Catalyst for selectively reducing nitrogen oxides from oxygen-containing exhaust gases

摘要

A catalyst for the selective catalytic reduction of nitrogen oxides by the use of ammonia as a reducing agent composed of a catalytically active constituent on a carrier having a honeycomb or parallel plate structure, the carrier being prepared from a slurry of crystallized calcium silicate prepared by mixing silicic acid and lime and heating the mixture under pressure, the calcium silicate having the structure of xonotrite and the formula 6 CaO.6 SiO2. H2O.