Difunctional integral material for CO2 in-situ efficient adsorption coupling conversion and preparation method of difunctional integral material

Abstract

The invention relates to the technical field of adsorption materials, in particular to a difunctional integral material for CO2 in-situ efficient adsorption coupling conversion and a preparation method of the difunctional integral material. On the basis of an in-situ coupling mechanism, a hydrothermal synthesis method is adopted, a metal and nonmetal multi-element doped material is prepared in situ, and the ion radius of framework metal is smaller than that of coupling metal; the framework metal is uniformly dispersed on the ZSM-5 framework, the metal oxide is highly dispersed on the ZSM-5 surface, and meanwhile, more active sites such as oxygen vacancies and acid sites are exposed on the surface of a ZSM-5 matrix; according to the invention, two hydrogen absorption metals and nitrogen elements in urea are subjected to in-situ coupling with the ZSM-5 molecular sieve to prepare a bifunctional integral material subjected to in-situ efficient adsorption coupling conversion, and the material has strong anti-interference capability and has no adsorbability to other foreign gases (such as nitrogen oxides, sulfur dioxide, hydrogen chloride and the like); and after the adsorption is completed, the material is adsorbed at high temperature to generate other green raw materials.

Description

Technical Field

[0001] The present invention relates to the technical field of adsorption materials, and in particular to a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 and a preparation method thereof. Background Art

[0002] As the main greenhouse gas, CO2 is currently mainly removed by capture and storage technology. For the deep removal of low-content CO2, there are usually membrane separation, conversion and adsorption methods. The adsorption method has the advantages of high removal accuracy, no pollution to the environment, simple operation and low cost. The materials used for CO2 adsorption are mainly activated carbon, zeolite molecular sieves, metal oxides and metal organic framework materials (MOFs). Both activated carbon and zeolite molecular sieves use the advantages of the material's own developed pore structure and specific surface area to adsorb the adsorbate through van der Waals force or weak chemical bonds. Among them, zeolite molecular sieves have the advantages of large specific surface area, different structures and pores, and adjustable pore size. They are widely used as matrix materials for CO2 solid adsorbents. However, the biggest problem facing zeolite molecular sieves is that they are very sensitive to temperature changes. They only show ideal adsorption performance for CO2 at room temperature or even lower temperature conditions (far lower than the combustion flue gas temperature). When the temperature rises, its CO2 adsorption capacity will gradually decrease. In addition, the adsorption capacity is relatively low, and the adsorption process often requires a large amount of adsorption material. If these problems can be effectively solved, zeolite materials will truly be feasible for capturing CO2.

[0003] Therefore, how to better improve the adsorption performance of zeolite molecular sieves, increase adsorption capacity, and improve temperature adaptability is an important problem that needs to be solved at present. The Chinese invention patent with publication number CN117983194A discloses a CO2 multi-level pore nanotube molecular sieve adsorbent and a preparation method thereof. The adsorbent has a high specific surface area, developed pores, and good gas diffusivity, which is conducive to the exposure of active sites and improves adsorption capacity and adsorption efficiency. However, the prior art does not disclose a material with strong adsorption capacity, no adsorption to other impurity gases (such as nitrogen oxides, sulfur dioxide, hydrogen chloride, etc.), and strong anti-interference ability. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2 and a preparation method thereof.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] In a first aspect, a method for preparing a bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2 is provided, which comprises the following steps:

[0007] S1: using sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, a mixed solution of silicon component, aluminum component, ammonia water, polyquaternary ammonium salt, and transition metal salt as raw materials, preparing M-ZSM-5 crystal nucleus solution L1 having a framework lattice metal;

[0008] S2: Urea and two heteronuclear metals A and B are added to the M-ZSM-5 crystal nucleus solution L1, and after nucleation at a certain pressure and temperature, nitrogen replaces oxygen, and the crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A is first prepared, so that the lattice structure is expanded, and the final in-situ efficient adsorption coupling bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3 is further obtained;

[0009] S3: Add a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the above-mentioned crystal nucleus solution L3, stir and dry gel by ultrasonic heating, transfer to a polytetrafluoroethylene reactor, crystallize under a certain pressure and temperature, and obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx after calcination; immerse the obtained ZSM-5 molecular sieve in an organic amine solvent, and obtain a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 after drying;

[0010] Among them, A and B represent metal elements with hydrogen absorption properties, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is the oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A.

[0011] Secondly, a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 is provided, which is a single-shell material with the general formula U@AOx / B-ZSM-5@Y; wherein A and B represent metal elements with hydrogen absorption, M represents a transition metal element, U and Y represent organic amines or silanes, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A; the material is a ZSM-5 molecular sieve co-modified with a skeleton lattice metal M and the inner and outer surfaces of AOx outside the skeleton, AOx is adjacent to the skeleton metal B, and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly binds with the ZSM-5 matrix; in addition, there is a layer of organic film composed of organic amines on the inner and outer surfaces of the adsorbent.

[0012] In a third aspect, a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 is provided, wherein the adsorbent is a double-shell adsorbent, and its general formula is U@AOx / B-ZSM-5@ROx / Q-ZSM-5@Y; wherein A, P and B, Q represent metal elements with hydrogen absorption, M represents a transition metal element, U and Y represent organic amines or silanes, B-ZSM-5 and Q-ZSM-5 are molecular sieves with MFI structure, AOx is an oxide of metal A in a highly dispersed state, A, P and B, Q are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A, and the metal ion radius of Q is The ion radius of the metal is higher than that of P; the inner layer of the material is a ZSM-5 molecular sieve modified with a framework lattice metal M and inner and outer surfaces of the framework AOx, AOx is adjacent to the framework metal B, and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly combines with the ZSM-5 matrix; the outer layer of the material is a ZSM-5 molecular sieve modified with an inner and outer surface of the framework lattice metal R and POx outside the framework, POx is adjacent to the framework metal Q, and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly combines with the ZSM-5 matrix to form an integral catalyst-adsorbent; in addition, there is an organic film composed of organic amines on the inner and outer surfaces of the adsorbent.

[0013] The beneficial effects of the present invention are:

[0014] The invention discloses a bifunctional monolithic material for in-situ efficient adsorption coupled conversion of CO2 and a preparation method thereof. Based on an in-situ coupling mechanism, a hydrothermal synthesis method is adopted to in-situ prepare a metal and non-metal multi-doped material, wherein the skeleton metal ion radius is smaller than the ion radius of the coupling metal; the skeleton metal is uniformly dispersed on a ZSM-5 skeleton, and metal oxides are highly dispersed on a ZSM-5 surface, while a large number of active sites such as oxygen vacancies and acid sites are exposed on the surface of a ZSM-5 matrix; the invention couples two hydrogen absorbing metals and nitrogen elements in urea with a ZSM-5 molecular sieve in-situ to prepare a bifunctional monolithic material for in-situ efficient adsorption coupled conversion, wherein the material has strong anti-interference ability and has no adsorption to other impurity gases (such as nitrogen oxides, sulfur dioxide, hydrogen chloride, etc.); and after the adsorption is completed, the material adsorbs and generates other green raw materials at high temperature. DETAILED DESCRIPTION

[0015] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0016] Example 1

[0017] A bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2, which is a single-shell material with a general formula of U@AOx / B-ZSM-5@Y; wherein A and B represent metal elements with hydrogen absorption, M represents a transition metal element, U and Y represent organic amines or silanes, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A; the material is a ZSM-5 molecular sieve co-modified with a skeleton lattice metal M and the inner and outer surfaces of AOx outside the skeleton, wherein AOx is adjacent to the skeleton metal B, is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly binds with the ZSM-5 matrix; in addition, there is an organic film composed of organic amines on the inner and outer surfaces of the adsorbent, respectively.

[0018] The preparation method comprises the following steps:

[0019] S1: using sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, a mixed solution of silicon component, aluminum component, ammonia water, polyquaternary ammonium salt, and transition metal salt as raw materials, preparing M-ZSM-5 crystal nucleus solution L1 having a framework lattice metal;

[0020] The method of step S1 specifically includes the following sub-steps:

[0021] S101: mixing a soluble salt of a transition metal M and deionized water in a certain proportion, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring, and then adding a certain amount of tetrapropylammonium hydroxide or tetrapropylammonium bromide, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring again to obtain a mixture a;

[0022] S102: dissolving a certain amount of sodium hydroxide in deionized water, adding a certain amount of aluminum component, adding a certain amount of silicon component after thermal radiation combined with ultrasound and magnetic stirring, and thermal radiation combined with ultrasound and magnetic stirring for a certain period of time to obtain a mixture b;

[0023] S103: slowly pouring mixture a into mixture b while maintaining thermal radiation stirring and ultrasonic vibration for a certain period of time to obtain mixture c;

[0024] S104: nucleating the mixture c for a certain period of time under a certain pressure and thermal radiation combined with microwave-assisted heating to obtain an M-ZSM-5 crystal nucleus solution L1.

[0025] The molar ratio of each component in the mixture c of steps S103 and S104 is:

[0026] SiO2:TPAOH or TPABr=100:(10-35);

[0027] SiO2:H2O=100:(1000-8000);

[0028] SiO2:Na2O=100:(10-30);

[0029] SiO2:M=100:(0.05-3);

[0030] SiO2:Al2O3=100:(10-600).

[0031] S2: Urea and two heteronuclear metals A and B are added to the M-ZSM-5 crystal nucleus solution L1, and after nucleation at a certain pressure and temperature, nitrogen replaces oxygen, and the crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A is first prepared, so that the lattice structure is expanded, and the final in-situ efficient adsorption coupling bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3 is further obtained;

[0032] The method of step S2 specifically includes the following sub-steps:

[0033] S201: adding a certain amount of metal A soluble salt, metal B soluble salt and urea to the crystal nucleus solution L1, and obtaining a mixture d after thermal radiation combined with ultrasound and magnetic stirring;

[0034] S202: nucleate the mixture d under a certain pressure and thermal radiation combined with microwave-assisted heating for a certain period of time to first obtain a crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A, and further react to obtain a crystal nucleus solution L3 of a bifunctional monolithic adsorbent B-ZSM-5 with final in-situ efficient adsorption coupling;

[0035] In step S202, the molar ratio of metal A to silicon component in mixture d is: SiO2:A=100:(0.05-3), and the molar ratio of metal B to silicon component is: SiO2:B=100:(0.05-3).

[0036] S3: Add a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the above-mentioned crystal nucleus solution L3, stir and dry gel by ultrasonic heating, crystallize under a certain pressure and temperature, and obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx after calcination; immerse the obtained ZSM-5 molecular sieve in an organic amine solvent, and obtain a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 after drying;

[0037] Among them, A and B represent metal elements with hydrogen absorption properties, M represents a transition metal element, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A.

[0038] The method of step S3 specifically includes the following sub-steps:

[0039] S301: adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide and polyquaternary ammonium salt solvent to the crystal nucleus solution L3, and obtaining a mixture g after thermal radiation combined with ultrasound and magnetic stirring;

[0040] S302: drying the mixture g by ultrasonic combined heating to a dry gel, crystallizing it under a certain pressure and temperature for a certain period of time, and calcining it to obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx;

[0041] S303: impregnating the ZSM-5 molecular sieve obtained in S302 in an organic amine solvent of a certain concentration, filtering and drying after impregnation for a certain period of time, and obtaining a bifunctional monolithic material for in-situ efficient CO2 adsorption and coupled conversion;

[0042] In step S301, the mass ratio of the added amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the SiO2 in the mixture is (0.05-0.8):1.

[0043] Step S302: During the crystallization process, a small amount of deionized water is added to the reaction kettle, the mass ratio of the added water to the dry glue is (0.5-2):1, the crystallization temperature is 140-200°C, and the crystallization time is 24-48h;

[0044] The calcination process in step S302 under air atmosphere is divided into three stages: in the first stage, the crystallized product is dried at 100-120°C for 2-3 hours; in the second stage, the temperature is slowly increased from 100-120°C to 300-400°C at a heating rate of 1-5°C, and the temperature is kept constant for 3-5 hours; in the third stage, the calcination temperature is slowly increased to 500-700°C at a heating rate of 1-5°C, and the temperature is kept constant for 4-6 hours;

[0045] In step S303, the immersion solid-liquid ratio is 10:1, wherein the mass concentration of the organic amine solution is 5-20%, and the drying temperature is 80-120°C.

[0046] As a preferred embodiment, in steps S1, S2 and S3, the ultrasonic power is 50-300W, the heating temperature is 50-80°C, the magnetic stirring speed is 400-800r / min, and the ultrasonic combined with thermal radiation magnetic stirring time is 60-120min;

[0047] As a preferred method, the nucleation in steps S1 and S2 is carried out in a sealed reactor, the nucleation temperature is 80-120° C., the pressure is adjusted according to the temperature, the microwave power is 300-600 W, and the nucleation time is 8-20 h.

[0048] Example 2

[0049] A bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2, the adsorbent is a double-shell adsorbent, and its general formula is U@AOx / B-ZSM-5@ROx / Q-ZSM-5@Y; wherein A, P and B, Q represent metal elements with hydrogen absorption, M represents a transition metal element, U and Y represent organic amines or silanes, B-ZSM-5 and Q-ZSM-5 are molecular sieves with MFI structure, AOx is an oxide of metal A in a highly dispersed state, A, P and B, Q are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A, and the metal ion radius of Q is The metal ion radius is higher than P; the inner layer of the material is a ZSM-5 molecular sieve modified with a framework lattice metal M and inner and outer surfaces of the framework AOx, AOx is adjacent to the framework metal B, and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly combines with the ZSM-5 matrix; the outer layer of the material is a ZSM-5 molecular sieve modified with a framework lattice metal R and inner and outer surfaces of the framework POx, POx is adjacent to the framework metal Q, and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly combines with the ZSM-5 matrix to form an integral catalyst-adsorbent; in addition, there is an organic film composed of organic amines on the inner and outer surfaces of the adsorbent.

[0050] The preparation method comprises the following steps:

[0051] S1: using sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, a mixed solution of silicon component, aluminum component, ammonia water, polyquaternary ammonium salt, and transition metal salt as raw materials, preparing M-ZSM-5 crystal nucleus solution L1 having a framework lattice metal;

[0052] The method of step S1 specifically includes the following sub-steps:

[0053] S101: mixing a soluble salt of a transition metal M and deionized water in a certain proportion, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring, and then adding a certain amount of tetrapropylammonium hydroxide or tetrapropylammonium bromide, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring again to obtain a mixture a;

[0054] S102: dissolving a certain amount of sodium hydroxide in deionized water, adding a certain amount of aluminum component, adding a certain amount of silicon component after thermal radiation combined with ultrasound and magnetic stirring, and thermal radiation combined with ultrasound and magnetic stirring for a certain period of time to obtain a mixture b;

[0055] S103: slowly pouring mixture a into mixture b while maintaining thermal radiation stirring and ultrasonic vibration for a certain period of time to obtain mixture c;

[0056] S104: nucleating the mixture c for a certain period of time under a certain pressure and thermal radiation combined with microwave-assisted heating to obtain an M-ZSM-5 crystal nucleus solution L1.

[0057] The molar ratio of each component in the mixture c of steps S103 and S104 is:

[0058] SiO2:TPAOH or TPABr=100:(10-35);

[0059] SiO2:H2O=100:(1000-8000);

[0060] SiO2:Na2O=100:(10-30);

[0061] SiO2:M=100:(0.05-3);

[0062] SiO2:Al2O3=100:(10-600).

[0063] S2: Urea and two heteronuclear metals A and B are added to the M-ZSM-5 crystal nucleus solution L1, and after nucleation at a certain pressure and temperature, nitrogen replaces oxygen, and the crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A is first prepared, so that the lattice structure is expanded, and the final in-situ efficient adsorption coupling bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3 is further obtained;

[0064] The method of step S2 specifically includes the following sub-steps:

[0065] S201: adding a certain amount of metal A soluble salt, metal B soluble salt and urea to the crystal nucleus solution L1, and obtaining a mixture d after thermal radiation combined with ultrasound and magnetic stirring;

[0066] S202: nucleate the mixture d under a certain pressure and thermal radiation combined with microwave-assisted heating for a certain period of time to first obtain a crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A, and further react to obtain a crystal nucleus solution L3 of a bifunctional monolithic adsorbent B-ZSM-5 with final in-situ efficient adsorption coupling;

[0067] In step S202, the molar ratio of metal A to silicon component in mixture d is: SiO2:A=100:(0.05-3), and the molar ratio of metal B to silicon component is: SiO2:B=100:(0.05-3).

[0068] S3: Add a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the above-mentioned crystal nucleus solution L3, stir and dry gel by ultrasonic heating, crystallize under a certain pressure and temperature, and obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx after calcination; immerse the obtained ZSM-5 molecular sieve in an organic amine solvent, and obtain a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 after drying;

[0069] Among them, A and B represent metal elements with hydrogen absorption properties, M represents a transition metal element, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A.

[0070] The method of step S3 specifically includes the following sub-steps:

[0071] S301: adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide and polyquaternary ammonium salt solvent to the crystal nucleus solution L3, and obtaining a mixture g after thermal radiation combined with ultrasound and magnetic stirring;

[0072] S302: drying the mixture g by ultrasonic combined heating to a dry gel, crystallizing it under a certain pressure and temperature for a certain period of time, and calcining it to obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx;

[0073] S303: impregnating the ZSM-5 molecular sieve obtained in S302 in an organic amine solvent of a certain concentration, filtering and drying after impregnation for a certain period of time, and obtaining a bifunctional monolithic material for in-situ efficient CO2 adsorption and coupled conversion;

[0074] In step S301, the mass ratio of the added amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the SiO2 in the mixture is (0.05-0.8):1.

[0075] Step S302: During the crystallization process, a small amount of deionized water is added to the reaction kettle, the mass ratio of the added water to the dry glue is (0.5-2):1, the crystallization temperature is 140-200°C, and the crystallization time is 24-48h;

[0076] The calcination process in step S302 under air atmosphere is divided into three stages: in the first stage, the crystallized product is dried at 100-120°C for 2-3 hours; in the second stage, the temperature is slowly increased from 100-120°C to 300-400°C at a heating rate of 1-5°C, and the temperature is kept constant for 3-5 hours; in the third stage, the calcination temperature is slowly increased to 500-700°C at a heating rate of 1-5°C, and the temperature is kept constant for 4-6 hours;

[0077] In step S303, the immersion solid-liquid ratio is 10:1, wherein the mass concentration of the organic amine solution is 5-20%, and the drying temperature is 80-120°C.

[0078] The method of step S4 further comprises the following sub-steps:

[0079] S401: According to the steps of S1 and S2, a crystal nucleus solution L4 is prepared, wherein the metal M in S1 is represented by the letter R, and the metals A and B in S2 are represented by the letters P and Q respectively;

[0080] S402: adding the ZSM-5 molecular sieve obtained in S302 to the crystal nucleus solution C, and adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent, and obtaining a mixture h after thermal radiation combined with ultrasound and magnetic stirring;

[0081] S403: drying the mixture h by ultrasonic combined heating to a dry gel, crystallizing it at a certain pressure and temperature for a certain time, and calcining it to obtain a P-ZSM-5 molecular sieve with an extra-framework ROx, and further obtaining a Q-ZSM-5 molecular sieve with an extra-framework POx;

[0082] S404: impregnating the Q-ZSM-5 molecular sieve obtained in S403 into an organic amine solvent of a certain concentration, filtering and drying after impregnation for a certain period of time, to obtain a multi-shell CO2 in-situ efficient adsorption coupled conversion bifunctional monolithic material;

[0083] In step S402, the mass ratio of the amount of ZSM-5 molecular sieve added to the amount of SiO2 in the mixture is (0.5-2):1;

[0084] In step S404, the solid-liquid ratio of the impregnation is 10:1, wherein the mass concentration of the organic amine solution is 5-20%, and the drying temperature is 80-120°C.

[0085] As a preferred embodiment, in steps S1, S2 and S3, the ultrasonic power is 50-300W, the heating temperature is 50-80°C, the magnetic stirring speed is 400-800r / min, and the ultrasonic combined with thermal radiation magnetic stirring time is 60-120min;

[0086] As a preferred method, the nucleation in steps S1 and S2 is carried out in a sealed reactor, the nucleation temperature is 80-120° C., the pressure is adjusted according to the temperature, the microwave power is 300-600 W, and the nucleation time is 8-20 h.

[0087] In summary, the present invention discloses a bifunctional integral material for in-situ efficient adsorption coupled conversion of CO2 and a preparation method thereof. Based on the in-situ coupling mechanism, a hydrothermal synthesis method is adopted to in-situ prepare a metal and non-metal multi-doped material, wherein the skeleton metal ion radius is smaller than the ion radius of the coupling metal; the skeleton metal is uniformly dispersed on the ZSM-5 skeleton, and the metal oxide is highly dispersed on the ZSM-5 surface, while a large number of active sites such as oxygen vacancies and acidic sites are exposed on the surface of the ZSM-5 matrix; the present invention couples two hydrogen-absorbing metals and the nitrogen element in urea with the ZSM-5 molecular sieve in situ to prepare a bifunctional integral material for in-situ efficient adsorption coupled conversion, the material has strong anti-interference ability, and has no adsorption to other impurity gases (such as nitrogen oxides, sulfur dioxide, hydrogen chloride, etc.); and after the adsorption is completed, the material adsorbs and generates other green raw materials at high temperature.

[0088] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0089] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2, characterized in that: The following steps are involved: S1: using sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, a mixed solution of silicon component, aluminum component, ammonia water, polyquaternary ammonium salt, and transition metal salt as raw materials, preparing M-ZSM-5 crystal nucleus solution L1 having a framework lattice metal; S2: Urea and two heteronuclear metals A and B are added to the M-ZSM-5 crystal nucleus solution L1, and after nucleation at a certain pressure and temperature, nitrogen replaces oxygen, and the crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A is first prepared, so that the lattice structure is expanded, and the final in-situ efficient adsorption coupling bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3 is further obtained; S3: Add a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the above-mentioned crystal nucleus solution L3, stir and dry gel by ultrasonic heating, crystallize under a certain pressure and temperature, and obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx after calcination; immerse the obtained ZSM-5 molecular sieve in an organic amine solvent, and obtain a bifunctional integral material for in-situ efficient adsorption and coupled conversion of CO2 after drying; Among them, A and B represent metal elements with hydrogen absorption properties, M represents a transition metal element, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A.

2. The preparation method according to claim 1, characterized in that: The method of step S1 specifically includes the following sub-steps: S101: mixing a soluble salt of a transition metal M and deionized water in a certain proportion, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring, and then adding a certain amount of tetrapropylammonium hydroxide or tetrapropylammonium bromide, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring again to obtain a mixture a; S102: dissolving a certain amount of sodium hydroxide in deionized water, adding a certain amount of aluminum component, adding a certain amount of silicon component after thermal radiation combined with ultrasound and magnetic stirring, and thermal radiation combined with ultrasound and magnetic stirring for a certain period of time to obtain a mixture b; S103: slowly pouring mixture a into mixture b while maintaining thermal radiation stirring and ultrasonic vibration for a certain period of time to obtain mixture c; S104: nucleating the mixture c for a certain period of time under a certain pressure and thermal radiation combined with microwave-assisted heating to obtain an M-ZSM-5 crystal nucleus solution L1.

3. The preparation method according to claim 2, characterized in that: The molar ratio of each component in the mixture c of steps S103 and S104 is: SiO2:TPAOH or TPABr=100:(10-35); SiO2:H2O=100:(1000-8000); SiO2:Na2O=100:(10-30); SiO2:M=100:(0.05-3); SiO2:Al2O3=100:(10-600).

4. The preparation method according to claim 1, characterized in that: The method of step S2 specifically includes the following sub-steps: S201: adding a certain amount of metal A soluble salt, metal B soluble salt and urea to the crystal nucleus solution L1, and obtaining a mixture d after thermal radiation combined with ultrasound and magnetic stirring; S202: nucleate the mixture d under a certain pressure and thermal radiation combined with microwave-assisted heating for a certain period of time to first obtain a crystal nucleus solution L2 of A-ZSM-5 with dispersed loading of surface metal A, and further react to obtain a crystal nucleus solution L3 of a bifunctional monolithic adsorbent B-ZSM-5 with final in-situ efficient adsorption coupling; In step S202, the molar ratio of metal A to silicon component in mixture d is: SiO2:A=100:(0.05-3), and the molar ratio of metal B to silicon component is: SiO2:B=100:(0.05-3).

5. The preparation method according to claim 1, characterized in that: The method of step S3 specifically includes the following sub-steps: S301: adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide and polyquaternary ammonium salt solvent to the crystal nucleus solution L3, and obtaining a mixture g after thermal radiation combined with ultrasound and magnetic stirring; S302: drying the mixture g by ultrasonic combined heating to a dry gel, crystallizing it under a certain pressure and temperature for a certain period of time, and calcining it to obtain a ZSM-5 molecular sieve co-modified with the framework lattice metal M and the inner and outer surfaces of the framework AOx; S303: impregnating the ZSM-5 molecular sieve obtained in S302 in an organic amine solvent of a certain concentration, filtering and drying after impregnation for a certain period of time, and obtaining a bifunctional monolithic material for in-situ efficient CO2 adsorption and coupled conversion; In step S301, the mass ratio of the added amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent to the SiO2 in the mixture is (0.05-0.8):

1.

6. The preparation method according to claim 5, characterized in that: Step S302: During the crystallization process, a small amount of deionized water is added to the reaction kettle, the mass ratio of the added water to the dry glue is (0.5-2):1, the crystallization temperature is 140-200°C, and the crystallization time is 24-48h; The calcination process in step S302 under air atmosphere is divided into three stages: in the first stage, the crystallized product is dried at 100-120°C for 2-3 hours; in the second stage, the temperature is slowly increased from 100-120°C to 300-400°C at a heating rate of 1-5°C, and the temperature is kept constant for 3-5 hours; in the third stage, the calcination temperature is slowly increased to 500-700°C at a heating rate of 1-5°C, and the temperature is kept constant for 4-6 hours; In step S303, the immersion solid-liquid ratio is 10:1, wherein the mass concentration of the organic amine solution is 5-20%, and the drying temperature is 80-120°C.

7. The preparation method according to claim 1, characterized in that: In steps S1, S2 and S3, the ultrasonic power is 50-300 W, the heating temperature is 50-80° C., the magnetic stirring speed is 400-800 r / min, and the ultrasonic combined with thermal radiation magnetic stirring time is 60-120 min; In steps S1 and S2, the nucleation is carried out in a sealed reactor, the nucleation temperature is 80-120° C., the pressure is adjusted according to the temperature, the microwave power is 300-600 W, and the nucleation time is 8-20 h.

8. The preparation method according to claim 5, characterized in that: The method further comprises step S4, wherein the method of step S4 specifically comprises the following sub-steps: S401: According to the steps of S1 and S2, a crystal nucleus solution L4 is prepared, wherein the metal M in S1 is represented by the letter R, and the metals A and B in S2 are represented by the letters P and Q respectively; S402: adding the ZSM-5 molecular sieve obtained in S302 to the crystal nucleus solution C, and adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and polyquaternary ammonium salt solvent, and obtaining a mixture h after thermal radiation combined with ultrasound and magnetic stirring; S403: drying the mixture h by ultrasonic combined heating to a dry gel, crystallizing it at a certain pressure and temperature for a certain time, and calcining it to obtain a P-ZSM-5 molecular sieve with an extra-framework ROx, and further obtaining a Q-ZSM-5 molecular sieve with an extra-framework POx; S404: impregnating the Q-ZSM-5 molecular sieve obtained in S403 into an organic amine solvent of a certain concentration, filtering and drying after impregnation for a certain period of time, to obtain a multi-shell CO2 in-situ efficient adsorption coupled conversion bifunctional monolithic material; In step S402, the mass ratio of the amount of ZSM-5 molecular sieve added to the amount of SiO2 in the mixture is (0.5-2):1; In step S404, the solid-liquid ratio of the impregnation is 10:1, wherein the mass concentration of the organic amine solution is 5-20%, and the drying temperature is 80-120°C.

9. A bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2, characterized in that: The material is a single-shell material with the general formula U@AOx / B-ZSM-5@Y; wherein A and B represent metal elements with hydrogen absorption, M represents a transition metal element, U and Y represent organic amines or silanes, B-ZSM-5 is a molecular sieve with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A and B are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A; the material is a ZSM-5 molecular sieve co-modified with the inner and outer surfaces of the skeleton lattice metal M and the outer skeleton AOx, AOx is adjacent to the skeleton metal B, and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly binds with the ZSM-5 matrix; in addition, there is an organic film composed of organic amines on the inner and outer surfaces of the adsorbent.

10. A bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2, characterized in that: The adsorbent is a double-shell adsorbent, and its general formula is U@AOx / B-ZSM-5@ROx / Q-ZSM-5@Y; wherein A, P and B, Q represent metal elements with hydrogen absorption, M represents a transition metal element, U and Y represent organic amines or silanes, B-ZSM-5 and Q-ZSM-5 are molecular sieves with an MFI structure, AOx is an oxide of metal A in a highly dispersed state, A, P and B, Q are metal elements with a metal ion radius higher than that of M, and the metal ion radius of B is higher than that of A, and the metal ion radius of Q is higher than that of P; The inner layer of the material is a ZSM-5 molecular sieve modified with a framework lattice metal M and inner and outer surfaces of AOx outside the framework, AOx is adjacent to the framework metal B, highly dispersed on the surface of the ZSM-5 matrix, and tightly bound to the ZSM-5 matrix through interaction; the outer layer of the material is a ZSM-5 molecular sieve modified with a framework lattice metal R and inner and outer surfaces of POx outside the framework, POx is adjacent to the framework metal Q, highly dispersed on the surface of the ZSM-5 matrix, and tightly bound to the ZSM-5 matrix through interaction, forming an integral catalyst-adsorbent; in addition, there is an organic film composed of organic amines on the inner and outer surfaces of the adsorbent.