High temperature amperometric total NOx sensors with platinum-loaded zeolite Y electrodes

Department of Chemistry, The Ohio State University, Columbus, OH 43210-1185, USA
Sensors and Actuators B Chemical (Impact Factor: 4.1). 05/2007; 123(2):929-936. DOI: 10.1016/j.snb.2006.10.052


An amperometic total-NOx sensor that integrates a Pt-loaded zeolite Y (PtY) catalyst for NOx equilibration with electrochemical oxidation of NO on an yttria-stabilized zirconia (YSZ) electrolyte is described in this paper. PtY is found to be an effective catalyst for equilibrating mixtures of NO, O2 and NO2 at temperatures in excess of 400 °C. By applying a low anodic potential of 80 mV, the NO in the NOx equilibrated mixture can be oxidized at a Pt working electrode on the YSZ electrolyte at 500 °C. The current thus generated provides a measure of the total NOx in the gas stream and is the basis of the sensing measurements in this study. The PtY can be held separate from the YSZ or coated onto the YSZ as a film, the latter being more appropriate for the practical embodiment of this design. We demonstrate that this sensor exhibits total-NOx detection capability, a low NOx detection limit (<1 ppm), high NOx selectivity relative to CO and oxygen, and linear dependence on NOx concentration.

29 Reads
  • Source
    • "The need for nitric oxide (NO) sensing is critical in a diverse variety of applications ranging from high temperature combustion [1] [2] [3] [4] [5] to clinical analysis [6] [7]. An example of a high temperature combustion application is monitoring and minimization of NO x emissions produced by lean burn engines [8]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We report on the development of miniaturized potentiometric nitric oxide (NO) sensors. This work covers the design, fabrication and testing of these NO sensors. In particular, microelectromechanical systems (MEMS) fabrication techniques were utilized to miniaturize the size of the sensors. Sensors were fabricated using both shadow mask and photoresist mask fabrication methods. Arrays of up to 15 sensors were electrically connected in series during the fabrication process to improve the signal of the overall device for a given NO concentration. Testing on these sensor arrays toward NO was carried out at 550 °C to compare the performance of the various designs of the sensor. Sensitivity below the ppm level was demonstrated with the photoresist-masked 15-sensor array. Long-term stability of the miniaturized sensor array when operating at high temperatures needs to be improved before practical applications of this MEMS sensor technology can be realized.
    Sensors and Actuators B Chemical 12/2014; 204:183–189. DOI:10.1016/j.snb.2014.06.108 · 4.10 Impact Factor
  • Source
    • "(A) Schematic of an amperometric sensor with a coating of Pt-zeolite Y; (B) comparison of the response of the sensor (bottom) with a chemiluminescence analyzer (top) towards NO and NO2 of varying concentrations (adapted from Reference [41]). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The unique properties of microporous zeolites, including ion-exchange properties, adsorption, molecular sieving, catalysis, conductivity have been exploited in improving the performance of gas sensors. Zeolites have been employed as physical and chemical filters to improve the sensitivity and selectivity of gas sensors. In addition, direct interaction of gas molecules with the extraframework cations in the nanoconfined space of zeolites has been explored as a basis for developing new impedance-type gas/vapor sensors. In this review, we summarize how these properties of zeolites have been used to develop new sensing paradigms. There is a considerable breadth of transduction processes that have been used for zeolite incorporated sensors, including frequency measurements, optical and the entire gamut of electrochemical measurements. It is clear from the published literature that zeolites provide a route to enhance sensor performance, and it is expected that commercial manifestation of some of the approaches discussed here will take place. The future of zeolite-based sensors will continue to exploit its unique properties and use of other microporous frameworks, including metal organic frameworks. Zeolite composites with electronic materials, including metals will lead to new paradigms in sensing. Use of nano-sized zeolite crystals and zeolite membranes will enhance sensor properties and make possible new routes of miniaturized sensors.
    Sensors 12/2012; 12(4):5170-94. DOI:10.3390/s120405170 · 2.25 Impact Factor
  • Source
    • "OSU NO sensors fabricated using two different approaches. (a) Standard fabrication approach used to produce the sensors described elsewhere [28]. (b) Basic sensor design fabricated using microprocessing techniques. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Breath analysis techniques offer a potential revolution in health care diagnostics, especially if these techniques can be brought into standard use in the clinic and at home. The advent of microsensors combined with smart sensor system technology enables a new generation of sensor systems with significantly enhanced capabilities and minimal size, weight and power consumption. This paper discusses the microsensor/smart sensor system approach and provides a summary of efforts to migrate this technology into human health breath monitoring applications. First, the basic capability of this approach to measure exhaled breath associated with exercise physiology is demonstrated. Building from this foundation, the development of a system for a portable asthma home health care system is described. A solid-state nitric oxide (NO) sensor for asthma monitoring has been identified, and efforts are underway to miniaturize this NO sensor technology and integrate it into a smart sensor system. It is concluded that base platform microsensor technology combined with smart sensor systems can address the needs of a range of breath monitoring applications and enable new capabilities for healthcare.
    Journal of Breath Research 09/2011; 5(3):037111. DOI:10.1088/1752-7155/5/3/037111 · 4.63 Impact Factor
Show more

Similar Publications