A hetero-faujasite zeolite and a method for preparing the same

Abstract

This invention relates to the field of solid adsorbent technology, specifically to a shaped honeycomb zeolite and its preparation method. The shaped honeycomb zeolite is an oblique parallelepiped, comprising a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. Several through-flow channels are formed on the inclined side faces, arranged in a honeycomb pattern with their through-flow direction parallel to the vertical side faces. The shaped honeycomb zeolite is prepared by mixing, extruding, drying, and calcining the following raw materials: ZSM-5 zeolite, mordenite, an organic-inorganic hybrid binder, a pore-forming agent, and deionized water. This invention, by employing a specific organic-inorganic hybrid binder and an oblique parallelepiped shaped structure, successfully prepares a shaped honeycomb zeolite possessing excellent mechanical strength, high thermal shock resistance, and high adsorption / desorption performance, exhibiting excellent adsorption capacity and desorption efficiency for styrene.

Description

Technical Field

[0001] This invention relates to the field of solid adsorbent technology, specifically to a shaped honeycomb zeolite and its preparation method. Background Technology

[0002] Honeycomb zeolite, as a highly efficient solid adsorbent, is widely used in waste gas treatment, air purification, and catalytic carrier fields due to its large specific surface area, excellent adsorption performance, and good air permeability.

[0003] In the prior art, CN120571554B discloses a zeolite-geopolymer / cordierite monolithic adsorbent and its preparation method, in which silica sol is used as a binder for the zeolite-geopolymer; CN107583604B discloses a hydrophobic honeycomb zeolite material and its preparation method and application, in which silica sol, alumina sol, and zirconium sol are used as adhesives for the hydrophobic honeycomb zeolite material. Although silica sol, alumina sol, and zirconium sol have good thermal stability, their bonding strength is limited, and in actual temperature fluctuation environments, their thermal stability is insufficient to support long-term stable use, which easily leads to low mechanical strength and poor thermal shock resistance of the product. Under repeated adsorption-desorption cycles or temperature shocks, cracking and pulverization are likely to occur, thus shortening the service life. Summary of the Invention

[0004] The purpose of this invention is to provide a shaped honeycomb zeolite and its preparation method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a shaped honeycomb zeolite, wherein the shaped honeycomb zeolite is an oblique parallelepiped and includes a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. The inclined side faces are provided with a plurality of through airflow channels, which are arranged in a honeycomb pattern and their through direction is parallel to the vertical side faces.

[0006] The irregular honeycomb zeolite is prepared by mixing, extruding, drying and calcining raw materials containing the following parts by weight: 38-45 parts of ZSM-5 zeolite, 16-19 parts of mordenite, 12-20 parts of organic-inorganic hybrid binder, 3-6 parts of pore-forming agent and 20-25 parts of deionized water.

[0007] The specific surface area of ​​the ZSM-5 zeolite is 400–500 m². 2 / g, and its average pore size is 0.55 nm; the specific surface area of ​​the mordenite is 200-300 m² / g. 2 / g, and its average pore size is 0.67 nm; the organic-inorganic hybrid binder includes a siloxane-aluminoxane inorganic network framework formed by hydrolysis condensation, and organic functional segments grafted onto the siloxane-aluminoxane inorganic network framework by chemical bonds, the organic functional segments including amino polyether segments and long-chain alkyl silane segments.

[0008] Optionally, the angle α between the inclined side and the end face satisfies: 30° o ≤α≤80 o .

[0009] Optionally, the cross-sectional shape of the airflow channel is rectangular, circular, or regular hexagonal, the aperture of the airflow channel is 1 to 5 mm, and the wall thickness of adjacent airflow channels is 1 to 2 mm.

[0010] Optionally, in the organic-inorganic hybrid binder, the precursors of the siloxane-aluminoxane inorganic network skeleton are tetraethyl orthosilicate and aluminum isopropoxide, and the raw materials for the organic functional segments include amino polyether silane and long-chain alkyl silane. The amino polyether silane is compounded by silane coupling agent KH-580 and polyether amine D230 in a mass ratio of 1:1 to 1:1.5, and the long-chain alkyl silane is dodecyltrimethoxysilane.

[0011] Optionally, the organic-inorganic hybrid binder is made from the following components in parts by weight: 33-38 parts of tetraethyl orthosilicate, 10-12 parts of aluminum isopropoxide, 13-15 parts of amino polyether silane, 3-5 parts of dodecyltrimethoxysilane, 2-3 parts of polyethylene glycol, and 31-34 parts of 0.1 mol / L aqueous acetic acid solution;

[0012] The preparation method of the organic-inorganic hybrid binder includes the following steps: (a) slowly adding tetraethyl orthosilicate and aluminum isopropoxide to a 0.1 mol / L aqueous acetic acid solution, stirring at 240-300 r / min for 30-60 min at 20-25°C to prepare an inorganic precursor solution; (b) heating the inorganic precursor solution to 50-52°C, adding amino polyether silane, dodecyltrimethoxysilane and polyethylene glycol in sequence, keeping warm and stirring at 240-300 r / min for 90-120 min to prepare a silicon-aluminum composite material; (c) cooling the silicon-aluminum composite material to room temperature, sealing and aging for 12-18 h to obtain the organic-inorganic hybrid binder.

[0013] Optionally, the organic-inorganic hybrid binder has an amino density ≥1.96 mmol / g and a mass residue rate of not less than 95.2% after calcination at 550℃ for 2 hours.

[0014] Optionally, the pore-forming agent is ammonium bicarbonate or starch, with a particle size D90 of 5–25 μm.

[0015] On the other hand, the present invention also discloses a method for preparing the above-mentioned irregular honeycomb zeolite, comprising the following steps:

[0016] S1. Mixing: Weigh out ZSM-5 zeolite, mordenite, organic-inorganic hybrid binder, pore-forming agent and deionized water in proportion, stir at 300-500 r / min for 60-120 min to prepare a blank.

[0017] S2. Extrusion molding: The preform is added into a mold adapted to the oblique parallelepiped structure and extruded. The extrusion pressure is 5-8 MPa and the extrusion rate is 5-10 mm / s to produce a special-shaped honeycomb preform.

[0018] S3. Drying: The irregular honeycomb blank is subjected to the first stage of drying and the second stage of drying in sequence. The conditions for the first stage of drying are: temperature 35-45℃, time 10-15 h, and the conditions for the second stage of drying are: temperature 45-55℃, time 8-12 h.

[0019] S4. Calcination: The dried shaped honeycomb blank is calcined at 550°C for 1-3 hours and cooled to room temperature to obtain the shaped honeycomb zeolite.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention successfully prepared a shaped honeycomb zeolite with excellent mechanical strength, high thermal shock resistance and high adsorption / desorption performance by using a specific organic-inorganic hybrid binder and a skewed parallelepiped irregular structure, which has excellent adsorption capacity and desorption efficiency for styrene;

[0022] 2. This invention employs an organic-inorganic hybrid binder, which forms a stable siloxane-aluminoxane inorganic network framework through the hydrolytic condensation of tetraethyl orthosilicate and aluminum isopropoxide. Simultaneously, it grafts amino polyether segments and long-chain alkyl silane segments, achieving a synergistic effect of strong support from the inorganic framework and strong affinity from the organic segments. This not only enhances the adsorption affinity but also reduces the binding energy between pollutant molecules and the zeolite surface, resulting in a desorption efficiency of 89.7%–90.5%, significantly higher than that of traditional products. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the irregular honeycomb zeolite in this invention;

[0024] Figure 2 This is a photograph of the irregular honeycomb zeolite prepared in Example 1 of this invention.

[0025] In the diagram: 100, irregular honeycomb zeolite; 101, end face; 102, vertical side; 103, inclined side; 104, airflow channel. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] This invention provides an irregularly shaped honeycomb zeolite, which is an oblique parallelepiped and includes a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. Several through-flow channels are formed on the inclined side faces, arranged in a honeycomb pattern and with their through-flow direction parallel to the vertical side faces. The angle α between the inclined side faces and the end faces is 72°. o The cross-sectional shape of the airflow channel is rectangular, the aperture of the airflow channel is 2.5 mm, and the wall thickness of adjacent airflow channels is 1.5 mm.

[0029] The irregular honeycomb zeolite is prepared by mixing, extruding, drying, and calcining raw materials comprising the following parts by weight: 40 parts ZSM-5 zeolite, 18 parts mordenite zeolite, 15 parts organic-inorganic hybrid binder, 4 parts pore-forming agent, and 23 parts deionized water. The pore-forming agent is ammonium bicarbonate.

[0030] The organic-inorganic hybrid binder comprises a siloxane-aluminoxane inorganic network framework formed by hydrolysis and condensation, and organic functional segments grafted onto the siloxane-aluminoxane inorganic network framework via chemical bonds. These organic functional segments include amino polyether segments and long-chain alkyl silane segments. In the organic-inorganic hybrid binder, the precursors of the siloxane-aluminoxane inorganic network framework are tetraethyl orthosilicate and aluminum isopropoxide. The raw materials for the organic functional segments include amino polyether silanes and long-chain alkyl silanes. The amino polyether silane is compounded from silane coupling agent KH-580 and polyether amine D230 at a mass ratio of 1:1.2. The long-chain alkyl silane is dodecyltrimethoxysilane. Specifically, the organic-inorganic hybrid binder is made from the following components in parts by weight: 37 parts tetraethyl orthosilicate, 10 parts aluminum isopropoxide, 14 parts amino polyether silane, 4 parts dodecyltrimethoxysilane, 2 parts polyethylene glycol, and 33 parts 0.1 mol / L aqueous acetic acid solution.

[0031] The preparation method of the organic-inorganic hybrid binder includes the following steps: (a) slowly adding tetraethyl orthosilicate and aluminum isopropoxide to a 0.1 mol / L aqueous acetic acid solution, stirring at 270 r / min for 45 min at 22℃ to prepare an inorganic precursor solution; (b) heating the inorganic precursor solution to 51℃, adding amino polyether silane, dodecyltrimethoxysilane and polyethylene glycol in sequence, keeping warm and stirring at 270 r / min for 105 min to prepare a silicon-aluminum composite material; (c) cooling the silicon-aluminum composite material to room temperature, sealing and curing for 15 h to obtain the organic-inorganic hybrid binder.

[0032] This invention also discloses a method for preparing the above-mentioned irregular honeycomb zeolite, comprising the following steps:

[0033] S1. Mixing: Weigh out ZSM-5 zeolite, mordenite, organic-inorganic hybrid binder, pore-forming agent and deionized water according to the proportion, stir at 400 r / min for 90 min to prepare the blank.

[0034] S2. Extrusion molding: The preform is added into a mold adapted to the oblique parallelepiped structure and extruded. The extrusion pressure is 6 MPa and the extrusion rate is 7 mm / s to produce a special-shaped honeycomb preform.

[0035] S3. Drying: The irregular honeycomb blank is subjected to the first stage of drying and the second stage of drying in sequence. The conditions for the first stage of drying are: temperature 40℃ and time 13 h. The conditions for the second stage of drying are: temperature 50℃ and time 10 h.

[0036] S4. Calcination: The dried irregular honeycomb blank is calcined at 550℃ for 2 hours and then cooled to room temperature to obtain irregular honeycomb zeolite.

[0037] Example 2

[0038] This invention provides an irregularly shaped honeycomb zeolite, which is an oblique parallelepiped and includes a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. Several through-flow channels are formed on the inclined side faces, arranged in a honeycomb pattern and with their through-flow direction parallel to the vertical side faces. The angle α between the inclined side faces and the end faces satisfies 30°. o The cross-sectional shape of the airflow channel is rectangular, the diameter of the airflow channel is 5 mm, and the wall thickness of adjacent airflow channels is 1 mm.

[0039] The irregular honeycomb zeolite is prepared by mixing, extruding, drying, and calcining raw materials comprising the following parts by weight: 45 parts ZSM-5 zeolite, 16 parts mordenite zeolite, 12 parts organic-inorganic hybrid binder, 4 parts pore-forming agent, and 23 parts deionized water. The pore-forming agent is ammonium bicarbonate.

[0040] The organic-inorganic hybrid binder comprises a siloxane-aluminoxane inorganic network framework formed by hydrolysis and condensation, and organic functional segments grafted onto the siloxane-aluminoxane inorganic network framework via chemical bonds. These organic functional segments include amino polyether segments and long-chain alkyl silane segments. In the organic-inorganic hybrid binder, the precursors of the siloxane-aluminoxane inorganic network framework are tetraethyl orthosilicate and aluminum isopropoxide. The raw materials for the organic functional segments include amino polyether silanes and long-chain alkyl silanes. The amino polyether silane is compounded from silane coupling agent KH-580 and polyether amine D230 at a mass ratio of 1:1.5. The long-chain alkyl silane is dodecyltrimethoxysilane. Specifically, the organic-inorganic hybrid binder is made from the following components in parts by weight: 38 parts tetraethyl orthosilicate, 12 parts aluminum isopropoxide, 13 parts amino polyether silane, 3 parts dodecyltrimethoxysilane, 3 parts polyethylene glycol, and 31 parts 0.1 mol / L aqueous acetic acid solution.

[0041] The preparation method of the organic-inorganic hybrid binder includes the following steps: (a) slowly adding tetraethyl orthosilicate and aluminum isopropoxide to a 0.1 mol / L aqueous acetic acid solution, stirring at 240 r / min for 30 min at 25°C to prepare an inorganic precursor solution; (b) heating the inorganic precursor solution to 52°C, adding amino polyether silane, dodecyltrimethoxysilane and polyethylene glycol in sequence, keeping warm and stirring at 300 r / min for 90 min to prepare a silicon-aluminum composite material; (c) cooling the silicon-aluminum composite material to room temperature, sealing and curing for 18 h to obtain the organic-inorganic hybrid binder.

[0042] This invention also discloses a method for preparing the above-mentioned irregular honeycomb zeolite, comprising the following steps:

[0043] S1. Mixing: Weigh ZSM-5 zeolite, mordenite, organic-inorganic hybrid binder, pore-forming agent and deionized water according to the proportion, stir at 500 r / min for 60 min to prepare the blank.

[0044] S2. Extrusion molding: The preform is added into a mold adapted to the oblique parallelepiped structure and extruded. The extrusion pressure is 5 MPa and the extrusion rate is 5 mm / s to produce a special-shaped honeycomb preform.

[0045] S3. Drying: The irregular honeycomb blank is subjected to the first stage of drying and the second stage of drying in sequence. The conditions for the first stage of drying are: temperature 45℃ and time 10 h. The conditions for the second stage of drying are: temperature 55℃ and time 8 h.

[0046] S4. Calcination: The dried irregular honeycomb blank is calcined at 550℃ for 3 hours and then cooled to room temperature to obtain irregular honeycomb zeolite.

[0047] Example 3

[0048] This invention provides an irregularly shaped honeycomb zeolite, which is an oblique parallelepiped and includes a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. Several through-flow channels are formed on the inclined side faces, arranged in a honeycomb pattern and with their through-flow direction parallel to the vertical side faces. The angle α between the inclined side faces and the end faces is 80°. o The cross-sectional shape of the airflow channel is rectangular, the diameter of the airflow channel is 1 mm, and the wall thickness of adjacent airflow channels is 2 mm.

[0049] The irregular honeycomb zeolite is prepared by mixing, extruding, drying, and calcining raw materials comprising the following parts by weight: 38 parts ZSM-5 zeolite, 19 parts mordenite zeolite, 20 parts organic-inorganic hybrid binder, 3 parts pore-forming agent, and 20 parts deionized water. The pore-forming agent is starch.

[0050] The organic-inorganic hybrid binder comprises a siloxane-aluminoxane inorganic network framework formed by hydrolysis and condensation, and organic functional segments grafted onto the siloxane-aluminoxane inorganic network framework via chemical bonds. These organic functional segments include amino polyether segments and long-chain alkyl silane segments. In the organic-inorganic hybrid binder, the precursors of the siloxane-aluminoxane inorganic network framework are tetraethyl orthosilicate and aluminum isopropoxide. The raw materials for the organic functional segments include amino polyether silanes and long-chain alkyl silanes. The amino polyether silane is prepared by compounding silane coupling agent KH-580 and polyether amine D230 in a 1:1 mass ratio. The long-chain alkyl silane is dodecyltrimethoxysilane. Specifically, the organic-inorganic hybrid binder is made from the following components in parts by weight: 33 parts tetraethyl orthosilicate, 11 parts aluminum isopropoxide, 15 parts amino polyether silane, 4 parts dodecyltrimethoxysilane, 3 parts polyethylene glycol, and 34 parts 0.1 mol / L aqueous acetic acid solution.

[0051] The preparation method of the organic-inorganic hybrid binder includes the following steps: (a) slowly adding tetraethyl orthosilicate and aluminum isopropoxide to a 0.1 mol / L aqueous acetic acid solution, stirring at 240 r / min for 60 min at 20 °C to prepare an inorganic precursor solution; (b) heating the inorganic precursor solution to 50 °C, adding amino polyether silane, dodecyltrimethoxysilane and polyethylene glycol in sequence, keeping warm and stirring at 240 r / min for 120 min to prepare a silicon-aluminum composite material; (c) cooling the silicon-aluminum composite material to room temperature, sealing and curing for 12 h to obtain the organic-inorganic hybrid binder.

[0052] This invention also discloses a method for preparing the above-mentioned irregular honeycomb zeolite, comprising the following steps:

[0053] S1. Mixing: Weigh ZSM-5 zeolite, mordenite, organic-inorganic hybrid binder, pore-forming agent and deionized water according to the proportion, stir at 300 r / min for 120 min to prepare the blank.

[0054] S2. Extrusion molding: The blank is added into a mold adapted to the oblique parallelepiped structure and extruded. The extrusion pressure is 8 MPa and the extrusion rate is 10 mm / s to produce a special-shaped honeycomb blank.

[0055] S3. Drying: The irregular honeycomb blank is subjected to the first stage of drying and the second stage of drying in sequence. The conditions for the first stage of drying are: temperature 35℃ and time 15 h. The conditions for the second stage of drying are: temperature 45℃ and time 12 h.

[0056] S4. Calcination: The dried irregular honeycomb blank is calcined at 550℃ for 3 hours and then cooled to room temperature to obtain irregular honeycomb zeolite.

[0057] Example 4

[0058] This invention provides an irregularly shaped honeycomb zeolite, which is an oblique parallelepiped and includes a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. Several through-flow channels are formed on the inclined side faces, arranged in a honeycomb pattern and with their through-flow direction parallel to the vertical side faces. The angle α between the inclined side faces and the end faces is 45°. o The cross-sectional shape of the airflow channel is rectangular, the diameter of the airflow channel is 2 mm, and the wall thickness of the adjacent airflow channels is 1.5 mm.

[0059] The irregular honeycomb zeolite is prepared by mixing, extruding, drying, and calcining raw materials comprising the following parts by weight: 39 parts ZSM-5 zeolite, 17 parts mordenite, 13 parts organic-inorganic hybrid binder, 6 parts pore-forming agent, and 25 parts deionized water. The pore-forming agent is starch.

[0060] The organic-inorganic hybrid binder comprises a siloxane-aluminoxane inorganic network framework formed by hydrolysis and condensation, and organic functional segments grafted onto the siloxane-aluminoxane inorganic network framework via chemical bonds. These organic functional segments include amino polyether segments and long-chain alkyl silane segments. In the organic-inorganic hybrid binder, the precursors of the siloxane-aluminoxane inorganic network framework are tetraethyl orthosilicate and aluminum isopropoxide. The raw materials for the organic functional segments include amino polyether silanes and long-chain alkyl silanes. The amino polyether silane is compounded from silane coupling agent KH-580 and polyether amine D230 at a mass ratio of 1:1.3. The long-chain alkyl silane is dodecyltrimethoxysilane. Specifically, the organic-inorganic hybrid binder is made from the following components in parts by weight: 36 parts tetraethyl orthosilicate, 11 parts aluminum isopropoxide, 14 parts amino polyether silane, 5 parts dodecyltrimethoxysilane, 2 parts polyethylene glycol, and 32 parts 0.1 mol / L aqueous acetic acid solution.

[0061] The preparation method of the organic-inorganic hybrid binder includes the following steps: (a) slowly adding tetraethyl orthosilicate and aluminum isopropoxide to a 0.1 mol / L aqueous acetic acid solution, stirring at 250 r / min for 50 min at 24 °C to prepare an inorganic precursor solution; (b) heating the inorganic precursor solution to 51 °C, adding amino polyether silane, dodecyltrimethoxysilane and polyethylene glycol in sequence, keeping warm and stirring at 250 r / min for 110 min to prepare a silicon-aluminum composite material; (c) cooling the silicon-aluminum composite material to room temperature, sealing and curing for 16 h to obtain the organic-inorganic hybrid binder.

[0062] This invention also discloses a method for preparing the above-mentioned irregular honeycomb zeolite, comprising the following steps:

[0063] S1. Mixing: Weigh out ZSM-5 zeolite, mordenite, organic-inorganic hybrid binder, pore-forming agent and deionized water according to the proportion, stir at 400 r / min for 90 min to prepare the blank.

[0064] S2. Extrusion molding: The blank is added into a mold adapted to the oblique parallelepiped structure and extruded. The extrusion pressure is 7 MPa and the extrusion rate is 8 mm / s to produce a special-shaped honeycomb blank.

[0065] S3. Drying: The irregular honeycomb blank is subjected to the first stage of drying and the second stage of drying in sequence. The conditions for the first stage of drying are: temperature 40℃ and time 12 h. The conditions for the second stage of drying are: temperature 50℃ and time 10 h.

[0066] S4. Calcination: The dried irregular honeycomb blank is calcined at 550℃ for 2 hours and then cooled to room temperature to obtain irregular honeycomb zeolite.

[0067] In Examples 1-4, the specific surface area of ​​ZSM-5 zeolite was 400-500 m². 2 / g, and its average pore size is 0.55nm; the specific surface area of ​​mordenite is 200-300 m² / g. 2 / g, and its average pore size is 0.67 nm; the particle size D90 of the pore-forming agent is 5-25 μm.

[0068] Example 5

[0069] It is basically the same as Example 1, except that the cross-sectional shape of the airflow channel is circular.

[0070] Example 6

[0071] It is basically the same as Example 1, except that the cross-sectional shape of the airflow channel is a regular hexagon.

[0072] Comparative Example 1

[0073] The example is basically the same as Example 1, except that silica sol is used instead of organic-inorganic hybrid binder. The silica sol is provided by Jinan Mingrun Chemical Co., Ltd. and has an effective ingredient content of 40%.

[0074] Comparative Example 2

[0075] The results are essentially the same as in Example 1, except that aluminum sol is used instead of the organic-inorganic hybrid binder. The aluminum sol was provided by Yangzhou Zhongtianli New Material Co., Ltd., and the effective ingredient content is 20%.

[0076] Comparative Example 3

[0077] It is basically the same as Example 1, except that the organic-inorganic hybrid binder is replaced by a mixture, which is made by a simple physical mixing of the raw materials of the organic-inorganic hybrid binder.

[0078] Comparative Example 4

[0079] The process is basically the same as in Example 1, except that in S2 the blank is added into a mold with a suitable cuboid structure to prepare a porous zeolite in the shape of a cuboid. The airflow channel parameters of the porous zeolite are the same as those in Example 1.

[0080] Experimental Example 1: Determination of amino density

[0081] Samples and reagents: The organic-inorganic hybrid binders prepared in Examples 1-4 were used as samples; freshly prepared ethanol-water mixed solvent (mass ratio 1:1); freshly prepared 0.1 mol / L hydrochloric acid standard solution; freshly prepared 0.1 mol / L sodium hydroxide standard solution.

[0082] Experimental steps:

[0083] 1. Sample preparation: Dry the sample in an oven to constant weight, accurately weigh 1.00 g and place it in a 150 mL beaker, add 100 mL of ethanol-water mixed solvent, and stir magnetically until the sample is completely and evenly dispersed.

[0084] 2. Acidification treatment: Accurately transfer 20.00 mL of hydrochloric acid standard solution using a pipette, slowly inject it into the sample solution, and continuously stir the reaction for 10 min to ensure complete amino protonation.

[0085] 3. Potentiometric titration: Immerse the pH meter electrode in the solution and slowly titrate with sodium hydroxide standard solution, monitoring the pH change in real time. Stop titrating when pH=4.5 (the characteristic endpoint of amino group) and record the volume consumed V1 (accurate to 0.01 mL).

[0086] 4. Blank test: Take another 500 mL clean beaker, add 100 mL of ethanol-water mixed solvent and 20.00 mL of hydrochloric acid standard solution in sequence, and titrate with sodium hydroxide standard solution to pH=4.5 under the same conditions, and record the blank consumption volume V0 (accurate to 0.01 mL).

[0087] 5. Calculation of Results: The amino density is calculated using the following formula:

[0088]

[0089] In the formula: C HCl V represents the concentration of the hydrochloric acid standard solution. HCl The volume (mL) of hydrochloric acid added is C NaOH m1 represents the concentration of the NaOH standard solution, and m1 represents the sample mass (g).

[0090] The results are recorded in Table 1.

[0091] Experimental Example 2: Determination of Residual Mass

[0092] Samples: The organic-inorganic hybrid binders prepared in Examples 1 to 4 were used as samples.

[0093] Experimental steps:

[0094] 1. Crucible constant weight: Place a clean, empty crucible in a muffle furnace and calcine at 550°C for 1 hour. After removal, cool to room temperature in a desiccator and weigh it, recording the weight as W (accurate to 0.0001 g). Repeat the calcination, cooling, and weighing steps until constant weight is achieved (the difference between two weighings ≤ 0.3 mg).

[0095] 2. Sample drying: Dry the sample in an oven at 105℃ until constant weight (the difference between two weighings ≤ 0.3 mg).

[0096] 3. Sample weighing: Weigh approximately 1.0 g of the dried sample and transfer it to a pre-weighed crucible. Record the mass m1 (accurate to 0.0001 g).

[0097] 4. High-temperature calcination: Place the crucible containing the sample into a muffle furnace, heat it to 550℃, and calcine at a constant temperature for 2 hours.

[0098] 5. Cooling and weighing: After ignition, quickly transfer the crucible to a desiccator to cool to room temperature, and weigh it as m2 (accurate to 0.0001 g).

[0099] 6. Result Calculation: The residual rate is calculated using the following formula:

[0100]

[0101] The results are recorded in Table 1.

[0102] Table 1 Results of amino density and mass residue determination

[0103]

[0104] Table 1 shows that the organic-inorganic hybrid binders prepared in Examples 1-4 possess both high-density amino loading and excellent thermal stability. The amino density ≥1.96 mmol / g indicates that a large amount of amino polyether silane was successfully grafted onto the inorganic framework via efficient hydrolysis-condensation reactions, forming Si-O-Si or Si-O-Al covalent bonds, rather than through physical mixing. The residual mass after calcination at 550℃ for 2 h was ≥95.2%, indicating that the inorganic framework (siloxane-aluminoxane network) structure is highly stable. The small mass loss mainly comes from the decomposition of unstable parts in the organic segments. This decomposition can generate micropores, further enhancing adsorption performance. In summary, the organic-inorganic hybrid binder exhibits stable physicochemical properties, fully withstands the preparation conditions of irregular honeycomb zeolites, and ensures the integrity of the final product's structure and function.

[0105] Test Example 3: Strength Test of Irregularly Shaped Honeycomb Zeolite

[0106] 1. Axial / radial compressive strength determination:

[0107] The irregularly shaped honeycomb zeolites prepared in Examples 1-6, Comparative Examples 1-3, and the porous zeolite in Comparative Example 4 were cut into cubes with a side length of 10 cm along the direction perpendicular to the airflow channel. Following the method disclosed in GB / T 1964-2023 "Test Method for Compressive Strength of Porous Ceramics at Room Temperature", the specimens were placed in the center of the pressure plate of a universal testing machine. During axial compressive strength testing, the pressure was applied perpendicularly to the direction of the airflow channel extension; during radial testing, the specimen was placed on its side, and the pressure was perpendicular to the direction outside the airflow channel. Loading was applied at a rate of 1 mm / min until the specimen failed, and the maximum load was recorded as F. The compressive strength was calculated using the formula σ=F / A (where A is the area of ​​force application), and the results were recorded in Table 2.

[0108] 2. Thermal shock resistance test:

[0109] Sample preparation was the same as above. Referring to ASTM C1525-18, "Standard Test Method for Determination of Thermal Shock Resistance of Advanced Ceramics by Water Quenching," the initial radial compressive strength σ1 of each group of samples was first determined; then, samples from the same batch were subjected to 10 thermal shock cycles (at room temperature). (After water quenching at 600℃), the radial compressive strength σ2 was measured again. The strength retention rate R = σ2 / σ1 × 100% was calculated, and the results were recorded in Table 2.

[0110] Table 2 Strength Test Results

[0111]

[0112] As shown in Table 2, Examples 1-6 use organic-inorganic hybrid binders, which have strong adhesion and excellent thermal stability. Therefore, their axial / radial compressive strengths are all in the range of 13.1-13.9 MPa and 10.9-11.6 MPa, respectively, and their thermal shock resistance retention rate is 86.9%-88.5%. Among them, Examples 5 (circular airflow channel) and Examples 6 (regular hexagonal airflow channel) have slightly higher compressive strength and strength retention rate than other examples because their structures are more uniformly stressed.

[0113] Comparative Examples 1 and 2 used single silica sol or alumina sol as binders. Due to the lack of flexible support and chemical bonding of organic segments, the interfacial bonding strength was insufficient, and their compressive strength and strength retention rate were significantly lower than those of the Examples. Comparative Example 3 used raw materials of an organic-inorganic hybrid binder for simple physical mixing, which did not form a continuous inorganic network skeleton. The components were only bonded by physical adsorption, resulting in poor mechanical properties and thermal shock resistance. Comparative Example 4 had the same formulation as Example 1. Although the overall structure was different, the compressive strength and strength retention rate were similar, indicating that the type of binder is the core factor determining the mechanical properties and thermal stability of the material.

[0114] Experimental Example 4: Elution and Desorption Test of Irregularly Shaped Honeycomb Zeolite

[0115] Experimental Procedure: Irregularly shaped honeycomb zeolites prepared in Examples 1-6 and Comparative Examples 1-3, as well as porous zeolite prepared in Comparative Example 4, were used as samples. A dynamic gas mixing system was employed, using clean air as the background gas. The vaporization rate of liquid styrene was precisely controlled by an injection pump to prepare a styrene / air mixture with a concentration of 500 ppm (v / v). The sample to be tested was fixed in an adsorption tube, and the mixed gas was introduced for dynamic adsorption at a flow rate of 1 L / min. The outlet gas concentration was monitored in real time, and the relationship between adsorption amount and time was recorded. When the outlet styrene concentration reached 10% of the inlet concentration, adsorption was considered saturated. The total adsorption time was recorded, and the adsorption amount was obtained by integrating the adsorption amount versus time curve. The results are recorded in Table 3.

[0116] After adsorption saturation, the flow rate was switched to a high-purity nitrogen gas stream at 200℃ (0.5 L / min), and the saturated sample was desorbed by programmed temperature purging for 1 h. The styrene concentration in the desorbed gas was monitored online using a gas chromatograph, and the desorption amount versus time curve was recorded and the total desorption amount was calculated cumulatively. The results are recorded in Table 3.

[0117] The desorption efficiency was obtained by calculating the ratio of adsorption to desorption. The results are recorded in Table 3.

[0118] Table 3 Results of Elution and Desorption Tests

[0119]

[0120] As shown in Table 3, the irregular honeycomb zeolites prepared in Examples 1-6 all exhibited high adsorption and desorption efficiencies for styrene (all exceeding 89%). This superior performance is mainly attributed to the dual effect of the organic-inorganic hybrid binder: firstly, the amino polyether segments in its molecular structure can weakly interact with styrene molecules through amino groups, while the long-chain alkyl silane segments, with their hydrophobic and oleophilic properties, generate strong van der Waals forces with hydrophobic styrene molecules. These two factors synergistically enhance the adsorption affinity of the zeolite surface for the target molecules. Secondly, the organic components in the organic-inorganic hybrid binder undergo partial decomposition during calcination at 550℃, thereby creating abundant micropores in situ within the robust siloxane-aluminoxane inorganic framework. This not only increases the specific surface area of ​​the material but also provides a large number of accessible adsorption sites for styrene molecules. In contrast, Comparative Examples 1-3 showed significantly reduced adsorption and desorption efficiencies due to insufficient binder performance. The adsorption capacity and desorption efficiency of Comparative Example 4 were lower than those of Example 1. This was because the differences in the overall structure or the distribution of the airflow channels affected the mass transfer efficiency. Comparative Examples 1 to 3 showed a significant decrease, which was due to the insufficient performance of the binder or the differences in the overall structure affecting the mass transfer efficiency.

[0121] The irregular honeycomb zeolite and its preparation method provided by this invention, by using a specific organic-inorganic hybrid binder and an oblique parallelepiped irregular structure, successfully prepared an irregular honeycomb zeolite with excellent mechanical strength, high thermal shock resistance and efficient adsorption / desorption performance. Its comprehensive performance is significantly better than that of products with traditional formulations and structures.

[0122] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A type of irregularly shaped honeycomb zeolite, characterized in that: The irregular honeycomb zeolite is an oblique parallelepiped, and it includes a pair of parallel end faces, a pair of vertical side faces perpendicular to the end faces, and a pair of inclined side faces perpendicular to the vertical side faces. Several through airflow channels are opened on the inclined side faces. The airflow channels are arranged in a honeycomb pattern and their through direction is parallel to the vertical side faces. The irregular honeycomb zeolite is prepared by mixing, extruding, drying and calcining raw materials containing the following parts by weight: 38-45 parts of ZSM-5 zeolite, 16-19 parts of mordenite, 12-20 parts of organic-inorganic hybrid binder, 3-6 parts of pore-forming agent and 20-25 parts of deionized water. The specific surface area of ​​the ZSM-5 zeolite is 400–500 m². 2 / g, and its average pore size is 0.55 nm; the specific surface area of ​​the mordenite is 200-300 m² / g. 2 / g, and its average pore size is 0.67 nm; the organic-inorganic hybrid binder includes a siloxane-aluminoxane inorganic network framework formed by hydrolysis condensation, and organic functional segments grafted onto the siloxane-aluminoxane inorganic network framework by chemical bonds, the organic functional segments including amino polyether segments and long-chain alkyl silane segments.

2. The irregular honeycomb zeolite according to claim 1, characterized in that: The angle α between the inclined side and the end face satisfies: 30° o ≤α≤80 o .

3. The irregular honeycomb zeolite according to claim 1, characterized in that: The cross-sectional shape of the airflow channel is rectangular, circular, or regular hexagonal, the aperture of the airflow channel is 1 to 5 mm, and the wall thickness of adjacent airflow channels is 1 to 2 mm.

4. The irregular honeycomb zeolite according to claim 1, characterized in that: In the organic-inorganic hybrid binder, the precursors of the siloxane-aluminoxane inorganic network skeleton are tetraethyl orthosilicate and aluminum isopropoxide, and the raw materials of the organic functional segments include amino polyether silane and long-chain alkyl silane. The amino polyether silane is compounded by silane coupling agent KH-580 and polyether amine D230 in a mass ratio of 1:1 to 1:1.

5. The long-chain alkyl silane is dodecyltrimethoxysilane.

5. The irregular honeycomb zeolite according to claim 4, characterized in that: The organic-inorganic hybrid binder is made from the following components in parts by weight: 33-38 parts of tetraethyl orthosilicate, 10-12 parts of aluminum isopropoxide, 13-15 parts of amino polyether silane, 3-5 parts of dodecyltrimethoxysilane, 2-3 parts of polyethylene glycol, and 31-34 parts of 0.1 mol / L aqueous acetic acid solution. The preparation method of the organic-inorganic hybrid binder includes the following steps: (a) slowly adding tetraethyl orthosilicate and aluminum isopropoxide to a 0.1 mol / L aqueous acetic acid solution, stirring at 240-300 r / min for 30-60 min at 20-25°C to prepare an inorganic precursor solution; (b) heating the inorganic precursor solution to 50-52°C, adding amino polyether silane, dodecyltrimethoxysilane and polyethylene glycol in sequence, keeping warm and stirring at 240-300 r / min for 90-120 min to prepare a silicon-aluminum composite material; (c) cooling the silicon-aluminum composite material to room temperature, sealing and aging for 12-18 h to obtain the organic-inorganic hybrid binder.

6. The irregular honeycomb zeolite according to claim 1, characterized in that: The organic-inorganic hybrid binder has an amino density ≥1.96 mmol / g and a mass residue rate of not less than 95.2% after calcination at 550℃ for 2 h.

7. The irregular honeycomb zeolite according to claim 1, characterized in that: The pore-forming agent is ammonium bicarbonate or starch, with a particle size D90 of 5–25 μm.

8. A method for preparing irregularly shaped honeycomb zeolite as described in any one of claims 1 to 7, characterized in that: Includes the following steps: S1. Mixing: Weigh out ZSM-5 zeolite, mordenite, organic-inorganic hybrid binder, pore-forming agent and deionized water in proportion, stir at 300-500 r / min for 60-120 min to prepare a blank; S2. Extrusion molding: The preform is added into a mold adapted to the oblique parallelepiped structure and extruded. The extrusion pressure is 5-8 MPa and the extrusion rate is 5-10 mm / s to produce a special-shaped honeycomb preform. S3. Drying: The irregular honeycomb blank is subjected to the first stage of drying and the second stage of drying in sequence. The conditions for the first stage of drying are: temperature 35-45℃, time 10-15 h, and the conditions for the second stage of drying are: temperature 45-55℃, time 8-12 h. S4. Calcination: The dried shaped honeycomb blank is calcined at 550°C for 1-3 hours and cooled to room temperature to obtain the shaped honeycomb zeolite.

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