NOx reduction from diesel emissions over a non-transition metal zeolite catalyst: Effect of water in the feed

Bin Wen, Young Hoon Yeom, Eric Weitz, Wolfgang M.H. Sachtler*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

NO reduction activity with acetaldehyde over BaY is low in a dry feed, but significantly higher in the presence of water vapor. Aldol condensation of acetaldehyde takes place, polymerization of the resulting crotonaldehyde deactivates the catalyst. Water vapor prevents the formation of large amounts of carbonaceous deposits, either by suppressing the dehydration of aldol to crotonadehyde or by interacting with carbonaceous deposits or their precursors, transforming them to CO, CO2 and H2. Temperature- programmed oxidation (TPO) shows much lower coke formation after tests in the presence of water vapor. TPD-MS data show that nitromethane, a possible intermediate in the NOx reduction process, reacts with water on BaY forming NH3, COx and isocyanic acid HNCO. NOx conversion over BaY reaches values near 90% at 200°C and a GHSV of 30,000h-1 if the NOx initially contains both NO and NO2. No transition metal is involved in the reduction of NO x to NH3 and N2 over BaY.

Original languageEnglish (US)
Pages (from-to)125-131
Number of pages7
JournalApplied Catalysis B: Environmental
Volume48
Issue number2
DOIs
StatePublished - Mar 18 2004

Keywords

  • Aldol condensation over BaY
  • BaY catalyst
  • Diesel emission
  • NO reduction with acetaldehyde

ASJC Scopus subject areas

  • Catalysis
  • Environmental Science(all)
  • Process Chemistry and Technology

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