초록 ▼

Catalysts for the selective catalytic reduction of NOx by ammonia are made from porous formed supports having a certain fraction of the pores with pore diameters larger than 600 Angstrom units. Thus macropores can be introduced in a formed TiO2 support by adding burnout materials or some inorganic o

Catalysts for the selective catalytic reduction of NOx by ammonia are made from porous formed supports having a certain fraction of the pores with pore diameters larger than 600 Angstrom units. Thus macropores can be introduced in a formed TiO2 support by adding burnout materials or some inorganic oxide prior to forming the titania into the formed support. Alternatively, titania is precipitated onto a porous inorganic oxide such as SiO2, Al2O3, ZrO2, AlPO4, Fe2O3 and B2O3 to form the support. Then conventional DeNOx catalytic metals are added. The support can be made by first impregnating the inorganic oxide particles with titania via a soluble precursor, forming titania and then shaping the coated particles into the desired shape such as a monolith. In a second embodiment, the inorganic oxide particles are first formed into the desired shape and then impregnated with the titania forming material. Barium sulfate can be added to the surface of the porous inorganic oxide to made an improved support.

대표청구항 ▼

A catalyst for the selective removal of nitrogen oxides from exhaust and waste gases in the presence of ammonia comprising: (a) a formed support of titania particles further containing other porous inorganic oxide particles, said formed support having (i) a total porosity of up to 0.80 cc/cc which i

A catalyst for the selective removal of nitrogen oxides from exhaust and waste gases in the presence of ammonia comprising: (a) a formed support of titania particles further containing other porous inorganic oxide particles, said formed support having (i) a total porosity of up to 0.80 cc/cc which is made up of a micropore porosity (comprising pores having a pore diameter 600 Angstrom units or less) of 0.05 to 0.5 cc/cc and a macroporosity (comprising pores having diameters greater than 600 Angstrom units) of 0.05 to 0.5 cc/cc, and (ii) said titania being substantially present in the anatase phase, and (b) a metal oxide catalytic component deposited on said support selected from the group consisting of V2O5, MoO3, WO3, Fe2O3, CuSO4, VOSO4, SnO2, Mn2O3, Mn3O4, and mixtures thereof, said metal oxide being present in an amount from a catalytically effective amount to 25% by weight of the entire catalyst. A catalyst according to claim 1, wherein said other inorganic oxide is selected from the group consisting of SiO2, Al2O3, ZrO2, AlPO4, Fe2O3, B2O3 and mixtures thereof. A catalyst according to claim 1, further comprising barium sulfate in an amount of from 1-15% by weight of the formed support. A catalyst according to claim 2, wherein the porous inorganic oxide is silica gel or precipitated silica.