Templated catalyst composition and associated method

Abstract

A composition includes a templated metal oxide substrate having a plurality of pores and a catalyst material includes silver. The composition under H 2 at 30 degrees Celsius, the composition at a wavelength that is in a range of from about 350 nm to about 500 nm has a VIS-UV absorbance intensity that is at least 20 percent less than a standard silver alumina catalyst (Ag STD). The standard alumina is Norton alumina, and which has the same amount of silver by weight.

1 . A composition, comprising:
 a templated metal oxide substrate having a plurality of pores; and   a catalyst material comprising silver, and the composition having a VIS-UV absorbance intensity that is at least 20 percent less than a standard silver alumina catalyst, and which has the same amount of silver by weight at a wavelength in a range of from about 350 nm to about 500 nm, under H 2  at 30 degrees Celsius, wherein the composition is made by reacting a metal alkoxide, a silver composition and a templating agent.   
     
     
         2 . The composition as defined in  claim 1 , wherein the templated metal oxide is alumina or silica-alumina. 
     
     
         3 . The composition as defined in  claim 1 , wherein the templated metal oxide has periodically arranged templated pores, wherein the average diameter of the pores is in a range of from about 2 nanometers to about 100 nanometers and the pores have a periodicity in a range of from about 50 Angstrom to about 130 Angstrom. 
     
     
         4 . The composition as defined in  claim 1 , wherein the templated metal oxide has a surface area greater than about 0.5 meter/ 2 gram. 
     
     
         5 . The composition as defined in  claim 1 , wherein the templated metal oxide is present in an amount greater than about 50 mole percent of the composition. 
     
     
         6 . The composition as defined in  claim 1 , wherein the silver is present in an amount in a range of from about 2 weight percent to about 10 weight percent of a total weight of the substrate. 
     
     
         7 . The composition as defined in  claim 1 , wherein the composition may further comprise a promoter. 
     
     
         8 . The composition as defined in  claim 1 , wherein the composition is free of alkaline earth metal. 
     
     
         9 . The composition as defined in  claim 1 , wherein the composition is capable of reducing NOx in reactive proximity therewith without absorbing the NOx on a catalyst material surface. 
     
     
         10 . The composition as defined in  claim 1 , wherein the composition has capability of reducing nitrogen oxide greater than 40 percent by volume at a temperature of about 325 degrees Celsius. 
     
     
         11 . A method, comprising:
 reacting a metal alkoxide with a silver composition and a templating agent to form a reaction product;   hydrolyzing the reaction product to form a hydrolyzed reaction product;   condensing the hydrolysed reaction product to form a templated substrate; and   controlling the reacting, hydrolyzing and condensing step to control the silver loading of the templated substrate, and the silver loaded templated substrate having a VIS-UV absorbance intensity that is at least 20 percent less than a standard silver alumina catalyst, and which has the same amount of silver by weight at a wavelength in a range of from about 350 nm to about 500 nm, under H 2  at 30 degrees Celsius.   
     
     
         12 . The method as defined in  claim 11 , wherein the condensing step includes calcinating. 
     
     
         13 . The method as defined in  claim 12 , wherein the calcinating is done at a temperature greater than 350 degrees Celsius for a time period greater than 10 minutes. 
     
     
         14 . The method as defined in  claim 11 , the metal alkoxide is aluminium alkoxide. 
     
     
         15 . The method as defined in  claim 11 , wherein the silver composition is selected from a group consisting of silver salt of inorganic acids, silver salt of organic acids, and silver oxides. 
     
     
         16 . The method as defined in  claim 11 , wherein the templating agent comprises a surfactant, cyclodextrin, or a crown ether. 
     
     
         17 . The method as defined in  claim 11 , controlling the silver loading wherein the silver is present in an amount of at least about 2 weight percent based on a total weight of the substrate. 
     
     
         18 . The method as defined in  claim 17 , wherein the silver further is in an amount of less than or equal to 10 weight percent of a total weight of the substrate. 
     
     
         19 . A method comprising:
 introducing a gas stream in a chamber having a composition comprising a templated metal oxide substrate having a plurality of pores, a catalyst material comprising an amount of silver, wherein the composition having a VIS-UV absorbance intensity that is at least 20 percent less than a standard silver alumina catalyst, and which has the same amount of silver by weight at a wavelength in a range of from about 350 nm to about 500 nm, under H 2  at 30 degrees Celsius; and   reducing nitrogen oxide present in the gas stream at a temperature in a range of from about 275 degrees Celsius to about 350 degrees Celsius in the chamber.   
     
     
         20 . The method as defined in  claim 19 , wherein reducing nitrogen oxide present in the gas stream occurs at a temperature, further, that is less than about 325 degrees Celsius in the chamber. 
     
     
         21 . The method as defined in  claim 19 , wherein reducing nitrogen oxide present in the gas stream occurs at a temperature in the range from about 300 degrees Celsius to about 325 degrees Celsius in the chamber.