Simultaneous Removal of NOx and Soot Particulate from Diesel Exhaust by in-situ Catalytic Generation and Utilisation of N2O

Research output: Contribution to journalArticle

Authors

  • Catherine Davies
  • Kate Thompson
  • Anna Cooper
  • Stan Golunski
  • Stuart Taylor

Colleges, School and Institutes

External organisations

  • Cardiff University

Abstract

One of the outstanding challenges in diesel exhaust catalysis is to integrate oxidation chemistry, soot filtration and NOx reduction in a single aftertreatment unit, while avoiding the need for fuel injection to regenerate the filter. Here we show that destruction of trapped soot can be initiated catalytically at 200 °C when its oxidation is coupled with non-selective NOx reduction (using NH3 as reductant), which acts as an in-situ source of N2O. In laboratory tests over an extended temperature range (up to 800 °C), using supported silver as a catalyst for both non-selective NOx-reduction and soot oxidation, the conversion of immobilised soot to CO2 can be resolved into four consecutive steps as the temperature rises: catalysed oxidation by N2O; non-catalysed oxidation by NO2; catalysed oxidation by O2; non-catalysed oxidation by O2. Initial engine tests indicate that the critical first step (C + N2O) can be replicated in a diesel exhaust.

Details

Original languageEnglish
Pages (from-to)10-15
JournalApplied Catalysis B Environmental
Volume239
Early online date29 Jul 2018
Publication statusPublished - 30 Dec 2018

Keywords

  • diesel exhaust, NOx reduction, soot oxidation, nitrous oxide, silver