Honeycomb catalyst body

Abstract

The honeycomb catalyst body is equipped with a honeycomb structure body having partition walls that define a plurality of cells extending from a first end face as one of the end faces to a second end face as the other end face and serving as through channels of a fluid. The partition walls each have a base layer containing from 50 to 90 mass % of zeolite and a coat layer with which the surface of the base layer 11 is coated with a thickness of from 1 to 50 μm. The coat layer is either a coat layer (A) containing from 1 to 5 mass % vanadia and titania or a coat layer (B) containing from 1 to 5 mass % vanadia and a composite oxide of titania and tungsten oxide.

What is claimed is: 
     
         1 . A honeycomb catalyst body comprising a honeycomb structure body:
 having partition walls that define a plurality of cells extending from a first end face as one of the end faces to a second end face as the other end face and serving as through channels of a fluid,   the partition walls each having a base layer containing from 50 to 90 mass % of zeolite and a coat layer with which the surface of the base layer is coated with a thickness of from 1 to 50 μm, and   the coat layer being either a coat layer (A) containing from 1 to 5 mass % vanadia and titania or a coat layer (B) containing from 1 to 5 mass % vanadia and a composite oxide of titania and tungsten oxide.   
     
     
         2 . A honeycomb catalyst body comprising:
 a honeycomb structural body having partition walls that define a plurality of cells extending from a first end face as one of the end faces to a second end face as the other end face, and serving as through channels of a fluid,   the partition walls each having a support layer composed mainly of ceramic, an intermediate layer with which the surface of the support layer is coated and that contains from 50 to 95 mass % of zeolite, and a coat layer with which the surface of the intermediate layer is coated, and   the coat layer being either a coat layer (A) containing from 1 to 5 mass % vanadia and titania or a coat layer (B) containing from 1 to 5 massa vanadia and a composite oxide of titania and tungsten oxide.   
     
     
         3 . The honeycomb catalyst body according to  claim 1 ,
 wherein the honeycomb structure body has an effective GSA (geometrical surface area) of from 10 to 50 cm 2 /cm 3 .   
     
     
         4 . The honeycomb catalyst body according to  claim 2 ,
 wherein the honeycomb structure body has an effective GSA (geometrical surface area) of from 10 to 50 cm 2 /cm 3 .   
     
     
         5 . The honeycomb catalyst body according to  claim 1 , wherein a ratio of the mass of the zeolite to a total of the mass of the vanadia and the mass of the titania in the coat layer (A) {(mass of zeolite):(total of mass of vanadia and mass of titania)} contained in the honeycomb structure body is from 99:1 to 60:40; or a ratio of the mass of the zeolite to a total of the mass of the vanadia, the mass of the titania, and the mass of the tungsten oxide in the coat layer (B) {(mass of zeolite):(total of mass of vanadia, mass of titania, and mass of tungsten oxide)} contained in the honeycomb structure body is from 99:1 to 60:40. 
     
     
         6 . The honeycomb catalyst body according to  claim 2 , wherein a ratio of the mass of the zeolite to a total of the mass of the vanadia and the mass of the titania in the coat layer (A) {(mass of zeolite) (total of mass of vanadia and mass of titania)} contained in the honeycomb structure body is from 99:1 to 60:40; or a ratio of the mass of the zeolite to a total of the mass of the vanadia, the mass of the titania, and the mass of the tungsten oxide in the coat layer (B) {(mass of zeolite):(total of mass of vanadia, mass of titania, and mass of tungsten oxide)} contained in the honeycomb structure body is from 99:1 to 60:40. 
     
     
         7 . The honeycomb catalyst body according to  claim 3 , wherein a ratio of the mass of the zeolite to a total of the mass of the vanadia and the mass of the titania in the coat layer (A) {(mass of zeolite):(total of mass of vanadia and mass of titania)} contained in the honeycomb structure body is from 99:1 to 60:40; or a ratio of the mass of the zeolite to a total of the mass of the vanadia, the mass of the titania, and the mass of the tungsten oxide in the coat layer (B) {(mass of zeolite):(total of mass of vanadia, mass of titania, and mass of tungsten oxide)} contained in the honeycomb structure body is from 99:1 to 60:40. 
     
     
         8 . The honeycomb catalyst body according to  claim 4 , wherein a ratio of the mass of the zeolite to a total of the mass of the vanadia and the mass of the titania in the coat layer (A) {(mass of zeolite):(total of mass of vanadia and mass of titania)} contained in the honeycomb structure body is from 99:1 to 60:40; or a ratio of the mass of the zeolite to a total of the mass of the vanadia, the mass of the titania, and the mass of the tungsten oxide in the coat layer (B) {(mass of zeolite):(total of mass of vanadia, mass of titania, and mass of tungsten oxide)} contained in the honeycomb structure body is from 99:1 to 60:40. 
     
     
         9 . The honeycomb catalyst body according to  claim 1 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         10 . The honeycomb catalyst body according to  claim 2 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         11 . The honeycomb catalyst body according to  claim 3 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         12 . The honeycomb catalyst body according to claim  4 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         13 . The honeycomb catalyst body according to  claim 5 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         14 . The honeycomb catalyst body according to  claim 6 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         15 . The honeycomb catalyst body according to  claim 7 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         16 . The honeycomb catalyst body according to  claim 8 ,
 wherein the honeycomb structure body has a thermal expansion coefficient at from 40 to 800° C. of 1.0 ppm/K or less.   
     
     
         17 . The honeycomb catalyst body according to  claim 1 ,
 wherein the coat layer contains from 1 to 30 mass of an inorganic binder that does not disappear at 500° C. or less.   
     
     
         18 . The honeycomb catalyst body according to  claim 2 ,
 wherein the coat layer contains from 1 to 30 mass of an inorganic binder that does not disappear at 500° C. or less.