A zirconium-silicon CHA molecular sieve, its preparation method and application

Abstract

The present invention relates to the fields of zeolite molecular sieve preparation and gas adsorption, and discloses a zirconium-silicon CHA molecular sieve, a preparation method thereof and an application thereof. The method includes: (1) mixing a lithium source with water, and then sequentially adding a silicon source and a structure-directing agent to obtain a mixed solution; (2) stirring and mixing the mixed solution with a zirconium source to obtain a mixed material; (3) placing the mixed material in a reaction kettle for hydrothermal reaction, and then performing washing, drying and calcination; the molar ratio of the silicon source, the zirconium source, the lithium source, the structure-directing agent and water is 1:0.0033-0.02:0.01-0.5:0.1-1.25:10-500. The method does not need to use fluorine-containing raw materials, and overcomes the safety hazards and environmental protection problems brought about by the use of fluorine-containing raw materials. The prepared zirconium-silicon CHA molecular sieve has a microporous structure, has good hydrophobicity, and has good application prospects in the fields of gas adsorption and the like.

Description

Technical Field

[0001] The present invention relates to the fields of zeolite molecular sieve preparation and gas adsorption, and particularly relates to a zirconium-silicon CHA molecular sieve, a preparation method thereof, and an application thereof. Background Art

[0002] As the main source of acidic impurities in natural gas and biogas, carbon dioxide will corrode pipelines and reduce the thermal energy of the gas in a humid environment. Removing carbon dioxide from natural gas and biogas is very important for improving the gas quality to meet the specifications of pipeline gas, and the carbon dioxide recovered from natural gas can become a useful resource for enhanced oil recovery.

[0003] Zeolite molecular sieve is a crystalline material with a uniform microporous structure, and its pore size is close to the molecular dynamic diameter of most industrial gases; in addition, zeolite molecular sieve also has a high specific surface area, adjustable hydrophobicity and hydrophilicity, good ion exchange ability and strong acidity, and can maintain good stability under harsh hydrothermal and chemical conditions, so it is widely used in the fields of gas adsorption and separation. The CHA zeolite molecular sieve has a pore structure of 0.38 nm × 0.38 nm, which is larger than the molecular dynamic diameter of CO 2 and equal to the molecular dynamic diameter of CH 4 , making it more advantageous in separating impurity gases in natural gas and biogas.

[0004] Diaz-Cabanas et al. (Chemical Communications 1998, 29(17), 1881-1882) synthesized a pure-silica CHA zeolite molecular sieve with a low framework density (15.4SiO 2 nm -3 ) and a large void volume fraction (close to 50%). Miyamoto et al. (Journal of Materials Chemistry 2012, 22(38), 20186-20189) used the pure-silica CHA zeolite molecular sieve for PSA adsorption separation of CO 2 , and its effective CO 2The adsorption performance is much higher than that of 13X zeolite molecular sieve and is not affected by coexisting water. Patent application CN104925825A discloses a preparation method of all-silica CHA molecular sieve. A silicon source and a templating agent N, N, N-trimethyl-1-adamantylammonium hydroxide are mixed, and then the pre-prepared all-silica CHA molecular sieve seeds are added. After stirring and mixing, an HF solution is added to form a synthesis mother liquor of all-silica CHA molecular sieve. The all-silica CHA molecular sieve with a particle size of 0.3 - 1 μm is synthesized by the dry gel method. This method prepares all-silica CHA molecular sieve crystals with uniform particle size at the sub-micron level. The above-mentioned literature and patents all adopt a fluorine-containing synthesis route when preparing all-silica CHA molecular sieve. During the preparation process, there are certain dangers and environmental pollution. Therefore, it is necessary to explore a green, convenient and environmentally friendly synthesis route - a fluorine-free route. Summary of the Invention

[0005] An object of the present invention is to overcome the problems of the existing technology that a fluorine-containing synthesis route is adopted when preparing CHA molecular sieve, and there are certain dangers and environmental pollution during the preparation process, and to provide a zirconium-silicon CHA molecular sieve, a preparation method thereof and an application.

[0006] To achieve the above object, on the one hand, the present invention provides a preparation method of zirconium-silicon CHA molecular sieve, and the method comprises the following steps:

[0007] (1) Mix a lithium source with water, and then sequentially add a silicon source and a structure-directing agent to obtain a mixed solution;

[0008] (2) Stir and mix the mixed solution with a zirconium source to obtain a mixed material;

[0009] (3) Place the mixed material in a reaction kettle for hydrothermal reaction, and then carry out washing, drying and calcination;

[0010] The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.0033 - 0.02:0.01 - 0.5:0.1 - 1.25:10 - 500, wherein the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 and the lithium source is calculated as Li 2 2O.

[0011] Preferably, the lithium source is selected from one or more of lithium chloride, lithium carbonate, lithium sulfate and lithium hydroxide.

[0012] Preferably, the silicon source is selected from one or more of fumed silica, tetraethyl orthosilicate, sodium silicate, tetramethyl orthosilicate, water glass and silica sol.

[0013] Preferably, the structure-directing agent is selected from one or more of N,N,N-trimethyladamantyl ammonium hydroxide, N,N,N-trimethyladamantyl ammonium bromide, N,N,N-trimethylbenzyl ammonium bromide, N,N,N-trimethyladamantyl ammonium iodide, N,N,N-trimethylbenzyl ammonium iodide, N,N,N-trimethylbenzyl ammonium hydroxide, and tetraethyl ammonium hydroxide.

[0014] Preferably, the zirconium source is selected from one or more of zirconium silicate, zirconium hydroxide, zirconium sulfate, zirconium oxide, zirconyl chloride, and zirconium tetrachloride.

[0015] Preferably, in step (2), the stirring and mixing time is 1 - 48 h.

[0016] Preferably, in step (3), the hydrothermal reaction conditions include: the temperature is 120 - 200 °C, and the time is 24 - 120 h.

[0017] Preferably, in step (3), the calcination conditions include: the calcination temperature is 200 - 600 °C, the calcination time is 1 - 24 h, and the heating rate is 0.2 - 2 °C / min.

[0018] The second aspect of the present invention provides the zirconium silicate CHA zeolite prepared by the above method.

[0019] The third aspect of the present invention provides the application of the above zirconium silicate CHA zeolite in the field of gas adsorption.

[0020] The present invention provides a method for synthesizing an environmentally friendly zirconium silicate CHA zeolite. During the preparation process, fluorine compounds are not required, overcoming the safety hazards and environmental protection problems caused by the use of fluorine-containing raw materials. The method is simple to operate, and the prepared zirconium silicate CHA zeolite has a microporous structure, good hydrophobicity, and good application prospects in the fields of gas adsorption and the like. Description of the Drawings

[0021] Figure 1 are the infrared characterization results of the products prepared in Example 1 and Comparative Example 1;

[0022] Figure 2 are the solid-state NMR characterization results of the products prepared in Example 1 and Comparative Example 1;

[0023] Figure 3 are the SEM characterization results of the products prepared in Example 1 and Comparative Example 1;

[0024] Figure 4 are the SEM characterization results of the products prepared in Comparative Examples 2 - 4;

[0025] Figure 5 are the XRD characterization results of the products prepared in Examples 1 - 3;

[0026] Figure 6 XRD characterization results of the product prepared in Comparative Example 1;

[0027] Figure 7 is the N 2 adsorption isotherm of the product prepared in Example 1 under the condition of 77K. Detailed Description of the Invention

[0028] The following further elaborates on the detailed implementation manners of the present invention in conjunction with the accompanying drawings. It should be understood that the detailed implementation manners described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0029] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0030] During the research process, the inventors of the present invention unexpectedly found that during the preparation of CHA zeolite, through the cooperation of zirconium source and lithium source, zirconium-silicon CHA zeolite with excellent performance can be prepared under fluoride-free conditions. Based on this, the present invention was completed.

[0031] On the one hand, the present invention provides a method for preparing zirconium-silicon CHA zeolite, and the method includes the following steps:

[0032] (1) Mix the lithium source with water, and then sequentially add the silicon source and the structure-directing agent to obtain a mixed solution;

[0033] (2) Stir and mix the mixed solution with the zirconium source to obtain a mixed material;

[0034] (3) Place the mixed material in a reaction kettle for hydrothermal reaction, and then perform washing, drying, and calcination;

[0035] The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent, and water is 1:0.0033 - 0.02:0.01 - 0.5:0.1 - 1.25:10 - 500, wherein the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 and the lithium source is calculated as Li 2 O.

[0036] In the present invention, in order to further improve the preparation efficiency and the performance of the prepared zeolite, the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent, and water can be reasonably controlled.

[0037] In a specific embodiment, the molar ratio of the silicon source to the zirconium source can be 1:0.0033, 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.01, 1:0.012, 1:0.015, 1:0.018 or 1:0.02.

[0038] In a specific embodiment, the molar ratio of the silicon source to the lithium source can be 1:0.01, 1:0.02, 1:0.04, 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4 or 1:0.5.

[0039] In a specific embodiment, the molar ratio of the silicon source to the structure directing agent (OSDA) can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1 or 1:1.25.

[0040] In a specific embodiment, the molar ratio of the silicon source to water can be 1:10, 1:20, 1:30, 1:50, 1:60, 1:80, 1:100, 1:150 or 200.

[0041] In a preferred embodiment, the lithium source is selected from one or more of lithium chloride, lithium carbonate, lithium sulfate and lithium hydroxide.

[0042] In a preferred embodiment, the silicon source is selected from one or more of fumed silica, tetraethyl orthosilicate, sodium silicate, tetramethyl orthosilicate, water glass and silica sol.

[0043] In a preferred embodiment, the structure directing agent is selected from one or more of N,N,N-trimethyladamantylammonium hydroxide, N,N,N-trimethyladamantylammonium bromide, N,N,N-trimethylbenzylammonium bromide, N,N,N-trimethyladamantylammonium iodide, N,N,N-trimethylbenzylammonium iodide, N,N,N-trimethylbenzylammonium hydroxide and tetraethylammonium hydroxide.

[0044] In a preferred embodiment, the zirconium source is selected from one or more of zirconium silicate, zirconium hydroxide, zirconium sulfate, zirconium oxide, zirconium oxychloride and zirconium tetrachloride.

[0045] In a preferred embodiment, in step (2), the stirring and mixing time is 1 - 48 h. Specifically, it can be 1 h, 2 h, 3 h, 5 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 45 h or 48 h.

[0046] In a preferred embodiment, the inner lining material of the reaction kettle is polytetrafluoroethylene.

[0047] In a preferred embodiment, the conditions of the hydrothermal reaction include: the temperature is 120 - 200 °C, and the time is 24 - 120 h. Specifically, the temperature of the hydrothermal reaction can be 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 155 °C, 160 °C, 165 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 195 °C or 200 °C; the time of the hydrothermal reaction can be 24 h, 36 h, 48 h, 72 h, 84 h, 96 h, 108 h or 120 h.

[0048] Preferably, in step (3), the conditions of the calcination include: the calcination temperature is 200 - 600 °C, the calcination time is 1 - 24 h, and the heating rate during calcination is 0.2 - 2 °C / min.

[0049] In a specific embodiment, there is no special requirement for the calcination atmosphere of the calcination, and various calcination atmospheres commonly used in the art can be used, for example, it can be ozone, air, oxygen, nitrogen or an oxygen / ozone mixture.

[0050] In a specific embodiment, the calcination temperature can be 200 °C, 250 °C, 300 °C, 350 °C, 400 °C, 450 °C, 500 °C, 550 °C or 600 °C; the calcination time can be 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h or 24 h.

[0051] In a preferred embodiment, the heating rate during calcination can be 0.2 - 2 °C / min. Specifically, it can be 0.2 °C / min, 0.3 °C / min, 0.4 °C / min, 0.5 °C / min, 0.8 °C / min, 1 °C / min, 1.5 °C / min or 2 °C / min.

[0052] The method of the present invention directly synthesizes zirconium silicate CHA zeolite by the hydrothermal method, and the preparation method is simple to operate. Compared with the traditional preparation method of all-silicon CHA zeolite, this method is a fluorine-free preparation route, replacing the traditional fluorine-containing preparation method, which is more environmentally friendly and greener. The synthesized zirconium silicate CHA zeolite is cubic and has a microporous structure, and has good hydrophobicity.

[0053] The second aspect of the present invention provides the zirconium silicate CHA zeolite prepared by the above method.

[0054] The third aspect of the present invention provides the application of the above zirconium silicate CHA zeolite in the field of gas adsorption.

[0055] The zirconium silicate CHA zeolite prepared by the method of the present invention for CO2 / CH 4 Exhibits excellent adsorption performance, has good hydrophobicity at the same time, and has good application prospects in the field of gas adsorption.

[0056] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0057] Example 1

[0058] (1) Mix the lithium source (lithium hydroxide) with water (deionized water), and then sequentially add the silicon source (fumed silica) and the structure-directing agent (N,N,N-trimethyl-1-adamantylammonium hydroxide) to obtain a mixed solution;

[0059] (2) Add the zirconium source (zirconium sulfate) to the mixed solution obtained in step (1), and stir and mix well for 1 h to obtain a mixed material;

[0060] (3) Place the mixed material in a hydrothermal reaction kettle with a polytetrafluoroethylene lining for hydrothermal reaction. The reaction temperature is 160 °C and the reaction time is 36 h. Wash the solid-phase product obtained by the reaction with deionized water until neutral, then dry it at 60 °C, and then put the dried product into a muffle furnace and heat it to 550 °C at a rate of 1 °C / min and calcine it in air for 6 h to obtain zirconium-silicon CHA zeolite S1;

[0061] The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.0033:0.04:0.4:30. Among them, the silicon source is calculated as SiO 2 counting, the zirconium source is calculated as ZrO 2 counting, and the lithium source is calculated as Li 2 O.

[0062] Example 2

[0063] Carry out according to the method described in Example 1, except that the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.01:0.04:0.4:30 to obtain zirconium-silicon CHA zeolite S2.

[0064] Example 3

[0065] Carry out according to the method described in Example 1, except that the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.02:0.04:0.4:30 to obtain zirconium-silicon CHA zeolite S3.

[0066] Example 4

[0067] The method described in Example 1 was implemented, except that the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water was 1:0.0033:0.5:0.4:30, to obtain the zirconium-silicon CHA molecular sieve S4.

[0068] Example 5

[0069] The method described in Example 1 was implemented, except that the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water was 1:0.0033:0.01:0.4:30, to obtain the zirconium-silicon CHA molecular sieve S5.

[0070] Example 6

[0071] The method described in Example 1 was implemented, except that the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water was 1:0.0033:0.04:1.25:30, to obtain the zirconium-silicon CHA molecular sieve S6.

[0072] Example 7

[0073] The method described in Example 1 was implemented, except that the molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water was 1:0.0033:0.04:0.1:30, to obtain the zirconium-silicon CHA molecular sieve S7.

[0074] Example 8

[0075] The method described in Example 1 was implemented, except that in step (2), the stirring time was 48 h, to obtain the zirconium-silicon CHA molecular sieve S8.

[0076] Example 9

[0077] The method described in Example 1 was implemented, except that in step (3), the hydrothermal reaction temperature was 200 °C and the hydrothermal reaction time was 24 h, to obtain the zirconium-silicon CHA molecular sieve S9.

[0078] Example 10

[0079] The method described in Example 1 was implemented, except that in step (3), the hydrothermal reaction temperature was 120 °C and the hydrothermal reaction time was 120 h, to obtain the zirconium-silicon CHA molecular sieve S10.

[0080] Example 11

[0081] (1) The lithium source (lithium hydroxide) was mixed with water (deionized water), and then the silicon source (tetraethyl orthosilicate) and the structure-directing agent (N,N,N-trimethyl-1-adamantylammonium bromide) were added in sequence to obtain a mixed solution;

[0082] (2) Add the zirconium source (zirconium sulfate) to the mixed solution obtained in step (1), stir and mix well for 24 h to obtain a mixed material;

[0083] (3) Place the mixed material in a hydrothermal reaction kettle with a polytetrafluoroethylene lining for hydrothermal reaction. The reaction temperature is 160 °C and the reaction time is 36 h. Wash the solid-phase product obtained from the reaction with deionized water until neutral, then dry it at 70 °C, and then put the dried product into a muffle furnace and heat it to 600 °C at a rate of 1 °C / min and calcine it in air for 5.5 h to obtain zirconium-silicon CHA zeolite S11;

[0084] The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.0033:0.04:0.4:30, where the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 and the lithium source is calculated as Li 2 2O.

[0085] Example 12

[0086] (1) Mix the lithium source (lithium hydroxide) with water (deionized water), and then successively add the silicon source (fumed silica) and the structure-directing agent (N,N,N-trimethyl-1-adamantylammonium hydroxide) to obtain a mixed solution;

[0087] (2) Add the zirconium source (zirconium sulfate) to the mixed solution obtained in step (2), stir and mix well for 3 h to obtain a mixed material;

[0088] (3) Place the mixed material in a hydrothermal reaction kettle with a polytetrafluoroethylene lining for hydrothermal reaction. The reaction temperature is 150 °C and the reaction time is 40 h. Wash the solid-phase product obtained from the reaction with deionized water until neutral, then dry it at 80 °C, and then put the dried product into a muffle furnace and heat it to 500 °C at a rate of 1 °C / min and calcine it in air for 7 h to obtain zirconium-silicon CHA zeolite S12;

[0089] The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.01:0.15:0.5:40, where the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 and the lithium source is calculated as Li 2 2O.

[0090] Example 13

[0091] (1) Mix the lithium source (lithium carbonate) with water (deionized water), and then successively add the silicon source (fumed silica) and the structure-directing agent (N,N,N-trimethyl-1-adamantylammonium hydroxide) to obtain a mixed solution;

[0092] (2) Add the zirconium source (zirconium sulfate) to the mixed solution obtained in step (1), and stir and mix thoroughly for 5 h to obtain a mixed material;

[0093] (3) Place the mixed material in a high-pressure reactor with a polytetrafluoroethylene lining for hydrothermal reaction. The reaction temperature is 180 °C, and the reaction time is 30 h. Wash the solid-phase product obtained from the reaction with deionized water until neutral, then dry it at 90 °C, and then put the dried product into a muffle furnace and heat it to 450 °C at a rate of 1 °C / min and calcine it in air for 12 h to obtain zirconium-silicon CHA zeolite S13;

[0094] The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.0033:0.04:0.4:50. Among them, the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 and the lithium source is calculated as Li 2 2O.

[0095] Comparative Example 1

[0096] Prepare all-silicon CHA zeolite according to the conventional method. The specific process is as follows:

[0097] (1) Add the silicon source (tetraethyl orthosilicate) to the structure-directing agent (N, N, N-trimethyl-1-adamantylammonium hydroxide), and mix and stir overnight;

[0098] (2) Heat the mixed solution obtained in step (1) to 90 °C, manually stir to evaporate ethanol and water, and then add hydrofluoric acid solution to the mixture and continue heating to reduce moisture; the molar composition of the obtained paste is: silicon source: structure-directing agent: HF: water = 1:0.5:0.5:3, and the silicon source is calculated as SiO 2 ;

[0099] (3) Transfer the paste obtained in step (2) to a reactor with a polytetrafluoroethylene lining, and react at 180 °C for 2 days; wash the solid-phase product obtained from the reaction with deionized water until neutral, put it in an oven at 100 °C and dry it overnight, and then put it into a muffle furnace and calcine it at 550 °C for 6 h with a heating rate of 1 °C / min to obtain all-silicon CHA zeolite D1.

[0100] Comparative Example 2

[0101] (1) Add the silicon source (fumed silica) and the structure-directing agent (N, N, N-trimethyl-1-adamantylammonium hydroxide) to deionized water in sequence to obtain a mixed solution;

[0102] (2) Add the zirconium source (zirconium sulfate) to the mixed solution obtained in step (1), and stir and mix thoroughly for 1 h to obtain a mixed material;

[0103] (3) Place the mixture in a high-pressure reactor with a polytetrafluoroethylene liner for hydrothermal reaction. The reaction temperature is 160 °C and the reaction time is 36 h. Wash the solid product obtained from the reaction with deionized water until neutral, then dry it at 60 °C. Then put the dried product into a muffle furnace and heat it to 550 °C at a rate of 1 °C / min and calcine it in air for 6 h to obtain product D2;

[0104] The molar ratio of the silicon source, zirconium source, structure-directing agent and water is 1:0.0033:0.4:30. Among them, the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 .

[0105] Comparative Example 3

[0106] (1) Mix the lithium source (lithium hydroxide) with deionized water, and then sequentially add the silicon source (fumed silica) and the structure-directing agent (N,N,N-trimethyl-1-adamantylammonium hydroxide) to obtain a mixed solution;

[0107] (2) Stir and mix the mixed solution obtained in step (1) thoroughly for 1 h to obtain a mixture;

[0108] (3) Place the mixture in a high-pressure reactor with a polytetrafluoroethylene liner for hydrothermal reaction. The reaction temperature is 160 °C and the reaction time is 36 h. Wash the solid product obtained from the reaction with deionized water until neutral, then dry it at 60 °C. Then put the dried product into a muffle furnace and heat it to 550 °C at a rate of 1 °C / min and calcine it in air for 6 h to obtain product D3;

[0109] The molar ratio of the silicon source, lithium source, structure-directing agent and water is 1:0.04:0.4:30. Among them, the silicon source is calculated as SiO 2 and the lithium source is calculated as Li 2 2O.

[0110] Comparative Example 4

[0111] (1) Sequentially add the silicon source (fumed silica) and the structure-directing agent (N,N,N-trimethyl-1-adamantylammonium hydroxide) to deionized water to obtain a mixed solution;

[0112] (2) Stir and mix the mixed solution obtained in step (1) thoroughly for 1 h to obtain a mixture;

[0113] (3) Place the mixture in a high-pressure reactor with a polytetrafluoroethylene lining for hydrothermal reaction. The reaction temperature is 160 °C and the reaction time is 36 h. Wash the solid product obtained from the reaction with deionized water until neutral, then dry it at 60 °C. Then, put the dried product into a muffle furnace and heat it to 550 °C at a rate of 1 °C / min and calcine it in air for 6 h to obtain product D4;

[0114] The molar ratio of the silicon source, structure-directing agent, and water is 1:0.4:30, where the silicon source is calculated as SiO 2 .

[0115] Test Example 1

[0116] Characterize the products prepared in Example 1 and Comparative Example 1 using a Fourier transform infrared spectrometer (Thermo Nicolet 8700), and the results are as Figure 1 shown; characterize the products prepared in Example 1 and Comparative Example 1 using solid-state NMR (Bruker AVANCEⅢHD), 29 and the Si MAS NMR spectrum is as Figure 2 shown.

[0117] It can be seen from Figure 1 that the absorption peaks of the products prepared in Example 1 and Comparative Example 1 are roughly similar. The product prepared in Example 1 shows a slight vibration band at 965 cm -1 , corresponding to the asymmetric stretching of [O 3 Si-O-Zr] and the Zr tetrahedron, indicating that Zr in the zeolite framework is replaced by Si. In addition, the wave number of the product prepared in Example 1 shifts to a lower wave number, indicating that the T atom is replaced by the Zr tetrahedron.

[0118] It can be seen from Figure 2 that in the framework of the product prepared in Example 1, SiO 4 is replaced by ZrO 4 . The same as the all-silica CHA zeolite in Comparative Example 1, there are no external cations in the zirconium-silica CHA zeolite framework.

[0119] Test Example 2

[0120] Characterize the products prepared in Example 1 and Comparative Example 1 using SEM (Hitachi S4800), and the results are as Figure 3 shown, Figure 3 where a and b in Figure 4 are the characterization results of Example 1 and Comparative Example 1 respectively; characterize the products prepared in Comparative Examples 2-4 using SEM, and the results are as Figure 4 shown,

[0121] where a, b, and c inFigure 3 It can be seen that the product prepared in Example 1 is cubic in shape with a size of about 1 μm; the product prepared in Comparative Example 1 is cubic in shape with a size of about 300 nm. This shows that the shape of the product prepared by the method of the present invention is similar to that of the all-silica CHA zeolite prepared by the conventional method.

[0122] It can be seen from Figure 4 that the products prepared in Comparative Examples 2-4 are amorphous products and zeolites with a CHA structure cannot be obtained.

[0123] Test Example 3

[0124] The products prepared in Examples 1-3 were characterized using an X-ray diffractometer (Ultima IV), and the results are as Figure 5 shown; the product prepared in Comparative Example 1 was characterized using an X-ray diffractometer, and the results are as Figure 6 shown.

[0125] It can be seen from Figure 5 and 6 that typical CHA characteristic diffraction peaks appeared in Examples 1-3 and Comparative Example 1. This shows that zeolites with a CHA structure can be successfully prepared by the method of the present invention.

[0126] Test Example 4

[0127] The product prepared in Example 1 was tested using the BET method (Belsorp-max). The low-temperature (77 K) N 2 adsorption isotherm of the product prepared in Example 1 is as Figure 7 shown.

[0128] It can be seen from Figure 7 that the prepared zirconium-silicon CHA zeolite has a microporous structure, and the measured BET specific surface area is 780 m 2 / g.

[0129] Test Example 5

[0130] Under the conditions of a temperature of 298 K and a relative pressure P / P 0 = 0.99, the adsorption performance of the products prepared in Examples 1-13 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0131] It can be seen from Table 1 that the products prepared by the method of the present invention show good adsorption performance for CO 2 and CH 4 and have good application prospects in the field of gas adsorption.

[0132] Meanwhile, the water adsorption capacity of the product prepared in Example 1 is 5.4 mmol / g, which is much lower than the adsorption content of existing conventional molecular sieve adsorbents, indicating that the zirconium-silicon CHA molecular sieve prepared by the method described in the present invention is more hydrophobic.

[0133] Table 1

[0134]

[0135] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A preparation method of zirconium-silicon CHA molecular sieve, characterized in that, the method comprises the following steps: (1) Mix a lithium source with water, and then sequentially add a silicon source and a structure-directing agent to obtain a mixed solution; (2) Stir and mix the mixed solution with a zirconium source to obtain a mixed material; (3) Place the mixed material in a reaction kettle for hydrothermal reaction, and then carry out washing, drying and calcination; The molar ratio of the silicon source, zirconium source, lithium source, structure-directing agent and water is 1:0.0033 - 0.02:0.01 - 0.5:0.1 - 0.5:10 - 500. Among them, the silicon source is calculated as SiO 2 and the zirconium source is calculated as ZrO 2 and the lithium source is calculated as Li 2 2O; the lithium source is selected from one or more of lithium chloride, lithium carbonate, lithium sulfate and lithium hydroxide; the silicon source is selected from one or more of fumed silica, tetraethyl orthosilicate, sodium silicate, tetramethyl orthosilicate, water glass and silica sol; the structure-directing agent is selected from one or more of N,N,N-trimethyladamantyl ammonium hydroxide, N,N,N-trimethyladamantyl ammonium bromide, N,N,N-trimethylbenzyl ammonium bromide, N,N,N-trimethyladamantyl ammonium iodide, N,N,N-trimethylbenzyl ammonium iodide, N,N,N-trimethylbenzyl ammonium hydroxide and tetraethyl ammonium hydroxide; the zirconium source is selected from one or more of zirconium silicate, zirconium hydroxide, zirconium sulfate, zirconium oxide, zirconyl chloride and zirconium tetrachloride; in step (3), the conditions of the hydrothermal reaction include: the temperature is 120-200 °C and the time is 24-120 h.

2. The method according to claim 1, characterized in that, in step (2), the stirring and mixing time is 1-48 h.

3. The method according to claim 1, characterized in that, in step (3), the conditions of the calcination include: the calcination temperature is 200-600 °C, the calcination time is 1-24 h, and the heating rate is 0.2-2 °C / min.

4. The zirconium-silicon CHA molecular sieve prepared by the method according to any one of claims 1-3.

5. The application of the zirconium-silicon CHA molecular sieve according to claim 4 in the field of gas adsorption.

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