The influence of surface acidity on NO2 reduction by propane under lean conditions
Artikel i vetenskaplig tidskrift, 2004

This investigation focuses on the influence of surface acidity on the continuous catalytic reduction of NOx by propane under lean conditions. The acidity was varied by studying noble metal free alumina, silica and co-precipitated aluminium-silicates with varying alumina-silica ratio. The catalysts were characterised by isopropylamine temperature programmed desorption (TPD), with respect to NOx reduction (NO2 and propane) and by Fourier Transform Infrared (FTIR) spectroscopy. The isopropylamine TPD was used to determine the sample acidity. The amount of Bronsted acid sites increased with increasing amount of alumina. The sample activity for NOx reduction with propane was found to correlate with the Bronsted-site density. Furthermore, no N2O was formed during the activity studies. The FTIR measurements implied formation of isocyanate species on the surface of the catalyst sample when NO/NO2, propane and oxygen were present in the gas phase. FTIR data also reveal an increasing amount of adsorbates on the surface with increasing amount of alumina in the sample. Moreover, with propane present, NO-species were consumed to a higher extent over samples containing a larger amount of alumina. Our results suggest a connection between the Bronsted-site density and the NOx reduction with propane under lean conditions.

propane

surface acidity

aluminum-silicate

lean NOx reduction

FTIR

Författare

Hanna Härelind

Kompetenscentrum katalys (KCK)

Chalmers, Institutionen för kemi och biovetenskap

Åsa Hildesson

Kompetenscentrum katalys (KCK)

Chalmers, Teknisk fysik, Kemisk fysik

Erik Fridell

Chalmers, Teknisk fysik, Kemisk fysik

Kompetenscentrum katalys (KCK)

Magnus Skoglundh

Kompetenscentrum katalys (KCK)

Chalmers, Institutionen för material- och ytkemi, Teknisk ytkemi

Journal of Molecular Catalysis A: Chemical

1381-1169 (ISSN)

Vol. 209 199-207

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Fysik

Kemiteknik

DOI

10.1016/j.molcata.2003.08.016