METHOD FOR THE REDUCTION OF NITROGEN OXIDES

PCT No. PCT/EP97/07091 Sec. 371 Date Jun. 16, 1999 Sec. 102(e) Date Jun. 16, 1999 PCT Filed Dec. 17, 1997 PCT Pub. No. WO98/26858 PCT Pub. Date Jun. 25, 1998A process for the catalytic reduction of NOx, the reduction taking place in the presence of a catalyst which comprises (a) from 20 to 97 wt % of A2O3, (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 Fe2O3, Cr2O3, Ga2O3 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 NOx, especially in combustion off-gases, the components (a), (b) and (c) forming a spinel which is doped with the components (d), (e) and (f).