CATALYST FOR TREATING EXHAUST GAS
Catalyst compositions and methods of preparation comprising: preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve; and incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.
1 . A method of preparing a catalyst composition comprising:
a. preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve;
b. incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.
2 . The method of claim 1 , wherein preparing the promoter metal-molecular sieve catalyst composition comprises adding the promoter metal to the molecular sieve through ion exchange.
3 . The method of claim 1 , wherein the iron salt is incorporated into the promoter metal-molecular sieve catalyst composition after adding the promoter metal to the molecular sieve through ion exchange.
4 . The method of claim 1 , further comprising incorporating a rare earth metal into the promoter metal-molecular sieve catalyst composition.
5 . The method of claim 1 , wherein the catalyst composition comprises an iron species on the surface of the molecular sieve.
6 . The method of claim 1 , wherein the iron salt comprises iron sulphate.
7 . The method of claim 1 , wherein the molecular sieve comprises CHA, AEI, or combinations thereof.
8 . The method of claim 1 , wherein the promoter metal comprises Cu, Mn, or combinations thereof.
9 . The method of claim 4 , wherein the rare earth metal comprises Ce.
10 . The method of claim 1 , wherein the catalyst composition comprises a promoter metal in an amount of about 1 wt % to about 5 wt % of the catalyst composition.
11 . The method of claim 1 , wherein the catalyst composition comprises an iron salt in an amount of about 25 g/ft 3 to about 250 g/ft 3 ; about 25 g/ft 3 to about 125 g/ft 3 ; about 50 g/ft 3 to about 100 g/ft 3 ; about 60 g/ft 3 to about 80 g/ft 3 ; about 100 g/ft 3 to about 200 g/ft 3 ; about 125 g/ft 3 to about 175 g/ft 3 ; or about 140 g/ft 3 to about 160 g/ft 3 .
12 . A catalyst composition prepared by the method of claim 1 .