초록 ▼

There is disclosed a hydrothermally stable microporous crystalline material comprising a molecular sieve or zeolite having an 8-ring pore opening structure, such as SAPO-34 or aluminosilicate zeolite, able to retain a specific percentage of its surface area and micropore volume after treatment with

There is disclosed a hydrothermally stable microporous crystalline material comprising a molecular sieve or zeolite having an 8-ring pore opening structure, such as SAPO-34 or aluminosilicate zeolite, able to retain a specific percentage of its surface area and micropore volume after treatment with heat and moisture, such as at least 80% of its surface area and micropore volume after exposure to temperatures of up to 900° C. in the presence of up to 10 volume percent water vapor for a time ranging from 1 to 16 hours. Methods of using the disclosed crystalline material, such as in the SCR of NOx in exhaust gas are also disclosed, as are methods of making such materials.

대표청구항 ▼

What we claim is: 1. A hydrothermally stable microporous crystalline material comprising SAPO-34 having a crystal size greater than 0.3 microns, which after exposure to temperatures ranging from 700 to 900° C. in the presence of up to 10 volume percent water vapor for a time of 16 hours, retai

What we claim is: 1. A hydrothermally stable microporous crystalline material comprising SAPO-34 having a crystal size greater than 0.3 microns, which after exposure to temperatures ranging from 700 to 900° C. in the presence of up to 10 volume percent water vapor for a time of 16 hours, retains at least 80% of its surface area and micropore volume and an acidity of at least 0.35 mmol/g. 2. A microporous crystalline material of claim 1, wherein said crystalline material comprises iron and/or copper. 3. A microporous crystalline material of claim 2, wherein said iron and/or copper are introduced into said solid by liquid-phase or solid ion-exchange or incorporated by direct-synthesis. 4. A microporous crystalline material of claim 1, wherein said SAPO-34 contains SiO2 in an amount ranging from 1-20%. 5. A microporous crystalline material of claim 1, wherein said SAPO-34 has a crystal size ranging from 0.3 to 5.0 microns. 6. A microporous crystalline material of claim 1, having an initial surface area of at least 650 m2/g. 7. A microporous crystalline material of claim 1, having an initial micropore volume of at least 0.25 cc/g. 8. A hydrothermally stable microporous crystalline material for SCR of NOxwith urea or ammonia, wherein said crystalline material comprises iron and/or copper containing SAPO-34 having a crystal size greater than 0.3 microns which retains at least 80% of its surface area and micropore volume after exposure to temperatures of up to 900 ° C. in the presence of up to 10 volume percent water vapor for up to 1 hour. 9. A microporous crystalline material of claim 8, wherein the iron and/or copper are introduced into said material by liquid-phase or solid ion-exchange or incorporated by direct-synthesis. 10. A microporous crystalline material of claim 8, wherein said iron comprises at least 0.20 weight percent of the total weight of said material. 11. A microporous crystalline material of claim 8, wherein said copper comprises at least 1.0 weight percent of the total weight of said material. 12. A microporous crystalline material of claim 8, wherein said SAPO-34 contains 1-20% of SiO2. 13. A method for making silicoaluminophosphate molecular sieve comprising SAPO-34, said method comprising: mixing sources of alumina, silica, and phosphate with a TEAOH solution and water to form a gel; heating said gel in an autoclave at a temperature ranging from 150 to 180° C. to form a product; cooling and optionally washing said product in water; calcining said product to form a molecular sieve comprising SAPO-34 having a crystal size greater than 0.3 microns and containing from 1-20% SiO2, wherein said molecular sieve after exposure to temperatures ranging from 700 to 900° C. in the presence of up to 10 volume percent water vapor for 16 hours, retains at least 80% of its surface area and micropore volume and has an acidity of at least 0.35 mmol/g. 14. The method of claim 13, wherein said source of alumina is pseudoboehmite alumina. 15. The method of claim 13, wherein said source of silica is a silica sol. 16. The method of claim 13, wherein said source of phosphate is phosphoric acid. 17. The method of claim 13, further comprising a cation exchange step. 18. The method of claim 17, wherein said cation is chosen from iron and copper. 19. The method of claim 13, wherein said gel is heated in an autoclave at a temperature of 180° C. 20. A microporous crystalline material of claim 1, wherein said exposure comprises a temperature of 900° C. 21. A microporous crystalline material of claim 1, wherein said crystalline material has an acidity value of at least 0.4 mmol/g after exposure. 22. A microporous crystalline material of claim 21, wherein said crystalline material has an acidity value ranging from 0.4 to 1.00 mmol/g after exposure. 23. A microporous crystalline material of claim 1, wherein said SAPO-34 has a crystal size ranging from 0.3 to 5.0 microns. 24. A hydrothermally stable microporous crystalline material comprising SAPO-34, having a crystal size greater than 0.3 microns and an acidity of at least 0.35 mmol/g and retains at least 80% of its surface area and micropore volume after hydrothermal aging comprising exposure to temperatures ranging from 700 to 900° C. in the presence of up to 10 volume percent water vapor for a time of 1 to 16 hours. 25. A microporous crystalline material of claim 24, wherein said SAPO-34 contains SiO2 in an amount ranging from 1-20%. 26. A microporous crystalline material of claim 24, having an initial surface area of at least 650 m2/g. 27. A microporous crystalline material of claim 24, having an initial micropore volume of at least 0.25 cc/g. 28. A hydrothermally stable microporous crystalline material of claim 8, wherein said SAPO-34 has a crystal size ranging from 0.3 to 5.0 microns. 29. A microporous crystalline material of claim 2, wherein said copper comprises about 2.0 weight percent of the total weight of said material. 30. A microporous crystalline material of claim 8, wherein said copper comprises about 2.0 weight percent of the total weight of said material.