A reference electrode is important for controlling electrochemical reactions. Evaluating properties such as the reduction potential of the elements is necessary to optimize the electrochemical processes in pyroprocessing, especially in a multicomponent environment. In molten chloride systems, which are widely used in pyroprocessing, a reference electrode is made by enclosing the silver wire and molten salt solution containing silver chloride into the membranes. However, owing to the high temperature of the molten salt, the choice of the membrane for the reference electrode is limited. In this study, three types of electroceramic, mullite, Pyrex, and quartz, were compared as reference electrode membranes. They are widely used in molten salt electrochemical processes. The potential measurements between the two reference electrode systems showed that the mullite membrane has potential deviations of approximately 50 mV or less at temperatures higher than 650℃, Pyrex at temperatures lower than 500℃, and quartz at temperatures higher than 800℃. Cyclic voltammograms with different membranes showed a significant potential shift when different membranes were utilized. This research demonstrated the uncertainties of potential measurement by a single membrane and the potential shift that occurs because of the use of different membranes.

1. Introduction
2. Criteria of Ideal Reference ElectrodeSystem
3. Experimental Setup
    3.1 Potential Materials for Reference ElectrodeMembrane: Mullite, Pyrex, and Quartz
    3.2 Preparation of Electrochemical Cells
    3.3 Electrochemical Apparatus and FurnaceSystem
    3.4 Electrochemical Measurements
4. Results and Discussion
    4.1 Mechanical Strength and Phase Stability
    4.2 Open Circuit Potential Measurements usingReference Electrode Systems
    4.3 Cyclic Voltammetry Measurement of CoCl2
    4.4 Potential Difference with Different AgClConcentrations in the Reference ElectrodeSolution
5. Conclusion
REFERENCES

• Seokjoo Yoon(Korea Advanced Institute of Science and Technology)
• Dokyu Kang(Korea Advanced Institute of Science and Technology)
• Sungjune Sohn(Korea Atomic Energy Research Institute)
• Jaeyeong Park(Ulsan National Institute of Science and Technology)
• Minho Lee(Korea Advanced Institute of Science and Technology) Corresponding Author.
• Sungyeol Choi(Korea Advanced Institute of Science and Technology) Corresponding Author.