Bimetal catalyst for catalyzing epoxide
By employing a bimetallic synergistic design and deep pretreatment process in the catalyst, a Ti-O-Co-Ce composite active structure is formed, which solves the problem of the difficulty in achieving both activity and selectivity in traditional catalysts, and realizes the selective conversion of epoxides with high efficiency.
Patent Information
- Application Number
- CN202511242595.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2026-05-05
AI Technical Summary
Existing single-metal or traditional bimetallic catalysts lack effective synergistic effects, making it difficult to balance activity and selectivity. The active components are poorly dispersed, and the lack of deep pretreatment of the support results in high ash residue, easy collapse of micropores, and weak mass transfer and adsorption capacity.
Employing a bimetallic synergistic design and using activated carbon as a carrier, a Ti-O-Co-Ce composite active structure is formed through deep pretreatment, sol agglomerate breaking, aging and drying, calcination activation, and molding and sieving processes. This achieves uniform loading of active components and improves catalytic efficiency.
The activity and selectivity of the catalyst were improved, the microporous structure retention rate of activated carbon was increased to 90%, and the active components were uniformly loaded with 5-10 nm particles, resulting in a significant improvement in catalytic efficiency.
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Figure CN121972171A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bimetallic catalyst technology, specifically to a bimetallic catalyst for catalyzing epoxides. Background Technology
[0002] Bimetallic catalysts are materials that enhance catalytic performance by introducing two active metal components, such as Ti-Co, Zn-Al, and Fe-Mn, during the synthesis, ring-opening, or conversion of epoxides. These components utilize the synergistic effect between the metals, electron transfer, complementary active sites, and valence state cycling to improve catalytic performance.
[0003] Existing single-metal or traditional bimetallic catalysts lack effective synergistic effects, making it difficult to balance activity and selectivity. Single-Ti catalysts have weak oxidation capacity, and single-Co catalysts are prone to over-oxidation. Traditional bimetallic catalysts are only physically mixed without chemical bonding. Furthermore, the active components are poorly dispersed, and traditional impregnation or precipitation methods easily form agglomerated particles larger than 100 nm, resulting in insufficient exposure of effective sites. At the same time, the support is not deeply pretreated, resulting in a large amount of ash residue, easy collapse of micropores, and weak mass transfer and adsorption capacity. Summary of the Invention
[0004] The purpose of this invention is to provide a bimetallic catalyst for catalyzing epoxides, which addresses the problems of existing materials by means of bimetallic synergistic design, support structure regulation, innovative loading process, and optimized calcination regime.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a bimetallic catalyst for catalyzing epoxides, wherein the raw materials include the following components: activated carbon, titanium tetrachloride, cobalt nitrate, cerium nitrate, glacial acetic acid, and deionized water; the components and their proportions are as follows: the activated carbon proportion is 80 parts; the titanium tetrachloride proportion is 4 parts; the cobalt nitrate proportion is 6 parts; the cerium nitrate proportion is 10 parts; the glacial acetic acid proportion is 20 mL; and the deionized water proportion is 50 mL. The glacial acetic acid and deionized water are added separately and are not included in the total amount. It also includes the following steps: Step 1: Deep pretreatment of activated carbon carrier; Step 2: Preparation of active component solution; Step 3: Break up the sol agglomerates; Step 4: Aging and Drying; Step 5: Calcination and activation; Step Six: Shaping and Screening.
[0006] Preferably, the deep pretreatment of the activated carbon carrier includes the following steps: Take 80 parts of activated carbon, add 10% hydrochloric acid solution (liquid-solid ratio 5:1), place in a constant temperature water bath, stir at 60°C for 2 hours to remove ash, wash repeatedly with deionized water until the pH of the filtrate is 6.5-7.0 to ensure no chloride ion residue, transfer to a forced-air drying oven, set to 110°C and airflow of 80 m³ / h. 3 Dry for 6 hours, then cool to room temperature for later use.
[0007] Preferably, the preparation of the active component solution includes the following steps: In a fume hood, take 4.0 parts of TiCl4 and slowly add 20 mL of glacial acetic acid while stirring at low speed with a magnetic stirrer to form a pale yellow titanium sol. Separately, take 6.0 parts of cobalt nitrate and 10.0 parts of cerium nitrate, dissolve them in 30 mL of deionized water, and stir for 10 min until completely dissolved to form a red and blue mixed nitrate solution. Slowly pour the nitrate solution into the titanium sol and continue stirring for 20 min to obtain a uniform dark brown mixed sol.
[0008] Preferably, breaking the sol agglomerates includes the following steps: adding 80.0 parts of pretreated activated carbon to the mixed sol, transferring it to a high-speed disperser, setting the rotation speed to 2000 r / min and the dispersion time to 30 min, stopping the machine every 10 min to observe, and ensuring that the sol uniformly coats the surface of the activated carbon.
[0009] Preferably, the aging and drying process includes the following steps: transferring the loaded material to a vacuum drying oven, first evacuating it for 30 minutes at room temperature and -0.05 MPa to remove air bubbles, then heating it to 70°C and vacuum degree -0.08 MPa, and drying it for 10 hours to obtain a black dry gel. After removing it, it is placed in a desiccator for 4 hours to balance the moisture content.
[0010] Preferably, the calcination activation includes the following steps: placing the dry gel in a box furnace, and programming the temperature under room temperature air, from room temperature to 100°C at a heating rate of 2°C / min, and holding for 1 hour; continuing to heat from 100°C to 300°C at a heating rate of 5°C / min, and holding for 2 hours; then heating from 300°C to 600°C at a heating rate of 5°C / min, and holding for 3 hours: forming a Ti-O-Co-Ce composite active structure, and finally naturally cooling to room temperature.
[0011] Preferably, the molding and sieving process includes the following steps: pressing the calcined catalyst into tablets using a tablet press at a pressure of 10 MPa for 30 seconds, crushing it into particles, and then passing it through a 20-40 mesh sieve to remove fine powder and large pieces, thereby obtaining the finished catalyst.
[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses 80 parts of high specific surface area activated carbon as a carrier, combined with 4 parts of TiCl4, 6 parts of cobalt nitrate, and 10 parts of cerium nitrate to form a highly efficient system with Ti-Co bimetallic synergy and Ce auxiliary agent regulation. Active units are constructed through Ti-O-Co bonds, enhancing activity and selectivity. The activated carbon, after acid washing to remove impurities and precise drying, retains more than 90% of its microporous structure, increasing the specific surface area to 950 m². 2 / g, increasing substrate adsorption capacity, breaking the high-speed dispersion technology of sol agglomerates, enabling the active components to be uniformly loaded with 5-10nm particles, thus improving catalytic efficiency. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation
[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0015] This invention provides a bimetallic catalyst for catalyzing epoxides, comprising the following raw materials: activated carbon, titanium tetrachloride, cobalt nitrate, cerium nitrate, glacial acetic acid, and deionized water; the composition and proportions are as follows: activated carbon 80 parts; titanium tetrachloride 4 parts; cobalt nitrate 6 parts; cerium nitrate 10 parts; glacial acetic acid 20 mL; deionized water 50 mL. Glacial acetic acid and deionized water are added separately and are not included in the total amount. It also includes the following steps: Step 1: Deep pretreatment of activated carbon carrier; Step 2: Preparation of active component solution; Step 3: Break up the sol agglomerates; Step 4: Aging and Drying; Step 5: Calcination and activation; Step Six: Forming and Screening; Activated carbon has a particle size of 20-50 μm and a specific surface area of 800-1000 m². 2 / g, total pore volume ≥0.8cm³ 3 / g, with ash content ≤0.5%, pH (7% suspension) 6.5-7.5, iodine adsorption value ≥800mg / g; titanium tetrachloride with purity ≥99.0% and density 1.726±0.002g / cm³. 3It has a boiling point of 136.4℃ and contains no free chlorine (Cl). - The content is ≤0.1%, and the appearance is a colorless to pale yellow transparent liquid without suspended matter; cobalt nitrate has a purity ≥99.0%, water solubility ≥99.5% (25℃), particle size ≤50μm, and cobalt content ≥20.5%, pH (1% aqueous solution) 4.0-6.0, and is free from deliquescence and agglomeration; cerium nitrate has a purity ≥99.0%, water solubility ≥99.0% (25℃), and Ce 3+ The content is ≥32%, and iron (Fe) ≤0.001%, heavy metals (as Pb) ≤0.0005%; glacial acetic acid with a purity ≥99.5%, freezing point 16.6℃, and density 1.049±0.001g / cm³. 3 Furthermore, the evaporation residue is ≤0.001%, and there are no reducing substances; the deionized water has a conductivity ≤10μS / cm, pH 6.5-7.5, total organic carbon (TOC) ≤50ppb, and no particulate matter (no residue after filtration through a 0.22μm filter membrane).
[0016] The deep pretreatment of activated carbon carrier includes the following steps: Take 80 parts of activated carbon, add 10% hydrochloric acid solution (liquid-solid ratio 5:1), place in a constant temperature water bath, stir at 60℃ for 2 hours to remove ash, wash repeatedly with deionized water until the pH of the filtrate is 6.5-7.0 to ensure no chloride ion residue, transfer to a forced-air drying oven, set to 110℃ and air volume 80m³ / h. 3 Dry for 6 hours, then cool to room temperature for later use; The constant temperature water bath, model HH-S2, removes impurities such as Fe and Ca to avoid interfering with the active centers. It provides a stable temperature environment to promote the reaction between hydrochloric acid and ash, and uses precise pH test paper to ensure no chloride ion residue remains. The forced-air drying oven, model GZX-9070MBE, uses a strong airflow to quickly remove moisture, preventing the activated carbon micropores from being blocked by water (the moisture content after drying must be ≤0.5%).
[0017] In a fume hood, take 4.0 parts of TiCl4 and slowly add 20 mL of glacial acetic acid while stirring at low speed with a magnetic stirrer to form a pale yellow titanium sol. Separately, take 6.0 parts of cobalt nitrate and 10.0 parts of cerium nitrate, dissolve them in 30 mL of deionized water, and stir for 10 min until completely dissolved to form a red and blue mixed nitrate solution. Slowly pour the nitrate solution into the titanium sol and continue stirring for 20 min to obtain a homogeneous dark brown mixed sol. Add 20 mL of glacial acetic acid at a rate of 1 drop / second, while simultaneously stirring at a low speed (300 r / min) with a magnetic stirrer of model 85-2 to form a pale yellow titanium sol. Avoid local overheating that could lead to hydrolysis. The molar ratio of TiCl4 to glacial acetic acid must be strictly controlled at 1:5; otherwise, incomplete hydrolysis will result in uneven distribution of the active components.
[0018] Breaking up sol agglomerates involves the following steps: adding 80.0 parts of pretreated activated carbon to the mixed sol, transferring it to a high-speed disperser, setting the speed to 2000 r / min and the dispersion time to 30 min, stopping the machine every 10 min to observe and ensure that the sol uniformly coats the surface of the activated carbon; The high-speed disperser is model FS-1100. The speed is set to 2000 r / min and the dispersion time is 30 min. The machine is stopped every 10 min to observe the material. The material is observed to be moist granules with no obvious liquid residue. The high-speed shear force breaks the sol agglomerates, so that the active components are loaded into the micropores of activated carbon as nano-sized particles (5-10 nm), which improves the dispersion compared with the traditional impregnation method.
[0019] The aging and drying process includes the following steps: after loading, the material is transferred to a vacuum drying oven, vacuumed for 30 minutes at room temperature and -0.05MPa to remove air bubbles, heated to 70℃ and vacuum degree -0.08MPa, and dried for 10 hours to obtain a black dry gel. After removal, the material is placed in a desiccator for 4 hours to balance the moisture content. The vacuum drying oven is model DZF-6050. During the 10-hour drying process, the gas is released every 2 hours to avoid the accumulation of solvent vapor. Slow drying prevents gel cracking and preserves the porous structure of activated carbon. The pore size distribution is concentrated in 2-5nm, which is suitable for the diffusion of olefin molecules.
[0020] The calcination activation includes the following steps: the dry gel is placed in a box furnace and the temperature is programmed to rise from room temperature to 100°C at a rate of 2°C / min and held for 1 hour; the temperature is then raised from 100°C to 300°C at a rate of 5°C / min and held for 2 hours; subsequently, the temperature is raised from 300°C to 600°C at a rate of 5°C / min and held for 3 hours to form a Ti-O-Co-Ce composite active structure; finally, the gel is allowed to cool naturally to room temperature. The box furnace, model BSX2-5-12, was used to heat the carbon from room temperature to 100°C at a rate of 2°C / min, holding the temperature for 1 hour to remove residual solvents such as glacial acetic acid and water. The temperature was then further increased from 100°C to 300°C, primarily decomposing nitrates to produce Co3O4 and CeO2. Subsequently, the temperature was raised from 300°C to 600°C to form a Ti-O-Co-Ce composite active structure. 600°C was the optimal calcination temperature; below this temperature, the active components lacked sufficient crystallinity, while above this temperature, the activated carbon would ablate.
[0021] The molding and sieving process includes the following steps: the calcined catalyst is pressed into tablets using a tablet press at a pressure of 10 MPa for 30 seconds, then crushed into granules and passed through a 20-40 mesh sieve to remove fine powder and large pieces, thus obtaining the finished catalyst. The tablet press model is YP-15; the screen mesh size is 0.45-0.85mm; controlling the particle size ensures moderate fluid resistance during the reaction, while avoiding fine powder clogging the reactor.
[0022] Working principle: Through the synergistic effect of Ti-Co bimetallic compounds and the regulation of Ce additives, stable Ti-O-Co-Ce composite active centers are formed on the activated carbon support, wherein Ti... 4+ / Ti 3+ Activated epoxides, Co 3+ / Co 2+ Promotes molecular oxygen dissociation, Ce 3+ The stable structure enables efficient catalysis. The working process is as follows: after acid washing and drying pretreatment, activated carbon is mixed with TiCl4-glacial acetic acid sol and cobalt nitrate and cerium nitrate solutions. The active components are uniformly loaded through high-speed dispersion. After aging and drying and programmed temperature calcination, the active phase is formed. The product is then pressed into tablets and sieved to obtain the finished product. During the reaction, the substrate diffuses in the micropores of activated carbon and is adsorbed by the active centers, completing the selective catalytic conversion of epoxides.
[0023] 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 bimetallic catalyst for catalyzing epoxides, wherein the raw materials comprise the following components: activated carbon, titanium tetrachloride, cobalt nitrate, cerium nitrate, glacial acetic acid, and deionized water; The ingredients and proportions are as follows: 80 parts activated carbon; 4 parts titanium tetrachloride; 6 parts cobalt nitrate; 10 parts cerium nitrate; 20 mL glacial acetic acid; and 50 mL deionized water. Glacial acetic acid and deionized water are added separately and are not included in the total amount. It also includes the following steps: Step 1: Deep pretreatment of activated carbon carrier; Step 2: Preparation of active component solution; Step 3: Break up the sol agglomerates; Step 4: Aging and Drying; Step 5: Calcination and activation; Step Six: Shaping and Screening.
2. The bimetallic catalyst for catalyzing epoxides according to claim 1, characterized in that, The deep pretreatment of the activated carbon carrier includes the following steps: Take 80 parts of activated carbon, add 10% hydrochloric acid solution (liquid-solid ratio 5:1), place in a constant temperature water bath, stir at 60℃ for 2 hours to remove ash, wash repeatedly with deionized water until the pH of the filtrate is 6.5-7.0 to ensure no chloride ion residue, transfer to a forced-air drying oven, set to 110℃ and air volume 80m³ / h. 3 Dry for 6 hours, then cool to room temperature for later use.
3. The bimetallic catalyst for catalyzing epoxides according to claim 1, characterized in that, The preparation of the active component solution includes the following steps: In a fume hood, take 4.0 parts of TiCl4 and slowly add 20 mL of glacial acetic acid while stirring at low speed with a magnetic stirrer to form a pale yellow titanium sol. Separately, take 6.0 parts of cobalt nitrate and 10.0 parts of cerium nitrate, dissolve them in 30 mL of deionized water, and stir for 10 min until completely dissolved to form a red and blue mixed nitrate solution. Slowly pour the nitrate solution into the titanium sol and continue stirring for 20 min to obtain a uniform dark brown mixed sol.
4. The bimetallic catalyst for catalyzing epoxides according to claim 1, characterized in that, Breaking the sol agglomerates includes the following steps: adding 80.0 parts of pretreated activated carbon to the mixed sol, transferring it to a high-speed disperser, setting the speed to 2000 r / min and the dispersion time to 30 min, stopping the machine every 10 min to observe, and ensuring that the sol uniformly coats the surface of the activated carbon.
5. The bimetallic catalyst for catalyzing epoxides according to claim 1, characterized in that, The aging and drying process includes the following steps: the loaded material is transferred to a vacuum drying oven, vacuumed for 30 minutes at room temperature and -0.05MPa to remove air bubbles, heated to 70℃ and vacuum degree -0.08MPa, and dried for 10 hours to obtain a black dry gel. After removal, the material is placed in a desiccator for 4 hours to balance the moisture content.
6. The bimetallic catalyst for catalyzing epoxides according to claim 1, characterized in that, The calcination activation includes the following steps: placing the dry gel in a box furnace, and programming the temperature under room temperature air, from room temperature to 100°C at a heating rate of 2°C / min, and holding for 1 hour; continuing to heat from 100°C to 300°C at a heating rate of 5°C / min, and holding for 2 hours; then heating from 300°C to 600°C at a heating rate of 5°C / min, and holding for 3 hours: forming a Ti-O-Co-Ce composite active structure, and finally naturally cooling to room temperature.
7. The bimetallic catalyst for catalyzing epoxides according to claim 1, characterized in that, The molding and sieving process includes the following steps: the calcined catalyst is pressed into tablets using a tablet press at a pressure of 10 MPa for 30 seconds, then crushed into granules and passed through a 20-40 mesh sieve to remove fine powder and large pieces, thus obtaining the finished catalyst.