Solid-State HCl Gas Sensor Using Na₅DySi₄O₁₂ and RuO₂ Electrode

Abstract

A potentiometric solid-state sensor using a Na₅DySi₄O₁₂ solid-electrolyte and oxide electrodes was tried to examine for monitoring HCl gas. Among the oxides tested, the sensor using RuO₂ electrode showed relatively good HCl response at 400°C. The electromotive force was almost linear to the logarithm of HCl concentration between 100 and 1000 ppm. This HCl sensor showed also good selectivity to CO₂, NO, and NO₂, and few effect of oxygen. A mixed potential sensing mechanism is tentatively proposed.