Efficient low temperature lean NOx reduction over Ag/Al2O3-A system approach
Artikel i vetenskaplig tidskrift, 2011

This study focuses on lean NOx reduction (LNR) by n-octane using silver-alumina based catalysts, with the addition of hydrogen. The work takes a system approach, where parameters such as temperature, reformate gas composition, fuel penalty and realistic monolith samples are considered. The LNR catalyst samples were prepared by impregnation and sol-gel methods and the NOx reduction performance was characterized by flow-reactor experiments, where realistic engine-out gas compositions were used. The hydrogen feed over the LNR catalyst samples was determined via data achieved by autothermal reforming experiments over a rhodium based catalyst, using real diesel as feedstock. The LNR catalyst samples generally show an enhanced NOx reduction when hydrogen is added to the gas feed. In particular, a 2 wt% silver-alumina sample with the addition of minute amounts of platinum, shows a high increase in NOx reduction when hydrogen is added to the feed. The addition of CO, a potential poison in the reaction and a by-product from the reforming, did not show any significant effect on the LNR catalyst performance at the conditions used. This is beneficial, since it renders a CO clean-up step in the reformer system unneeded. Ammonia formation is discussed in terms of a possible dual-SCR system. Finally, the fuel penalty for hydrogen production and hydrocarbon addition is taken into consideration. It is found that an addition of 1000 ppm H-2 leads to unacceptable fuel penalties. (C) 2011 Elsevier B.V. All rights reserved.

in-situ ftir

nitric-oxide

engine exhaust

Fuel economy

Ag/Al2O3

higher hydrocarbons

Fuel reforming

diesel

selective catalytic-reduction

Lean NOx reduction

rhodium-oxide

silver-alumina catalysts

nitrogen-oxides

Pt

silver/alumina catalyst

Författare

Hannes Kannisto

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

X. Karatzas

Kungliga Tekniska Högskolan (KTH)

J. Edvardsson

Volvo

Lars Pettersson

Kungliga Tekniska Högskolan (KTH)

Hanna Härelind

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Applied Catalysis B: Environmental

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

Vol. 104 1-2 74-83

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Kemi

DOI

10.1016/j.apcatb.2011.02.026