A method for preparing 2,3-butanediol from ethanol
By adding metal salt additives to the photocatalytic reaction, combining semiconductor photocatalysts and cocatalysts, the problem of difficult reaction selectivity in the prior art is solved, and the efficient selectivity and high conversion rate of 2,3-butanediol are achieved , reduces the generation of by-products.
Patent Information
- Application Number
- CN202111339250.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-11-12
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2041-11-12
AI Technical Summary
In the prior art, in the process of photocatalytic conversion of ethanol to 2,3-butanediol, reaction selectivity is difficult to improve, and the by-product is mainly acetaldehyde, and the production cost is relatively high.
By adding metal salt additives to the photocatalytic reaction, combining semiconductor photocatalysts and cocatalysts, the reaction selectivity and rate are regulated, and the selectivity and photoenergy utilization of 2,3-butanediol are improved.
The selectivity of 2,3-butanediol and the conversion rate of ethanol are significantly improved, the utilization rate of light energy is improved, and the generation of by-products is reduced.
Smart Images
Figure QLYQS_1 
Figure BDA0003351254890000021
Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing 2,3-butanediol from ethanol, and specifically to a method for converting ethanol into 2,3-butanediol by using a semiconductor photocatalyst and a metal salt additive under light. Background Art
[0002] 2,3-Butanediol is a widely used fine chemical raw material. It can be used as a hygroscopic agent, plasticizer and coupling agent, and can also be used as a solvent and a raw material for synthetic resins. 2,3-Butanediol diacetate, which is produced by the esterification reaction of 2,3-butanediol and acetic acid, can be added to cream as a food additive. 2,3-Butanediol can be used to prepare 3-hydroxy-2-butanone (acetoin) and diacetyl through oxidative dehydrogenation. They can be used as edible flavorings and are also widely used in functional materials, pharmaceutical production and chemical synthesis. The freezing point of the left-handed isomer of 2,3-butanediol is -60°C, so it can be used as an antifreeze. In addition, methyl ethyl ketone can be obtained by removing one molecule of water from 2,3-butanediol, which can be used in the resin and paint industries and is also a high-value fuel. 1,3-butadiene can be obtained by removing two molecules of water from 2,3-butanediol, which can be used in the preparation of synthetic rubber, polyester and polyurethane.
[0003] At present, 2,3-butanediol is mainly prepared by biological fermentation. Although the fermentation process has made certain progress, the environmental requirements of the fermentation process are very high, resulting in a production cost of 60,000-130,000 yuan / ton. There are also reports on the chemical synthesis of 2,3-butanediol. For example, under ultraviolet light, ethanol can be converted into 2,3-butanediol on the surface of rutile titanium dioxide loaded with platinum (ChemCatChem2015,7,2384); under visible light, ethanol can be converted into 2,3-butanediol on an indium zinc sulfide catalyst loaded with a promoter (Chem. Commun.,2020,56,1776). In these reaction systems, there is a problem that the reaction selectivity is difficult to improve, and the main by-product is acetaldehyde.
[0004] The above-mentioned methods for chemically synthesizing 2,3-butanediol all undergo a photocatalytic process, involving the transformation of free radical intermediates. Adding metal complex additives to the system is an effective means of controlling free radical reactions (Science Bulletin 2018, 63, 1006), but it is mostly used for free radical intermediates with more complex structures, and the reaction is generally a homogeneous system. Summary of the invention
[0005] The significance of the present invention is to improve the selectivity and rate of photocatalytic conversion of ethanol into 2,3-butanediol and hydrogen by adding a metal salt additive.
[0006] The solvent is not added or added to the reactor, ethanol, semiconductor photocatalyst and metal salt additive are added, the atmosphere in the reaction system is replaced with an inert atmosphere, the reaction is carried out under light irradiation, and the 2,3-butanediol product is obtained by purification.
[0007] Semiconductor photocatalysts are composed of two parts: a semiconductor carrier and a co-catalyst; the co-catalyst is loaded on the semiconductor photocarrier.
[0008] The promoter includes one or more of gold, silver, copper, iron, palladium, platinum, nickel, ruthenium, rhodium, iridium, cadmium, indium, bismuth, nickel phosphide, cobalt phosphide, molybdenum disulfide, tungsten disulfide, copper sulfide, graphene, and cobalt sulfide.
[0009] The mass ratio of the co-catalyst to the semiconductor light carrier is 0.001 to 0.2.
[0010] The metal salt additive includes one or more of metal organic salts and metal inorganic salts of lithium, sodium, potassium, calcium, strontium, barium, aluminum, gallium, indium, vanadium, chromium, niobium, molybdenum, tungsten, manganese, iron, cobalt, copper, zinc, lanthanum, cerium, and praseodymium.
[0011] The reaction process is as follows:
[0012]
[0013] The semiconductor carrier includes one or more of the following:
[0014] Oxygen-containing compounds of one or more of Ti, Zr, Fe, Zn, Sr, La, W, Mo, V, Cu, Ce, In, Ta or Nb; sulfur-containing compounds of one or more of Cd, Zn, W, Mo or Bi; nitrogen-containing compounds of one or more of Ti, Ga, Ge or Ta.
[0015] The solvent is one or more of water, acetonitrile, ethanol, tetrahydrofuran, n-hexane, acetone, ethyl acetate, dichloromethane, toluene and chloroform.
[0016] The metal organic salt includes one or more of formates, acetates, oxalates, hydrogen oxalates, citrates, tartrates, and acetylacetonates.
[0017] The metal inorganic salt includes one or more of metal halides, sulfates, sulfites, thiosulfates, carbonates, bicarbonates, nitrates, phosphates, hydrogen phosphates, dihydrogen phosphates, borates, silicates, molybdates, and chromates.
[0018] The volume ratio of the solvent to ethanol is 0-100, the mass fraction of the semiconductor photocatalyst to the total mass of the system is 0.02-5%, the mass ratio of the metal salt additive to the semiconductor photocatalyst is 0.1-10, stirring, light reaction under inert atmosphere, the selected light wavelength is 300-700nm, the reaction temperature is 0-100℃, and the light reaction time is 1-100h.
[0019] The volume ratio of solvent to ethanol is preferably 0-10, the mass ratio of co-catalyst to semiconductor photocarrier is preferably 0.01-0.1, the mass fraction of semiconductor photocatalyst to the total mass of the system is preferably 0.1-1%, and the mass ratio of metal salt additive to semiconductor photocatalyst is preferably 0.5-5.
[0020] The inert atmosphere is an atmosphere of one or more gases selected from argon, nitrogen, and helium.
[0021] The wavelength of light is preferably 300 to 500 nm, the reaction temperature under light irradiation is preferably 5 to 40° C., and the light irradiation reaction time is preferably 20 to 100 h.
[0022] Compared with the prior art, the present invention introduces a metal salt additive to adjust the selectivity, and has the following advantages: (1) the selectivity of 2,3-butanediol is improved; (2) the conversion rate of ethanol is improved; (3) the utilization rate of light energy is improved, that is, the quantum yield is improved. DETAILED DESCRIPTION
[0023] In order to further explain the present invention in detail, several specific implementation cases are given below, but the present invention is not limited to these embodiments.
[0024] Embodiment 1:
[0025] 0.9 mL of ethanol, 0.1 mL of acetone, 2 mg of sodium citrate, and 10 mg of titanium dioxide loaded with metal platinum (mass loading amount is 1%) were added to a quartz reaction tube, and Ar was replaced for 5 min in a glove box. The reaction was sealed and stirred at 30 ° C for 20 h under 365 nm LED light. The selectivity of 2,3-butanediol was 44%, the quantum yield was 3%, and the conversion rate of ethanol was 21.2 mmol g cat. - 1 h -1 .
[0026] Embodiment 2:
[0027] 0.8 mL of ethanol, 0.2 mL of acetone, 4 mg of copper acetate, and 10 mg of zinc sulfide loaded with metal gold (mass loading amount is 1%) were added to a quartz reaction tube, and Ar was replaced for 5 min in a glove box. The reaction was sealed and stirred at 30 ° C for 10 h under 365 nm LED light. The selectivity of 2,3-butanediol was 78%, the quantum yield was 2.6%, and the conversion rate of ethanol was 15.3 mmol g cat. -1 h -1 .
[0028] Embodiment 3:
[0029] 0.9 mL of ethanol, 0.1 mL of ethyl acetate, 3 mg of potassium oxalate, and 5 mg of molybdenum disulfide-loaded gallium nitride (mass loading amount is 3%) were added to a quartz reaction tube, and Ar was replaced for 5 min in a glove box. The reaction was sealed and stirred at 25 ° C for 10 h under irradiation of a 400-700 nm xenon lamp. The selectivity of 2,3-butanediol was 69%, the quantum yield was 1.2%, and the conversion rate of ethanol was 10.6 mmol g cat. -1 h -1 .
[0030] Embodiment 4:
[0031] 1.0 mL of ethanol, 5 mg of sodium hydrogen phosphate, and 5 mg of cadmium sulfide loaded with cobalt phosphide (mass loading amount is 5%) were added to a quartz reaction tube, replaced with N2 for 5 min in a glove box, sealed, and stirred at 20 ° C for 10 h under 455 nm LED light. The selectivity of 2,3-butanediol was 82%, the quantum yield was 3.6%, and the conversion rate of ethanol was 26.8 mmol g cat. -1 h -1 .
[0032] Embodiment 5:
[0033] 1.0 mL of ethanol, 5 mg of cobalt acetylacetonate, and 2 mg of bismuth vanadate loaded with copper (mass loading of 2%) were added to a quartz reaction tube, replaced with N2 for 5 min in a glove box, and then sealed and stirred at 40 °C for 50 h under 455 nm LED light. The selectivity of 2,3-butanediol was 55%, the quantum yield was 2.4%, and the conversion rate of ethanol was 18.4 mmol g cat. -1 h -1 .
[0034] Embodiment 6:
[0035] 0.6 mL of ethanol, 0.4 mL of dichloromethane, 1 mg of cerium acetylacetonate, and 8 mg of indium oxide loaded with metal ruthenium (mass loading amount is 0.5%) were added to a quartz reaction tube, and N2 was replaced for 5 min in a glove box. The reaction was sealed and stirred at 40 °C for 40 h under irradiation with a 350-700 nm xenon lamp. The selectivity of 2,3-butanediol was 62%, the quantum yield was 2.1%, and the conversion rate of ethanol was 14.6 mmol g cat. -1 h -1 .
[0036] Embodiment 7:
[0037] 0.3 mL of ethanol, 0.7 mL of acetonitrile, 5 mg of copper tartrate, and 1 mg of indium zinc sulfide loaded with metal nickel (mass loading amount is 4%) were added to a quartz reaction tube, replaced with N2 for 5 min in a glove box, sealed, and stirred at 25 ° C for 50 h under 535 nm LED light irradiation. The selectivity of 2,3-butanediol was 70%, the quantum yield was 4.3%, and the conversion rate of ethanol was 22.9 mmol g cat. -1 h -1 .
[0038] Embodiment 8:
[0039] 0.8 mL of ethanol, 0.2 mL of water, 10 mg of manganese acetylacetonate, and 10 mg of iridium-loaded (3% mass loading) cadmium sulfide were added to a quartz reaction tube, replaced with N2 for 5 min in a glove box, and then sealed and stirred at 25 °C for 5 h under 475 nm LED light. The selectivity of 2,3-butanediol was 74%, the quantum yield was 5.2%, and the conversion rate of ethanol was 29.8 mmol g cat. -1 h -1 .
[0040] Embodiment 9:
[0041] 0.8 mL of ethanol, 0.2 mL of toluene, 3 mg of cerium nitrate, and 7 mg of cadmium sulfide loaded with nickel phosphide (mass loading amount is 20%) were added to a quartz reaction tube, replaced with N2 for 5 min in a glove box, and then sealed and stirred at 45 °C for 45 h under 455 nm LED light. The selectivity of 2,3-butanediol was 88%, the quantum yield was 2.6%, and the conversion rate of ethanol was 13.8 mmol g cat. -1 h -1 .
[0042] Embodiment 10:
[0043] 0.8 mL of ethanol, 0.2 mL of benzene, 5 mg of sodium molybdate, and 10 mg of graphene-loaded titanium dioxide (mass loading of 10%) were added to a quartz reaction tube, and the reaction was carried out in a glove box with Ar substitution for 5 min. The reaction was sealed and stirred at 5 °C for 20 h under 380 nm LED light irradiation. The selectivity of 2,3-butanediol was 32%, the quantum yield was 0.8%, and the conversion rate of ethanol was 15.5 mmol g cat. - 1 h -1 .
[0044] Embodiment 11:
[0045] 0.8 mL of ethanol, 0.2 mL of tetrahydrofuran, 5 mg of ferric iodide, and 10 mg of titanium dioxide loaded with metal palladium (mass loading amount is 1%) were added to a quartz reaction tube, and Ar was replaced for 5 min in a glove box. The reaction was sealed and stirred at 25 ° C for 20 h under 380 nm LED light. The selectivity of 2,3-butanediol was 20%, the quantum yield was 0.4%, and the conversion rate of ethanol was 25.5 mmol g cat. -1 h -1 .
[0046] Embodiment 12:
[0047] 1.0 mL of ethanol, 5 mg of cerium acetylacetonate, and 5 mg of zinc sulfide loaded with tungsten disulfide (mass loading amount of 5%) were added to a quartz reaction tube, and the tube was replaced with Ar in a glove box for 5 min. The tube was sealed and stirred at 35 °C for 30 h under 355 nm LED light irradiation. The selectivity of 2,3-butanediol was 89%, the quantum yield was 5.9%, and the conversion rate of ethanol was 23.3 mmol g cat. -1 h -1 .
[0048] Embodiment 13:
[0049] 1.0 mL of ethanol, 1 mg of praseodymium nitrate, and 1 mg of zinc sulfide loaded with metal rhodium (mass loading amount of 0.2%) were added to a quartz reaction tube, and the reaction was carried out in a glove box with Ar substitution for 5 min. The reaction was sealed and stirred at 25 °C for 30 h under 355 nm LED light irradiation. The selectivity of 2,3-butanediol was 81%, the quantum yield was 2.7%, and the conversion rate of ethanol was 25.1 mmol g cat. -1 h -1 .
[0050] Embodiment 14:
[0051] 0.5 mL of ethanol, 0.5 mL of n-hexane, 1 mg of manganese acetylacetonate, and 5 mg of indium oxide were added to a quartz reaction tube, and the tube was replaced with Ar in a glove box for 5 min. The tube was sealed and stirred at 25 °C for 30 h under 380 nm LED light. The selectivity of 2,3-butanediol was 50%, the quantum yield was 1.4%, and the conversion rate of ethanol was 3.6 mmol g cat. -1 h -1 .
[0052] Embodiment 15:
[0053] 0.8 mL of ethanol, 0.2 mL of n-hexane, 1 mg of cerium acetylacetonate, and 5 mg of cadmium sulfide loaded with metal gold (mass loading amount is 1%) were added to a quartz reaction tube, and Ar was replaced for 5 min in a glove box. The reaction was sealed and stirred at 25 ° C for 30 h under 455 nm LED light. The selectivity of 2,3-butanediol was 92%, the quantum yield was 6.2%, and the conversion rate of ethanol was 28.3 mmol g cat. -1 h -1 .
[0054] Comparative Example 1:
[0055] 0.8 mL of ethanol, 0.2 mL of n-hexane, and 5 mg of cadmium sulfide loaded with metal gold (mass loading of 1%) were added to a quartz reaction tube without adding metal salt additives. The reaction was carried out in a glove box with Ar replacement for 5 min. The reaction was sealed and stirred at 25 °C for 30 h under 455 nm LED light. The selectivity of 2,3-butanediol was 20%, the quantum yield was 0.3%, and the conversion rate of ethanol was 10.8 mmol g cat. -1 h -1 .
Claims
1. A method for preparing 2,3-butanediol from ethanol, characterized in that: Adding ethanol, semiconductor photocatalyst and metal salt additives to the reactor without or with a solvent, replacing the atmosphere in the reaction system with an inert atmosphere, irradiating the reaction with light, and purifying to obtain the 2,3-butanediol product; Semiconductor photocatalysts are composed of semiconductor carriers and co-catalysts. The co-catalysts are loaded on the semiconductor photocarriers. The promoter includes one or more of gold, silver, copper, iron, palladium, platinum, nickel, ruthenium, rhodium, iridium, cadmium, indium, bismuth, nickel phosphide, cobalt phosphide, molybdenum disulfide, tungsten disulfide, copper sulfide, graphene, and cobalt sulfide; The mass ratio of the co-catalyst to the semiconductor photocarrier is 0.001~0.2; The metal salt additive includes one or more of metal organic salts and metal inorganic salts of lithium, sodium, potassium, calcium, strontium, barium, aluminum, gallium, indium, vanadium, chromium, niobium, molybdenum, tungsten, manganese, iron, cobalt, copper, zinc, lanthanum, cerium, and praseodymium; The metal organic salt includes one or more of formates, acetates, oxalates, hydrogen oxalates, citrates, tartrates, and acetylacetonates; The metal inorganic salt includes one or more of metal halides, sulfates, sulfites, thiosulfates, carbonates, bicarbonates, nitrates, phosphates, hydrogen phosphates, dihydrogen phosphates, borates, silicates, molybdates, and chromates.
2. The method according to claim 1, characterized in that: The reaction process is as follows: 。 3. The method according to claim 1 or 2, characterized in that: in, The semiconductor carrier includes one or more of the following: Oxygen-containing compounds of one or more of Ti, Zr, Fe, Zn, Sr, La, W, Mo, V, Cu, Ce, In, Ta or Nb; sulfur-containing compounds of one or more of Cd, Zn, W, Mo or Bi; nitrogen-containing compounds of one or more of Ti, Ga, Ge or Ta.
4. The method according to claim 1, characterized in that: The solvent is one or more of water, acetonitrile, ethanol, tetrahydrofuran, n-hexane, acetone, ethyl acetate, dichloromethane, toluene and chloroform.
5. The method according to claim 1, characterized in that: The volume ratio of the solvent to ethanol is 0-100, the mass fraction of the semiconductor photocatalyst to the total mass of the system is 0.02-5%, the mass ratio of the metal salt additive to the semiconductor photocatalyst is 0.1-10, stirring, light reaction under inert atmosphere, the selected light wavelength is 300-700 nm, the reaction temperature is 0-100 °C, and the light reaction time is 1-100 h.
6. The method according to claim 1, characterized in that: The volume ratio of solvent to ethanol is 0-10, the mass ratio of co-catalyst to semiconductor photocarrier is 0.01-0.1, the mass fraction of semiconductor photocatalyst in the total mass of the system is 0.1-1%, and the mass ratio of metal salt additive to semiconductor photocatalyst is 0.5-5. The inert atmosphere is one or more of argon, nitrogen and helium; The light wavelength is 300~500 nm, the reaction temperature under illumination is 5~40℃, and the illumination reaction time is 20~100 h.