CN112758954A - Composite molecular sieve with core-shell structure and synthesis method thereof - Google Patents

Composite molecular sieve with core-shell structure and synthesis method thereof Download PDF

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CN112758954A
CN112758954A CN202110167440.6A CN202110167440A CN112758954A CN 112758954 A CN112758954 A CN 112758954A CN 202110167440 A CN202110167440 A CN 202110167440A CN 112758954 A CN112758954 A CN 112758954A
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molecular sieve
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刘中清
王倩
赵峰
邓兆敬
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China Chemical Technology Research Institute
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Abstract

The invention provides a composite molecular sieve with a core-shell structure and a synthesis method thereof. The composite molecular sieve with the core-shell structure takes a Cu-SSZ-39 molecular sieve as a core and takes an SSZ-39 molecular sieve or an AFX molecular sieve as a shell. The invention also provides a synthesis method of the composite molecular sieve with the core-shell structure. According to the invention, a Cu-SSZ-39@ SSZ-39 or Cu-SSZ-39@ AFX composite structure is constructed, and the shell SSZ-39 or AFX provides an exchange site for Cu species migrating outwards in the core, so that the generation of agglomerated CuO particles can be inhibited, the hydrothermal stability of the Cu-SSZ-39 catalyst under a severe reaction condition is improved, and the catalytic performance of the catalyst in a high-temperature region is further improved.

Description

Composite molecular sieve with core-shell structure and synthesis method thereof
Technical Field
The invention relates to a composite molecular sieve with a core-shell structure and a synthesis method thereof, belonging to the technical field of molecular sieve preparation.
Background
SSZ-39 is a molecular sieve with an AEI topology made of AlO4And SiO4The tetrahedra are connected end to end via oxygen atoms and are arranged in order to form double six-membered rings (D6R), which are linked by partial four-membered rings to form a three-dimensional channel structure with a maximum of eight-membered rings. Currently, research on the application of SSZ-39 is primarily focused on ammonia-selective catalytic reduction (NH) to reduce nitrogen oxides (NOx) in diesel exhaust3-SCR) reaction.
Studies have shown that SSZ-39 is via Cu2+After exchange, its active temperature window width and N2The selectivity can be greatly improved, and the mechanism research proves that Cu2+Is the main active site in SCR (appl.catal.b: environ, 2020,264,118511). However, with the continued upgrading of diesel aftertreatment systems, particularly after upstream addition of a diesel particulate trap (DPF), the regeneration process for particulate matter can reach as high as 800 ℃, at which temperature Cu is isolated2+Is difficult to be stabilized at the initial position, and gradually migrates to the surface of the molecular sieve crystal and is agglomerated to form CuO particles. The formation of CuO not only causes the loss of SCR active sites, but also destroys the long-range ordered structure of the molecular sieve, directly causes the inactivation of the molecular sieve catalyst, so that the hydrothermal stability becomes NH3Important evaluation criteria for SCR catalysts.
The hydrothermal treatment can obviously reduce the specific surface area and the pore volume of the Cu-SSZ-39 catalyst, and causes active site Cu2+Migrate to the outside of the molecular sieve to aggregate into CuO particles, so that NH3-reduction of SCR activity. Thus, Cu is suppressed2+The agglomeration of CuO is the key for improving the hydrothermal stability of the Cu-SSZ-39 molecular sieve catalyst.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a composite molecular sieve with a core-shell structure and a synthesis method thereof. The composite molecular sieve with the core-shell structure takes the Cu-SSZ-39 molecular sieve as a core and takes the SSZ-39 molecular sieve or the AFX molecular sieve as a shell, so that CuO agglomeration can be inhibited and the inactivation of a catalyst can be weakened in hydrothermal treatment.
In order to achieve the purpose, the invention provides a composite molecular sieve with a core-shell structure, wherein the composite molecular sieve takes a Cu-SSZ-39 molecular sieve as a core and takes an SSZ-39 molecular sieve or an AFX molecular sieve as a shell.
The composite molecular sieve (Cu-SSZ-39@ SSZ-39 or Cu-SSZ-39@ AFX) with the core-shell structure is a Cu-SSZ-39 molecular sieve which is a core layer material (the core layer material is solid particles) and is compounded with a SSZ-39 molecular sieve or an AFX molecular sieve without Cu to obtain the Cu-SSZ-39 molecular sieve with the copper-rich crystal core. The molecular sieve with the structure of Cu-SSZ-39@ SSZ-39 or Cu-SSZ-39@ AFX can be provided with the SSZ-39 or AFX shell of Cu when Cu species in the core Cu-SSZ-39 migrate to the outside of the molecular sieve under severe hydrothermal conditions2+A large number of exchange sites are provided, so that the generation of agglomerated CuO particles can be suppressed and the deactivation of the catalyst can be reduced.
According to a specific embodiment of the present invention, preferably, the Cu-SSZ-39 molecular sieve has a CuO content of 0.1 wt% to 20 wt%, more preferably 1 wt% to 10 wt%. The Cu-SSZ-39 molecular sieve may be prepared by any means.
According to a specific embodiment of the present invention, preferably, the Cu-SSZ-39 molecular sieve as the core layer accounts for 1 wt% to 99 wt%, more preferably 10 wt% to 80 wt%, and further preferably 20 wt% to 50 wt% of the total mass of the composite molecular sieve.
The invention also provides a synthesis method of the composite molecular sieve with the core-shell structure (taking the Cu-SSZ-39 molecular sieve as a core and the SSZ-39 molecular sieve as a shell), wherein the synthesis method comprises the following steps:
the first synthesis method comprises the following steps:
mixing the molecular sieve, an alkali source, an organic template agent and water, and aging for 0.1-100 h at room temperature to 100 ℃ to obtain a gel for synthesizing the SSZ-39 molecular sieve;
adding a Cu-SSZ-39 molecular sieve into the gel for synthesizing the SSZ-39 molecular sieve, and then crystallizing the gel in an autoclave at the temperature of 120-DEG C and 200 ℃ for 10-100 h;
cooling, filtering, washing, drying and roasting to obtain the composite molecular sieve with the core-shell structure;
and a second synthesis method comprises the following steps:
mixing the molecular sieve, an alkali source, an organic template agent and water, and aging for 0.1-100 h at room temperature to 100 ℃ to obtain a gel for synthesizing the SSZ-39 molecular sieve;
crystallizing the gel of the synthesized SSZ-39 molecular sieve in an autoclave at 120-200 ℃ for 0.1-40 h;
adding a Cu-SSZ-39 molecular sieve into an autoclave, and then crystallizing at 120-200 ℃ for 0.1-100 h;
and cooling, filtering, washing, drying and roasting to obtain the composite molecular sieve with the core-shell structure.
Wherein, the second synthesis method can shorten the soaking time of the Cu-SSZ-39 molecular sieve as the nuclear material in a strong alkaline crystallization system, and can reduce the dissolution and the damage of the nuclear material Cu-SSZ-39. In some embodiments, the gel of the synthesized SSZ-39 molecular sieve can be crystallized in an autoclave at 120 ℃ to 200 ℃ for 0.1h to 40h, and then the Cu-SSZ-39 molecular sieve is added into the autoclave and crystallized at 120 ℃ to 200 ℃ for 0.1h to 50 h.
In the above synthesis method, preferably, the molecular sieves used in the raw material of the gel for synthesizing the SSZ-39 molecular sieve include USY molecular sieve, NaY molecular sieve and NH4One or a combination of two or more of the Y molecular sieves.
In the above synthesis method, preferably, the raw material for synthesizing the gel of the SSZ-39 molecular sieve further comprises a silicon source; more preferably, the silicon source includes but is not limited to one or a combination of two or more of silicate, tetraethoxysilane, white carbon black and silica sol, and more preferably silica sol.
In the above synthesis method, preferably, the mass ratio of the gel of the synthesized SSZ-39 molecular sieve to the Cu-SSZ-39 molecular sieve is 80 to 0.8, preferably 40 to 1, and more preferably 10 to 2.
In the above synthesis method, it is preferable that SiO of the molecular sieve used in the raw material for synthesizing the gel of the SSZ-39 molecular sieve2/Al2O35-100, molar ratio. The molecular sieve (e.g., USY molecular sieve) may be prepared by any means that functions to provide a source of aluminum and a source of silicon.
In the above synthesis method, preferably, the alkali source is sodium hydroxide and/or potassium hydroxide.
In the above synthesis method, preferably, the organic template includes N, N-diethyl-2, 6-dimethylpiperidine ion, 1,3, 5-tetramethylpiperidine ion, 2, 6-dimethyl-5-azoniaspiro- [4.5] -decane ion, N-diethyl-2-ethylpiperidine ion, N-ethyl-N-propyl-2, 6-dimethylpiperidine ion, N-methyl-N-ethyl-2-ethylpiperidine ion, 2, 5-dimethyl-N, N-diethylpyrrole ion, 2, 6-dimethyl-N, N-dimethylpiperidine ion, N-dimethyl-N, N-dimethylpiperidine ion, N-diethylpiperidine ion, N-diethyl, One or a combination of two or more of salts and/or bases of 3, 5-dimethyl-N, N-dimethylpiperidinium ion, 2-ethyl-N, N-dimethylpiperidinium ion, 2,6, 6-tetramethyl-N-methyl-ethylpiperidinium ion, N-cyclooctyl-pyridinium ion, 2,6, 6-tetramethyl-N, N-dimethylpiperidinium ion and N, N-dimethyl-N, N-bicyclononanium ion, and preferably one or a combination of two or more of salts and/or bases of N, N-diethyl-2, 6-dimethylpiperidinium ion and/or 3, 5-dimethyl-N, N-dimethylpiperidinium ion.
In the above synthesis method, preferably, in the raw material for synthesizing the gel of the SSZ-39 molecular sieve, the molar ratio of the molecular sieve, the alkali source, the organic template and water satisfies the following condition: SiO 22/Al2O3＝5-100，OH-/SiO2＝0.1-0.5，H2O/SiO2＝3-60，R/SiO20.01-0.5; wherein R represents an organic template.
In the above synthesis method, preferably, when the raw material for synthesizing the gel of the SSZ-39 molecular sieve further includes a silicon source, the molar ratio of the silicon source, the molecular sieve, the alkali source, the organic template, and water satisfies the following condition: SiO 22/Al2O3＝5-100，OH-/SiO2＝0.1-0.5，H2O/SiO2＝3-60，R/SiO20.01-0.5; wherein R represents an organic template.
In the above synthesis method, preferably, the temperature is reduced to 60 ℃ or lower.
When the AFX molecular sieve is used as the shell, the synthesis can be carried out by referring to the first synthesis method and the second synthesis method.
The Cu-SSZ-39 molecular sieve is taken as a core, mixed with the synthetic gel of the SSZ-39 molecular sieve or the AFX molecular sieve which does not contain copper, and crystallized to prepare the composite molecular sieve which only has the copper-rich inner core. Under a severe hydrothermal condition, when Cu species in the core Cu-SSZ-39 are migrated to the outside of the molecular sieve, the catalyst with the Cu-SSZ-39@ SSZ-39 or Cu-SSZ-39@ AFX structure provides a large number of exchange sites for the Cu species, so that the generation of agglomerated CuO particles can be inhibited, the inactivation of the catalyst is weakened, and the hydrothermal stability and the catalytic performance in a high-temperature region of the catalyst are improved.
Compared with the prior art, the invention provides an exchange site for Cu species migrating outwards in the core by constructing the Cu-SSZ-39@ SSZ-39 and Cu-SSZ-39@ AFX composite structures and using the shell SSZ-39 or AFX as the exchange site, so that the generation of agglomerated CuO particles can be inhibited, the hydrothermal stability of the Cu-SSZ-39 catalyst under severe reaction conditions is improved, and the catalytic performance of the catalyst in a high-temperature region is further improved.
Drawings
FIGS. 1-6 are X-ray diffraction patterns of the composite molecular sieve Cu-SSZ-39@ SSZ-39 prepared in examples 1-6, respectively.
FIG. 7 is an XPS depth profile and a plot of surface copper atom concentration versus profile depth for the Cu-SSZ-39@ SSZ-39 molecular sieve prepared in example 1.
FIG. 8 is an XPS depth profile and a plot of surface copper atom concentration versus profile depth for a Cu-SSZ-39@ SSZ-39 molecular sieve prepared in a comparative example.
Detailed Description
The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.
Example 1
This example provides a composite molecular sieve Cu-SSZ-39@ SSZ-39 having a core-shell structure, which was synthesized by:
1) taking USY molecular sieve, NaOH, N-diethyl-2, 6-dimethyl piperidine hydroxide and water as raw materials of the synthetic gel of the shell SSZ-39 molecular sieve according to the following raw material molar ratio:
SiO2/Al2O3＝15，R/SiO2＝0.2，OH-/SiO2＝0.4，H2O/SiO 220; r represents N, N-diethyl-2, 6-dimethyl piperidine hydroxide.
2) 1.20g of sodium hydroxide is dissolved in 40.81g of deionized water, 18.70g of an aqueous solution of N, N-diethyl-2, 6-dimethylpiperidine hydroxide with a mass fraction of 30% are added after complete dissolution, and 10g of SiO are added with rapid stirring2/Al2O3The resulting mixture was transferred to a stainless steel autoclave lined with polytetrafluoroethylene and aged at 80 ℃ for 12h to give a gel of synthetic SSZ-39 molecular sieve.
3) The content of CuO is 5 percent and SiO is used2/Al2O3Taking commercial Cu-SSZ-39 of which the mass is 15 as a core layer material, adding 10g of the commercial Cu-SSZ-39 as a core layer material into the gel of the synthesized SSZ-39 molecular sieve prepared in the step 2), uniformly mixing, then putting into an autoclave, and heating to 190 ℃ under stirring for crystallization for 72 hours;
4) and (3) cooling to below 60 ℃ after crystallization is stopped, washing the product with deionized water, filtering and collecting, drying at 100 ℃ for 12h, and then placing in a muffle furnace to calcine at 550 ℃ for 8h to remove the structure directing agent, thus obtaining the composite molecular sieve Cu-SSZ-39@ SSZ-39 with the core-shell structure.
The X-ray diffraction pattern of the composite molecular sieve Cu-SSZ-39@ SSZ-39 is shown in figure 1. N is a radical of2The result of physical adsorption shows that the specific surface area of the molecular sieve is 521m2/g。
Example 2
This example provides a method for preparing a Cu-SSZ-39@ SSZ-39 core-shell molecular sieve, comprising the steps of:
1) preparation of SSZ-39 molecular sieve synthesis gel: substantially the same as in step (2) of example 1, except that no aging operation was conducted, an SSZ-39 molecular sieve synthesis gel was obtained.
2) The other preparation process is exactly the same as in example 1.
The X-ray diffraction pattern of the composite molecular sieve Cu-SSZ-39@ SSZ-39 prepared in this example is shown in FIG. 2. N is a radical of2The measurement result of a physical adsorption instrument shows that the specific surface area of the molecular sieve is 530m2/g。
Example 3
This example provides a method for preparing a Cu-SSZ-39@ SSZ-39 core-shell molecular sieve, comprising the steps of:
1) preparation of SSZ-39 molecular sieve synthesis gel: the procedure was exactly the same as in step (2) of example 1.
2) SiO in the same CuO content of 5%2/Al2O3Commercial Cu-SSZ-39 as a core layer material, 15 g, different from the example 1 step (3), in that the ratio of shell layer to core (i.e., the ratio of SSZ-39 to Cu-SSZ-39) was adjusted, 20.00g of Cu-SSZ-39 was added to the SSZ-39 molecular sieve synthesis gel, and the resulting mixture was transferred to a charge autoclave to be crystallized under the same conditions.
3) The other preparation process is exactly the same as in example 1.
The X-ray diffraction pattern of the composite molecular sieve Cu-SSZ-39@ SSZ-39 prepared in this example is shown in FIG. 3. N is a radical of2The result of physical adsorption shows that the specific surface area of the molecular sieve is 546m2/g。
Example 4
This example provides a composite molecular sieve Cu-SSZ-39@ SSZ-39 having a core-shell structure, which was synthesized by:
1) taking USY molecular sieve, silica sol, NaOH, 1,3, 5-tetramethyl piperidine and water as raw materials of the synthetic gel of the shell SSZ-39 molecular sieve according to the following raw material molar ratio:
SiO2/Al2O3＝50，R/SiO2＝0.4，OH-/SiO2＝0.5，H2O/SiO 220; r represents 1,1,3, 5-tetramethyl piperidine.
2) Dissolving 0.44g of sodium hydroxide in 12.87g of deionized water, adding 28.36g of 25 mass percent 1,1,3, 5-tetramethylpiperidine aqueous solution after complete dissolution, then adding 10.00g of 40 mass percent silica sol under rapid stirring, adding 2.92g of SiO after uniform mixing2/Al2O3The resulting mixture was transferred to a stainless steel autoclave lined with polytetrafluoroethylene and aged at 80 ℃ for 12h to give a gel of synthetic SSZ-39 molecular sieve.
3) Putting the gel of the synthesized SSZ-39 molecular sieve prepared in the step 2) into an autoclave, and heating to 180 ℃ for crystallization for 40 hours under stirring.
4) The content of CuO is 5 percent and SiO is used2/Al2O33.46g of commercial Cu-SSZ-39 as a core layer material was added to the synthetic gel prepared in step 3), mixed well, charged into an autoclave, and crystallized at 180 ℃ for 60 hours with stirring.
5) And (3) cooling to below 60 ℃ after crystallization is stopped, washing the product with deionized water, filtering and collecting, drying at 100 ℃ for 12h, and then placing in a muffle furnace to calcine at 550 ℃ for 8h to remove the structure directing agent, thus obtaining the composite molecular sieve Cu-SSZ-39@ SSZ-39 with the core-shell structure.
The X-ray diffraction pattern of the composite molecular sieve Cu-SSZ-39@ SSZ-39 is shown in figure 4. N is a radical of2The measurement result of a physical adsorption instrument shows that the specific surface area of the molecular sieve is 554m2/g。
Example 5
This example provides a composite molecular sieve Cu-SSZ-39@ SSZ-39 having a core-shell structure, which was synthesized by:
1) taking a NaY molecular sieve, silica sol, NaOH, 1,3, 5-tetramethyl piperidine and water as raw materials of the synthetic gel of the shell SSZ-39 molecular sieve according to the following raw material molar ratio:
SiO2/Al2O3＝75，R/SiO2＝0.5，OH-/SiO2＝0.35，H2O/SiO 230; r represents 1,1,3, 5-tetramethyl piperidine.
2) At 21.47gAdding 28.96g of 25 mass percent 1,1,3, 5-tetramethylpiperidine aqueous solution into ionized water, then adding 10.00g of 40 mass percent silica sol under rapid stirring, and adding 1.59g of SiO after uniform mixing2/Al2O3The resulting mixture was transferred to a stainless steel autoclave lined with teflon and aged at 80 ℃ for 12h to give a gel of synthetic SSZ-39 molecular sieve.
3) Putting the gel of the synthesized SSZ-39 molecular sieve prepared in the step 2) into an autoclave, and heating to 150 ℃ for crystallization for 80 hours under stirring.
4) The content of CuO is 8 percent and SiO is used2/Al2O3Commercial Cu-SSZ-39 of 40 as a core layer material, 27.95g was added to the synthetic gel prepared in step 3), mixed well, charged into an autoclave, and crystallized at 150 ℃ for 80 hours with stirring.
5) And (3) cooling to below 60 ℃ after crystallization is stopped, washing the product with deionized water, filtering and collecting, drying at 100 ℃ for 12h, and then placing in a muffle furnace to calcine at 550 ℃ for 8h to remove the structure directing agent, thus obtaining the composite molecular sieve Cu-SSZ-39@ SSZ-39 with the core-shell structure.
The X-ray diffraction pattern of the composite molecular sieve Cu-SSZ-39@ SSZ-39 is shown in figure 5. N is a radical of2The physical adsorption apparatus determination result shows that the specific surface area of the molecular sieve is 568m2/g。
Example 6
This example provides a composite molecular sieve Cu-SSZ-39@ SSZ-39 having a core-shell structure, which was synthesized by:
1) taking USY molecular sieve, white carbon black, NaOH, 1,3, 5-tetramethyl piperidine, N-methyl-N-ethyl-2-ethyl piperidine and water as raw materials of the synthetic gel of the shell SSZ-39 molecular sieve according to the following raw material molar ratio:
SiO2/Al2O3＝20，R/SiO2＝0.1，OH-/SiO2＝0.25，H2O/SiO 210; r represents 1,1,3, 5-tetramethylpiperidine, N-methyl-N-ethyl-2-ethylpiperidine.
2) To 14.82g of deionized water was addedAdding 3.64g of 25 mass percent 1,1,3, 5-tetramethylpiperidine aqueous solution and 3.57g of 30 mass percent N, N-diethyl-2, 6-dimethylpiperidine aqueous solution, then adding 5.00g of white carbon black under rapid stirring, adding 2.55g of SiO after uniformly mixing2/Al2O3The resulting mixture was transferred to a stainless steel autoclave lined with teflon and aged at 60 ℃ for 12h to give a gel of synthetic SSZ-39 molecular sieve.
3) Putting the gel of the synthesized SSZ-39 molecular sieve prepared in the step 2) into an autoclave, and heating to 200 ℃ for crystallization for 18 hours under stirring.
4) The content of CuO is 12 percent and SiO is used2/Al2O3Commercial Cu-SSZ-39 of 40 as a core layer material, 30.20g was added to the synthetic gel prepared in step 3), mixed well, charged into an autoclave, and crystallized at 150 ℃ for 80 hours with stirring.
5) And (3) cooling to below 60 ℃ after crystallization is stopped, washing the product with deionized water, filtering and collecting, drying at 100 ℃ for 12h, and then placing in a muffle furnace to calcine at 550 ℃ for 8h to remove the structure directing agent, thus obtaining the composite molecular sieve Cu-SSZ-39@ SSZ-39 with the core-shell structure.
The X-ray diffraction pattern of the composite molecular sieve Cu-SSZ-39@ SSZ-39 is shown in figure 6. N is a radical of2The measurement result of a physical adsorption instrument shows that the specific surface area of the molecular sieve is 526m2/g。
Comparative example
This comparative example a SSZ-39 molecular sieve was synthesized according to the method disclosed in US patent 5958370A, which preparation method included the steps of:
1) reacting NH4Y molecular sieve, water glass (SiO)228-29 percent of content), NaOH, N-diethyl-2, 6-dimethyl piperidine hydroxide (concentration is 25 percent) and water are used as raw materials of the synthesis gel of the SSZ-39 molecular sieve according to the following raw material molar ratio:
SiO2/Al2O3＝25，R/SiO2＝0.152，OH-/SiO2＝0.682，H2O/SiO243.3; r represents N, N-diethyl-2, 6-dimethyl piperidine hydroxide.
2) 0.27g of sodium hydroxide is dissolved in 342g of deionized water, 70.5g of an aqueous 25% by weight N, N-diethyl-2, 6-dimethylpiperidine hydroxide solution are added after complete dissolution, and 10.4g of NH are added with rapid stirring4Y molecular sieve, transferring the obtained mixture into a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, and crystallizing for 7 days at 135 ℃.
3) And (3) cooling to below 60 ℃ after crystallization is stopped, washing the product with deionized water, filtering and collecting, drying at 100 ℃ for 12h, and then placing in a muffle furnace for calcining at 550 ℃ for 8h to remove the structure directing agent to obtain the molecular sieve SSZ-39 with the core-shell structure.
N2The result of physical adsorption shows that the specific surface area of the molecular sieve is 517m2/g。
Cu-SSZ-39@ SSZ-39 core-shell molecular sieve catalyst activity test
The catalytic denitration performance of the molecular sieves prepared in the above examples and comparative examples is considered, and the specific operation is as follows:
ammonium exchange of molecular sieve: the molecular sieves prepared in examples 1-6 of the invention and comparative examples were prepared according to ammonium nitrate: molecular sieve: water (mass ratio) 1: 1: 10 mixing, exchanging for 1h at 90 ℃ under the stirring state, filtering, washing, drying and roasting for 2h at 550 ℃. Repeating the above process for 3 times until Na in the molecular sieve2The O content is less than 0.1 mass%.
And (3) copper exchange of a molecular sieve: the ammonium exchanged comparative molecular sieve was prepared according to molecular sieve: water (mass ratio) 1: 10, adding a certain amount of copper acetate (5 percent of CuO loading according to a molecular sieve) under stirring, exchanging for 1 hour at 90 ℃, adjusting the pH value to 8-8.5 by ammonia water, filtering, washing, drying, and roasting for 2 hours at 550 ℃.
Respectively tabletting, grinding and sieving the molecular sieves of the examples 1-6 after ammonium exchange and the molecular sieves of the comparative examples after ammonium exchange and copper exchange, and taking 60-mesh samples as granules for standby; taking 0.5g of a granular sample for NH3-SCR reaction, wherein the composition of the reaction mixture is: 1000ppmNO, 1100ppmNH3、10Vol％O2、10Vol％H2O，N2As balance gas, the volume space velocity is 120000h-1The reaction temperature is 150-2And N2The O concentration. Conversion rate of nitrogen oxides in reaction mixed gas at different temperatures and N2The selectivities are shown in tables 1 and 2.
NOxThe conversion is defined as:
Figure BDA0002936584800000091
TABLE 1 conversion of nitrogen oxides in the reaction mixture at different temperatures and N2Selectivity is
Figure BDA0002936584800000092
TABLE 2 conversion of nitrogen oxides in the reaction mixture at different temperatures and N2Selectivity is
Figure BDA0002936584800000093
Figure BDA0002936584800000101
As can be seen from the data in tables 1 and 2, the Cu-SSZ-39@ SSZ-39 core-shell molecular sieve prepared by the preparation method provided by the embodiment of the invention maintains higher catalytic activity in the temperature range of 200-550 ℃, and the conversion rate of nitrogen oxide is basically maintained above 90%, the Cu-SSZ-39 molecular sieve prepared by the comparative example only has higher catalytic activity in the temperature range of 200-400 ℃, and when the temperature exceeds 400 ℃, the conversion rate of nitrogen oxide is continuously reduced, and the high-temperature activity is poor.
The Cu-SSZ-39 molecular sieve prepared by the comparative example is subjected to hydrothermal treatment at high temperatureIsolated Cu2+The Cu-SSZ-39@ SSZ-39 core-shell type molecular sieve prepared in examples 1-5 has isolated Cu in the core Cu-SSZ-39 molecular sieve under high temperature condition2+The shell SSZ-39 molecular sieve can be Cu when migrating to the outside of the molecular sieve2+And a large number of exchange sites are provided, so that the generation of agglomerated CuO particles can be inhibited, the inactivation of the catalyst is weakened, the Cu-SSZ-39@ SSZ-39 core-shell type molecular sieve has high hydrothermal stability under severe reaction conditions, and the catalytic performance of the catalyst in a high-temperature zone is improved. However, when the mass of shell SSZ-39 is higher than the total weight of the molecular sieve, for example, the mass fraction of SSZ-39 in example 4 is 66.7%, the approach of gas molecules to the active sites of Cu-SSZ-39 is affected, and the catalytic activity of Cu-SSZ-39 is inhibited to some extent.
As can be seen from the data in tables 1 and 2, the Cu-SSZ-39@ SSZ-39 core-shell molecular sieve prepared by the preparation method provided by the embodiment of the invention has excellent N in the whole temperature range2And (4) selectivity.
Anti-aging performance test of Cu-SSZ-39@ SSZ-39 core-shell type molecular sieve
The molecular sieves prepared in examples 1-6 of the present invention and comparative examples were aged at 800 ℃ with 10% H2O pretreatment for 30h, taking 0.5g of aged granular sample for NH3-SCR reaction, wherein the composition of the reaction mixture is: 1000ppmNO, 1100ppmNH3、10Vol％O2、10Vol％H2O，N2As balance gas, the volume space velocity is 120000h-1The reaction temperature is 150 ℃, 300 ℃ and 550 ℃, and a Nicolet infrared gas analyzer is used for detecting NO and NO in the tail gas on line2And N2Concentration of O to obtain NOxAnd (4) conversion rate. The conversion of nitrogen oxides in the reaction mixture at different temperatures is shown in table 3.
TABLE 3 conversion of nitrogen oxides in reaction mixture at different temperatures
150℃ 300℃ 550℃
Example 1 7％ 94％ 86％
Example 2 7％ 92％ 85％
Example 3 9％ 94％ 82％
Example 4 10％ 92％ 85％
Example 5 6％ 93％ 86％
Example 6 8％ 94％ 83％
Comparative example 3％ 75％ 32％
The Cu-SSZ-39@ SSZ-39 core-shell type molecular sieves prepared in the examples 1 to 6 are subjected to hydrothermal treatment at 800 ℃ for 30 hours, the conversion rate of nitrogen oxides at 300 ℃ is more than 90%, and the conversion rate of nitrogen oxides at 550 ℃ is more than 80%, which shows that the composite molecular sieve has high hydrothermal stability. And after the Cu-SSZ-39 molecular sieve prepared by the comparative example is subjected to hydrothermal treatment at 800 ℃ for 30 hours, the catalytic activity disappears at 150 ℃, the conversion rate of nitrogen oxides at 300 ℃ and 550 ℃ is less than 10%, and the hydrothermal stability is very poor.
FIG. 7 is an XPS depth profile and a plot of surface copper atom concentration versus profile depth for the Cu-SSZ-39@ SSZ-39 molecular sieve prepared in example 1.
The results shown in FIG. 7 indicate that the molar concentration of Cu atoms is almost 0 in the depth range of 10nm from the surface of the sample, indicating that the shell contains no Cu element. And when the analysis depth is increased to more than 15nm, the Cu atomic concentration is gradually increased to 1.2 percent, which shows that the Cu element is distributed in the core. This result is favorable evidence for the synthesis of a Cu-SSZ-39@ SSZ-39 core-shell molecular sieve with a heterogeneous Cu distribution. After hydrothermal aging, the molar concentration of Cu atoms in the depth range from the surface to 10nm is obviously improved, and the molar concentration of Cu atoms above 15nm is reduced, which indicates that part of Cu atoms migrate outwards in the hydrothermal aging process.
FIG. 8 is an XPS depth profile and a plot of surface copper atom concentration versus profile depth for a Cu-SSZ-39@ SSZ-39 molecular sieve prepared in a comparative example.
The results shown in FIG. 8 are similar to those shown in FIG. 7, except that SSZ-39 has a low shell mass fraction and a thin shell, and thus has a weak effect of inhibiting core Cu atoms migrating after hydrothermal aging, and the surface Cu concentration increases more significantly.

Claims (10)

1. The composite molecular sieve with a core-shell structure takes a Cu-SSZ-39 molecular sieve as a core and takes an SSZ-39 molecular sieve or an AFX molecular sieve as a shell.
2. The composite molecular sieve having a core-shell structure according to claim 1, wherein the CuO content in the Cu-SSZ-39 molecular sieve is 0.1 wt% to 20 wt%, preferably 1 wt% to 10 wt%.
3. The composite molecular sieve having a core-shell structure according to claim 1 or 2, wherein the Cu-SSZ-39 molecular sieve as the core accounts for 1 wt% to 99 wt%, preferably 10 wt% to 80 wt%, more preferably 20 wt% to 50 wt% of the total mass of the composite molecular sieve.
4. A method of synthesizing a composite molecular sieve having a core-shell structure according to any one of claims 1 to 3, wherein the method of synthesizing comprises the steps of:
mixing the molecular sieve, an alkali source, an organic template agent and water, and aging for 0.1-100 h at room temperature to 100 ℃ to obtain a gel for synthesizing the SSZ-39 molecular sieve;
adding the Cu-SSZ-39 molecular sieve into the gel for synthesizing the SSZ-39 molecular sieve, and then crystallizing for 10-100h at 120-200 ℃ in a high-pressure kettle;
cooling, filtering, washing, drying and roasting to obtain the composite molecular sieve with the core-shell structure;
alternatively, the first and second electrodes may be,
mixing the molecular sieve, an alkali source, an organic template agent and water, and aging for 0.1-100 h at room temperature to 100 ℃ to obtain a gel for synthesizing the SSZ-39 molecular sieve;
crystallizing the gel of the synthesized SSZ-39 molecular sieve in an autoclave at 120-200 ℃ for 0.1-40 h;
adding a Cu-SSZ-39 molecular sieve into an autoclave, and then crystallizing at 120-200 ℃ for 0.1-100 h;
and cooling, filtering, washing, drying and roasting to obtain the composite molecular sieve with the core-shell structure.
5. The synthesis method of claim 4, wherein the molecular sieves used in the feedstock for the synthesis of the SSZ-39 molecular sieve gel comprise USY molecular sieve, NaY molecular sieve and NH4One or a combination of more than two of Y molecular sieves;
preferably, the starting material for the synthesis of the SSZ-39 molecular sieve gel further comprises a silicon source;
preferably, the silicon source comprises one or a combination of more than two of silicate, tetraethoxysilane, white carbon black and silica sol; silica sol is preferred.
6. The synthesis method according to claim 4, wherein the mass ratio of the gel of the synthesized SSZ-39 molecular sieve to the Cu-SSZ-39 molecular sieve is 80-0.8, preferably 40-1, more preferably 10-2.
7. The synthesis method of claim 4, wherein in the starting material for the synthesis of the gel of SSZ-39 molecular sieve, the SiO of the molecular sieve2/Al2O35-100, molar ratio.
8. The synthesis of claim 4, wherein the alkali source is sodium hydroxide and/or potassium hydroxide.
9. The synthetic method of claim 4, wherein the organic template comprises N, N-diethyl-2, 6-dimethylpiperidinium ion, 1,3, 5-tetramethylpiperidinium ion, 2, 6-dimethyl-5-azoniaspiro- [4.5] -decane ion, N-diethyl-2-ethylpiperidinium ion, N-ethyl-N-propyl-2, 6-dimethylpiperidinium ion, N-methyl-N-ethyl-2-ethylpiperidinium ion, 2, 5-dimethyl-N, N-diethylpyrrolium ion, 2, 6-dimethyl-N, n-dimethylpiperidinium ion, 3, 5-dimethyl-N, N-dimethylpiperidinium ion, 2-ethyl-N, N-dimethylpiperidinium ion, one or a combination of two or more of salts and/or bases of 2,2,6, 6-tetramethyl-N-methyl-N-ethylpiperidinium ion, N-cyclooctyl-pyridinium ion, 2,6, 6-tetramethyl-N, N-dimethylpiperidinium ion and N, N-dimethyl-N, N-bicyclononane ion, and preferably one or a combination of two or more of salts and/or bases of N, N-diethyl-2, 6-dimethylpiperidinium ion and/or 3, 5-dimethyl-N, N-dimethylpiperidinium ion.
10. The synthesis method according to claim 4 or 5, wherein, in the starting material for synthesizing the gel of SSZ-39 molecular sieve, the molar ratio of the molecular sieve, the alkali source, the organic template and the water satisfies the following condition:
SiO2/Al2O3＝5-100，OH-/SiO2＝0.1-0.5，H2O/SiO2＝3-60，R/SiO2＝0.01-0.5；
wherein R represents an organic template;
preferably, when the raw material for synthesizing the gel of the SSZ-39 molecular sieve further comprises a silicon source, the molar ratio of the silicon source, the molecular sieve, the alkali source, the organic template and the water satisfies the following condition:
SiO2/Al2O3＝5-100，OH-/SiO2＝0.1-0.5，H2O/SiO2＝3-60，R/SiO2＝0.01-0.5；
wherein R represents an organic template.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113651340A (en) * 2021-08-23 2021-11-16 中化学科学技术研究有限公司 SSZ-39 molecular sieve, preparation method of SSZ-39 molecular sieve and NH3-SCR reaction catalyst
CN114261974A (en) * 2021-12-31 2022-04-01 南京谊明新材料科技有限公司 SSZ-39 molecular sieve and preparation method thereof
CN116062764A (en) * 2021-10-29 2023-05-05 中国石油化工股份有限公司 Y-Y composite molecular sieve with core-shell structure, and preparation method and application thereof
CN114261974B (en) * 2021-12-31 2024-06-04 南京谊明新材料科技有限公司 SSZ-39 molecular sieve and preparation method thereof

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105944753A (en) * 2016-05-09 2016-09-21 清华大学 Cu-SSZ-13 molecular sieve based catalyst adopting core-shell structure as well as preparation and application of catalyst
CN106799255A (en) * 2017-02-23 2017-06-06 华中科技大学 The preparation method and applications of the molecular sieve catalysts of one-step synthesis method Cu SSZ 39
CN110467200A (en) * 2019-09-20 2019-11-19 中国科学院生态环境研究中心 A kind of Cu-SSZ-39 molecular sieve and its preparation method and application
WO2019224093A1 (en) * 2018-05-24 2019-11-28 IFP Energies Nouvelles Method for preparing a zeolite composite containing copper and a mixture of zeolites of afx structural type and bea structural type
CN110510635A (en) * 2019-09-20 2019-11-29 中国科学院生态环境研究中心 A kind of Cu-SSZ-39 molecular sieve and its preparation method and application
CN111001437A (en) * 2019-12-14 2020-04-14 中触媒新材料股份有限公司 AEI/AFX structure symbiotic composite molecular sieve, preparation method and SCR application thereof
CN112279266A (en) * 2020-12-29 2021-01-29 中化学科学技术研究有限公司 Cu-SSZ-13@ SSZ-13 core-shell type molecular sieve and preparation method and application thereof
CN112299436A (en) * 2020-12-29 2021-02-02 中化学科学技术研究有限公司 Cu-SSZ-39@ SSZ-39 core-shell molecular sieve and preparation method and application thereof

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105944753A (en) * 2016-05-09 2016-09-21 清华大学 Cu-SSZ-13 molecular sieve based catalyst adopting core-shell structure as well as preparation and application of catalyst
CN106799255A (en) * 2017-02-23 2017-06-06 华中科技大学 The preparation method and applications of the molecular sieve catalysts of one-step synthesis method Cu SSZ 39
WO2019224093A1 (en) * 2018-05-24 2019-11-28 IFP Energies Nouvelles Method for preparing a zeolite composite containing copper and a mixture of zeolites of afx structural type and bea structural type
CN110467200A (en) * 2019-09-20 2019-11-19 中国科学院生态环境研究中心 A kind of Cu-SSZ-39 molecular sieve and its preparation method and application
CN110510635A (en) * 2019-09-20 2019-11-29 中国科学院生态环境研究中心 A kind of Cu-SSZ-39 molecular sieve and its preparation method and application
CN111001437A (en) * 2019-12-14 2020-04-14 中触媒新材料股份有限公司 AEI/AFX structure symbiotic composite molecular sieve, preparation method and SCR application thereof
CN112279266A (en) * 2020-12-29 2021-01-29 中化学科学技术研究有限公司 Cu-SSZ-13@ SSZ-13 core-shell type molecular sieve and preparation method and application thereof
CN112299436A (en) * 2020-12-29 2021-02-02 中化学科学技术研究有限公司 Cu-SSZ-39@ SSZ-39 core-shell molecular sieve and preparation method and application thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113651340A (en) * 2021-08-23 2021-11-16 中化学科学技术研究有限公司 SSZ-39 molecular sieve, preparation method of SSZ-39 molecular sieve and NH3-SCR reaction catalyst
CN116062764A (en) * 2021-10-29 2023-05-05 中国石油化工股份有限公司 Y-Y composite molecular sieve with core-shell structure, and preparation method and application thereof
CN116062764B (en) * 2021-10-29 2024-05-10 中国石油化工股份有限公司 Y-Y composite molecular sieve with core-shell structure, and preparation method and application thereof
CN114261974A (en) * 2021-12-31 2022-04-01 南京谊明新材料科技有限公司 SSZ-39 molecular sieve and preparation method thereof
CN114261974B (en) * 2021-12-31 2024-06-04 南京谊明新材料科技有限公司 SSZ-39 molecular sieve and preparation method thereof

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