Selective catalytic reduction catalyst composition

Abstract

A SCR catalyst composition comprises a SCR catalyst; and a binder comprising a porous inorganic material, wherein the porous inorganic material comprises a disordered arrangement of delaminated layers, has a disordered porous structure, and has a multimodal pore size distribution comprising at least a first modal maximum having a macroporous or mesoporous pore size and a second modal maximum having a microporous pore size. The SCR catalyst composition can be manufactured using the method comprising the steps of: (i) providing an inorganic material having a layered structure; (ii) contacting the material with a cationic surfactant to form a swollen material; (iii) agitating the swollen material to form an agitated material; and (iv) calcining the agitated material to recover a delaminated inorganic material, wherein an SCR catalyst is mixed with the inorganic material prior to step (iv).

1 . A selective catalytic reduction (SCR) catalyst composition comprising:
 a SCR catalyst; and   a binder comprising a porous inorganic material,   
       wherein the porous inorganic material comprises a disordered arrangement of delaminated layers, has a disordered porous structure, and has a multimodal pore size distribution comprising at least a first modal maximum having a macroporous or mesoporous pore size and a second modal maximum having a microporous pore size. 
     
     
         2 . The SCR catalyst composition of  claim 1 , wherein the multimodal pore size distribution is bimodal. 
     
     
         3 . The SCR catalyst composition of  claim 1 , wherein a powder X-ray diffraction pattern of the porous inorganic material obtained using Cu Kαradiation is devoid of peaks at 2θ values of 10° or less. 
     
     
         4 . The SCR catalyst composition of  claim 1 , wherein the first modal maximum has a mesoporous and/or macroporous pore size. 
     
     
         5 . The SCR catalyst of  claim 1 , wherein the delaminated layers are delaminated silicate layers. 
     
     
         6 . The SCR catalyst composition of  claim 1 , wherein the porous inorganic material comprises one or more of: a clay mineral, graphite, graphene, a layered silicate, a layered phosphate, a layered zeolite, a layered double hydroxide, hydrotalcite, a layered perovskite, attapulgite, sepiolite and vermiculite. 
     
     
         7 . The SCR catalyst composition of  claim 6 , wherein the porous inorganic material comprises a clay mineral comprising a three-layered (2:1) clay mineral. 
     
     
         8 . The SCR catalyst composition of  claim 7 , wherein the clay mineral comprises bentonite. 
     
     
         9 . The SCR catalyst composition of  claim 1 , wherein the porous inorganic material is substantially non-pillared. 
     
     
         10 . The SCR catalyst composition of  claim 1 , wherein the porous inorganic material is functionalised with one or more of Cu, Fe, Ce, Mn, V, Zn, Mo, Pt, Pd, Rh, Ir and Ni. 
     
     
         11 . The SCR catalyst composition of  claim 1 , wherein the porous inorganic material is functionalised with Cu and/or Fe. 
     
     
         12 . The SCR catalyst composition of  claim 1 , wherein the SCR catalyst comprises a zeolite. 
     
     
         13 . The SCR catalyst composition of  claim 1 , wherein the SCR catalyst comprises a titania and the porous inorganic material is functionalised with V and/or Fe. 
     
     
         14 . The SCR catalyst composition of  claim 13 , wherein the titania comprises W, Si and/or Mo and the porous inorganic material is functionalised with V. 
     
     
         15 . The SCR catalyst composition of  claim 1 , wherein the porous inorganic material comprises from 0.01 to 5 wt. % Fe. 
     
     
         16 . The SCR catalyst composition of  claim 1 , wherein the SCR catalyst composition is extrudable. 
     
     
         17 . The SCR catalyst composition of  claim 1  in the form of pellets or a sheet or having a honeycomb structure. 
     
     
         18 . An emission treatment system for treating a flow of a combustion exhaust gas, the system comprising a source of combustion exhaust gas in fluid communication with the SCR catalyst composition of  claim 1 , and a source of nitrogenous reductant arranged upstream of said SCR catalyst composition. 
     
     
         19 . A method for the manufacture of a SCR catalyst composition, the method comprising:
 (i) providing an inorganic material having a layered structure;   (ii) contacting the material with a cationic surfactant to form a swollen material;   (iii) agitating the swollen material to form an agitated material; and   (iv) calcining the agitated material to recover a delaminated inorganic material,   
       wherein an SCR catalyst is mixed with the inorganic material prior to step (iv). 
     
     
         20 . The method of  claim 19 , wherein the cationic surfactant comprises a carbon chain having at least 10 carbon atoms. 
     
     
         21 . The method of  claim 19 , wherein step (ii) comprises mixing the material and an aqueous solution of the cationic surfactant to form a mixture, followed by storing the mixture for a period of from 1 to 3 days, wherein the storing is carried out at a temperature of from 30 to 50° C. 
     
     
         22 . The method of  claim 19 , wherein the agitating comprises sonication and/or the application of microwaves, wherein the sonication comprises ultrasonication. 
     
     
         23 . The method of  claim 19 , wherein step (iii) is carried out for a period of from 1 to 4 hours, and/or at a temperature of from 15 to 35° C. 
     
     
         24 . The method of  claim 19 , further comprising contacting the agitated material and/or delaminated inorganic material with a solution of metal ions to incorporate at least some of the metal ions into the agitated material and/or delaminated inorganic material, the metal selected from one or more of Cu, Fe, Ce, Mn, V, Zn, Mo, Pt, Pd, Rh, Ir and Ni. 
     
     
         25 . The method of  claim 19 , further comprising forming the material into a desired shape, wherein the forming comprises extrusion and the desired shape comprises pellets or a sheet or a honeycomb structure. 
     
     
         26 . The method of  claim 19 , wherein the SCR catalyst composition comprises a SCR catalyst; and
 a binder comprising a porous inorganic material,   
       wherein the porous inorganic material comprises a disordered arrangement of delaminated layers, has a disordered porous structure, and has a multimodal pore size distribution comprising at least a first modal maximum having a macroporous or mesoporous pore size and a second modal maximum having a microporous pore size. 
     
     
         27 . A method for the manufacture of a porous inorganic material, the method comprising:
 (i) providing an inorganic material having a layered structure;   (ii) contacting the material with a cationic surfactant to form a swollen material;   (iii) agitating the swollen material to form an agitated material; and   (iv) calcining the agitated material to recover a delaminated inorganic material.   
     
     
         28 . A porous inorganic material comprising a disordered arrangement of delaminated silicate layers, a disordered porous structure, a pore size distribution comprising at least a first modal maximum having a macroporous or mesoporous pore size and a second modal maximum having a microporous pore size, the porous inorganic material obtainable by the method of  claim 27 . 
     
     
         29 . (canceled) 
     
     
         30 . (canceled)