RT journal article
T1 Performance of a Direct Methane Solid Oxide Fuel Cell Using Nickel-Ceria-Yttria Stabilized Zirconia as the Anode
A1 Escudero, María José
A1 Yeste Sigüenza, María del Pilar
A1 Cauqui López, Miguel Ángel
A1 Muñoz, Miguel Ángel
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 alternative anode
K1 Ni-Ce-YSZ
K1 methane oxidation
K1 SOFC
K1 impedance spectroscopy
K1 ong-term tests
AB A nickel-ceria-yttria stabilized zirconia (Ni-CYSZ) cermet material was synthesized and tested as the anode for the direct oxidation of methane in a solid oxide fuel cell (SOFC) with YSZ as the electrolyte and strontium-doped lanthanum manganite (LSM) as the cathode. Initially, the electrochemical behavior was investigated under several load demands in wet (3% H2O) CH4 at 850 degrees C during 144 h using I-V curves, impedance spectra, and potentiostatic measurements. Long-term tests were subsequently conducted under 180 mAcm(-2) in wet CH4 for 236 h and dry CH4 for 526 h at 850 degrees C in order to assess the cell stability. Material analysis was carried out by SEM-EDS after operation was complete. Similar cell performance was observed with wet (3% H2O) and dry CH4, and this indicates that the presence of water is not relevant under the applied load demand. Impedance spectra of the cell showed that at least three processes govern the direct electrochemical oxidation of methane on the Ni-CYSZ anode and these are related to charge transfer at high frequency, the adsorption/desorption of charged species at medium frequency and the non-charge transfer processes at low frequency. The cell was operated for more than 900 h in CH4 and 806 h under load demand, with a low degradation rate of similar to 0.2 mVh(-1) observed during this period. The low degradation in performance was mainly caused by the increase in charge transfer resistance, which can be attributed to carbon deposition on the anode causing a reduction in the number of active centers. Carbon deposits were detected mostly on the surface of Ni particles but not near the anode/electrolyte interface or the cerium surface. Therefore, the incorporation of cerium in the anode structure could improve the cell lifetime by reducing carbon formation
PB MDPI
SN 1996-1944
YR 2020
FD 2020-02
LK http://hdl.handle.net/10498/22895
UL http://hdl.handle.net/10498/22895
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 15-nov-2026