesis gas in SOFC-type reactors. (C) 2003 Elsevier B.V. All rights reserved.
keywords
OXIDE FUEL-CELLS; SYNTHESIS GAS; SYNGAS; CERIA; MICROSTRUCTURE; HYDROCARBON; CONDUCTION; REACTOR; CR
subject category
Chemistry
authors
Yaremchenko, AA; Valente, AA; Kharton, VV; Bashmakov, IA; Rocha, J; Marques, FMB
our authors
Aleksey Yaremchenko
Principal Researcher
Anabela Tavares Aguiar Valente
Principal Researcher
Fernando Manuel Bico Marques
Full professor
João Rocha
Full Professor