Sulfur dioxide gas sensor based on Zr~(4+) and O~(2-) ion conducting solid electrolytes with lanthanum oxysulfate as an auxiliary sensing electrode

摘要

A solid electrolyte type SO_2 gas sensor based on tetravalent Zr~(4+) ion conducting Zr_(39/40)TaP_(2.9)W_(0.1)O_(12) and O~(2-) ion conducting (ZrO_2)_(0.92)(Y_2O_3)_(0.08) solid electrolytes with 0.7La_2O_2SO_4-0.3(0.8Li_2SO_4 + 0.2K_2SO_4) as an auxiliary sensing electrode was developed. The present sensor exhibited a continuous, reproducible, and quantitative response for SO_2 gas, and the relationship between the sensor EMF output and the logarithm of the SO_2 gas concentration obeyed the Nernst equation at temperatures as low as 480℃ over 80 days. Thus, it is expected to be a good candidate as a practical SO_2 gas sensor for on site measurements.