Abstract
The electrochemical oxidation of humid hydrogen was investigated on a Y(0.20)Ti(0.18)Zr(0.62)O(1.90) (YTZ) anode in a high temperature planar solid oxide fuel cell. Cells using platinum counter and reference electrodes on a YSZ based electrolyte were fabricated and tested in H(2)/H(2)O atmospheres versus air in the temperature range (788-932)degrees C. Steady state polarisation measurements, cyclic voltammetry and impedance analysis were used to characterise the behaviour of the anode and determine kinetic parameters of the electro-oxidation reaction. The power output of the cell H(2), H(2)O/YTZ//YSZ-Al(2)O(3)//Pt/air was stable over an operation period of 500 h. For 97% H(2)/3% H(2)O at 932 degrees C it amounted to 37 mW cm(-2) and the maximum current density obtained was 203 mA cm(-2). The apparent reaction order with respect to hydrogen was calculated to be in the region of 0.5 at 932 degrees C. The impedance spectra showed three apparent processes dependent on temperature, fuel concentration and overpotential. Anode polarisation resistance decreased significantly with anodic overpotential. At open and short circuit (E(cell) = 0 V) conditions the total area specific polarisation resistance was 12.67 and 0.96 Omega cm(2) respectively.
Original language | English |
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Pages (from-to) | 226-232 |
Number of pages | 7 |
Journal | Fuel Cells Bulletin |
Volume | 1 |
Issue number | 3-4 |
Publication status | Published - Dec 2001 |