Copper-promoted GMElinite and use thereof in the selective catalytic reduction of NOX
A catalyst for the selective catalytic reduction of NOx comprises a zeolitic material which comprises (A) one or more zeolites having a GME framework structure containing YO 2 and X 2 O 3 , and optionally further comprises one or more zeolites having a CHA framework structure containing YO 2 and X 2 O 3 , and/or comprises, (B) one or more zeolite intergrowth phases of one or more zeolites having a GME framework structure containing YO 2 and X 2 O 3 and one or more zeolites having a CHA framework structure containing YO 2 and X 2 O 3 , wherein Y is a tetravalent element, and X is a trivalent element, and the zeolitic material contains Cu and/or Fe as non-framework elements in an amount ranging from 0.1 to 15 wt. % calculated as the element and based on 100 wt. % of YO contained in the zeolitic material. Also provided are a process for its preparation, and a use in a method for the selective catalytic reduction of NOx.
1. A process for producing a catalyst comprising a zeolitic material, the process comprising:
crystallizing a mixture comprising a source of SiO 2 , a source of Al 2 O 3 , and optionally comprising a seed crystal, to obtain a first zeolitic material comprising a GME framework zeolite and a CHA framework zeolite, and/or to obtain a second zeolitic material comprising a zeolite intergrowth phase comprising a GME framework zeolite and a CHA framework zeolite;
optionally isolating the first and/or second zeolitic material;
optionally washing the first and/or second zeolitic material;
and
optionally drying the first and/or second zeolitic material;
ion-exchanging the first and/or second zeolitic material with Cu and/or Fe; and
obtaining the catalyst which is suitable for selective catalytic reduction of NOx,
wherein the zeolitic material of the catalyst comprises:
Cu and/or Fe; and
(A) a GME framework zeolite comprising SiO 2 and Al 2 O 3 , and a CHA framework zeolite comprising SiO 2 and Al 2 O 3 : and/or (B) a zeolite intergrowth phase comprising a GME framework zeolite comprising SiO 2 and Al 2 O 3 and a CHA framework zeolite comprising SiO 2 and Al 2 O 3 , and
wherein a relative amount of the CHA framework zeolite in the zeolitic material, calculated from an X-ray powder diffraction pattern of the zeolitic material using a Relative Intensity Ratio method, and based on 100% of phases in the zeolitic material comprising the GME and CHA framework zeolite, is in a range of from 10 to 60%.
2. The process of claim 1 , wherein the mixture in the crystallizing further comprises a solvent system comprising a solvent.
3. The process of claim 1 , wherein the mixture in the crystallizing comprises substantially no phosphorous and/or phosphorous containing compounds.
4. A catalyst, produced by the process comprising:
crystallizing a mixture comprising a source of SiO 2 , a source of Al 2 O 3 , and optionally comprising a seed crystal, to obtain a first zeolitic material comprising a GME framework zeolite and a CHA framework zeolite, and/or to obtain a second zeolitic material comprising a zeolite intergrowth phase comprising a GME framework zeolite and a CHA framework zeolite;
ion-exchanging the first and/or second zeolitic material with Cu and/or Fe; and
obtaining the catalyst which is suitable for selective catalytic reduction of NOx,
wherein the first and/or second zeolitic material of the catalyst comprises:
Cu and/or Fe: and
(A) a GME framework zeolite comprising SiO 2 and Al 2 O 3 and a CHA framework zeolite comprising SiO 2 and Al 2 O 3 : and/or (B) a zeolite intergrowth phase comprising a GME framework zeolite comprising SiO 2 and Al 2 O 3 and a CHA framework zeolite comprising SiO 2 and Al 2 O 3 , and
wherein a relative amount of the CHA framework zeolite in the zeolitic material, calculated from an X-ray powder diffraction pattern of the zeolitic material using a Relative Intensity Ratio method, and based on 100% of phases in the zeolitic material comprising the GME and CHA framework zeolite, is in a range of from 10% to 60%; and
wherein the zeolite material has a degree of crystallinity greater than 50%.
5. A catalyst, comprising a zeolitic material comprising:
(A) a zeolite having a GME framework structure comprising SiO 2 and Al 2 O 3 and a zeolite having a CHA framework structure comprising SiO 2 and Al 2 O 3 , and/or
(B) a zeolite intergrowth phase of one or more zeolites having a GME framework structure comprising SiO 2 and Al 2 O 3 and one or more zeolites having a CHA framework structure comprising SiO 2 and Al 2 O 3 ,
wherein the zeolitic material comprises Cu and/or Fe as a non-framework element in a range of from 0.1 wt.-% to 15 wt.-% calculated as an element and based on 100 wt.-% of SiO 2 contained in the zeolitic material, and
wherein the catalyst is suitable for selective catalytic reduction of NOx, and wherein a relative amount of the CHA framework structure in the zeolitic material, calculated from an X-ray powder diffraction pattern of the zeolitic material using a Relative Intensity Ratio method, and based on 100% of phases in the zeolitic material comprising the GME and CHA framework structure, is in a range of from 10% to 60%; and
wherein the zeolite material has a degree of crystallinity greater than 50%.
6. The catalyst of claim 5 , wherein a framework of the zeolitic material comprises substantially no phosphorous.
7. A method for selective catalytic reduction of NOx, the method comprising contacting a gas stream comprising NOx with the catalyst of claim 4 .
8. A method, comprising:
contacting a gas stream comprising NOx with the catalyst according to claim 4 .
9. The catalyst of claim 5 , wherein the zeolitic material comprises (A) the zeolite having a GME framework structure comprising SiO 2 and Al 2 O 3 and the zeolite having a CHA framework structure comprising SiO 2 and Al 2 O 3 .
10. The catalyst of claim 5 , wherein the zeolitic material comprises (B) the zeolite intergrowth phase of one or more zeolites having a GME framework structure comprising SiO 2 and Al 2 O 3 and the one or more zeolites having a CHA framework structure comprising SiO 2 and Al 2 O 3 .
11. The catalyst of claim 5 , wherein the non-framework element comprises Cu.
12. The catalyst of claim 5 , wherein the non-framework element comprises Fe.
13. The catalyst of claim 5 , wherein the non-framework element comprises Cu and Fe.
14. The catalyst of claim 5 , wherein Cu and/or Fe are present in a range of from 0.5 wt.-% to 10 wt.-%.
15. The catalyst of claim 5 , wherein Cu and/or Fe are present in a range of from 2 wt.-% to 5 wt.-%.
16. The catalyst of claim 5 , wherein the relative amount is in a range of from 15 to 50%.
17. The catalyst of claim 5 , wherein the relative amount is in a range of from 20 to 45%.
18. The catalyst of claim 5 , wherein the zeolitic material comprises the SiO 2 and the Al 2 O 3 in an SiO 2 :Al 2 O 3 molar ratio in a range of from 2 to 50.
19. The catalyst of claim 5 , wherein the zeolitic material comprises the SiO 2 and the Al 2 O 3 in an SiO 2 :Al 2 O 3 molar ratio in a range of from 5 to 12.