NOx Reduction with added oxygenates: Mechanism and the role of NO as a reductant

Younghoon Yeom*, Aditya Savara, Meijun Li, Wolfgang M.H. Sachtler, Eric Weitz

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This presentation will focus on the selective reduction of NOx with added oxygenates over BaNa/Y and Ag/Y zeolites and Ag/γ-Al2O3. This chemistry involves a complex set of coupled reactions with a number of common crucial intermediates. In these reactions, over the indicated catalysts, acetaldehyde, which can be directly introduced or formed via oxidation of ethanol, is oxidized to form acetate ions. The acetate ions react with NO2 to form nitromethane which decomposes to HNCO via a dintiromethane intermediate. HNCO can then be hydrolyzed to give NH3 which can react with HONO to form ammonium nitrite, which can then efficiently decompose to N2 and H2O at low temperatures. Since nitric acid is also present, surface nitrates and ammonium nitrate can form. Data will be presented to show that NO acts as a reductant of nitrate ions, ammonium nitrate and nitric acid, converting less desirable species to the more volatile nitrite analogs. When nitromethane is directly introduced to a NOx stream over Ag/Y∼100% conversion of NOx to N2 is achieved at temperatures as low as 140 °C. This result coupled with data on the reactivity of surface acetate provides insights into the rate limiting step in deNOx chemistry in these systems.

Original languageEnglish (US)
Title of host publicationAmerican Chemical Society - 235th National Meeting, Abstracts of Scientific Papers
StatePublished - Dec 1 2008
Event235th National Meeting of the American Chemical Society, ACS 2008 - New Orleans, LA, United States
Duration: Apr 6 2008Apr 10 2008

Other

Other235th National Meeting of the American Chemical Society, ACS 2008
CountryUnited States
CityNew Orleans, LA
Period4/6/084/10/08

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

Fingerprint Dive into the research topics of 'NOx Reduction with added oxygenates: Mechanism and the role of NO as a reductant'. Together they form a unique fingerprint.

Cite this