Design of Pt electrode in a SO2 gas sensor based on LaF3solid electrolyte

For electrochemical gas sensors, solid electrolytes play increasingly significant role in improving stability, life-span and other properties. One new but emerging solid electrolyte LaF₃ is attractive because of its possible application at room temperature, in addition to other advantages and it has been investigated for measuring various types of gases. Since Pt/LaF₃ sensitive interface is a core part of this kind of gas sensor, reasonable design and fabrication Pt working electrode micro-structure is a crucial approach to improve sensitivity, reduce response time of the sensor. In this paper, micro SO₂ gas sensor based on Pt/LaF₃ is proposed, and fluid dynamic simulation software Fluent was used to simulate gas flow around gas/Pt/LaF₃ three-phase-boundary (TPB). Pt micro-structure at different micro-scales simulated by Fluent indicates that the scale influences gas-flow status around three-phase-boundary, and actually determines sensitivity and response property.