| abstract |
The invention relates to a process for producing a porous catalyst structure in the form of sheets or with a honeycomb structure for the gas phase reduction of nitrogen oxides. The process comprises the following steps: size reduction or grinding of an inorganic fibre in water in order to form a slurry, forming the slurry into a sheet by means of paper-manufacturing appliances, and drying of the sheet; impregnating the sheet or a honeycomb structure produced therefrom and having a porosity from 60 to 85%, with an impregnating slurry which contains titanium dioxide or its precursor compound in a concentration of at least 100 g/l and has a viscosity of 5-250 . 10<3> Pas (5-250 cps) at normal temperature, drying and, if required, firing of the structure and subsequent immersion of the structure in a solution which contains a catalytically active agent or its precursor, drying and firing of the structure, whereby a porous catalyst structure is obtained which, therein or thereon, contains titanium dioxide and the catalytically active agent in a virtually uniformly dispersed and carried manner. |