Ordered mesoporous polypyridine-Schiff base framework material for gaseous sulfide catalysis as well as preparation method and application of ordered mesoporous polypyridine-Schiff base framework material

Abstract

The invention relates to an ordered mesoporous polypyridine-Schiff base framework material for gaseous sulfide catalysis as well as a preparation method and application of the ordered mesoporous polypyridine-Schiff base framework material. The method adopts a mechanochemical synthesis strategy and comprises the following steps: firstly, grinding to realize uniform dispersion of medicines; then, a template agent is introduced for directional assembly; performing low-temperature curing to obtain a polymer with a regular mesoscopic pore channel structure; and finally performing high-temperature carbonization on the polymer to obtain the framework material. By adopting a solid-phase hot-melting self-assembly technology, the limitation of a traditional phenolic resin route in the field of nitrogen-doped ordered mesoporous polymer design is broken through. The strong interaction between the nitrogen-containing precursor and the block copolymer template ensures the formation of an ordered mesoporous structure, and the copolymerization reaction between ligands constructs a stable polypyridine-Schiff base framework material. The nitrogen-doped ordered mesoporous carbon material of the obtained polymer material has barrier-free through mesoporous channels and ultrahigh nitrogen content, and is endowed with excellent performance for catalytic removal of gaseous sulfides.

Description

Technical Field:

[0001] The present invention belongs to the technical field of organic materials, and particularly relates to an ordered mesoporous polypyridine-Schiff base framework material for catalytic oxidation of gaseous sulfides, a preparation method thereof, and an application thereof. Background Art:

[0002] With the increasing shortage of non-renewable energy and the continuous improvement of global environmental protection standards, natural gas resources with economic, safe, and environmentally friendly characteristics are becoming the key development targets of national energy strategies. However, whether as a civil fuel or an industrial raw material, gaseous sulfides (COS and H2S) commonly present in natural gas can cause multiple problems. Their corrosiveness not only accelerates the loss of equipment and pipelines but also leads to catalyst poisoning effects. At the same time, the sulfur dioxide emissions generated after the oxidation of gaseous sulfides will form air pollution. In view of China's full-process control standards for natural gas quality, the development of efficient desulfurization technologies has become the key breakthrough point for realizing the safe utilization of clean energy, reducing operating costs, and meeting environmental protection regulations, which has important practical significance for promoting the sustainable development of the natural gas industry.

[0003] Currently, the natural gas desulfurization technologies applied in industry mainly include amine methods, solid adsorption methods, and biological desulfurization methods, etc. The amine method chemically absorbs gaseous sulfides through an organic amine solution. Although it has high desulfurization efficiency and mature technology, it has problems such as high regeneration energy consumption and secondary pollution caused by amine solution degradation products. The solid adsorption method uses iron oxide, activated carbon, etc. as the adsorption medium. Although the equipment is simple and the cost is low, its sulfur capacity is limited and the regeneration performance decays quickly, making it difficult to meet the requirements of continuous large-scale desulfurization. In contrast, the catalytic desulfurization technology directly converts gaseous sulfides into elemental sulfur, which has advantages such as easy product recovery and no secondary pollution, but its performance highly depends on the development of the catalyst system.

[0004] In the field of catalytic oxidation desulfurization, traditional catalyst systems mainly include transition metal oxides (such as Fe2O3, CuO, MnO2, etc.), supported activated carbon, and molecular sieve materials. Although transition metal oxide catalysts have high oxidation activity, their active components are easily deactivated due to sulfur deposition or high-temperature sintering, and sulfate by-products are easily generated during the reaction, resulting in pore blockage. Although activated carbon-based catalysts have a rich pore structure, it is difficult to regulate their surface chemical properties, and the distribution of nitrogen and oxygen functional groups is uneven, resulting in low sulfur selectivity. Although molecular sieve materials can improve the reaction selectivity through the confinement effect, their microporous structure is easily blocked by sulfur particles, and the acidic sites are prone to cause excessive oxidation of H2S to generate SO2.

[0005] In contrast, metal-free nitrogen-doped carbon-based catalysts have attracted much attention due to their good sulfur resistance, excellent hydrothermal stability and catalytic activity. The COS hydrolysis reaction and the selective oxidation reaction of H2S require that the nitrogen-doped carbon catalyst has both a high nitrogen content and an orderly expanded mesoporous structure to achieve optimal performance. The structure-activity relationship can be summarized as follows: on the one hand, nitrogen atoms (especially pyridine nitrogen and pyrrole nitrogen with lone pair electrons) can act as active sites to promote the adsorption, activation and dissociation of gaseous sulfides, and then drive their selective conversion into elemental sulfur; on the other hand, the orderly mesoporous structure can provide an unobstructed diffusion channel for viscous polysulfide products, avoiding pore blockage and coverage of nitrogen active sites. However, in the design of orderly mesoporous catalysts, it is difficult to balance the nitrogen doping level and the orderly mesoporous structure, and this contradictory problem has not been effectively solved.

[0006] Based on this, this patent proposes a green and simple method for preparing an orderly mesoporous polypyridine-Schiff base framework and its derived carbon materials for the catalytic removal and resource utilization of gaseous sulfides. In this study, an orderly mesoporous polypyridine-Schiff base framework material with a nitrogen content of 19.3 wt% was successfully constructed, getting rid of the evaporation-induced self-assembly route relying on the chemical guidance of novolac resin in the design process of traditional orderly mesoporous materials. It is realized by the solid-phase hot-melt self-assembly strategy of block copolymer template, 2,6-diaminopyridine (DAP) monomer and terephthalaldehyde cross-linking agent, and has the ability of kilogram-scale production to meet the industrial requirements. The core breakthrough of this technology lies in the dual function of the DAP monomer: it not only ensures the self-assembly of the F127 template to form orderly mesopores through strong interactions, but also copolymerizes with terephthalaldehyde to construct a stable polypyridine-Schiff base framework. This characteristic firmly anchors nitrogen atoms in the polymer network, showing the lowest nitrogen loss rate during the template removal calcination and carbonization preparation processes, thus increasing the nitrogen content in the orderly mesoporous material and being not prone to sulfation during the catalytic process of gaseous sulfides. Summary of the Invention: The present invention aims at the key technical problems existing in the catalysts in the traditional natural gas desulfurization process, such as complex synthesis process, easy pore blockage, low sulfur selectivity and poor stability, etc., and provides an orderly mesoporous polypyridine-Schiff base framework material for catalytic use of gaseous sulfides, its preparation method and application. The orderly mesoporous polypyridine-Schiff base framework material prepared by the present invention uses aldehyde substances, 2,6-diaminopyridine and a template agent as basic raw materials, and obtains an orderly mesoporous polypyridine-Schiff base framework and its derived carbon materials through technological processes such as mechanical mixing, low-temperature curing and nitrogen roasting. The present invention not only has innovation in the technical route, with mild reaction conditions, fast reaction kinetics and excellent repeatability; moreover, the prepared material has a mesoporous structure, solves the industrial problem of catalyst poisoning caused by sulfur blockage, and provides a new solution idea for the low-cost and high-efficiency preparation of catalysts for gaseous sulfide removal.

[0008] To achieve the above object, the present invention adopts the following technical solutions: A preparation method of an ordered mesoporous polypyridine-Schiff base framework material for gaseous sulfide catalysis, which mechanically mixes an aldehyde compound, 2,6-diaminopyridine and a template agent in a certain proportion, transfers the sample to a polytetrafluoroethylene inner liner, and then puts the whole inner liner into an oven for curing reaction. After the curing is completed, the template agent is removed in a nitrogen atmosphere to obtain a primary product with a two-dimensional hexagonal mesoporous structure; the primary product is subjected to high-temperature carbonization to obtain an ordered mesoporous polypyridine-Schiff base framework material for gaseous sulfide catalytic removal and resource utilization.

[0009] The above preparation method of an ordered mesoporous polypyridine-Schiff base framework material for gaseous sulfide catalysis includes the following steps: (1) Mix an aldehyde compound, 2,6-diaminopyridine and a template agent according to a certain molar ratio, and grind them evenly in a mortar; (2) After grinding, transfer it to a polytetrafluoroethylene inner liner reaction kettle, and put the whole inner liner into an oven for curing reaction; (3) Remove the template agent from the cured sample in a nitrogen atmosphere; (4) Calcinate and carbonize the obtained polymer in a nitrogen atmosphere; The aldehyde compound described in the above step (1) includes glyoxal, paraformaldehyde, paraformaldehyde or terephthalaldehyde.

[0010] The template agent described in the above step (1) is any one of the triblock copolymers F127, F108 or P123.

[0011] Further, in the above step (1), the molar ratio of the aldehyde compound to 2,6-diaminopyridine is 1:2 to 1:4, and the grinding time is 5-20 min.

[0012] Further, in the above step (1), the dosage of the template agent is 0.5-2 times the sum of the masses of the aldehyde compound and 2,6-diaminopyridine.

[0013] In the above step (2), the curing reaction temperature is 100-200 °C, and the time is 1-24 h.

[0014] In the above step (3), the temperature for removing the template agent is 350-400 °C, and the time is 2-6 h.

[0015] In the above step (4), the temperature for calcination and carbonization is 600-900 °C, and the time is 2-6 h.

[0016] An ordered mesoporous polypyridine-Schiff base framework material for gaseous sulfide catalysis prepared by the above method.

[0017] The application of the above-mentioned ordered mesoporous poly(pyridine)-Schiff base framework material for gaseous sulfide catalysis in the catalytic removal and resource utilization of gaseous sulfides includes: using COS as the feed gas and the ordered mesoporous poly(pyridine)-Schiff base framework material as the catalyst to carry out a hydrolysis reaction; or using H2S and O2 as the feed gases and the ordered mesoporous poly(pyridine)-Schiff base framework material as the catalyst to carry out a catalytic oxidation reaction.

[0018] The advantages of the present invention are as follows: (1) In terms of the preparation process, the method of the present invention abandons the high energy consumption defect of the traditional solvent method, and proposes a ratio-guided solvent-free soft template method. By regulating the nitrogen content and assembly behavior of the precursor polymer through the monomer stoichiometric ratio, an ordered mesoporous poly(pyridine)-Schiff base framework material is constructed.

[0019] (2) It gets rid of the evaporation-induced self-assembly route relying on the chemical guidance of novolac resin in the design process of traditional ordered mesoporous materials.

[0020] (3) The stable poly(pyridine)-Schiff base framework constructed by precursor copolymerization can maximize the avoidance of nitrogen loss during the carbonization process.

[0021] (4) The ordered mesoporous nitrogen-doped carbon material prepared by the present invention has rich active sites and excellent structural properties. At 90 °C, the COS conversion rate is close to 100%, and the H2S conversion rate can reach 90.1%. Its ordered mesoporous structure can effectively promote the mass transfer of polysulfide products. Description of the drawings: Figure 1 It is the small-angle XRD spectra of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 1-4.

[0023] Figure 2 It is the wide-angle XRD spectra of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 1-4.

[0024] Figure 3 It is the N2 adsorption-desorption isotherms (a) and pore size distribution diagrams (b) of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 1-4.

[0025] Figure 4 It is the SEM and TEM images of the ordered mesoporous poly(pyridine)-Schiff base framework material prepared in Example 1. a, b are SEM images; c, d are TEM images.

[0026] Figure 5 It is the activity comparison diagram of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 4-7 applied to the COS hydrolysis reaction.

[0027] Figure 6Activity comparison diagram of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 4-7 for the catalytic oxidation reaction of H2S. Specific implementation method: A preparation method of an ordered mesoporous poly(pyridine)-Schiff base framework material for catalyzing gaseous sulfides, comprising the following steps: (1) An aldehyde compound, 2,6-diaminopyridine, and a template agent are mixed in a certain molar ratio and ground evenly in a mortar; the aldehyde compound includes glyoxal, paraformaldehyde, paraformaldehyde, or terephthalaldehyde; the template agent is a triblock copolymer F127, F108, or P123; the molar ratio of the aldehyde compound to 2,6-diaminopyridine is 1:2 to 1:4, and the grinding time is 5-20 min; the dosage of the template agent is 0.5-2 times the sum of the masses of the aldehyde compound and 2,6-diaminopyridine.

[0029] (2) After grinding, transfer to a polytetrafluoroethylene-lined reaction kettle for curing; the curing reaction temperature is 100-200 °C, and the time is 1-24 h.

[0030] (3) Remove the template agent from the cured sample under a nitrogen atmosphere; the temperature for removing the template agent is 350-400 °C, and the time is 2-6 h.

[0031] (4) The obtained polymer is calcined and carbonized under a nitrogen atmosphere; the temperature for calcination and carbonization is 600-900 °C, and the time is 2-6 h.

[0032] The following details the specific implementation method of the present invention. The specific implementation method described herein is only used to illustrate and explain the present invention and is not used to limit the present invention.

[0033] Example 1: Place 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine, and 0.70 g of F127 in an agate mortar and grind for 5 min. Transfer the mixed material to the polytetrafluoroethylene lining of a hydrothermal kettle and react at 140 °C for 24 h. After the system cools to room temperature, place the product in a tube furnace for heat treatment, protected by nitrogen throughout, and heat up to 360 °C at a rate of 1 °C / min and hold for 4 h. The obtained product is labeled as sample A.

[0034] Example 2: Place 0.13 g of terephthalaldehyde, 0.33 g of 2,6-diaminopyridine and 0.92 g of F127 in an agate mortar and grind for 5 min. Transfer the mixed materials to the polytetrafluoroethylene liner of a hydrothermal autoclave and react at 140 °C for 24 h. After the system cools to room temperature, place the product in a tube furnace for heat treatment under nitrogen protection throughout the process. Heat it up to 360 °C at a rate of 1 °C / min and keep it at a constant temperature for 4 h. The obtained product is labeled as sample B.

[0035] Example 3: Place 0.13 g of terephthalaldehyde, 0.44 g of 2,6-diaminopyridine and 1.14 g of F127 in an agate mortar and grind for 5 min. Transfer the mixed materials to the polytetrafluoroethylene liner of a hydrothermal autoclave and react at 140 °C for 24 h. After the system cools to room temperature, place the product in a tube furnace for heat treatment under nitrogen protection throughout the process. Heat it up to 360 °C at a rate of 1 °C / min and keep it at a constant temperature for 4 h. The obtained product is labeled as sample C.

[0036] Example 4: Place 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine and 0.70 g of F127 in an agate mortar and grind for 5 min. Transfer the mixed materials to the polytetrafluoroethylene liner of a hydrothermal autoclave and react at 140 °C for 24 h. After the system cools to room temperature, place the product in a tube furnace for heat treatment under nitrogen protection throughout the process. Heat it up to 360 °C at a rate of 1 °C / min and keep it at a constant temperature for 4 h, and then heat it up to 600 °C at a rate of 3 °C / min for carbonization for 2 h. The obtained product is labeled as sample D.

[0037] Example 5: Place 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine and 0.70 g of F127 in an agate mortar and grind for 5 min. Transfer the mixed materials to the polytetrafluoroethylene liner of a hydrothermal autoclave and react at 140 °C for 24 h. After the system cools to room temperature, place the product in a tube furnace for heat treatment under nitrogen protection throughout the process. Heat it up to 360 °C at a rate of 1 °C / min and keep it at a constant temperature for 4 h, and then heat it up to 700 °C at a rate of 3 °C / min for carbonization for 2 h. The obtained product is labeled as sample E.

[0038] Example 6: 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine and 0.70 g of F127 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to the polytetrafluoroethylene inner liner of a hydrothermal reactor and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tubular furnace for heat treatment under nitrogen protection throughout the process. The temperature was raised to 360 °C at a rate of 1 °C / min and kept constant for 4 h, and then raised to 800 °C at a rate of 3 °C / min for carbonization for 2 h. The obtained product was labeled as sample F.

[0039] Example 7: 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine and 0.70 g of F127 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to the polytetrafluoroethylene inner liner of a hydrothermal reactor and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tubular furnace for heat treatment under nitrogen protection throughout the process. The temperature was raised to 360 °C at a rate of 1 °C / min and kept constant for 4 h, and then raised to 900 °C at a rate of 3 °C / min for carbonization for 2 h. The obtained product was labeled as sample G.

[0040] Comparative Example 1: 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine and 0.70 g of F108 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to the polytetrafluoroethylene inner liner and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tubular furnace for heat treatment under nitrogen protection throughout the process. The temperature was raised to 360 °C at a rate of 1 °C / min and kept constant for 4 h. Under nitrogen protection throughout the process, the temperature was raised to 360 °C at a rate of 1 °C / min and kept constant for 4 h. The obtained product was labeled as sample H.

[0041] Comparative Example 2: 0.13 g of terephthalaldehyde, 0.22 g of 2,6-diaminopyridine and 0.70 g of P123 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to the polytetrafluoroethylene inner liner and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tubular furnace for heat treatment under nitrogen protection throughout the process. The temperature was raised to 360 °C at a rate of 1 °C / min and kept constant for 4 h. The obtained product was labeled as sample I.

[0042] Analysis method: Comparative Example 3: 0.06 g of glyoxal, 0.22 g of 2,6-diaminopyridine and 0.56 g of F127 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to a polytetrafluoroethylene inner liner and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tube furnace for heat treatment. Under nitrogen protection throughout the process, the temperature was increased to 360 °C at a rate of 1 °C / min and held at a constant temperature for 4 h. The obtained product was labeled as sample J.

[0043] Comparative Example 4: 0.09 g of paraformaldehyde, 0.22 g of 2,6-diaminopyridine and 0.62 g of F127 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to a polytetrafluoroethylene inner liner and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tube furnace for heat treatment. Under nitrogen protection throughout the process, the temperature was increased to 360 °C at a rate of 1 °C / min and held at a constant temperature for 4 h. The obtained product was labeled as sample K.

[0044] Comparative Example 5: 0.18 g of paraformaldehyde, 0.22 g of 2,6-diaminopyridine and 0.80 g of F127 were placed in an agate mortar and ground for 5 min. The mixed materials were transferred to a polytetrafluoroethylene inner liner and reacted at 140 °C for 24 h. After the system was cooled to room temperature, the product was placed in a tube furnace for heat treatment. Under nitrogen protection throughout the process, the temperature was increased to 360 °C at a rate of 1 °C / min and held at a constant temperature for 4 h. The obtained product was labeled as sample L.

[0045] Analysis method: Characterization: X-ray diffraction (XRD) tests were carried out on a X'Pert3 powder diffractometer. The X-rays were from Cu Kα radiation (λ = 1.5418 Å), and the voltage and current were V = 45 kV and I = 40 mA respectively. The surface micro-nano structures of different samples were studied by scanning electron microscopy (SEM, S-4800 Hitachi, acceleration voltage 5 kV). The internal nano-structures of the samples were studied on a FEI Tecnai G2 F20 transmission electron microscope. The BET specific surface areas and pore volumes of various samples were evaluated on a Micromeritics TriStarⅡ 3020 system. Before measurement, the samples were degassed at 200 °C for 12 h.

[0046] Desulfurization performance test: The equipment selected for the performance test of the catalytic reaction is a micro-tubular catalyst evaluation device of model Beijing MRT-3203-G. A thermal conductivity detector (TCD) equipped in a Fuli GC9720 gas chromatograph is used to online detect the outlet gas concentration before and after the reaction. Before the test, the sample needs to be pressed into tablets and sieved to 20 - 40 mesh, and then placed in a vacuum drying oven at 150 °C for 12 h to complete the activation treatment. The catalyst dosage is 100 mg. In the COS hydrolysis reaction, the raw material gas is COS (97.21 mg / m 3 ), and the balance gas is N2; in the H2S oxidation reaction, the raw material gas composition is H2S / O2 / N2 (0.5% / 0.25% / 99.25%), and the gas flow range is 10 - 40 mL / min; the test temperature range is 30 - 210 °C.

[0047] Analysis results: The obtained ordered mesoporous poly(pyridine)-Schiff base framework material was subjected to corresponding analysis and testing: Figure 1 Small-angle XRD patterns of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 1 - 4. Diffraction peaks related to the (100) crystal plane reflection can be observed at about 2θ = 0.84° for all samples, indicating that the synthesized materials have a long-range ordered mesoporous structure. In addition, as the dosage of 2,6-diaminopyridine increases, the intensity of the (100) peak weakens, indicating that excessive dosage of 2,6-diaminopyridine has a negative impact on its ordered structure. Figure 2 Wide-angle XRD patterns of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 1 - 4 and the sample prepared in Comparative Example 1. Samples A - C have relatively broad diffraction peaks at about 2θ = 21.5º, which are related to the (002) crystal plane reflection, indicating the presence of an amorphous carbon network. After carbonization, a sharp diffraction peak appears at 43.4° for Sample D, proving that high-temperature pyrolysis induces partial graphitization transformation.

[0048] Figure 3 N2 adsorption-desorption isotherms (a) and pore size distribution curves (b) of the ordered mesoporous poly(pyridine)-Schiff base framework materials prepared in Examples 1 - 4 and the sample prepared in Comparative Example 1. Samples A - D in Figure a all show typical Type IV curve characteristics. Among them, Samples A, B, and D show H1-type hysteresis loops and capillary condensation steps in the relative pressure range of P / P0 = 0.65 - 0.9, indicating that the materials have a regular mesoporous structure. The platform of Sample C is not obvious, indicating that moderate nitrogen doping can optimize the porosity and structural order. The pore size distribution curve (b) further clarifies the structural differences: the mesopore centers of Samples A and B are located at 3.6 nm and 6.0 nm respectively, confirming the controllable mesoporous construction ability during the synthesis process. The structural parameters and nitrogen content are shown in the following table: Figure 4 The ordered mesoporous poly(pyridine)-Schiff base framework material prepared in Example 1. It can be clearly seen that the sample is composed of uniformly arranged polymers, thus forming a highly oriented layered pore network. In the TEM image, the sample shows clear stripes, indicating that the pores are uniformly arranged. This is in good agreement with the results of the small-angle XRD spectrum and the N2 isotherm experiment.

[0049] Figure 5 Conversion rate diagrams of the samples prepared in Examples 4-7 for the catalytic hydrolysis reaction of COS. In the temperature range of 30 °C to 150 °C, among them, sample D (calcined at 600 °C) exhibits excellent catalytic activity under the same conditions: at the reaction temperature of 90 °C, a COS conversion rate close to 100% is achieved, significantly superior to samples E (87.3%), F (78.6%), and G (78.15%) calcined at 700 °C to 900 °C.

[0050] Figure 6 Conversion rate diagrams of the samples prepared in Examples 4-7 for the catalytic oxidation reaction of H2S. In the temperature range of 30 °C to 150 °C, the H2S conversion rates of all samples increase with the increase of the reaction temperature. Among them, sample D (calcined at 600 °C) exhibits excellent catalytic activity under the same conditions: the conversion rate reaches 90.1% at 90 °C, significantly higher than samples E (67.3%), F (58.9%), and G (39.21%) calcined at 700 °C to 900 °C. After 150 °C, the catalytic oxidation performance of E, F, and G decreases to varying degrees, while D remains unchanged, indicating that its ordered mesoporous poly(pyridine)-Schiff base structure has excellent stability. The measurement results are shown in the following table: The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A preparation method of an ordered mesoporous polypyridine-Schiff base framework material for catalytic removal and resource utilization of gaseous sulfides, characterized in that: Mechanically mix an aldehyde compound, 2,6-diaminopyridine and a templating agent in proportion, transfer the sample to a polytetrafluoroethylene liner, and then place the entire liner in an oven for a curing reaction. After the curing is completed, remove the templating agent in a nitrogen atmosphere to obtain a primary product with a two-dimensional hexagonal mesoporous structure; subject the primary product to high-temperature carbonization to obtain an ordered mesoporous poly(pyridine-Schiff base) framework material for catalytic removal and resource utilization of gaseous sulfides.

2. The preparation method according to claim 1, wherein It includes the following specific steps: (1) Mix an aldehyde compound, 2,6-diaminopyridine and a templating agent according to a certain molar ratio, and grind them evenly in a mortar; (2) After the grinding is completed, transfer it to a polytetrafluoroethylene-lined reaction kettle, and place the entire liner in an oven for a curing reaction; (3) Remove the templating agent from the cured sample in a nitrogen atmosphere; (4) Calcinate and carbonize the obtained polymer in a nitrogen atmosphere.

3. The preparation method according to claim 1, characterized in that: The aldehyde compound described in step (1) includes glyoxal, paraformaldehyde, paraformaldehyde or terephthalaldehyde.

4. The preparation method according to claim 1, wherein: The templating agent described in step (1) is any one of the triblock copolymers P123, F127 or F108.

5. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of the aldehyde compound to 2,6-diaminopyridine is 1:2 to 1:4, and the grinding time is 5 - 20 min; the dosage of the templating agent is 0.5 - 2 times the sum of the masses of the aldehyde compound and 2,6-diaminopyridine.

6. The preparation method according to claim 1, characterized in that: In step (2), the temperature of the curing reaction is 100 - 200 °C, and the time is 1 - 24 h.

7. The preparation method according to claim 1, characterized in that: In step (3), the temperature for removing the templating agent is 350 - 400 °C, and the time is 2 - 6 h.

8. The preparation method according to claim 1, characterized in that: In step (4), the carbonization temperature is 600 - 900 °C, and the time is 2 - 6 h.

9. An ordered mesoporous poly(pyridine-Schiff base) framework material for gaseous sulfide catalysis prepared by the method according to any one of claims 1 - 8.

10. An application of the ordered mesoporous poly(pyridine-Schiff base) framework material as claimed in claim 9 in the catalytic removal of gaseous sulfides.

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