Electrochemical moisture analysis by combining oxygen- and proton-conducting ceramic electrolytes

- A new electrochemical cell with H+- and O2 −-conducting electrolytes was prepared.
- The electrochemical characterization of this cell was carried out.
- The limiting current was a measurable parameter used to determine the pH2O values.
- Water concentrations and mutual diffusion coefficients for N2/H2O can be determined.

The fabrication and characterization of a new intermediate-temperature electrochemical cell for analyzing moisture concentrations in gas mixtures are discussed in the present investigation. The as-fabricated electrochemical cell consists of a diffusion barrier and two ceramic materials based on a yttria-stabilized zirconia (YSZ) electrolyte with unipolar oxygen ion conductivity and a Sr-doped lanthanum yttrate (La0.9Sr0.1YO3 − δ, LSY) electrolyte with proton transport properties. The possibility of measuring humidity in a nitrogen atmosphere is demonstrated and the operational capability of the cell is evaluated. The original design of the proposed electrochemical cell opens new opportunities in electrochemical analysis and in the application of proton-conducting electrolytes, including the simultaneous measurement of the concentration and the mutual diffusion coefficient of water in gases.

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