A catalyst for preparing methyl ethyl carbonate and a preparation method and application thereof

Abstract

The present application relates to a kind of catalyst for preparing methyl ethyl carbonate, for preparing methyl ethyl carbonate with dimethyl carbonate and ethanol as raw material.The catalyst is composite catalyst M1 / FeM2O x Wherein, M1 is selected from one or several of Pd, Pt, Ni and Co metal state, M2 is selected from at least one of metal Mg, Zr, Ce and Zn, iron is divalent or trivalent, and x is 1-10.The present application also relates to a kind of preparation method of catalyst for preparing methyl ethyl carbonate, and a kind of method for preparing methyl ethyl carbonate.The composite catalyst M1 / FeM2O x Provided by the present application, due to the presence of M1, iron greatly improves the catalytic performance of M2 oxide, solves the problem of low activity of heterogeneous catalyst and easy loss of active component.

Description

Technical Field

[0001] This invention relates to the technical field of preparing methyl ethyl carbonate, and more particularly to a catalyst for preparing methyl ethyl carbonate and its preparation method, as well as a method for preparing methyl ethyl carbonate by transesterification of dimethyl carbonate and ethanol. Background Technology

[0002] Ethyl methyl carbonate (EMC) has the molecular formula C4H8O3 and a molecular weight of 104.1. It is a colorless, transparent, flammable liquid with a density (at 20°C) of 1.00 g / cm³. 3 With a melting point of 55℃, boiling point of 109℃, flash point of 23℃, and dielectric constant of 2.9 c / vm, EMC is immiscible with water, has a slight ethanol-like odor, and is non-toxic. It is a widely used green chemical product. In recent years, it has been discovered that EMC, when used as a solvent for lithium-ion battery electrolytes (lithium cobalt oxide, lithium manganese oxide, etc.), has significant advantages over other carbonate materials. When used as a solvent for lithium-ion battery electrolytes, EMC can improve the ionic conductivity of lithium ions, enhance the stability, reliability, safety performance, and memory effect of lithium batteries, and also significantly extend the battery's lifespan. With the widespread application of lithium-ion batteries in various fields, the synthesis industry of EMC has also developed rapidly.

[0003] Regarding the synthesis of EMC, the literature has reported a large number of homogeneous catalysts, mainly including soluble alkali metal hydroxides, alkoxides, alkali metal carbonates, and organic bases, such as potassium hydroxide, sodium methoxide, sodium carbonate, and triethylamine; acidic catalysts, including inorganic acids such as H2SO4, and also organic acids, such as organic sulfonic acids, organic carboxylic acids, and organic phosphoric acids, have shown good catalytic performance.

[0004] Patent CN1900047A discloses a heterogeneous catalytic synthesis of ethyl methyl carbonate using a supported catalyst. The active components of the catalyst are metal oxides and alkali metal oxides such as KOH, NaOH, NaHCO3, CaO, and ZrO2. The catalyst support is alumina, activated carbon, molecular sieves, etc. The co-catalyst components are transition metal oxides or group IB and IIB metal oxides. CN101704751A prepared a supported solid base catalyst with active components such as sodium oxide, potassium oxide, magnesium oxide, calcium oxide, and barium oxide. The support is activated carbon or mesoporous carbon. It has high catalytic efficiency in a batch reactor, but the catalyst needs to be calcined after filtration before it can be recycled. Li Lin et al. [Synthetic Chemistry, 2004(1)12, 197-200] used K2CO3 as a catalyst to catalyze this reaction, discussed the effects of reaction conditions such as the ratio of reactants, the amount of catalyst, and the reaction time, and analyzed the separation process of the reaction products. Homogeneous organic bases exhibit good activity as catalysts, but separation is difficult. The greatest advantage of heterogeneous catalysts is their immiscibility with the reaction solution; after the reaction, the catalyst can be recovered through simple filtration, and the subsequent separation of reactants is easy. In contrast, heterogeneous catalysts have very low catalytic activity, low conversion rates of reactants, and low selectivity and yield of the target product EMC. Summary of the Invention

[0005] Based on the above, the purpose of this invention is to solve the technical problems of poor activity and poor stability of heterogeneous catalysts in the prior art, and to provide a catalyst for the preparation of methyl ethyl carbonate, which has the characteristics of high activity and selectivity and that the active components are not easily lost.

[0006] To address the aforementioned technical problems, in a first aspect, the present invention provides a catalyst for the preparation of methyl ethyl carbonate, particularly a catalyst for preparing methyl ethyl carbonate from dimethyl carbonate and ethanol, wherein the catalyst is a composite catalyst M1 / FeM2O. x M1 is selected from one or more of the metallic states of Pd, Pt, Ni and Co, M2 is selected from at least one of the metals Mg, Zr, Ce and Zn, iron is divalent or trivalent, and x is 1-10.

[0007] As a specific embodiment of the present invention, preferably, M2 in the catalyst is Mg or Zn; and / or M1 in the catalyst is Co and Ni.

[0008] As a specific embodiment of the present invention, preferably, the mass content of M1 in the catalyst is 0.1-5% based on M1 metal; and / or the mass content of Fe is 5-80% based on Fe metal, preferably 10-70%.

[0009] In a specific embodiment of the present invention, preferably, x is 1.5-9.5.

[0010] Therefore, in a second aspect, the present invention provides a method for preparing the above-mentioned catalyst for preparing methyl ethyl carbonate, comprising the following steps:

[0011] (1) Dissolve the soluble salt containing M1, the soluble salt containing M2, and the soluble salt containing iron in water to obtain solution A;

[0012] (2) Dissolve the precipitant in water to obtain solution B;

[0013] (3) Under stirring conditions, solution B is added dropwise to solution A, then aged and filtered. The resulting filter cake is washed with deionized water, dried and calcined to obtain the catalyst precursor. Preferably, the dropping rate is 2-8 mL / min and / or the stirring rate is 300-1000 rpm.

[0014] (4) The catalyst precursor is reduced to obtain catalyst M1 / FeM2O x .

[0015] As a specific embodiment of the present invention, preferably, the soluble salt containing M1 is selected from at least one of nitrates, hydrochlorides, sulfates and halides, more preferably nitrates; and / or the soluble salt containing M2 is selected from at least one of nitrates, hydrochlorides, sulfates and halides, more preferably nitrates; and / or the soluble salt containing iron is selected from at least one of nitrates, hydrochlorides, sulfates and halides, more preferably nitrates.

[0016] As a specific embodiment of the present invention, preferably, the precipitant is selected from at least one of alkali metal carbonates and alkali metal hydroxides, more preferably an alkali metal carbonate; more preferably, the alkali metal is selected from at least one of Li, Na, K, and Rb, and even more preferably Na.

[0017] As a specific embodiment of the present invention, preferably, the aging conditions include: a temperature of 40~90°C. o C, further optimized to 50~80 o C; time 1~100 h, more preferably 1~40 h; and / or the drying conditions include: temperature 100~140 o C, time 12-48h; and / or the calcination conditions include: temperature 200~900 o C, further optimized from 300~700 o C, time 3-7h; and / or the reduction conditions include: in a reducing atmosphere in which reducing gas is formed, temperature 200-900°C. oC, further optimized from 300~700 o C, time 2-5h; more preferably, the reducing gas is selected from hydrogen, a mixture of hydrogen and argon.

[0018] As a specific embodiment of the present invention, preferably, in step (3), in order to ensure complete precipitation of salt, solution B is added dropwise to solution A until the system pH ≥ 8, preferably pH ≥ 11.

[0019] Therefore, in a third aspect, the present invention provides a method for preparing ethyl methyl carbonate, wherein dimethyl carbonate and ethanol are used as raw materials, and the reaction is carried out under the catalysis of the above-mentioned catalyst or the catalyst prepared by the above-mentioned preparation method to generate ethyl methyl carbonate.

[0020] In a preferred embodiment of the present invention, the reaction temperature is 60-160°C. o C, time is 1-5h; the molar ratio of the dimethyl carbonate and the ethanol is 2-10:1; the weight ratio of the catalyst to the raw material is 0.005-0.5:1.

[0021] In a preferred embodiment of the present invention, the reaction temperature is 80-140°C. o C, the molar ratio of the dimethyl carbonate to the ethanol is 3 to 8:1, and the weight ratio of the catalyst to the raw material is 0.01 to 0.2:1.

[0022] The beneficial effects of this invention are as follows:

[0023] The composite catalyst M1 / FeM2O provided by this invention x The presence of M1 and iron greatly improves the catalytic performance of M2 oxide, solving the problems of low activity and easy loss of active components in heterogeneous catalysts.

[0024] The method for preparing the composite catalyst provided by this invention is simple, easy to operate, and easy to industrialize.

[0025] The composite catalyst provided by this invention achieves a 99.9% conversion rate of ethanol and a 99.9% selectivity for methyl ethyl carbonate when used to prepare methyl ethyl carbonate. Furthermore, the catalyst exhibits an activity decrease of less than 5% after being reused five times, demonstrating excellent technical performance. Detailed Implementation

[0026] The method provided by the present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0027] In the following examples and comparative examples, the catalyst composition was analyzed using XRD and ICP.

[0028] Example 1

[0029] Weigh out 1.8 g of nickel nitrate, 24.2 g of ferric nitrate, and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 19.7 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 600 rpm, until the pH reaches 11, then add the solution at 60°C. o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 12 hours, then at 600°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 4 h. It was then subjected to 400 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 3 hours, the catalyst Ni / FeMgO was obtained. 2.3 It contains 4.7 wt% Ni and 46 wt% iron, and is labeled as S1.

[0030] Example 2

[0031] Weigh out 0.9 g of nickel nitrate, 24.2 g of ferric nitrate, and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 27 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 800 rpm, until the pH reaches 11, then heat at 60°C. o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 16 hours, then at 600°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 4 h. It was then subjected to 450 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 6 hours, the catalyst Ni / FeMgO was obtained. 2.3 It contains 2.4 wt% Ni and 47 wt% iron, and is labeled as S2.

[0032] Example 3

[0033] Weigh out 0.5 g of nickel nitrate, 24.2 g of ferric nitrate, and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 19.7 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 400 rpm, until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 600°C.o The catalyst precursor was obtained by calcination in a C muffle furnace for 4 h. It was then subjected to 400 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 3 hours, the catalyst Ni / FeMgO was obtained. 2.3 It contains 1.3 wt% Ni and 47 wt% iron, and is labeled as S3.

[0034] Example 4

[0035] Weigh out 1.8g of nickel nitrate, 30g of ferric nitrate, and 8g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 40g of anhydrous sodium carbonate in 200 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 500 rpm, continuing until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 18 hours, then at 500°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 500 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Ni / FeMg was obtained. 0.4 O 1.8 It contains 4.6 wt% Ni and 56 wt% iron, and is labeled as S4.

[0036] Example 5

[0037] Weigh out 0.6 g of nickel nitrate, 3 g of ferric nitrate, and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 36 hours, then at 300°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Ni / FeMg was obtained. 7.3 O 8.6 It contains 3.7 wt% Ni and 13 wt% iron, and is labeled as S5.

[0038] Example 6

[0039] Weigh out 0.4 g of nickel nitrate, 3 g of ferric nitrate, and 18.9 g of zinc nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C. o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Ni / FeZn was obtained. 8.1 O 9.4 It contains 1.1 wt% Ni and 7.6 wt% iron, and is labeled as S6.

[0040] Example 7

[0041] Weigh out 0.9 g of nickel nitrate, 12 g of ferric nitrate, and 12 g of zinc nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, continuing until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 400°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 500 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 6 hours, the catalyst Ni / FeZn was obtained. 1.3 O 2.3 It contains 2.3 wt% Ni and 30 wt% iron, and is labeled as S7.

[0042] Example 8

[0043] Weigh out 0.4 g of nickel nitrate, 24.2 g of ferric nitrate, and 3 g of zinc nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. oThe catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Ni / FeZn was obtained. 0.2 O 1.5 It contains 0.8 wt% Ni and 61 wt% iron, and is labeled as S8.

[0044] Example 9

[0045] Weigh out 0.3g of cobalt nitrate, 24.2g of ferric nitrate, and 14.8g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Co / FeMg1.1O was obtained. 2.4 It contains 1.7 wt% Co and 14 wt% iron, and is labeled as S9.

[0046] Example 10

[0047] Weigh out 1.1 g of cobalt nitrate, 10 g of ferric nitrate, and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C. o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction of C for 5 hours, the catalyst Co / FeMg was obtained. 0.3 O 1.7 It contains 4.7 wt% Co and 31 wt% iron, and is labeled as S10.

[0048] Example 11

[0049] Weigh out 0.6 g of nickel nitrate, 10 g of ferric nitrate, and 18 g of cerium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, continuing until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction of C for 5 hours, the catalyst Ni / FeCe was obtained. 1.7 O3, containing 1.2 wt% Ni and 14 wt% iron, is labeled as S11.

[0050] Example 12

[0051] Weigh out 0.5 g of chloroplatinic acid, 24.2 g of ferric nitrate, and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g of anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C. o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. o The catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Pt / FeMgO was obtained. 2.3 It contains 1.2 wt% platinum and 45 wt% iron, and is labeled as S12.

[0052] Example 13

[0053] Weigh out 0.5 g sodium chloropalladium, 24.2 g ferric nitrate, and 14.8 g magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 20 g anhydrous sodium carbonate in 100 mL of water to form solution B; add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm, until the pH reaches 11, then heat at 60°C... o After aging at C for 10 hours, the filter was used. The resulting filter cake was washed three times with deionized water and then cooled at 120°C. o Dry in a C oven for 24 hours, then at 300°C. oThe catalyst precursor was obtained by calcination in a C muffle furnace for 6 h. It was then subjected to 600 °C in a 10 v% hydrogen / argon mixed atmosphere. o After high-temperature reduction at C for 5 hours, the catalyst Pd / FeMgO was obtained. 2.3 It contains 1.2 wt% palladium and 45 wt% iron, and is labeled as S13.

[0054] Comparative Example 1

[0055] Weigh out 1.8 g of nickel nitrate, 24.2 g of ferric nitrate, and 14.8 g of magnesium nitrate, and dissolve them in 500 mL of water to form solution A. Dissolve 19.7 g of anhydrous sodium carbonate in 100 mL of water to form solution B. While stirring at 700 rpm, add solution B dropwise to solution A at a rate of 5 mL / min at room temperature. Continue adding until the pH reaches 11, then heat at 60°C. o After aging at C for 10 hours, the mixture was filtered, and the resulting filter cake was washed three times with water and then heated at 120°C. o Dry in a C oven for 24 hours, then at 600°C. o After calcination in a C muffle furnace for 4 h, a comparative catalyst NiO / Fe2O3-MgO was obtained, in which the Ni content was 5.7 wt% and the iron content was 56 wt%, and it was labeled as C1.

[0056] Comparative Example 2

[0057] Weigh out 24.2 g of ferric nitrate and 14.8 g of magnesium nitrate and dissolve them in 500 mL of water to form solution A; dissolve 19.7 g of anhydrous sodium carbonate in 100 mL of water to form solution B. Add solution B dropwise to solution A at a rate of 5 mL / min at room temperature while stirring at 700 rpm. Continue adding until the pH reaches 11, then heat at 60°C. o After aging at C for 10 hours, the mixture was filtered, and the resulting filter cake was washed three times with water and then heated at 120°C. o Dry in a C oven for 24 hours, then at 600°C. o The comparative catalyst Fe2O3-MgO, with an iron content of 60%, was obtained by calcination in a C muffle furnace for 4 h and labeled as C2.

[0058] Example 14

[0059] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S1 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 8 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0060] Example 15

[0061] 135 g of dimethyl carbonate, 23 g of ethanol, and 25 g of catalyst S2 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 3:1, and the weight ratio of catalyst to reaction solution was 0.15:1). The reaction was carried out at 100 °C for 8 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0062] Example 16

[0063] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S3 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 90 °C for 6 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0064] Example 17

[0065] 225 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S4 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 5:1, and the weight ratio of catalyst to reaction solution was 0.06:1). The reaction was carried out at 110 °C for 6 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0066] Example 18

[0067] 270 g of dimethyl carbonate, 23 g of ethanol, and 20 g of catalyst S5 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 6:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 80 °C for 5 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0068] Example 19

[0069] 315 g of dimethyl carbonate, 23 g of ethanol, and 20 g of catalyst S6 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 7:1, and the weight ratio of catalyst to reaction solution was 0.06:1). The reaction was carried out at 90 °C for 2 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0070] Example 20

[0071] 360 g of dimethyl carbonate, 23 g of ethanol, and 10 g of catalyst S7 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 8:1, and the weight ratio of catalyst to reaction solution was 0.03:1). The reaction was carried out at 130 °C for 2 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0072] Example 21

[0073] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S8 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 3 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0074] Example 22

[0075] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S9 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 4 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0076] Example 23

[0077] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S10 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 5 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0078] Example 24

[0079] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S11 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 4 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0080] Example 25

[0081] 180 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S12 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 7 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0082] Example 26

[0083] 270 g of dimethyl carbonate, 23 g of ethanol, and 15 g of catalyst S13 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.05:1). The reaction was carried out at 100 °C for 5 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 99.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0084] Example 27

[0085] The catalyst used in Example 14 was filtered, dried, and reused. The operating conditions were as follows: 270 g of dimethyl carbonate, 23 g of ethanol, and 15 g of the recovered catalyst were placed in a 100 mL three-necked flask equipped with a distillation column (molar ratio of methyl ethyl carbonate to ethanol: 4:1, weight ratio of catalyst to reaction solution: 0.05:1), and reacted at 100°C for 5 hours. After the reaction, the flask was cooled to room temperature. Gas chromatography analysis of the liquid product showed a 99.9% conversion of ethanol and a 99.9% selectivity for methyl ethyl carbonate. The catalyst was reused five times, and its performance remained stable.

[0086] Comparative Example 3

[0087] 180 g of dimethyl carbonate, 23 g of ethanol, and 25 g of catalyst C1 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 8 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 76.9% and the selectivity of methyl ethyl carbonate was 99.9%.

[0088] Comparative Example 4

[0089] 180 g of dimethyl carbonate, 23 g of ethanol, and 25 g of catalyst C2 were placed in a 100 mL three-necked flask equipped with a distillation column (the molar ratio of methyl ethyl carbonate to ethanol was 4:1, and the weight ratio of catalyst to reaction solution was 0.07:1). The reaction was carried out at 100 °C for 8 hours. After the reaction was completed, the flask was cooled to room temperature. The liquid product was analyzed by gas chromatography, which showed that the conversion rate of ethanol was 85.4% and the selectivity of methyl ethyl carbonate was 99.9%.

[0090] As can be seen from the comparison between Example 14 and Comparative Example 3, the conversion rate of ethanol decreased significantly during the preparation of ethyl methyl carbonate because the catalyst C1 was not reduced.

[0091] As can be seen from the comparison between Example 14 and Comparative Example 4, the conversion rate of ethanol decreased significantly during the preparation of ethyl methyl carbonate because catalyst C2 does not contain nickel.

[0092] In summary, the composite catalyst M1 / FeM2O provided by this invention... x The presence of M1 and iron significantly improves the catalytic performance of M2 oxide, solving the problems of low activity and easy loss of active components in heterogeneous catalysts. The composite catalyst provided by this invention is used to prepare ethyl methyl carbonate, achieving an ethanol conversion rate of 99.9% and a selectivity of 99.9% for ethyl methyl carbonate. Furthermore, the catalyst exhibits an activity decrease of less than 5% after being reused five times, demonstrating excellent technical performance.

[0093] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50-90, in this specification it means specifically listing values ​​such as 51-89, 52-88… and 69-71 and 70-71, etc. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0094] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for preparing methyl ethyl carbonate, characterized in that, Dimethyl carbonate and ethanol are reacted as raw materials to produce ethyl methyl carbonate under the catalysis of a catalyst, wherein the catalyst is a composite catalyst M1 / FeM2O. x M1 is selected from one or more of the metallic states of Pd, Pt, Ni and Co, M2 is selected from at least one of the metals Mg, Zr, Ce and Zn, iron is divalent or iron is divalent and trivalent coexisting, and x is 1-10.

2. The method according to claim 1, characterized in that, In the catalyst, M2 is Mg or Zn; and / or in the catalyst, M1 is Co and Ni.

3. The method according to claim 1 or 2, characterized in that, In the catalyst, the mass content of M1 is 0.1-5% based on M1 metal; and / or the mass content of Fe is 5-80% based on Fe metal.

4. The method according to claim 3, characterized in that, In the catalyst, the mass content of Fe, calculated as Fe metal, is 10-70%.

5. The method according to claim 1 or 2, characterized in that, The value of x is 1.5-9.

5.

6. The method according to claim 1 or 2, characterized in that, The method for preparing the catalyst includes the following steps: (1) Dissolve the soluble salt containing M1, the soluble salt containing M2, and the soluble salt containing iron in water to obtain solution A; (2) Dissolve the precipitant in water to obtain solution B; (3) Under stirring conditions, solution B is added dropwise to solution A, then aged and filtered. The resulting filter cake is washed with deionized water, dried and calcined to obtain the catalyst precursor; and / or the stirring rate is 300-1000 rpm. (4) The catalyst precursor is reduced to obtain catalyst M1 / FeM2O x .

7. The method according to claim 6, characterized in that, The soluble salt containing M1 is selected from at least one of nitrates, sulfates, and halides; and / or the soluble salt containing M2 is selected from at least one of nitrates, sulfates, and halides; and / or the soluble salt containing iron is selected from at least one of nitrates, sulfates, and halides.

8. The method according to claim 7, characterized in that, The soluble salt containing M1 is selected from nitrates; and / or the soluble salt containing M2 is selected from nitrates; and / or the soluble salt containing iron is selected from nitrates.

9. The method according to claim 6, characterized in that, The precipitant is selected from at least one of alkali metal carbonates and alkali metal hydroxides.

10. The method according to claim 9, characterized in that, The precipitant is selected from alkali metal carbonates; and / or the alkali metal is selected from at least one of Li, Na, K, and Rb.

11. The method according to claim 10, characterized in that, The alkali metal is Na.

12. The method according to claim 6, characterized in that, The aging conditions include: temperature 40 ~ 90℃; time 1 ~ 100 h; and / or the drying conditions include: temperature 100 ~ 140℃; time 12 ~ 48 h; and / or the calcination conditions include: temperature 200 ~ 900℃; time 3 ~ 7 h; and / or the reduction conditions include: in a reducing atmosphere formed by reducing gas, temperature 200 ~ 900℃; time 2 ~ 5 h.

13. The method according to claim 12, characterized in that, The aging conditions include: a temperature of 50~80℃ and / or a time of 1~40 h; and / or the calcination conditions include: a temperature of 300~700℃; and / or the reduction temperature of 300~700℃; and / or the reducing gas is selected from hydrogen, a mixture of hydrogen and argon.

14. The method according to claim 6, characterized in that, In step (3), solution B is added dropwise to solution A until the pH of the system is ≥8.

15. The method according to claim 6, characterized in that, In step (3), solution B is added dropwise to solution A until the pH of the system is ≥11.

16. The method according to claim 1 or 2, characterized in that, The reaction is carried out at a temperature of 60-160°C for 1-5 hours; and / or the molar ratio of dimethyl carbonate to ethanol is 2-10:1; and / or the weight ratio of catalyst to raw material is 0.005-0.5:

1.

17. The method according to claim 1 or 2, characterized in that, The reaction temperature is 80 ~ 140℃; and / or, the molar ratio of the dimethyl carbonate to the ethanol is 3 ~ 8:1; and / or, the weight ratio of the catalyst to the raw material is 0.01 ~ 0.2:1.