Abstract
The potentials of cells 
and 
have been determined in the ternary eutectic 
between 510° and 800°C. At 800°C the potential resulting from the 
cell indicated that the reaction occurring at the Au electrode was 
. At 700°C and lower, the cell potential confirmed that the reaction 
dominates the high 
partial pressure range. At lower temperatures the reaction 
was observed to proceed to the right, consuming part of the incoming 
stream so that the cell potential appeared to deviate from the Nernst slope (corresponding to the reaction 
). The Nernst slopes and cell potentials follow the thermodynamic prediction for the electrochemical reactions occurring at the Au electrode.
The potentials resulting from the 
cell were in agreement with the thermodynamically calculated potential for the reaction 
occurring on the Au electrode between 510° and 670°C. At low 
flow rates over the entire temperature range and at all flow rates at higher temperatures the cell potential differed considerably from the predictions for the above reaction. The reaction 
is seen as a possible explanation for this behavior.