NOX Sensor for Diesel Engine Emissions Systems

With increasingly stringent regulation of nitrogen oxide emissions, there is a world-wide need for better NOX sensor products for both transportation and industrial markets. Currently, only one sensor is commercially available, and it lacks the low concentration accuracy and fast response time to meet these growing needs. NexTech Materials has developed a new NOX sensing technology that leverages a unique electro-catalytic effect to rapidly and selectively measure NOX in diesel engine exhaust streams. The sensor enables quantification of NOX emissions at concentrations below 10 ppm with response time less than 200 milliseconds a capability that is particularly enabling for improved closed-loop emissions monitoring in diesel engine exhaust after-treatment systems. Additionally, NexTech has demonstrated the ability to tune its sensor technology to also detect ammonia emissions, providing the opportunity to sense and report both NOX and NH3 concentrations in a single sensor device, adding significant value to diesel exhaust systems employing selective catalytic reduction (SCR) systems over the commercial NOX sensor. In the proposed SBIR project, NexTech Materials will leverage its NOX sensing technology to develop a low cost device capable of accurately quantifying NOX concentrations in the harsh exhaust stream of diesel passenger cars and heavy duty trucks. Efforts will focus on quantifying the lowest detectable NO and NO2 concentrations and investigating materials modifications to further enhance sensitivity at these levels. Additional efforts will focus on evaluating and optimizing the sensor for long term stability under application-specific operating conditions, as well as developing device strategies for dual NOX and NH3 sensing. Successful completion of this project will result in a sensor with improved performance and lower cost than the competitive sensor device, enabling lower emissions and improved competitive pricing to vehicle manufacturers. Additionally, successful development of a low cost NOX sensor with accuracy at concentrations below 10 ppm will have applicability in off-road and industrial applications, which are becoming increasingly regulated. The project will culminate with fabrication and delivery of prototype sensors to automotive OEM test partners.