An integrated solution for NOx‐reduction and ‐control under lean‐burn conditions |
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Authors: | B Saruhan Dr‐Ing habil M Stranzenbach G C Mondragón Rodríguez |
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Affiliation: | Deutsches Zentrum für Luft‐ und Raumfahrt (DLR), Institut für Werkstoff‐Forschung, 51147 K?ln |
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Abstract: | Upcoming emission regulations order highly effective NOx‐reduction systems in lean‐burn engines requiring new catalytic materials and integrated control of the reduction process. Thus, new approaches for NOx‐reduction and its monitoring over an On‐Board‐Diagnostic (OBD) system are suggested throughout the globe. A promising attempt is the development of a catalytic system having an integrated NOx‐sensor, based on selective catalytic reduction process and impedance sensors. The study displays the results achieved both with a perovskite type of self‐regenerative catalyst functioning by H2‐reductant and with impedance NOx‐sensors. The catalysts were tested at the temperature range of 150 °C to 360 °C yielding NOx conversion rates of 92 % with high selectivity to N2. Impedance sensors having NiCr2O4‐ and NiO‐SE and PYSZ‐ and FYSZ‐electrolytes are developed and tested at 600 °C under lean atmosphere (5 vol. % O2). Better sensing behaviour towards NO and lower cross‐selectivity towards O2, CO, CO2 and CH4 have been observed with sensors having NiO‐SE. |
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Keywords: | H2‐SCR substituted perovskite catalyst self‐regeneration impedance‐metric NOx sensor NiO NiCr2O4 sensing electrode H2‐SCR dotierter selbst‐regenerativer perowskitscher Katalysator Impedanz‐NOx‐Sensor NiO‐Sensorelektrode NiCr2O4‐Sensorelektrode |
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