A bifunctional monolithic material for in-situ efficient CO2 adsorption and coupled conversion and its preparation method

Abstract

The present invention relates to the technical field of adsorption materials, and in particular to a bifunctional monolithic material for the in-situ efficient adsorption coupling conversion of CO2 and a preparation method thereof. The present invention is based on an in-situ coupling mechanism, and adopts a hydrothermal synthesis method to prepare a metal and non-metal multinary doped material in situ, wherein the skeleton metal ion radius is less than the ion radius of the coupling metal; the skeleton metal is evenly dispersed on the ZSM-5 skeleton, and the metal oxide is highly dispersed on the ZSM-5 surface, while exposing more active sites such as oxygen vacancies and acidic sites on the surface of the ZSM-5 matrix; the present invention couples the nitrogen element in two hydrogen-absorbing metals and urea with the ZSM-5 molecular sieve in situ, prepares a bifunctional monolithic material for the in-situ efficient adsorption coupling conversion, the material has strong anti-interference ability, and has no adsorptivity to other impurity gases (such as nitrogen oxides, sulfur dioxide, hydrogen chloride, etc.); and after adsorption is completed, the material adsorbs and generates other green raw materials at high temperature.

Description

Technical Field

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

[0002] CO2, a major greenhouse gas, is currently primarily removed on a large scale through capture and storage technologies. Deep removal of lower levels of CO2 is typically achieved through membrane separation, conversion, and adsorption. Adsorption offers advantages such as high removal accuracy, environmental friendliness, simplicity, and low cost. Materials used for CO2 adsorption primarily include activated carbon, zeolite molecular sieves, metal oxides, and metal-organic frameworks (MOFs). Both activated carbon and zeolite molecular sieves utilize their inherently developed pore structure and specific surface area to adsorb the adsorbate via van der Waals forces or weak chemical bonds. Zeolite molecular sieves, with their large specific surface area, diverse structure and pore channels, and adjustable pore size, are widely used as matrix materials for solid CO2 adsorbents. However, the primary challenge facing zeolite molecular sieves is their extreme sensitivity to temperature fluctuations. They exhibit optimal CO2 adsorption performance at ambient or even lower temperatures (well below the combustion flue gas temperature), but their CO2 adsorption capacity gradually decreases as temperatures rise. Furthermore, their adsorption capacity is relatively low, and adsorption processes often require large amounts of adsorbent material. If these problems can be effectively solved, zeolite materials will truly be feasible for capturing CO2.

[0003] Therefore, improving the adsorption performance, adsorption capacity, and temperature adaptability of zeolite molecular sieves is a critical issue currently in need of resolution. Chinese invention patent publication number CN117983194A discloses a CO2 multi-level porous nanotube molecular sieve adsorbent and its preparation method. This adsorbent exhibits a high specific surface area, well-developed pores, and excellent gas diffusivity, which facilitates the exposure of active sites and improves adsorption capacity and efficiency. However, the prior art does not disclose materials with strong adsorption capacity while also being non-adsorbent to other impurity gases (such as nitrogen oxides, sulfur dioxide, and hydrogen chloride) and exhibiting strong anti-interference capabilities. 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, comprising the following steps:

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

[0008] S2: Urea and two heteronuclear metals A and B are added to the M-ZSM-5 crystal nucleus solution L1. After nucleation at a certain pressure and temperature, the M-ZSM-5 first reacts with urea to partially replace the oxygen element in the molecular sieve framework with nitrogen. Subsequently, the nitrogen-modified M-ZSM-5 molecular sieve reacts with the compound of metal A, and metal A combines with the skeleton metal to form the A-ZSM-5 crystal nucleus solution L2; finally, A-ZSM-5 reacts with the compound of metal B, and metal B replaces metal A through a replacement reaction to obtain the final in-situ efficient adsorption coupled bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3, while simultaneously replacing AOx with hydrogen absorption;

[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, transfer to a polytetrafluoroethylene reactor, crystallize under a certain pressure and temperature, and calcine to obtain a ZSM-5 molecular sieve with the inner and outer surfaces of the framework lattice metal MOx and the outer framework AOx co-modified; impregnate the obtained ZSM-5 molecular sieve into an organic amine solvent, and after drying, obtain a bifunctional monolithic material with high-efficiency in-situ adsorption and coupled conversion of CO2;

[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, which is 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 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 properties, 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, which is highly dispersed, 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 MOx and the outer AOx of 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 amine on the inner and outer surfaces of the adsorbent.

[0012] The third aspect provides a bifunctional integral material for in-situ efficient adsorption coupled conversion of CO2, wherein the adsorbent is a double-shell adsorbent with the general formula of 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, which is 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 skeleton lattice metal MOx and the inner layer of AOx outside the skeleton is a metal ion. The outer surface of the ZSM-5 molecular sieve is co-modified, and AOx is adjacent to the skeleton 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 with the inner and outer surfaces co-modified with the skeleton lattice metal R and the outer skeleton POx, POx is adjacent to the skeleton metal Q and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly combines with the ZSM-5 matrix, tightly combining into an integral catalyst-adsorbent; in addition, there is a layer of organic film composed of organic amine on the inner and outer surfaces of the adsorbent.

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

[0014] The present invention discloses a bifunctional monolithic 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, the metal oxide is highly dispersed on the ZSM-5 surface, and 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 in-situ couples two hydrogen-absorbing metals and the nitrogen element in urea with the ZSM-5 molecular sieve to prepare a bifunctional monolithic material for in-situ efficient adsorption coupled conversion, the material has strong anti-interference ability and 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 embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0016] Example 1

[0017] A bifunctional monolithic material for in-situ efficient CO2 adsorption coupled conversion is disclosed. The material is a single-shell material with the general formula U@AOx / B-ZSM-5@Y. A and B represent metal elements with hydrogen absorption properties, 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 a highly dispersed oxide of metal A, A and B are metal elements with a metal ion radius greater than that of M, and the metal ion radius of B is greater than that of A. The material is a ZSM-5 molecular sieve co-modified with a skeleton lattice metal MOx and the inner and outer surfaces of the skeleton AOx. AOx is adjacent to the skeleton metal B, is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly bonds with the ZSM-5 matrix. In addition, an organic film composed of organic amines is present on the inner and outer surfaces of the adsorbent, respectively.

[0018] The preparation method comprises the following steps:

[0019] S1: using a mixture of sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, silicon component, aluminum component, ammonia water, polyquaternium salt, and transition metal salt as raw materials, preparing an M-ZSM-5 crystal nucleus solution L1 having a skeleton 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, 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 an aluminum component, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring, adding a certain amount of a silicon component, and subjecting the mixture to 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. After nucleation at a certain pressure and temperature, the M-ZSM-5 first reacts with urea to partially replace the oxygen element in the molecular sieve framework with nitrogen. Subsequently, the nitrogen-modified M-ZSM-5 molecular sieve reacts with the compound of metal A, and metal A combines with the skeleton metal to form the A-ZSM-5 crystal nucleus solution L2; finally, A-ZSM-5 reacts with the compound of metal B, and metal B replaces metal A through a replacement reaction to obtain the final in-situ efficient adsorption coupled bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3, while simultaneously replacing AOx with hydrogen absorption;

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

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

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

[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, crystallize under a certain pressure and temperature, and calcine to obtain a ZSM-5 molecular sieve with the inner and outer surfaces of the framework lattice metal MOx and the outer framework AOx co-modified; impregnate the obtained ZSM-5 molecular sieve into an organic amine solvent, and after drying, obtain a bifunctional monolithic material with high-efficiency in-situ adsorption and coupled conversion of CO2;

[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, and is 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 a polyquaternium salt solvent to the crystal nucleus solution L3, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring to obtain a mixture g;

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

[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, to obtain a bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2;

[0042] In step S301, the mass ratio of the added amount of EDTA, cetyltrimethylammonium bromide, and polyquaternium salt solvent to the SiO2 in the mixture is (0.05-0.8):1.

[0043] During the crystallization process in step S302, a small amount of deionized water is added to the reactor. The mass ratio of water to dry glue is (0.5-2):1. The crystallization temperature is 140-200°C and the crystallization time is 24-48 hours.

[0044] The calcination process in air atmosphere in step S302 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 maintained at this temperature for 3-5 hours; in the third stage, the calcination temperature is slowly increased at a heating rate of 1-5°C to 500-700°C and maintained at this temperature for 4-6 hours;

[0045] In step S303 , the solid-liquid ratio of the impregnation is 10:1, 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 50-300 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;

[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 higher than that of P; the inner layer of the material is a skeleton lattice metal MOx and the outer layer of the skeleton AOx is inner. The outer surface of the ZSM-5 molecular sieve is co-modified, and AOx is adjacent to the skeleton 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 with the inner and outer surfaces co-modified with the skeleton lattice metal R and the outer skeleton POx, POx is adjacent to the skeleton metal Q and is highly dispersed on the surface of the ZSM-5 matrix, and interacts and tightly combines with the ZSM-5 matrix, tightly combining into an integral catalyst-adsorbent; in addition, there is a layer of organic film composed of organic amine on the inner and outer surfaces of the adsorbent.

[0050] The preparation method comprises the following steps:

[0051] S1: using a mixture of sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, silicon component, aluminum component, ammonia water, polyquaternium salt, and transition metal salt as raw materials, preparing an M-ZSM-5 crystal nucleus solution L1 having a skeleton 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, 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 an aluminum component, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring, adding a certain amount of a silicon component, and subjecting the mixture to 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. After nucleation at a certain pressure and temperature, the M-ZSM-5 first reacts with urea to partially replace the oxygen element in the molecular sieve framework with nitrogen. Subsequently, the nitrogen-modified M-ZSM-5 molecular sieve reacts with the compound of metal A, and metal A combines with the skeleton metal to form the A-ZSM-5 crystal nucleus solution L2; finally, A-ZSM-5 reacts with the compound of metal B, and metal B replaces metal A through a replacement reaction to obtain the final in-situ efficient adsorption coupled bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3, while simultaneously replacing AOx with hydrogen absorption;

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

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

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

[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, crystallize under a certain pressure and temperature, and calcine to obtain a ZSM-5 molecular sieve with the inner and outer surfaces of the framework lattice metal MOx and the outer framework AOx co-modified; impregnate the obtained ZSM-5 molecular sieve into an organic amine solvent, and after drying, obtain a bifunctional monolithic material with high-efficiency in-situ adsorption and coupled conversion of CO2;

[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, and is 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 a polyquaternium salt solvent to the crystal nucleus solution L3, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring to obtain a mixture g;

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

[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, to obtain a bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2;

[0074] In step S301, the mass ratio of the added amount of EDTA, cetyltrimethylammonium bromide, and polyquaternium salt solvent to the SiO2 in the mixture is (0.05-0.8):1.

[0075] During the crystallization process in step S302, a small amount of deionized water is added to the reactor. The mass ratio of water to dry glue is (0.5-2):1. The crystallization temperature is 140-200°C and the crystallization time is 24-48 hours.

[0076] The calcination process in air atmosphere in step S302 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 maintained at this temperature for 3-5 hours; in the third stage, the calcination temperature is slowly increased at a heating rate of 1-5°C to 500-700°C and maintained at this temperature for 4-6 hours;

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

[0078] The method further includes step S4, wherein the method of step S4 specifically includes the following sub-steps:

[0079] S401: According to the steps of S1 and S2, a crystal nucleation 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 simultaneously adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and a polyquaternium salt solvent, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring to obtain a mixture h;

[0081] S403: drying the mixture h by ultrasonic combined with heating to a dry gel, crystallizing it under a certain pressure and temperature for a certain time, and calcining it to first obtain a P-ZSM-5 molecular sieve with an extra-framework ROx, and further obtain 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 SiO2 in the mixture is (0.5-2):1;

[0084] In step S404, the solid-liquid ratio of the impregnation is 10:1, 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 50-300 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;

[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 monolithic 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. At the same time, 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 monolithic 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 embodied in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0089] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method 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 can also be appropriately combined to form other implementation methods 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 a mixture of sodium hydroxide, tetrapropylammonium hydroxide or tetrapropylammonium bromide, silicon component, aluminum component, ammonia water, polyquaternium salt, and transition metal salt as raw materials, preparing an M-ZSM-5 crystal nucleus solution L1 having a skeleton lattice metal; S2: Urea and two heteronuclear metals A and B are added to the M-ZSM-5 crystal nucleus solution L1. After nucleation at a certain pressure and temperature, the M-ZSM-5 first reacts with urea to partially replace the oxygen element in the molecular sieve framework with nitrogen. Subsequently, the nitrogen-modified M-ZSM-5 molecular sieve reacts with the compound of metal A, and metal A combines with the skeleton metal to form the A-ZSM-5 crystal nucleus solution L2; finally, A-ZSM-5 reacts with the compound of metal B, and metal B replaces metal A through a replacement reaction to obtain the final in-situ efficient adsorption coupled bifunctional monolithic adsorbent B-ZSM-5 crystal nucleus solution L3, while simultaneously replacing AOx with hydrogen absorption; 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, crystallize under a certain pressure and temperature, and calcine to obtain a ZSM-5 molecular sieve with the inner and outer surfaces of the framework lattice metal MOx and the outer framework AOx co-modified; impregnate the obtained ZSM-5 molecular sieve into an organic amine solvent, and after drying, obtain a bifunctional monolithic material with high-efficiency in-situ adsorption and coupled conversion of CO2; 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, and is 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, 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 an aluminum component, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring, adding a certain amount of a silicon component, and subjecting the mixture to 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 soluble salt of metal A, soluble salt of metal B and urea to the crystal nucleus solution L1, and obtaining a mixture d after thermal radiation combined with ultrasonic and magnetic stirring; S202: nucleating the mixture d under a certain pressure and thermal radiation combined with microwave-assisted heating for a certain time to first obtain a crystal nucleus solution L2 of A-ZSM-5 with dispersed surface metal A, and further reacting to obtain a crystal nucleus solution L3 of the final in-situ efficient adsorption-coupled bifunctional monolithic adsorbent B-ZSM-5; 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 a polyquaternium salt solvent to the crystal nucleus solution L3, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring to obtain a mixture g; S302: drying the mixture g by ultrasonic combined with heating until it becomes a dry gel, crystallizing it under a certain pressure and temperature for a certain time, and calcining it to obtain a ZSM-5 molecular sieve with the framework lattice metal MOx and the outer and inner surfaces of the framework AOx co-modified; 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, to obtain a bifunctional monolithic material for in-situ efficient adsorption and coupled conversion of CO2; In step S301, the mass ratio of the added amount of EDTA, cetyltrimethylammonium bromide, and polyquaternium 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 During the crystallization process in step S302, a small amount of deionized water is added to the reactor. The mass ratio of water to dry glue is (0.5-2):

1. The crystallization temperature is 140-200°C and the crystallization time is 24-48 hours. The calcination process in air atmosphere in step S302 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 maintained at this temperature for 3-5 hours; in the third stage, the calcination temperature is slowly increased at a heating rate of 1-5°C to 500-700°C and maintained at this temperature for 4-6 hours; In step S303 , the solid-liquid ratio of the impregnation is 10:1, 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 rpm, 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 at a nucleation temperature of 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 includes step S4, wherein the method of step S4 specifically includes the following sub-steps: S401: According to the steps of S1 and S2, a crystal nucleation 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 simultaneously adding a certain amount of ethylenediaminetetraacetic acid, hexadecyltrimethylammonium bromide, and a polyquaternium salt solvent, and subjecting the mixture to thermal radiation combined with ultrasound and magnetic stirring to obtain a mixture h; S403: drying the mixture h by ultrasonic combined with heating to a dry gel, crystallizing it under a certain pressure and temperature for a certain time, and calcining it to first obtain a P-ZSM-5 molecular sieve with an extra-framework ROx, and further obtain 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 SiO2 in the mixture is (0.5-2):1; In step S404, the solid-liquid ratio of the impregnation is 10:1, 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 prepared by the method according to any one of claims 1 to 8.