Electrochemical preparation of standard gas mixtures using solid-state electrolyte membrane

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Calibration of gas-analytical equipment requires accurate standard gas mixtures.
• Traditional methods using liquid electrolytes face challenges like solvent evaporation and condensation.
• Solid-state electrolyte membranes offer a promising alternative for electrochemical gas generation.

Purpose of the Study:

• To develop a novel electrochemical method for preparing standard gas mixtures (O2, H2, CO).
• To evaluate the efficiency and accuracy of this method using solid-state electrolytes.
• To analyze uncertainties associated with the calibration procedure.

Main Methods:

• Electrochemical generation and conversion of analytes (O2, H2, CO) using solid-state electrolyte membranes.
• Anodic evolution of oxygen and cathodic generation of carbon monoxide.
• Analysis of calibration uncertainties, including flow controller precision and gas mixture composition.

Main Results:

• The electrochemical method achieves nearly 100% efficiency for analyte generation/conversion.
• Lowest systematic errors were observed when calibrants were generated during electrolysis (O2, CO).
• Relative total errors for oxygen calibration were 5-6%, comparable to chromatographic analysis using this method.

Conclusions:

• Solid-state electrolyte membranes provide an efficient and reliable approach for preparing standard gas mixtures.
• The method minimizes issues associated with liquid electrolytes, improving calibration accuracy.
• This electrochemical technique is suitable for calibrating gas-analytical equipment for O2, H2, and CO.