Solid-state amperometric CH 4 sensor using, LaGaO 3-based electrolyte

Abstract

A solid-state amperometric CH 4 sensor using a LaGaO 3-based electrolyte was studied. For this sensor, a combination of active (anode) and inactive (cathode) electrodes for CH 4 oxidation was applied. Among the various active electrode materials studied, Pd mixed with tin-doped In 2O 3 (ITO) was found to be the most active electrode and RuO 2 the most inactive one. The sensitivities of the sensor using La 0.9Sr 0.1Ga 0.8Mg 0.2O 3 (LSGM) electrolyte to CH 4 were approximately 797 µA/decade at 673 K and 188 µA/decade at 873 K. The changes in oxygen pumping current upon exposure to CH 4 could be attributed to the mixed potential generated by the difference in oxidation activity between the active and inactive electrodes.