کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1292337 | 1497926 | 2016 | 14 صفحه PDF | دانلود رایگان |
• Ni-free, Ce-based IT-SOFCs are tested with syngas and biogas at 600 and 650 °C.
• The electro-oxidations of CO and of H2 are active in parallel and contemporarily.
• A 1D, dynamic, heterogeneous and physically-sound MEA model of the cell is applied.
• The polarization curves and the EIS spectra are simulated based with the model.
• Power law rate equations are derived for the electro-oxidation of H2 and of CO.
By means of model analysis, we show that, in the presence of syngas, the electro-oxidation of H2 and that of CO occur in parallel and contemporarily on Samaria-doped Ceria (Sm0.2Ce0.8O1.9, SDC) Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs). The activation of a co-oxidative route is a most distinguishing feature of Ce-based cells, compared to traditional SOFCs. SDC electrolyte supported IT-SOFCs with Cu–Pd-CZ80 composite anodes and LSCF cathodes were tested under a wide range of operating conditions. Polarization and EIS measurements were collected at 600 °C and 650 °C with syngas mixtures (2.3–0.4H2/CO ratio), H2/N2 mixtures (from 97 to 30% H2 v/v) and CO/CO2 mixtures (from 97 to 50% CO v/v). A 1D, dynamic and heterogeneous model of the cell was applied to analyze the polarization and the EIS curves. The kinetics of the reactions of H2 electro-oxidation, CO electro-oxidation and O2 reduction were individually investigated and global power law rates were derived. The syngas experiments were simulated on a fully predictive basis and no parameter adjustment, confirming that the polarization behavior could be best reproduced exclusively by assuming the presence of the co-oxidative route. The IT-SOFCs were also exposed to biogas mixtures, revealing that the dry-reforming reaction was active.
Figure optionsDownload as PowerPoint slide
Journal: Journal of Power Sources - Volume 306, 29 February 2016, Pages 467–480