Method for the reduction of nitrogen oxides

US6153162A · kind A · utility

Assignees

• BASF SE
• Daimler-Benz AG · DE

Inventors

• Thomas Fetzer · Speyer, DE
• Bernd Morsbach · Ludwigshafen, DE
• Otto Kumberger · Mannheim, DE
• Martin Hartweg · Erbach, DE
• Rolf-Dirc Roitzheim · Blaustein, DE
• Andrea Seibold · Blaustein, DE
• Leonhard Walz · Rastatt, DE

Key dates

• Filing date: Jun 16, 1999
• Grant date: Nov 28, 2000
• Expiry date: Jun 16, 2019

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S502/524
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the catalytic reduction of NO.sub.x, the reduction taking place in the presence of a catalyst which comprises (a) from 20 to 97 wt % of A.sub.2 O.sub.3, (b) from 1 to 40 wt % of CuO, (c) from 1 to 50 wt % of ZnO, (d) from 1 to 40 wt % of Ag, (e) from 0 to 2 wt % of Pt, (f) from 0 to 20 wt % of oxides of rare earth metals, elements of the 3rd subgroup of the Periodic Table of the Elements or mixtures thereof, based on the total weight of the components (a) to (e), which adds up to 100 wt %, wherein, in each case, up to half the weight of the component (a) may be replaced by Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, Ga.sub.2 O.sub.3 or mixtures thereof, of the component (b) by CoO, of the component (c) by MgO, of the component (d) by Au and of the component (e) by Pd, Ru, Os, Ir, Rh, Re or mixtures thereof, is used for reducing NO.sub.x, especially in combustion off-gases, the components (a), (b) and (c) forming a spinel which is doped with the components (d), (e) and (f).