CN112871205A - Preparation method of high-activity low-byproduct propylene gas-phase epoxidation catalyst - Google Patents
Preparation method of high-activity low-byproduct propylene gas-phase epoxidation catalyst Download PDFInfo
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Abstract
The invention discloses a preparation method of a high-activity low-byproduct propylene gas-phase epoxidation catalyst. The defect site assistant and the S assistant are added in the preparation process of the catalyst, so that titanium-rich defect sites suitable for Au loading are obtained, amorphous species on the catalyst are stabilized by S, the high-activity propylene gas-phase epoxidation catalyst is further obtained, and alkali metal ions are introduced together with the S assistant, so that the production probability of byproducts can be reduced, and the conversion rate of propylene, the selectivity of PO and the hydrogen efficiency are greatly improved.
Description
Technical Field
The invention belongs to the technical field of catalytic synthesis, and particularly relates to a preparation method of a propylene gas-phase epoxidation catalyst.
Background
At present, all production devices of liquid-phase HPPO process use methanol as solvent. However, the methanol solvent also contributes to the HPPO process. Firstly, methanol is easy to generate solvolysis side reaction with propylene oxide product to generate high boiling point propane diAlcohol monomethyl ether and the like. These by-products not only severely reduce the selectivity of propylene oxide, but also increase the difficulty of wastewater treatment. Secondly, the methanol solvent must be recycled, and complicated refining treatment (including hydrogenation, rectification and resin adsorption) is required before recycling, so that the HPPO process flow is complicated, and the investment and energy consumption are high. Worse still, the recycled methanol solvent still has over ten and even over twenty trace impurities (including fusel, aldehydes, ethers, esters and oxacycles) difficult to remove after complicated refining treatments. These trace impurities return to the reactor with the circulating methanol, accelerating the deactivation of the catalyst, severely shortening the life cycle and the life of the catalyst. Thus, propylene and H2O2HPPO processes for the production of PO by liquid phase epoxidation also have significant disadvantages.
For the above reasons, researchers at home and abroad have been unique to a propylene gas phase epoxidation process which does not involve organic solvents and can keep the advantage of green chemistry. One of the routes for the gas phase epoxidation of propylene in the presence of hydrogen with molecular oxygen as the oxidant is the propylene gas phase epoxidation route. H was first reported in 19982/O2The study of the gas phase epoxidation reaction with propylene on a Au/Ti-HMS catalyst found. In the process, Au on the catalyst activates hydrogen and oxygen to firstly form hydrogen peroxide species, and then the hydrogen peroxide species is transferred to a Ti center to carry out epoxidation reaction with propylene, and the reaction can be realized only by the cooperation of Au-Ti active centers. Most of the current researches on propylene gas phase epoxidation catalysts still focus on taking Au as an active center and loading the Au on a titanium-containing molecular sieve. Research results show that in order to obtain high-activity Au species and epoxidized Ti centers as much as possible and better approach reactants, the titanium silicalite molecular sieve is modified after being synthesized, so that more active Ti sites are exposed and more defect sites for Au loading are generated, and amorphous Ti species can cause ineffective decomposition of hydrogen peroxide.
The prior art shows that the theoretical extreme value of the content of framework titanium in the titanium-silicon molecular sieve is 2.5 percent, namely the molar ratio of silicon to titanium is 40:1, and the result limits the quantity of Ti active sites of the TS-1 molecular sieve. Researchers have reduced the silicon-titanium ratio for the purpose of increasing the framework titanium, but at the same time have the problem of large amounts of amorphous titanium species.
Disclosure of Invention
In order to make up the defects of the prior art, the catalyst for preparing propylene oxide by gas-phase epoxidation of propylene provided by the invention is an Au-loaded titanium silicalite molecular sieve, the chemical composition of the Au-loaded titanium silicalite molecular sieve is Au/TS-1, the content of each component in the catalyst is calculated according to the mass ratio, the titanium silicalite molecular sieve TS-1 accounts for 98-99.8%, and the content of Au accounts for 0.2-2%.
The invention is realized by the following technical scheme:
a preparation method of a catalyst for preparing propylene oxide by gas-phase epoxidation of propylene is characterized in that: the preparation method of the catalyst specifically comprises the following steps:
(1) uniformly mixing a defect site auxiliary agent, a silicon source, a template agent and deionized water to obtain a silicon source hydrolysate A;
(2) uniformly mixing a titanium source and a complexing agent, dropwise adding the mixture into the silicon source hydrolysate A, and uniformly stirring to obtain a silicon-titanium hydrolysate B;
(3) heating the silicon-titanium hydrolysate B to remove alcohol, supplementing corresponding water and S auxiliary agent, and uniformly stirring to obtain silicon-titanium gel C;
(4) the silicon-titanium gel C is filled into a crystallization kettle and crystallized for 20-120h at the temperature of 150-210 ℃ to obtain a crystallization product, and the titanium-silicon molecular sieve TS-1 is obtained after filtration, separation, drying, washing and roasting;
(5) loading gold on the titanium silicalite TS-1 by an impregnation method to obtain the catalyst, namely powdery Au/TS-1;
further, the auxiliary agent in the step (3) is one or a mixture of more of sodium sulfite, sodium bisulfite, potassium sulfite, potassium bisulfite, rubidium sulfite, rubidium bisulfite, cesium sulfite and cesium bisulfite.
Preferably, the defect site assistant in step (1) is one or a mixture of soluble starch, sodium carboxymethyl cellulose, polyacrylamide and polyethyleneimine.
Further, the titanium-silicon ratio of the titanium-silicon molecular sieve is 31-33; the content of framework titanium is 3.0-3.2 wt%;
further, the step (5) comprises the following steps: according to the mass ratio, the titanium-silicon molecular sieve TS-1 is 98-99.8%, the Au is 0.2-2%, 0.01mol/L chloroauric acid aqueous solution is taken, the pH value is adjusted to 7.0, TS-1 molecular sieve carrier is added, the pH value of the solution is kept to 7.0, and after stirring, suction filtration, washing, drying and hydrogen atmosphere roasting are carried out, so as to obtain the powdery catalyst Au/TS-1.
Further, the stirring temperature in the step (5) is preferably 60-70 ℃, the stirring time is preferably 1-2h, the drying temperature is preferably 60-90 ℃, the roasting temperature is preferably 350-400 ℃, and the roasting time is preferably 4-8 h.
Furthermore, the titanium silicalite TS-1 accounts for 98.5-99.7%, and the Au accounts for 0.3-1.5%.
Further, the composition of the substance molar ratio in the silicon-titanium gel C in the step (3) is SiO2：TiO2: template agent: defect site assistant: auxiliary agent: h2O＝1：(0.033-0.05)：(0.25-0.4)：(0.001-0.01)：(0.001-0.01)：(25-30)；
More preferably, the silicon-titanium gel C has a composition of SiO in terms of molar ratio2：TiO2: template agent: defect site assistant: auxiliary agent: h2O＝1:(0.035-0.05):(0.25-0.35):(0.002-0.008):(0.003-0.01):(25-30)。
Further, the drying temperature in the step (4) is preferably 80-120 ℃, and the roasting temperature is preferably 500-650 ℃.
Preferably, in the step (1), the silicon source is one or a mixture of more of tetraethyl orthosilicate, tetramethyl orthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate.
Further, the template agent in the step (1) is tetrapropylammonium hydroxide (TPAOH).
Preferably, in the step (2), the titanium source is one or a mixture of more of tetraethyl orthotitanate, tetrabutyl orthotitanate, tetraisopropyl titanate, titanium trichloride and titanium tetrachloride, and more preferably tetrabutyl orthotitanate.
Further, in the step (2), the complexing agent is one of isopropanol, acetylacetone and ethanol.
The catalyst prepared by the invention can be applied to the preparation of propylene oxide by propylene gas phase epoxidation. The catalytic propylene gas phase epoxidation reaction is carried out in a fixed bed reactor at normal pressure. The reaction temperature is 140 ℃ and 200 ℃, and the reaction gas composition is C3H6/H2/O2/N21/1/1/7 (volume ratio), and the space velocity is 5000--1·g-1 catThe reaction tail gas is detected and analyzed by gas chromatography FID and TCD. The reaction was run for 10 hours each time, and the results of the reaction at 6 hours were compared.
The invention has the beneficial effects that:
adding an S auxiliary agent in the preparation process of the titanium silicalite TS-1, wherein the S auxiliary agent can greatly reduce the pH value of a synthetic glue solution, so that the crystallization process is slowed down, the crystallization process is matched with the speed of Ti entering a framework and the growth of crystals, the content of framework titanium is 3.1 percent, and the TS-1 with high framework titanium content, which cannot be obtained by the traditional preparation method, is obtained;
and S in the auxiliary agent can also stabilize amorphous titanium generated in the synthesis process to form Ti-S-O bonds and reduce H pairs2O2Decomposition of (2); na + and K + ions introduced simultaneously with S can reduce the acidity of the catalyst and inhibit the occurrence of side reactions. The defect site auxiliary agent is added, so that a better environment can be provided for subsequent Au loading, and the loading of Au on the TS-1 molecular sieve with lower isoelectric point is facilitated, so that the loading rate and the stability of Au are improved;
in addition, the sulfur group introduced into the auxiliary agent can also play a role in stabilizing the Au active center. The catalyst obtained by the invention has excellent catalytic activity, has positive effects on the aspects of improving PO selectivity and hydrogen efficiency, avoids the multi-step post-treatment process of the existing catalyst, simplifies the preparation process of the catalyst, has simple operation method, reduces the cost of the catalyst, and is beneficial to the industrial popularization of the catalyst.
Detailed Description
Comparative example 1
Mixing 45g of SiO2Silica sol with a content of 30%Adding into a three-neck flask with a jacket, adding 5.6g of TPABr and 90g of water, and stirring at normal temperature for 0.5h to obtain a silicon source hydrolysate; dissolving 3.8g of tetrabutyl titanate in 5.0g of acetylacetone, stirring for 15min to obtain a titanium source hydrolysate, dropwise adding the titanium source hydrolysate into the silicon source hydrolysate, and stirring for 0.5 h; finally adding 29g of n-butylamine, stirring for 1h, filling the obtained solution into a crystallization kettle, crystallizing for 3d at 175 ℃, washing and drying a crystallized product, and then washing the crystallized product by adopting 1M HCl aqueous solution (the liquid-solid ratio is 50ml g)-1) And roasting the mixture for 6 hours at 550 ℃ in air, and testing by XRF to obtain a TS-1 sample with a Si/Ti ratio of 50.5.
And (2) taking 20.8mL of chloroauric acid aqueous solution with the concentration of 0.01mol/L, adding 100mL of deionized water for dilution, adjusting the pH value to 7.0, adding 1g of the TS-1 molecular sieve carrier obtained above, keeping the pH value of the solution to be 7.0, stirring for 1h at 65 ℃, performing suction filtration and washing, drying for 10h at 80 ℃, and roasting for 4h at 400 ℃ in a hydrogen atmosphere to obtain 0.38% Au/TS-1-A.
Comparative example 2
Adding 46.2g of tetraethyl orthosilicate into a beaker, stirring, adding 44g of 25 wt% TPAOH aqueous solution and 38g of water, and hydrolyzing at 30 ℃ for 2 hours to obtain a silicon source hydrolysis mixture; dissolving 3.8g of tetrabutyl titanate in 18.7g of isopropanol, and then stirring for 30min to obtain a titanium source hydrolysis mixture; mixing a hydrolysis mixture of a titanium source and a silicon source, removing alcohol at 80 ℃ for 1.5h, supplementing water for 50.2g, stirring for 30min, filling the obtained transparent glue solution into a crystallization kettle for crystallization, crystallizing at 170 ℃ for 3d, washing and drying the obtained crystallized product, and washing with 1M HCl aqueous solution (the liquid-solid ratio is 50ml g)-1) And roasting the mixture for 6 hours at 550 ℃ in air, and testing by XRF to obtain a TS-1 sample with a Si/Ti ratio of 50.8.
The Au loading procedure of comparative example 1 was repeated to obtain a catalyst having 0.38% Au/TS-1-B.
Comparative example 3
Adding 0.2g of soluble starch and 38g of water into a beaker, stirring, then sequentially adding 44g of 25 wt% TPAOH aqueous solution and 46.2g of tetraethyl orthosilicate, and hydrolyzing for 3 hours at 40 ℃ to obtain a silicon source hydrolysis mixture; dissolving 3.8g of tetrabutyl titanate in 18.7g of isopropanol, and then stirring for 30min to obtainA titanium source hydrolysis mixture; mixing a hydrolysis mixture of a titanium source and a silicon source, removing alcohol at 80 ℃ for 1.5h, supplementing water for 50.2g, stirring for 30min, filling the obtained transparent glue solution into a crystallization kettle for crystallization, crystallizing at 170 ℃ for 3d, washing and drying the obtained crystallized product, and washing with 1M HCl aqueous solution (the liquid-solid ratio is 50ml g)-1) And roasting the mixture for 6 hours at 550 ℃ in air, and testing by XRF to obtain a TS-1 sample with a Si/Ti ratio of 51.2.
The Au loading procedure of comparative example 1 was repeated to obtain a catalyst with 0.38% Au/TS-1-C.
Comparative example 4
Adding 38g of water into a beaker, stirring, sequentially adding 44g of 25 wt% TPAOH aqueous solution and 46.2g of tetraethyl orthosilicate, and hydrolyzing at 40 ℃ for 3 hours to obtain a silicon source hydrolysis mixture; dissolving 3.8g of tetrabutyl titanate in 18.7g of isopropanol, and then stirring for 30min to obtain a titanium source hydrolysis mixture; mixing a hydrolysis mixture of a titanium source and a silicon source, removing alcohol at 80 ℃ for 1.5h, supplementing water with 50.2g and 0.045g of sodium sulfite, stirring for 30min, putting the obtained transparent glue liquid into a crystallization kettle for crystallization, crystallizing at 170 ℃ for 3d, washing and drying the obtained crystallized product, and washing with 1M HCl aqueous solution (the liquid-solid ratio is 50ml g)-1) And roasting the mixture for 6 hours at 550 ℃ in air, and testing by XRF to obtain a TS-1 sample with a Si/Ti ratio of 31.2. The Au loading procedure of comparative example 1 was repeated to obtain a catalyst having 0.38% Au/TS-1-D.
Comparative example 5
Adding 0.2g of soluble starch and 38g of water into a beaker, stirring, then sequentially adding 44g of 25 wt% TPAOH aqueous solution and 46.2g of tetraethyl orthosilicate, and hydrolyzing for 3 hours at 40 ℃ to obtain a silicon source hydrolysis mixture; dissolving 3.8g of tetrabutyl titanate in 18.7g of isopropanol, and then stirring for 30min to obtain a titanium source hydrolysis mixture; mixing a hydrolysis mixture of a titanium source and a silicon source, removing alcohol for 1.5h at 80 ℃, supplementing water for 50.2g and 0.045g of ammonium sulfite, stirring for 30min, putting the obtained transparent glue liquid into a crystallization kettle for crystallization, crystallizing for 3d at 170 ℃, washing and drying the obtained crystallized product, and then washing with 1M HCl aqueous solution (the liquid-solid ratio is 50ml g)-1) S obtained by roasting at 550 ℃ for 6h in air and testing by XRFTS-1 samples with an i/Ti ratio of 31.6. The Au loading procedure of comparative example 1 was repeated to obtain a catalyst having 0.38% Au/TS-1-E.
Example 1
Adding 0.2g of soluble starch and 38g of water into a beaker, stirring, then sequentially adding 44g of 25 wt% TPAOH aqueous solution and 46.2g of tetraethyl orthosilicate, and hydrolyzing for 3 hours at 30 ℃ to obtain a silicon source hydrolysis mixture; dissolving 3.8g of tetrabutyl titanate in 18.7g of isopropanol, and then stirring for 30min to obtain a titanium source hydrolysis mixture; removing alcohol at 80 deg.C for 1.5h, adding water 50.2g and 0.045g sodium sulfite, stirring for 30min, crystallizing the obtained transparent glue solution in a crystallization kettle, placing the obtained solution in the crystallization kettle, crystallizing at 175 deg.C for 3d, washing the crystallized product with 1M HCl aqueous solution (liquid-solid ratio of 50ml g)-1) And roasting the mixture for 6 hours at 550 ℃ in air, and testing by XRF to obtain a TS-1 sample with a Si/Ti ratio of 31.2.
The procedure of supporting Au in comparative example 1 was repeated, followed by carrying out the supporting of Au to obtain a catalyst No. 0.38% Au/TS-1-F.
Example 2
Example 1 is repeated, the defect site assistant soluble starch in the TS-1 preparation process is replaced by sodium carboxymethylcellulose, polyacrylamide and polyethyleneimine, the amount of the component substances is kept unchanged, and after crystallization, washing and drying are carried out, and then washing is carried out by adopting 1M HCl aqueous solution (the liquid-solid ratio is 50ml g)-1) And roasting the mixture in air at 550 ℃ for 6 hours, and obtaining TS-1 samples with Si/Ti ratios of 31.6, 31.9 and 31.8 through XRF test, and then carrying out Au loading to obtain the catalysts with the numbers of 0.38% Au/TS-1-G, 0.38% Au/TS-1-H and 0.38% Au/TS-1-I.
Example 3
Example 1 was repeated, the amounts of tetraethyl orthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate in the preparation of TS-1 were changed to the amounts of tetramethyl orthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate in the preparation of TS-1, and after crystallization, washing and drying were carried out, and then washing was carried out with 1M aqueous HCl (liquid-solid ratio: 50ml g/g)-1) Roasting in air at 550 ℃ for 6h, XRF testing to obtain TS-1 samples with Si/Ti ratios of 31.9, 32.0 and 31.8, and loading Au to obtain the catalyst with the number of 0.38%Au/TS-1-J、0.38％Au/TS-1-K、0.38％Au/TS-1-L。
Example 4
Example 1 was repeated, tetrabutyl titanate in the preparation of TS-1 was replaced with tetramethyl titanate, tetraethyl titanate and tetrapropyl titanate, the amounts of the component substances were kept constant, and after crystallization, washing and drying were carried out, and then washing with 1M aqueous HCl (liquid-solid ratio: 50ml g/g)-1) And roasting the mixture in air at 550 ℃ for 6 hours, and obtaining TS-1 samples with Si/Ti ratios of 31.7, 31.9 and 32.0 through XRF test, and then carrying out Au loading to obtain the catalysts with the numbers of 0.38% Au/TS-1-M, 0.38% Au/TS-1-N and 0.38% Au/TS-1-O.
Example 5
Example 1 was repeated, the complexing agent in the preparation of TS-1 was replaced with isopropanol and ethanol, the amounts of the component substances were kept constant, and after crystallization, washing and drying were carried out, followed by washing with 1M HCl aqueous solution (liquid-to-solid ratio 50ml g/g)-1) And roasting the mixture in air at 550 ℃ for 6 hours, and obtaining TS-1 samples with Si/Ti ratios of 31.6, 31.9 and 31.8 through XRF test, and then carrying out Au loading to obtain the catalysts with the numbers of 0.38% Au/TS-1-P and 0.38% Au/TS-1-Q.
Example 6
Example 1 was repeated, the amount of the S auxiliary agent in the preparation of TS-1 was changed to sodium bisulfite, potassium sulfite, rubidium bisulfite, cesium sulfite, and cesium bisulfite, and after crystallization, the product was washed with 1M HCl aqueous solution (liquid-solid ratio: 50ml g/g) after washing and drying-1) And roasting the mixture in air at 550 ℃ for 6 hours, and obtaining TS-1 samples with Si/Ti ratios of 32.1, 31.9, 32.2, 32.1, 31.8 and 32.0 through XRF test, and then carrying out Au loading to obtain the catalysts with the serial numbers of 0.38% Au/TS-1-R, 0.38% Au/TS-1-S, 0.38% Au/TS-1-T, 0.38% Au/TS-1-U, 0.38% Au/TS-1-V and 0.38% Au/TS-1-W.
Example 7
The catalytic propylene gas phase epoxidation reaction is carried out in a fixed bed reactor at normal pressure. The reaction temperature is 160 ℃, and the reaction gas composition is C3H6/H2/O2/N21/1/1/7 (volume ratio), and the space velocity is 7000 mL. h-1·g-1 catAnd reaction tail gas is detected and analyzed by gas chromatography FID and TCD. The reaction was run for 10 hours each time, and the results of the reaction at 6 hours were compared.
The results are shown in Table 1. Wherein, the hydrogen efficiency means the effective utilization rate of hydrogen, and the calculation mode is the amount of PO generated substance/H2The amount of converted material of (a) 100%.
TABLE 1 gas phase epoxidation Performance data of Au/TS-samples
As can be seen from the results in the table, the defect site assistant, the S assistant and Na+、K+The addition of the ions greatly improves the activity of the catalyst, so that the conversion rate, the selectivity and the hydrogen efficiency of the propylene are improved to a great extent; is an effect which cannot be achieved by adding the defect site assistant or the S assistant alone.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical solutions and the inventive concepts of the present invention within the technical scope of the present invention.
Claims (10)
1. A preparation method of a catalyst for preparing propylene oxide by gas-phase epoxidation of propylene is characterized by comprising the following steps:
(1) uniformly mixing a defect site auxiliary agent, a silicon source, a template agent and deionized water to obtain a silicon source hydrolysate A;
(2) uniformly mixing a titanium source and a complexing agent, dropwise adding the mixture into the silicon source hydrolysate A, and uniformly stirring to obtain a silicon-titanium hydrolysate B;
(3) heating the silicon-titanium hydrolysate B to remove alcohol, supplementing corresponding water and S auxiliary agent, and uniformly stirring to obtain silicon-titanium gel C;
(4) the silicon-titanium gel C is filled into a crystallization kettle and crystallized for 20-120h at the temperature of 150-210 ℃ to obtain a crystallization product, and the titanium-silicon molecular sieve TS-1 is obtained after filtration, separation, drying, washing and roasting;
(5) loading gold on the titanium silicalite TS-1 by an impregnation method to obtain the catalyst, namely powdery Au/TS-1;
the defect site auxiliary agent is one or a mixture of more of soluble starch, sodium carboxymethylcellulose, polyacrylamide and polyethyleneimine;
the S auxiliary agent is one or a mixture of more of sodium sulfite, sodium bisulfite, potassium sulfite, potassium bisulfite, rubidium sulfite, rubidium bisulfite, cesium sulfite and cesium bisulfite.
2. The production method according to claim 1,
the titanium-silicon ratio of the titanium-silicon molecular sieve is 31-33; the content of framework titanium is 3.0-3.2 wt%;
the silicon-titanium gel C in the step (3) has the composition of SiO in the molar ratio2：TiO2: template agent: defect site assistant: and (2) S auxiliary agent: h2O＝1：(0.033-0.05)：(0.25-0.4)：(0.001-0.01)：(0.001-0.01)：(25-30)；
In the step (4), the drying temperature is 80-120 ℃, and the roasting temperature is 500-650 ℃.
3. The method according to claim 2, wherein the molar ratio of the substances in the silicon-titanium gel C in the step (3) is SiO2：TiO2: template agent: defect site assistant: auxiliary agent: h2O＝1:(0.035-0.05):(0.25-0.35):(0.002-0.008):(0.003-0.01):(25-30)。
4. The method according to claim 1, wherein the step (5) comprises the steps of:
according to the mass ratio, the titanium silicalite TS-1 is 98-99.8%, the Au is 0.2-2%, the chloroauric acid water solution is taken, the pH value is adjusted to 7.0, the TS-1 molecular sieve carrier is added, the pH value of the solution is kept to 7.0, the solution is stirred, filtered, washed, dried and roasted in hydrogen atmosphere, and the powdery catalyst Au/TS-1 is obtained;
in the step (5), the stirring temperature is 60-70 ℃, the stirring time is 1-2h, the drying temperature is 60-90 ℃, the roasting temperature is 350-.
5. The preparation method of claim 4, wherein the titanium silicalite TS-1 is 98.5-99.7% and the Au content is 0.3-1.5%.
6. The preparation method according to claim 1, wherein in the step (1), the silicon source is one or a mixture of more of tetraethyl orthosilicate, tetramethyl orthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate; the template agent is tetrapropylammonium hydroxide.
7. The preparation method according to claim 1, wherein in the step (2), the titanium source is one or a mixture of more of tetraethyl orthotitanate, tetrabutyl orthotitanate, tetraisopropyl titanate, titanium trichloride and titanium tetrachloride, and is further preferably tetrabutyl orthotitanate; the complexing agent is one of isopropanol, acetylacetone and ethanol.
8. A catalyst prepared by the method of any one of claims 1 to 7.
9. Use of the catalyst of claim 8 in the gas phase epoxidation of propylene to propylene oxide.
10. The use as claimed in claim 9, wherein the reaction is carried out in an atmospheric fixed bed reactor at a temperature of 140 ℃ to 200 ℃ and a reaction gas composition C3H6/H2/O2/N21/1/1/7 (volume ratio), space velocity of 5000--1.g-1cat。
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112871204A (en) * | 2021-01-19 | 2021-06-01 | 中国科学院大连化学物理研究所 | High-activity propylene gas-phase epoxidation catalyst and preparation method thereof |
| CN115155653A (en) * | 2022-08-12 | 2022-10-11 | 华东理工大学 | Sulfur-assistant-modified titanium-silicon molecular sieve-supported gold catalyst and preparation method and application thereof |
| CN115845916A (en) * | 2022-12-23 | 2023-03-28 | 大连理工大学 | Preparation method and application of Au/TS-1 nano microsphere catalyst for propylene gas phase epoxidation |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100234623A1 (en) * | 2009-03-13 | 2010-09-16 | Tokyo Metropolitan University | Method for producing propylene oxide |
| CN102502688A (en) * | 2011-10-31 | 2012-06-20 | 大连理工大学 | Titanium silicon molecular sieve modifying method based on mixed solution of TPAOH (tetrapropylammonium hydroxide) with sulfur-contained metal salts |
| CN107032366A (en) * | 2016-08-10 | 2017-08-11 | 大连理工大学 | A kind of method for preparing the HTS TS 1 with high skeleton Ti content |
| CN107265474A (en) * | 2017-05-26 | 2017-10-20 | 中国石油大学(华东) | A kind of honeycomb hexagon HTS and its production and use |
| CN108793179A (en) * | 2017-12-15 | 2018-11-13 | 中国科学院大连化学物理研究所 | A kind of Titanium Sieve Molecular Sieve and its preparation and application |
| CN109928942A (en) * | 2017-12-15 | 2019-06-25 | 中国科学院大连化学物理研究所 | Bimetallic additive modification preparing epoxypropane by epoxidation of propene catalyst and application |
| CN110903265A (en) * | 2018-09-14 | 2020-03-24 | 中国科学院大连化学物理研究所 | Method for carrying out gas phase propylene epoxidation reaction in palladium membrane reactor |
| CN111017946A (en) * | 2019-12-25 | 2020-04-17 | 中国科学院大连化学物理研究所 | Preparation method of titanium-containing molecular sieve for olefin epoxidation process |
| CN111036290A (en) * | 2019-12-25 | 2020-04-21 | 中国科学院大连化学物理研究所 | Preparation method of titanium silicalite molecular sieve for inhibiting byproduct generation in propylene epoxidation process |
-
2021
- 2021-01-19 CN CN202110070615.1A patent/CN112871205A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100234623A1 (en) * | 2009-03-13 | 2010-09-16 | Tokyo Metropolitan University | Method for producing propylene oxide |
| CN102502688A (en) * | 2011-10-31 | 2012-06-20 | 大连理工大学 | Titanium silicon molecular sieve modifying method based on mixed solution of TPAOH (tetrapropylammonium hydroxide) with sulfur-contained metal salts |
| CN107032366A (en) * | 2016-08-10 | 2017-08-11 | 大连理工大学 | A kind of method for preparing the HTS TS 1 with high skeleton Ti content |
| CN107265474A (en) * | 2017-05-26 | 2017-10-20 | 中国石油大学(华东) | A kind of honeycomb hexagon HTS and its production and use |
| CN108793179A (en) * | 2017-12-15 | 2018-11-13 | 中国科学院大连化学物理研究所 | A kind of Titanium Sieve Molecular Sieve and its preparation and application |
| CN109928942A (en) * | 2017-12-15 | 2019-06-25 | 中国科学院大连化学物理研究所 | Bimetallic additive modification preparing epoxypropane by epoxidation of propene catalyst and application |
| CN110903265A (en) * | 2018-09-14 | 2020-03-24 | 中国科学院大连化学物理研究所 | Method for carrying out gas phase propylene epoxidation reaction in palladium membrane reactor |
| CN111017946A (en) * | 2019-12-25 | 2020-04-17 | 中国科学院大连化学物理研究所 | Preparation method of titanium-containing molecular sieve for olefin epoxidation process |
| CN111036290A (en) * | 2019-12-25 | 2020-04-21 | 中国科学院大连化学物理研究所 | Preparation method of titanium silicalite molecular sieve for inhibiting byproduct generation in propylene epoxidation process |
Non-Patent Citations (3)
| Title |
|---|
| ZHANG, T ET AL.: "Synthesis of Titanium Silicalite-1 with High Catalytic Performance for 1-Butene Epoxidation by Eliminating the Extraframework Ti", 《ACS OMEGA》 * |
| 易涵潇: "丙烯和氧气在Au/TS-1催化剂上的选择氧化反应研究", 《中国优秀硕士学位论文全文数据库 工程科技I辑》 * |
| 邵秀丽: "TS-1分子筛催化剂的制备和表征", 《工业催化》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112871204A (en) * | 2021-01-19 | 2021-06-01 | 中国科学院大连化学物理研究所 | High-activity propylene gas-phase epoxidation catalyst and preparation method thereof |
| CN115155653A (en) * | 2022-08-12 | 2022-10-11 | 华东理工大学 | Sulfur-assistant-modified titanium-silicon molecular sieve-supported gold catalyst and preparation method and application thereof |
| CN115845916A (en) * | 2022-12-23 | 2023-03-28 | 大连理工大学 | Preparation method and application of Au/TS-1 nano microsphere catalyst for propylene gas phase epoxidation |
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