Carboxylic resin catalyst for hydration of acrolein to 3-hydroxypropionaldehyde, its preparation method and use

Abstract

The application discloses a carboxylic resin catalyst for preparing 3-hydroxypropionaldehyde by hydrating propenal and a preparation method and application thereof, and relates to the technical field of catalysts. The resin is first swelled, then a cage cavity structure organic matter is added for pore filling and reconstruction, then a Friedel-Crafts acylation and amination are carried out to graft an amino carboxylic acid group, and finally an H type resin catalyst is obtained through acidification. The resin catalyst has stable pore structure and high active site abundance, and when used for a propenal hydration reaction, the space velocity can reach 5h ‑1 , the propenal conversion rate is greater than or equal to 75%, the 3-hydroxypropionaldehyde selectivity is greater than 93%, and after a tubular fixed bed reaction continuous evaluation for 100 hours, the decrease ranges of the propenal conversion rate and the 3-hydroxypropionaldehyde selectivity are less than 2%, and the catalytic performance and stability are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropionaldehyde, its preparation method, and its application. Background Technology

[0002] 1,3-Propanediol, abbreviated as 1,3-PDO, is a colorless, odorless, viscous liquid soluble in water, alcohols, ethers, and many other solvents. It is an important chemical raw material widely used in polyesters, polyurethanes, cosmetics, biodegradable plastics, pharmaceutical intermediates, inks, printing and dyeing, lubricants, and other fields. However, its primary use is as a polymer monomer, replacing ethylene glycol and butanediol in the production of polyol polyesters, used to manufacture high-performance new polyester fibers (PTT), which are then applied in the clothing, carpet, electronics, and automotive markets. In recent years, the rapid development of 1,3-propanediol has been mainly driven by the downstream PTT consumption market.

[0003] With the research and development of PTT in China and the continuous maturation of the downstream market, the cost of 1,3-propanediol largely determines the market competitiveness of PTT. Optimizing and improving the production technology of 1,3-propanediol is the only way to reduce the production cost of PTT and accelerate the future market development of PTT. Therefore, developing low-cost 1,3-propanediol products has become a research hotspot for scientific research institutes and enterprises.

[0004] The main technologies for synthesizing 1,3-propanediol include biological methods, propylene methods, and ethylene oxide methods. In China, the production cost of 1,3-propanediol via biological methods is high, while the propylene and ethylene oxide methods have not yet been industrialized. The propylene method involves oxidizing propylene to acrolein, hydrating acrolein to obtain 3-hydroxypropanal (3-HPA), and then using a two-stage hydrogenation process to obtain 1,3-propanediol. The propylene method has advantages such as simple process, well-defined catalyst system, and low equipment requirements.

[0005] The hydration of acrolein to prepare 3-hydroxypropanal is a key step in the propylene process for 1,3-propanediol. Initially, inorganic acids were used as catalysts, but these methods resulted in low selectivity and yield, and acrolein and 3-hydroxypropanal were prone to condensation or polymerization reactions. To address these issues, weakly acidic ion exchange resins were employed as catalysts, but these methods suffer from drawbacks such as slow reaction rates, low space-time yields, and difficulty in regenerating the catalyst after deactivation.

[0006] Degussa and Hoechst have both researched and developed inorganic supported acidic catalysts. Degussa uses catalysts with a surface area of ​​50 m². 2Using TiO2 or γ-Al2O3 as a support, and impregnated with H3PO4 or NaH2PO4 solution, a Ti-OP structured active catalyst was prepared. The hydration conversion rate of acrolein obtained from the reaction was 50%, and the selectivity for 3-hydroxypropionaldehyde could reach 81%. Hoechst's catalyst, using ZSM-5 molecular sieve as the active component, showed almost no change in activity when the acrolein mass fraction was 18-19%, the reaction temperature was 80℃, and it was continuously operated in a fixed-bed reactor for 1500 h. The average conversion rate of acrolein was approximately 44.3%, and the average selectivity for 3-hydroxypropionaldehyde was approximately 87.7%. DuPont used a pyridine ion-type hydration catalyst at a reaction temperature of 45-60℃ and a mass hourly space velocity (HHSV) of 0.5-0.6 h⁻¹. -1 The average single-pass conversion rate of acrolein was 51%, and the average selectivity of 3-hydroxypropionaldehyde was 83%.

[0007] my country has also conducted extensive research and development on the reaction technology for the preparation of 3-hydroxypropanal from acrolein via the hydration of acrolein in the propylene process for 1,3-propanediol. CNOOC Tianjin Chemical Research and Design Institute Co., Ltd. used a modified molecular sieve catalyst and a fixed-bed reactor for the hydration reaction. Under low temperature and slightly positive pressure conditions, the average single-pass conversion rate of acrolein was >50%, and the average selectivity of 3-hydroxypropanal was >90%. Sinopec Shanghai Petrochemical Co., Ltd. used a mercaptocarboxylic acid resin catalyst and a fixed-bed hydration reactor at a reaction temperature of 45-55℃ and a mass hourly space velocity (HHSV) of 0.5-0.75 h⁻¹. -1 The average single-pass conversion rate of acrolein was 45%, and the average selectivity for 3-hydroxypropionaldehyde was 89%. The Lanzhou Chemical Research Center of China National Petroleum Corporation used an aminocarboxylic acid / aminophosphoric acid resin catalyst in a fixed-bed reactor for the hydration reaction at a temperature of 50-55℃ and a mass hourly space velocity (HHSV) of 0.1-0.5 h⁻¹. -1 The single-pass average conversion rate of acrolein is ≥50%, the selectivity of 3-hydroxypropanal is ≥95%, and the overall yield is ≥47.5%. Shanghai Huayi Acrylic Acid Co., Ltd.'s invention patent CN100417443C discloses a novel resin catalyst for the hydration of acrolein to 3-hydroxypropanal and its application. This catalyst uses a chelating ion exchange resin to facilitate the hydration reaction of acrolein to 3-hydroxypropanal. The reaction can be carried out at relatively low temperatures, under mild conditions, and is easy to control and operate, exhibiting excellent hydration reaction performance with an acrolein conversion rate >60%. Shanghai Normal University used an aminocarboxylic acid / aminophosphate type resin catalyst in a fixed-bed reactor for the hydration reaction at a reaction temperature of 40-70℃ and a mass hourly space velocity (HHSV) of 0.5-1 h⁻¹. -1The average single-pass conversion rate of acrolein was 53%, and the average selectivity for 3-hydroxypropanal was 89%. The Petrochemical Research Institute of the Heilongjiang Academy of Sciences used a modified cation exchange resin as a catalyst for the acrolein hydration reaction, achieving an average single-pass conversion rate of >45% for acrolein and a selectivity for 3-hydroxypropanal >85%. Shanghai Jiao Tong University investigated the stability of the acrolein hydration reaction using a fixed-bed continuous flow reactor with a reaction mass hourly space velocity (HHSV) of 1 h⁻¹. -1 The mass fraction of acrolein is 10-12%, the conversion rate of acrolein is maintained at around 50%, and the selectivity of 3-hydroxypropionaldehyde is maintained at 89%. The acrolein hydration catalysts mentioned above still suffer from disadvantages such as low mass hourly space velocity (MHV), low throughput, low acrolein conversion rate, and low overall 3-hydroxypropanal product yield. Furthermore, acrolein recovery and 3-hydroxypropanal purification steps are required at the intermediate output stage, making it difficult to effectively balance material and energy consumption. The main reason is insufficient catalyst stability. Taking resin catalysts as an example, surface active groups may detach or H+ may be present during the reaction. + The activity decreases as the number of active centers is reduced due to the exchange of metal ions in the aqueous solution. Secondly, any catalyst with a porous structure, such as resin-type or molecular sieve-type catalysts, suffers from the problem of surface active centers being covered by polymers generated during the reaction. This leads to a decrease in the number of active centers or an increase in internal diffusion resistance, ultimately causing a rapid decline in catalytic activity, a decrease in the effective throughput of the device, and an increase in the pressure of the intermediate distillation and purification modules, which brings technical limitations to pilot-scale and industrial-scale design. Summary of the Invention

[0008] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropionaldehyde, its preparation method, and its application. When the prepared resin catalyst is used in the hydration reaction of acrolein, the mass hourly space velocity can reach 5 h⁻¹. -1 The reaction conditions require milder conditions, with acrolein conversion rate ≥75% and 3-hydroxypropionaldehyde selectivity >93%.

[0009] The technical solution of this invention is as follows: In a first aspect, the present invention provides a method for preparing a carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional, comprising the following steps: S1 Resin Swelling: The carboxylic acid resin catalyst is added to an organic solvent and stirred to carry out swelling treatment; the organic solvent is dichloromethane or dioxane; the swelling treatment temperature is 30-60℃; the stirring speed is 300-800 rpm; S2 Resin Skeleton Support and Reconstruction: After swelling, a cage-like organic material is added for pore support and reconstruction. The mixture is then stirred and ultrasonically treated. The stirring speed is 500-1000 rpm, and the stirring time is 2-5 hours. The ultrasonic frequency is 50-150 kHz, and the ultrasonic time is 1-2 hours. The resulting swollen resin is filtered to obtain a solid-phase swollen resin. The cage-like organic material is a polymer of 1,4-phenylenedialdehyde and tetrakis(4-aminophenyl)methane (COF-300), NU-1000 (Zr6O4(OH)4(H2O)4(TBAPy)2), or MIL-101 (Cr3O(F,OH)(H2O)2(BDC)3). The amount of cage-like organic material added, based on the dry weight of the carboxylic acid resin catalyst, is 1-10 wt.% of the carboxylic acid resin catalyst in step S1. S3 resin grafting aminocarboxylic acid group modification: aminocarboxylic acid groups are grafted onto the solid swollen resin by first Friedel-Crafts acylation and then amination to increase the abundance of active sites on the resin surface and obtain modified resin catalyst. S4 acidification treatment: The modified resin catalyst is subjected to ion exchange through acidification treatment to obtain H-type resin catalyst.

[0010] Preferably, in step S3, the Friedel-Crafts acylation process is as follows: AlCl3 is added to dichloromethane, stirred and dissolved, then the reagent used for Friedel-Crafts acylation is added, and stirring is continued to obtain a solution; then the solid-phase swollen resin obtained in step S2 is added to the solution and stirred, that is, the acyl groups are grafted onto the aromatic ring of the resin catalyst.

[0011] Preferably, based on the dry weight of the carboxylic acid resin catalyst, the molar ratio of the carboxylic acid resin catalyst, AlCl3, and the reagent used for Friedel-Crafts acylation in step S1 is 1:1:(0.5-3), and the reagent used for Friedel-Crafts acylation is chloroacetyl chloride, dichloroacetyl chloride, or 2-chloropropionyl chloride.

[0012] Preferably, the amination process is as follows: After grafting the acyl group onto the aromatic ring of the resin catalyst, hydrochloric acid solution is added to the system to quench it, and after filtration, it is ultrasonically washed with water until neutral to obtain an acylated resin intermediate. The acylated resin intermediate is added to dichloromethane, stirred and dispersed, and then the amination reagent and sodium hydroxide are added. After ultrasonic dissolution, the mixture is stirred continuously until the reaction is complete, filtered, and washed with water until neutral to obtain the modified resin catalyst.

[0013] Preferably, based on the dry weight of the carboxylic acid resin catalyst, the molar ratio of the carboxylic acid resin catalyst, sodium hydroxide, and the reagent used for amination in step S1 is 1:2.5:(3-8), and the reagent used for amination is iminodiacetic acid, ethylenediaminetetraacetic acid, or hydroxyethyliminodiacetic acid.

[0014] Preferably, in step S4, the modified resin catalyst is acidified using an H ion exchange reagent, which is a hydrochloric acid solution or a nitric acid solution, and the concentration of the hydrochloric acid solution or nitric acid solution is 3-8 wt.%.

[0015] Secondly, the present invention provides a carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropionaldehyde, which is prepared by the above-described method for preparing the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropionaldehyde.

[0016] Thirdly, the present invention provides the application of the above-mentioned carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional, wherein the catalyst is packed in a fixed-bed reactor, with a 5-15 wt.% acrolein aqueous solution as feed, and the reactor is subjected to a reaction at 30-60°C and a mass hourly space velocity of 0.5-5 h⁻¹. -1 Under certain conditions, continuous feeding causes acrolein to undergo a hydration reaction, yielding 3-hydroxypropionaldehyde.

[0017] Compared with the prior art, the present invention has the following advantages: 1. This invention involves adding a cage-like organic material to the resin skeleton during the swelling stage of the resin catalyst before grafting aminocarboxylic acid groups, providing structural support and pore reconstruction. After the resin catalyst swells, the resin skeleton expands, releasing the pore structure and exposing active sites. However, after the resin skeleton shrinks, the previously exposed active sites are lost due to the collapse and closure of the pore structure, resulting in a significant reduction in the effectiveness of grafting aminocarboxylic acid groups. In contrast, the cage-like organic material possesses closed / semi-closed polyhedral pores with a stable structure. After the skeleton shrinks, it can effectively support the original pore structure, forming new macroporous structures and creating mass transfer space for active agents, thereby achieving new pore reconstruction, increasing the overall abundance of grafted aminocarboxylic acid active sites, and enhancing catalytic activity.

[0018] 2. The cage-like organic structure of the present invention can adjust the size of the cage and the polarity and hydrophobicity within the cage according to the requirements of the reaction environment, thereby controlling the mass transfer of the modifying agent and the reaction raw materials within the cage. The acrolein raw material and the 3-hydroxypropionaldehyde product can flow freely under the given reaction conditions, avoiding the occurrence of polymer side reactions. Without increasing the internal diffusion resistance, it reduces the risk of polymer covering the active sites, thereby maintaining the high activity level of the catalyst.

[0019] 3. The resin catalyst prepared in this invention, after activation, enhances the conversion rate and selectivity of the acrolein hydration reaction; it possesses a large specific surface area, large pore volume, and excellent active site abundance. Furthermore, the resin catalyst exhibits good mass transfer and thermal stability, maintaining high conversion rate and selectivity even under extreme reaction conditions. There is no polymer aggregation or accumulation on the resin catalyst surface, which affects the catalyst lifetime, and the reaction mass hourly space velocity can reach 5 h⁻¹. -1The reaction conditions are milder, the raw material conversion rate is higher (acrylaldehyde conversion rate ≥75%), the product selectivity is higher (3-hydroxypropanal selectivity >93%), the product yield is high (>69%), and after continuous evaluation of the tubular fixed bed reaction for 100 hours, the acrolein conversion rate and 3-hydroxypropanal selectivity decrease by less than 2%, indicating good stability of the resin catalyst. Attached Figure Description

[0020] Figure 1 This is a SEM image of the resin catalyst prepared in Example 1 of this invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0022] Example 1 The preparation method of the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional in this embodiment includes the following steps: S1 added D751 resin catalyst (Zhejiang Zhengguang Industrial Co., Ltd.) to dichloromethane, maintained the temperature at 30℃ and the stirring speed at 300rpm, and carried out swelling treatment.

[0023] After the S2 swelling is complete, add MIL-101 at 1 wt.% of the dry weight of the D751 resin catalyst, stir at 500 rpm for 2 h, then sonicate at 50 kHz for 1 h, and then filter to obtain solid-phase swollen resin.

[0024] S3 involves Friedel-Crafts acylation of a solid-phase swollen resin with chloroacetyl chloride, followed by amination with iminodiacetic acid to graft aminocarboxylic acid groups onto the solid-phase swollen resin, yielding a modified resin catalyst. The Friedel-Crafts acylation process is as follows: AlCl3 is added to dichloromethane and stirred until dissolved; then chloroacetyl chloride is added and stirring continues to obtain a solution; the solid-phase swollen resin obtained in step S2 is then added to this solution and stirred, thereby grafting acyl groups onto the aromatic ring of the resin catalyst. The molar ratio of AlCl3, chloroacetyl chloride, and the carboxylic acid resin catalyst in step S1 is 1:1:1. The amination process is as follows: After grafting acyl groups onto the aromatic ring of the resin catalyst, 5 wt.% hydrochloric acid solution is added to the system for quenching. After filtration, the mixture is ultrasonically washed with water until neutral to obtain an acylated resin intermediate. The acylated resin intermediate is added to dichloromethane and stirred to disperse. Then, iminodiacetic acid and sodium hydroxide are added, dissolved by ultrasonication, and stirred continuously until the reaction is complete. After filtration, the mixture is washed with water until neutral to obtain the modified resin catalyst. The molar ratio of iminodiacetic acid to the carboxylic acid resin catalyst and sodium hydroxide in step S1 is 6:1:2.5.

[0025] S4 The modified resin catalyst was added to a 3 wt.% dilute hydrochloric acid solution, stirred, and acidified to perform ion exchange, obtaining the H-type resin catalyst. Its SEM image is shown below. Figure 1 As shown. By Figure 1 As can be seen, the H-type resin catalyst possesses a typical disordered porous structure with a clearly visible extended framework. The presence of numerous through-pores provides favorable conditions for the grafting of active groups onto the catalyst and for mass transfer, adsorption, and desorption of raw material and product molecules. This further demonstrates the correctness of the modification strategy of using cage-like organic materials for structural support and pore reconstruction. The specific surface area, pore volume, and average pore size of the resin catalyst prepared in this embodiment are shown in Table 2.

[0026] The resin catalyst of this embodiment was loaded into a fixed-bed reactor for the hydration of acrolein to produce 3-hydroxypropional. The reaction mass hourly space velocity (H₂S) was evaluated to be 0.5 h⁻¹. -1 The reaction temperature was 30°C, and the concentration of acrolein solution was 5 wt.%. Using the resin catalyst of this embodiment, the product yield was 69.9%, the acrolein conversion rate was 75%, and the selectivity of 3-hydroxypropionaldehyde was 93.2% (as shown in Table 1).

[0027] Example 2 The preparation method of the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional in this embodiment includes the following steps: S1 added D751 resin catalyst (Zhejiang Zhengguang Industrial Co., Ltd.) to dioxane, and carried out swelling treatment while maintaining a temperature of 60℃ and a stirring speed of 800rpm.

[0028] After the S2 swelling is complete, NU-1000, accounting for 10 wt.% of the dry weight of the D751 resin catalyst, is added. The mixture is stirred at 1000 rpm for 2 hours, then sonicated at 150 kHz for 1 hour, and finally filtered to obtain the solid-phase swollen resin.

[0029] S3 involves Friedel-Crafts acylation of a solid-phase swollen resin with 2-chloropropionyl chloride, followed by amination with ethylenediaminetetraacetic acid (EDTA) to graft aminocarboxylic acid groups onto the solid-phase swollen resin, yielding a modified resin catalyst. The Friedel-Crafts acylation process is as follows: AlCl3 is added to dichloromethane and stirred until dissolved. Then, 2-chloropropionyl chloride is added and stirred continuously to obtain a solution. The solid-phase swollen resin obtained in step S2 is then added to this solution and stirred, thereby grafting acyl groups onto the aromatic ring of the resin catalyst. The molar ratio of AlCl3, 2-chloropropionyl chloride, and the carboxylic acid resin catalyst in step S1 is 1:0.5:1. The amination process is as follows: After grafting acyl groups onto the aromatic ring of the resin catalyst, 5 wt.% hydrochloric acid solution is added to the system for quenching. After filtration, the mixture is ultrasonically washed with water until neutral to obtain an acylated resin intermediate. The acylated resin intermediate is added to dichloromethane and stirred to disperse. Then, ethylenediaminetetraacetic acid (EDTA) and sodium hydroxide are added, dissolved by ultrasonication, and stirred continuously until the reaction is complete. After filtration, the mixture is washed with water until neutral to obtain the modified resin catalyst. The molar ratio of EDTA to the carboxylic acid resin catalyst and sodium hydroxide in step S1 is 3:1:2.5.

[0030] S4. The modified resin catalyst was added to a 5 wt.% dilute hydrochloric acid solution, and the mixture was stirred and acidified to perform ion exchange, thereby obtaining the H-type resin catalyst. The specific surface area, pore volume, and average pore size of the resin catalyst prepared in this embodiment are shown in Table 2.

[0031] The resin catalyst of this embodiment was loaded into a fixed-bed reactor for the hydration of acrolein to produce 3-hydroxypropional. The reaction mass hourly space velocity (H₂S₀) was 5 h⁻¹. -1 The reaction temperature was 60°C, and the concentration of the acrolein solution was 15 wt.%. Using the resin catalyst of this embodiment, the product yield was 73.6%, the acrolein conversion rate was 78%, and the selectivity of 3-hydroxypropionaldehyde was 94.4% (as shown in Table 1).

[0032] Example 3 The preparation method of the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional in this embodiment includes the following steps: S1 added D751 resin catalyst (Zhejiang Zhengguang Industrial Co., Ltd.) to dichloromethane, maintained the temperature at 40℃ and the stirring speed at 500rpm, and carried out swelling treatment.

[0033] After the S2 swelling is complete, add MIL-101 at 6 wt.% of the dry weight of the D751 resin catalyst, stir at 800 rpm for 5 h, then sonicate at 100 kHz for 2 h, and then filter to obtain solid-phase swollen resin.

[0034] S3 involves Friedel-Crafts acylation of a solid-phase swollen resin with chloroacetyl chloride, followed by amination with iminodiacetic acid to graft aminocarboxylic acid groups onto the solid-phase swollen resin, yielding a modified resin catalyst. The Friedel-Crafts acylation process is as follows: AlCl3 is added to dichloromethane and stirred until dissolved; then chloroacetyl chloride is added and stirring continues to obtain a solution; the solid-phase swollen resin obtained in step S2 is then added to this solution and stirred, thereby grafting acyl groups onto the aromatic ring of the resin catalyst. The molar ratio of AlCl3, chloroacetyl chloride, and the carboxylic acid resin catalyst in step S1 is 1:3:1. The amination process is as follows: After grafting acyl groups onto the aromatic ring of the resin catalyst, 5 wt.% hydrochloric acid solution is added to the system for quenching. After filtration, the mixture is ultrasonically washed with water until neutral to obtain an acylated resin intermediate. The acylated resin intermediate is added to dichloromethane and stirred to disperse. Then, iminodiacetic acid and sodium hydroxide are added, and the mixture is ultrasonically dissolved and stirred continuously until the reaction is complete. After filtration, the mixture is washed with water until neutral to obtain the modified resin catalyst. The molar ratio of iminodiacetic acid to the carboxylic acid resin catalyst and sodium hydroxide in step S1 is 8:1:2.5.

[0035] S4. The modified resin catalyst was added to an 8 wt.% dilute hydrochloric acid solution, and the mixture was stirred and acidified to perform ion exchange, thereby obtaining the H-type resin catalyst. The specific surface area, pore volume, and average pore size of the resin catalyst prepared in this embodiment are shown in Table 2.

[0036] The resin catalyst of this embodiment was loaded into a fixed-bed reactor for the hydration of acrolein to produce 3-hydroxypropional. Evaluation: The mass hourly space velocity (H₂S₀) was 3 h⁻¹. -1 The reaction temperature was 45°C, and the concentration of the acrolein solution was 10 wt.%. Using the resin catalyst of this embodiment, the product yield was 74.3%, the acrolein conversion rate was 78%, and the selectivity of 3-hydroxypropionaldehyde was 95.3% (as shown in Table 1).

[0037] Example 4 The preparation method of the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional in this embodiment includes the following steps: S1 added D751 resin catalyst (Zhejiang Zhengguang Industrial Co., Ltd.) to dichloromethane, maintained the temperature at 50℃ and the stirring speed at 600rpm, and carried out swelling treatment.

[0038] After the S2 swelling is complete, COF-300, accounting for 8 wt.% of the dry weight of the D751 resin catalyst, is added, and the mixture is stirred at 600 rpm for 4 h, then sonicated at 80 kHz for 2 h, and finally filtered to obtain the solid-phase swollen resin.

[0039] S3 involves Friedel-Crafts acylation of a solid-phase swollen resin with dichloroacetyl chloride, followed by amination with hydroxyethyliminodiacetic acid to graft aminocarboxylic acid groups onto the solid-phase swollen resin, yielding a modified resin catalyst. The Friedel-Crafts acylation process is as follows: AlCl3 is added to dichloromethane and stirred until dissolved; then dichloroacetyl chloride is added and stirring continues to obtain a solution; the solid-phase swollen resin obtained in step S2 is then added to this solution and stirred, thereby grafting acyl groups onto the aromatic ring of the resin catalyst. The molar ratio of AlCl3, dichloroacetyl chloride, and the carboxylic acid resin catalyst in step S1 is 1:1:1. The amination process is as follows: After grafting acyl groups onto the aromatic ring of the resin catalyst, 5 wt.% hydrochloric acid solution is added to the system for quenching. After filtration, the mixture is ultrasonically washed with water until neutral to obtain an acylated resin intermediate. The acylated resin intermediate is added to dichloromethane and stirred to disperse. Then, hydroxyethyliminodiacetic acid and sodium hydroxide are added, dissolved by ultrasonication, and stirred continuously until the reaction is complete. After filtration, the mixture is washed with water until neutral to obtain the modified resin catalyst. The molar ratio of hydroxyethyliminodiacetic acid to the carboxylic acid resin catalyst and sodium hydroxide in step S1 is 6:1:2.5.

[0040] S4. The modified resin catalyst was added to a 5 wt.% dilute nitric acid solution, stirred, and acidified to perform ion exchange, thereby obtaining the H-type resin catalyst. The specific surface area, pore volume, and average pore size of the resin catalyst prepared in this embodiment are shown in Table 2.

[0041] The resin catalyst of this embodiment was loaded into a fixed-bed reactor for the hydration of acrolein to produce 3-hydroxypropional. The reaction mass hourly space velocity (H₂S₀) was 5 h⁻¹. -1 The reaction temperature was 45°C, and the acrolein solution concentration was 15 wt.%. Using the resin catalyst of this embodiment, the product yield was 74.1%, the acrolein conversion rate was 77.5%, and the 3-hydroxypropanal selectivity was 95.6% (as shown in Table 1). After continuous reaction for 100 h, the acrolein conversion rate was 76.3%, and the 3-hydroxypropanal selectivity was 94.5%.

[0042] Comparative Example 1 The difference from Example 1 is that in step S1, no stirring is performed during the swelling treatment; the swelling is allowed to proceed only by standing. The specific surface area, pore volume, and average pore size of the prepared resin catalyst are shown in Table 2.

[0043] The resin catalyst of Comparative Example 1 was loaded into a fixed-bed reactor for evaluation of the acrolein hydration to 3-hydroxypropanal conversion: the evaluation conditions were the same as in Example 1. Ultimately, the product yield was 59.3%, the acrolein conversion rate was 65.2%, and the 3-hydroxypropanal selectivity was 91.0% (as shown in Table 1).

[0044] Compared with Example 1, the resin catalyst prepared in Comparative Example 1 performed poorly. The main reason is that the framework of the D751 resin catalyst could not be effectively expanded under static conditions, which affected the release of the pore structure and the exposure of active sites. As a result, the subsequent modification effect of the cage structure organic matter was reduced, which ultimately led to a decrease in acrolein conversion rate and 3-hydroxypropionaldehyde selectivity to varying degrees, especially the decrease in acrolein conversion rate was more obvious.

[0045] Comparative Example 2 The difference from Example 2 is that in step S2, the stirring time and ultrasonication time were reduced to 0.5 h. The specific surface area, pore volume, and average pore size of the prepared resin catalyst are shown in Table 2.

[0046] The resin catalyst of Comparative Example 2 was loaded into a fixed-bed reactor for evaluation of the acrolein hydration to 3-hydroxypropanal conversion: the evaluation conditions were the same as in Example 2. Ultimately, the product yield was 67.7%, the acrolein conversion rate was 73%, and the 3-hydroxypropanal selectivity was 92.7% (as shown in Table 1).

[0047] Compared with Example 2, the resin catalyst prepared in Comparative Example 2 performed poorly. The main reason is that the organic molecules in the cage structure are relatively large in size and have a large steric hindrance effect. Therefore, it is necessary to use rapid stirring and ultrasonic compounding to diffuse the molecules into the skeleton structure in a local area, which ultimately leads to a decrease in acrolein conversion rate and 3-hydroxypropionaldehyde selectivity to varying degrees.

[0048] Comparative Example 3 The difference from Example 3 is that in step S2, MIL-101 is replaced with MIL-53. The specific surface area, pore volume, and average pore size of the prepared resin catalyst are shown in Table 2.

[0049] The resin catalyst of Comparative Example 3 was loaded into a fixed-bed reactor for evaluation of the acrolein hydration to 3-hydroxypropanal process: the evaluation conditions were the same as in Example 3. Ultimately, the product yield was 70.0%, the acrolein conversion rate was 74.6%, and the 3-hydroxypropanal selectivity was 93.7% (as shown in Table 1).

[0050] Compared with Example 3, the resin catalyst prepared in Comparative Example 3 performed poorly. The main reason is that MIL-53 is a flexible framework with inferior structural stability compared to MIL-101. Therefore, after the resin framework shrinks, its support and stability are affected, and it cannot fully play its role in framework support and reconstruction. Although the acrolein conversion rate and 3-hydroxypropionaldehyde selectivity decreased, they still remained at a high level.

[0051] Comparative Example 4 The difference from Example 4 is that steps S1 and S2 are omitted, and steps S3 and S4 are performed directly. The specific surface area, pore volume, and average pore size of the prepared resin catalyst are shown in Table 2.

[0052] The resin catalyst of Comparative Example 4 was loaded into a fixed-bed reactor for the evaluation of acrolein hydration to 3-hydroxypropanal: the evaluation conditions were the same as in Example 4. Ultimately, the product yield was 52.0%, the acrolein conversion rate was 62.6%, and the 3-hydroxypropanal selectivity was 83.0% (as shown in Table 1). After continuous reaction for 100 h, the acrolein conversion rate was 55.1%, and the 3-hydroxypropanal selectivity was 75.6%.

[0053] Compared with Example 4, the resin catalyst prepared in Comparative Example 4 performed poorly. The main reason is that, in the absence of organic matter with a cage structure, the resin skeleton shrank, and the previously exposed active sites were lost due to the collapse and closure of the pore structure, resulting in a large loss of active sites and surfaces. This greatly reduced the effect of grafting aminocarboxylic acid active groups, ultimately leading to a decrease in acrolein conversion rate and 3-hydroxypropionaldehyde selectivity. Moreover, after 100 hours of continuous reaction, the decrease in acrolein conversion rate and 3-hydroxypropionaldehyde selectivity was greater than 5%, indicating that the stability of the resin catalyst was worse than that of Example 4.

[0054] Comparative Example 5 The difference from Example 1 is that step S3 is omitted. The specific surface area, pore volume, and average pore size of the prepared resin catalyst are shown in Table 2.

[0055] The resin catalyst of Comparative Example 5 was loaded into a fixed-bed reactor for evaluation of the acrolein hydration to 3-hydroxypropanal conversion: the evaluation conditions were the same as in Example 1. Ultimately, the product yield was 36.0%, the acrolein conversion rate was 53.5%, and the 3-hydroxypropanal selectivity was 67.2% (as shown in Table 1).

[0056] Compared with Example 1, the resin catalyst prepared in Comparative Example 5 performed poorly. The main reason is that it lacked acylation and amination processes, resulting in a sharp reduction in the number of grafted active groups. The aminocarboxylic acid active sites carried by the resin itself could not support high catalytic activity.

[0057] Comparative Example 6 The difference from Example 1 is that in step S2, the added MIL-101 accounts for 12 wt.% of the dry weight of the D751 resin catalyst. The specific surface area, pore volume, and average pore size of the prepared resin catalyst are shown in Table 2.

[0058] The resin catalyst of Comparative Example 6 was loaded into a fixed-bed reactor for evaluation of the acrolein hydration to 3-hydroxypropanal conversion: the evaluation conditions were the same as in Example 1. Ultimately, the product yield was 64.8%, the acrolein conversion rate was 70.8%, and the 3-hydroxypropanal selectivity was 91.5% (as shown in Table 1).

[0059] Compared with Example 1, the resin catalyst prepared in Comparative Example 6 performed poorly. The main reason is that during the resin pore modification process, an excessive amount of cage-like organic matter was added, which stacked in the micropore and mesopore regions, resulting in a reverse steric hindrance effect, causing a certain degree of reduction in conversion rate and selectivity. However, the overall catalyst efficiency remained at a high level.

[0060] Table 1. Acrolein conversion and 3-hydroxypropanal selectivity of the resin catalysts prepared in Examples 1-4 and Comparative Examples 1-6

[0061] The specific surface area, pore volume, and average pore size of the resin catalysts prepared in Examples 1-4 and Comparative Examples 1-6 are shown in Table 2. Table 2. Specific surface area, pore volume, and average pore size of the resin catalysts prepared in Examples 1-4 and Comparative Examples 1-6.

Claims

1. A method for preparing a carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional, characterized in that, Includes the following steps: S1 involves adding a carboxylic acid resin catalyst to an organic solvent and stirring to induce swelling. The organic solvent is dichloromethane or dioxane. The swelling temperature is 30-60℃, and the stirring speed is 300-800 rpm. After swelling in step S2, the cage-structured organic material is added, followed by stirring and ultrasonic treatment. The stirring speed is 500-1000 rpm, and the stirring time is 2-5 h. The ultrasonic frequency is 50-150 kHz, and the ultrasonic treatment time is 1-2 h. The solid-phase swollen resin is obtained by filtration. The cage-structured organic material is a polymer of 1,4-phenylenedialdehyde and tetrakis(4-aminophenyl)methane, NU-1000, or MIL-101. The amount of cage-structured organic material added is 1-10 wt.% of the carboxylic acid resin catalyst in step S1, based on the dry weight of the carboxylic acid resin catalyst. S3 is modified resin catalyst by grafting aminocarboxylic acid groups onto a solid swollen resin through a process of first Friedel-Crafts acylation followed by amination. S4 modifies the resin catalyst by acidification and ion exchange to obtain the H-type resin catalyst.

2. The method for preparing the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional as described in claim 1, characterized in that, In step S3, the Friedel-Crafts acylation process is as follows: AlCl3 is added to dichloromethane and stirred to dissolve. Then, the reagent used for Friedel-Crafts acylation is added and stirred continuously to obtain a solution. The solid-phase swollen resin obtained in step S2 is then added to the solution and stirred to graft the acyl groups onto the aromatic ring of the resin catalyst.

3. The method for preparing the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional as described in claim 2, characterized in that, Based on the dry weight of the carboxylic acid resin catalyst, the molar ratio of the carboxylic acid resin catalyst, AlCl3 and the reagent used for Friedel-Crafts acylation in step S1 is 1:1:(0.5-3). The reagent used for Friedel-Crafts acylation is chloroacetyl chloride, dichloroacetyl chloride or 2-chloropropionyl chloride.

4. The method for preparing the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional as described in claim 2, characterized in that, The amination process is as follows: After grafting the acyl group onto the aromatic ring of the resin catalyst, hydrochloric acid solution is added to the system to quench it. After filtration, the mixture is ultrasonically washed with water until neutral to obtain an acylated resin intermediate. The acylated resin intermediate is added to dichloromethane and stirred to disperse it. Then, the amination reagent and sodium hydroxide are added, and the mixture is ultrasonically dissolved and stirred continuously until the reaction is complete. After filtration, the mixture is washed with water until neutral to obtain the modified resin catalyst.

5. The method for preparing the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional as described in claim 4, characterized in that, Based on the dry weight of the carboxylic acid resin catalyst, the molar ratio of the carboxylic acid resin catalyst, sodium hydroxide, and the reagent used for amination in step S1 is 1:2.5:(3-8), and the reagent used for amination is iminodiacetic acid, ethylenediaminetetraacetic acid, or hydroxyethyliminodiacetic acid.

6. The method for preparing the carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional as described in claim 1, characterized in that, In step S4, the modified resin catalyst is acidified using an H ion exchange reagent, which is a hydrochloric acid solution or a nitric acid solution, with a concentration of 3-8 wt.%.

7. A carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional, characterized in that, It was prepared by the method for preparing a carboxylic acid resin catalyst for the hydration of acrolein to 3-hydroxypropional as described in any one of claims 1-6.

8. The application of the carboxylic acid resin catalyst as described in claim 7 for the hydration of acrolein to 3-hydroxypropional, characterized in that, It was packed into a fixed-bed reactor, using a 5-15 wt.% acrolein aqueous solution as feed, and heated at 30-60°C with a mass hourly space velocity of 0.5-5 h⁻¹. -1 Under certain conditions, continuous feeding causes acrolein to undergo a hydration reaction, yielding 3-hydroxypropionaldehyde.

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