The Transported Entropy of Oxygen Ion in

The transported entropy of oxygen ion, S~2-, in yttria-stabilized zirconia (YSZ) has been determined from measure-ments of Seebeck coefficients of the cell (T1, p)(Pt)O2(g){YSZ{O2(g)(Pt)(T2, p). The value obtained, 51 J K- ' F-1, is sub-stantially different from results for YSZ which can be calculated from other investigations. The value does not vary with oxygen pressure, in accordance with results obtained for calcia-stabilized zirconia. The results indicate that the sintering temperature for YSZ is important for obtaining uniform temperature conditions in fuel cells. With the advance of solid-state oxide ionic onductors there is a renewed interest in fuel cells which make use of such oxides as electrolytes (1). One of the promising ox-ides is yttria-stabilized zirconia nd a simple fuel cell react-ing hydrogen with oxygen is (Pt)H2(g), H~O(g){YSZ{O2(g)(Pt) [a] with the cell reaction Anode: 1/2 H2(g) + 1/2 O2-(an)---> 1/2 H20(g) + e