Catalyst for removing nitrogen oxides and a process for producing the

Abstract

A catalyst or a catalyst structure for removing nitrogen oxides contained in exhaust gases, having a small pressure loss and hard to cause ash deposition, and a process for producing the same are provided, which catalyst comprises a mixture of a catalyst composition of titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, and inorganic fibers, the clearances of the inorganic fibers are filled with said catalyst composition; the ration by weight of said catalyst composition to said inorganic fibers is 3 or more; and the apparent density of said catalyst is 0.8 g/cm.sup.3 or more; and which process comprises providing a composition containing titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, calcining said composition at 500.degree.-650.degree. C., crushing the calcined material so that powder of 20.mu. or less can occupy 90% by weight or more of the crushed material, adding water to the crushed material to form a slurry, impregnating an inorganic fiber sheet with the above slurry, placing the resulting sheet between porous molds, drying and molding it, and clacining the resulting molded material at 300.degree.-650.degree. C.