Alumina substrate-supported electrochemical device for potential application as a diesel particulate matter sensor

作者：Shen Yanbai; Takeuchi Takashi; Teranishi Shinya; Hibino Takashi^*

来源：Sensors and Actuators B: Chemical , 2010, 145(2): 708-712.

DOI：10.1016/j.snb.2010.01.030

• Carbon sensing
• Active oxygen
• Alumina substrate
• Proton conductor
• Diesel particulate matter

The carbon oxidation activity and sensing performance of an alumina substrate-supported sensor comprised of Sn(0.9)In(0.1)P(2)O(7) as a proton conductor and Pt as an electrocatalyst were investigated. Electrochemically formed active oxygen species exhibited high activity for carbon oxidation, where the current efficiency was estimated from the four-electron reaction (C + 2H(2)O --> CO(2) + H(+) + 4e(-)) and reached approximately 90%. An operating temperature of 225 degrees C was found to be the most effective to achieve the highest possible electrochemical carbon oxidation and the lowest possible non-electrochemical carbon oxidation. When carbon introduced to the Sn(0.9)In(0.1)P(2)O(7)-Pt interface was oxidized by active oxygen, a large potential jump was observed due to a significant increase in the polarization resistance, which was strongly dependent on the carbon content in the working electrode. Two types of carbon sensors, amperometric and potentiometric, were tested in a feed mixture of 3 vol% water vapor and 10 vol% O(2). In the case of the amperometric sensor, the current increased linearly with increasing carbon content, which enabled the determination of a wide range of carbon content from the current signal. In the case of the potentiometric sensor, a threshold quantity of carbon could be recognized by selection of the current and subsequent monitoring of the sudden potential increase.

• 出版日期2010-3-19