Catalyst for the reduction of NO to N2 with ethanol or ethanol and hydrogen under lean DENOx conditions
Title
Catalyst for the reduction of NO to N2 with ethanol or ethanol and hydrogen under lean DENOx conditions
Date Issued
2010-12-23
Major Field of Science
Natural Sciences
Field Category
Chemical Sciences
Date Issued
December 23, 2010
Type
Patents
Application
EP20100390001
Affiliation
Abstract
The invention relates to a novel catalyst having excellent activity, selectivity and stability for reducing nitric oxide to gas nitrogen, with ethanol or an ethanol-hydrogen mixture being used as a reducing agent, in the low temperature range of 150-300 °C and in the presence of an excess of oxygen (e.g., 5 % vol), H2O (5 % vol) and SO2 (50 ppm) in the supply. The inventive catalyst consists of silver crystals which are in contact with the phases of a mixed MgO, CeO2 and Al2O3 medium. The Ag/MgO-CeO2-Al2O3 catalyst can be used to obtain NO conversion levels which are greater than 40 %, nitrogen selectivity values of greater than 95 % and CO2 selectivity values greater than 97% under NOx oxidation conditions in the 150-400 °C temperature range and for a surface contact time of 0.09 s. In particular, 90% NO conversion is obtained as well as N2 and CO2 selectivity levels of 99 % at 250 °C with a reaction mixture of 500 ppm NO/1000 ppm C2H5OH /5% O2 /5% H2O / 50ppm SO2/He: