초록 ▼

A catalyst for the selective reduction with ammonia of nitrogen oxides from an intimate mixture of at least 3 metals in the form of their oxides, namely, titanium, tungsten and at least one of the metals vanadium, iron, niobium, molybdenum, with an atomic ratio of Ti to the other metals of 1:0.001 t

A catalyst for the selective reduction with ammonia of nitrogen oxides from an intimate mixture of at least 3 metals in the form of their oxides, namely, titanium, tungsten and at least one of the metals vanadium, iron, niobium, molybdenum, with an atomic ratio of Ti to the other metals of 1:0.001 to 1, wherein there is used as oxide of the titanium a product obtained by flame hydrolysis, which product is impregnated with solutions of the salts of the other metals and is dried and calcined at a high temperature.

대표청구항 ▼

A catalyst for the selective reduction with ammonia of nitrogen oxides in oxygen containing exhaust gas comprising an intimate mixture of at least three metals each in the form of their oxides, namely, (A) titanium as constituent A, (B1) tungsten as the first constituent B, and (B2) at least one of

A catalyst for the selective reduction with ammonia of nitrogen oxides in oxygen containing exhaust gas comprising an intimate mixture of at least three metals each in the form of their oxides, namely, (A) titanium as constituent A, (B1) tungsten as the first constituent B, and (B2) at least one of the metals selected from the group consisting of vanadium, iron, niobium, and molybdenum as the second constituent B with an atomic ratio of constituent (A) to (B) of 1 : 0.001 to 1, wherein the constituent (A) is present in the form of a finely divided oxide obtained by flame hydrolysis of TiCl4 and wherein said finely divided oxide has the following properties: ________________________________ -BET surface area m2/g 50 +/-15 average size of primary particles nm 30 tamp density(1) g/L ca. 150 loss on drying(2) wt. % 1.5 (2 h at 105°C.) loss on ignition(2)(4) wt. % 2 (2 h at 1000°C.) pH(3) 3-4 (in 4% aqueous dispersion) x-ray structure mainly anatase isoelectric point at pH 6.6 density g/cm3 3.8 Al2O3(5) wt. % 0.3 TiO2(5) wt. % 99.5 SiO2(5) wt. % 0.2 Fe2O3(5) wt. % 0.01 HCL(5)(6) wt. % 0.3 ________________________________ (1)according to DIN 53194 or ISO 787/XI -(2)according to DIN 55921 or ISO 787/II, or ASTM D 280-30 (loss on drying) and ASTM D1208-65 (loss on ignition) -(3)according to DIN 53200 or ISO 787/IX, or ASTM D 1208-65 -(4)based on the substance dried 2 hours at 105°C. -(5)based on the substance calcined 2 hours at 1000°C. -(6)HCl content is a part of the loss on ignition - and the catalyst is obtained by impregnation of the said titanium dioxide with solutions of salts of the metals of group (B), drying and calcination at 100-650°C.