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.

performance

low-temperatures

CYA

HNCO hydrolysis

Biuret

gamma-Al(2)O(3)

diesel-engine

thermal-decomposition

SCR

scr catalysts

Urea decomposition

Zeolite

MS

adsorption

Micro-calorimetry

Fe-Beta

nox

emissions

metal-exchanged zeolites

selective catalytic-reduction

TiO(2)

Författare

Andreas Lundström

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik, Kemisk reaktionsteknik

T. Snelling

Chalmers University of Technology

P. Morsing

Pär Gabrielsson

E. Senar

Louise Olsson

Chalmers, Kemi- och bioteknik, Kemisk reaktionsteknik

Kompetenscentrum katalys (KCK)

Applied Catalysis B: Environmental

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

Vol. 106 273-279

Styrkeområden

Transport

Energi

Materialvetenskap

Ämneskategorier

Kemi

DOI

10.1016/j.apcatb.2011.05.010