Urea decomposition and HNCO hydrolysis studied over titanium dioxide, Fe-Beta and gamma-Alumina
Artikel i vetenskaplig tidskrift, 2011

The catalytic effect of titanium dioxide, Fe-Beta, gamma-Alumina, on the thermal decomposition of urea and hydrolysis of HNCO, was investigated using differential scanning calorimetry (DSC) and mass spectrometry (MS). The catalytic materials were coated on cordierite substrates and a pure cordierite sample was also used for comparison. The urea was administered by impregnating the monoliths with an urea/water solution. The experiments were performed using a constant heating rate of 10 K/min and over a temperature range of 25-500 degrees C. A sweep gas flow rate of 80 mL/min of either dry or humid Ar was used. The results show that TiO(2) is the best hydrolysis catalyst. Fe-Beta showed a very large ammonia production, due to selective adsorption of urea during the impregnation of the monolith in the urea solution. One experiment with lower flow, higher urea loading and increased ramp speed conducted in dry Ar over TiO(2) showed a large formation of biproducts. This experiment was repeated in the presence of water and this decreased the formation of CYA and biuret significantly. The reason for this is the effective hydrolysis of the HNCO over titania, which hindered the bi-product formation.

selective catalytic-reduction

HNCO hydrolysis

metal-exchanged zeolites

diesel-engine

Zeolite

TiO(2)

emissions

thermal-decomposition

Micro-calorimetry

performance

scr catalysts

Fe-Beta

adsorption

SCR

nox

Urea decomposition

gamma-Al(2)O(3)

low-temperatures

MS

Biuret

CYA

Författare

Andreas Lundström

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik, Kemisk reaktionsteknik

T. Snelling

Kemisk reaktionsteknik

Kompetenscentrum katalys (KCK)

P. Morsing

Haldor Topsoe

Pär Gabrielsson

Haldor Topsoe

E. Senar

Haldor Topsoe

Louise Olsson

Chalmers, Kemi- och bioteknik, Kemisk reaktionsteknik

Kompetenscentrum katalys (KCK)

Applied Catalysis B: Environmental

0926-3373 (ISSN) 1873-3883 (eISSN)

Vol. 106 3-4 273-279

Styrkeområden

Transport

Energi

Materialvetenskap

Ämneskategorier

Kemi

DOI

10.1016/j.apcatb.2011.05.010

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Senast uppdaterat

2019-05-24