Koichi Hamamoto (Post-Doctoral Research Scientist) of the Functional Assembly Technology Group (Leader: Masanobu Awano), the Advanced Manufacturing Research Institute (Director: Hideto Mitome) of the National Institute of Advanced Industrial Science and Technology (President: Hiroyuki Yoshikawa) (hereinafter referred to as AIST) has developed a high-sensitive NOX sensor with a rapid response.
Conventional NOX sensors do not have sufficient robustness or heat resistance in the harsh environment of engine exhaust gases. To solve this problem, a multi-chamber sensor that uses a solid oxide electrolyte (oxygen-ion conductor) has been developed. This, however, inherently does not give a high-speed response, because it has a rather complicated structure and it measures NOX concentrations by combining multistep electrochemical reactions. This poses a problem in relation to the purification of exhaust gases and reduction of fuel consumption.
The newly developed sensor has extremely high selectivity toward NOX molecules as a result of precise control of the nanostructure of the sensing electrode that detects NOX. This structural improvement to the electrochemical cell gives the speed of response for the direct detection of NOX molecules that is five times as fast as that of a conventional sensor and the detection sensitivity that is doubled.
The control of engine combustion with the aid of the high-performance sensor is expected to reduce NOX emissions, particularly from diesel vehicles, thereby contributing to preserving the atmospheric environment and reducing carbon dioxide emissions.
The results of this research are scheduled to be presented at the 16th International Conference on Solid State Ionics, to be held in Shanghai, China, on 2nd6th of July.