Method for preparing glycolaldehyde dimer through one-step oxidation of ethylene

Abstract

The invention discloses a preparation method of glycolaldehyde dimer, which comprises the following step: in the presence of a titanium-silicon catalyst and an organic alkali assistant, carrying out contact reaction on hydrogen peroxide, a solvent and ethylene. According to the method disclosed by the invention, ethylene is used as a raw material, hydrogen peroxide is used as an oxidant, and a titanium-silicon catalyst and an organic alkali aid are used, so that the glycolaldehyde dimer with high added value can be generated through catalytic reaction. According to the method, the raw material ethylene is easy to obtain, the hydrogen peroxide is low in price, the supported titanium silicalite molecular sieve is cheaper than a rhodium catalyst and is not easy to inactivate, the solvent can be recycled, and the target product is high in selectivity.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound synthesis, and particularly relates to a method for preparing glycolaldehyde dimer by one-step oxidation of ethylene. Background Art

[0002] Glycolaldehyde dimer is an important fine chemical intermediate widely used in pharmaceuticals, pesticides, dyes, and other organic syntheses. Existing methods for preparing glycolaldehyde dimer mainly include formaldehyde hydroformylation, thermal fragmentation of sugar alcohols, and biological methods.

[0003] At present, among the chemical synthesis methods of glycolaldehyde dimer, a more common one is the formaldehyde hydroformylation reaction based on rhodium catalyst. CN105618035A uses formaldehyde as raw material, introduces carbon monoxide and hydrogen under the action of rhodium-based catalyst, and carries out hydroformylation reaction at higher temperature (100-150 DEG C) and higher pressure (5-10MPa) to generate glycolaldehyde product. Although this method has certain reactivity and product selectivity, the catalyst used is precious metal rhodium, the catalyst cost is high, and deactivation or poisoning is easily occurred during use, and carbon monoxide toxicity is high, which affects the economy of its industrial application.

[0004] CN109790098A uses a salt-poor carbohydrate feedstock containing 20 wt / wt% monosaccharides and / or disaccharides and less than 200 ppm of salt to thermally decompose and fragment to obtain ethanolaldehyde. Although the crude sugar is treated with ion exchange to reduce purification costs, the high salt content has a significant impact on the yield of ethanolaldehyde.

[0005] In his paper, "Study on the Biocatalytic Synthesis of Glycolaldehyde from Ethylene Glycol," Ning Yufeng detailed a biocatalytic method for synthesizing glycolaldehyde dimers using ethylene glycol as the raw material, by screening specific strains and utilizing alcohol dehydrogenase catalysis. This research involved screening strains capable of growing on ethylene glycol as the sole carbon source, identifying high-yielding strains, and then screening, cloning, and expressing their alcohol dehydrogenases. While biocatalytic methods offer advantages such as mild reaction conditions, a high degree of pollution avoidance, and environmental friendliness, they suffer from long production cycles, strain sensitivity to reaction conditions, and difficulty in product isolation. Summary of the Invention

[0006] The present invention aims to provide a new method for preparing glycolaldehyde dimer, which is a one-step synthesis method from ethylene, with simple steps, mild reaction conditions, clean and environmentally friendly properties, and good industrial application value.

[0007] The invention provides a method for preparing glycolaldehyde dimer, comprising the following steps: in the presence of a titanium silicon catalyst and an organic base auxiliary agent, contacting hydrogen peroxide, a solvent and ethylene for reaction.

[0008] In the present invention, the contact reaction is carried out under dynamic conditions as needed, and the specific stirring rate can be selected and adjusted according to experimental needs.

[0009] As long as the contact reaction is carried out, there is no special requirement for how the substances are contacted and in what reactor. Various reactors and contact methods are applicable to the present invention. The following exemplifies an embodiment, but the method of the present invention is not limited to this embodiment.

[0010] In the present invention, glycolaldehyde dimer refers to a substance having the following structural formula.

[0011]

[0012] According to one embodiment of the present invention, the method of the present invention is carried out in a tank reactor, and the specific steps include: in the presence of a titanium silicon catalyst and an organic base auxiliary agent, hydrogen peroxide and a solvent are prepared into a slurry and added to the tank reactor, and ethylene is introduced to cause an oxidation reaction.

[0013] There are no special requirements for the titanium silicate catalyst in the present invention. Various catalysts containing titanium silicate molecular sieves can be applied to the present invention. For example, when the process is carried out in a kettle reactor, the titanium silicate catalyst is one or more of titanium silicate molecular sieves and / or metal-loaded modified titanium silicate molecular sieves; when the process is carried out in a fixed bed reactor, various powdered catalysts can be formed and used accordingly.

[0014] In the present invention, various metal-modified catalysts are applicable to the present invention. After long-term research and testing, the present invention has found that when the metal is Au, the selectivity of glycolaldehyde dimer can be greatly improved.

[0015] In the present invention, the content of the metal in the metal-supported modified titanium silicate can be selected in a wide range and can be adjusted according to needs. Preferably, the content of the metal in the metal-supported modified titanium silicate is 0.1-5 wt %.

[0016] In the present invention, the titanium silicate molecular sieve may be various titanium silicate molecular sieves, for example, TS-1 titanium silicate molecular sieve and / or HTS titanium silicate molecular sieve. Other types of titanium silicate molecular sieves are also applicable to the present invention.

[0017] In the present invention, the titanium silicate molecular sieve can be synthesized according to various synthesis methods, or can be a commercially available product, such as TS-1 prepared according to US4410501A and / or the hollow titanium silicate molecular sieve HTS produced by Hunan Jianchang Petrochemical Co., Ltd.

[0018] In the present invention, the organic base auxiliary agent can be various organic bases, preferably one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide (TPAOH), and tetrabutylammonium hydroxide, preferably tetrapropylammonium hydroxide (TPAOH).

[0019] In the present invention, the solvent can be various solvents, preferably one or more of alcohol solvents, ketone solvents, ester solvents, nitrile solvents, and water, preferably one or more of alcohol solvents, ketone solvents, ester solvents, and nitrile solvents.

[0020] According to a preferred embodiment of the present invention, the alcohol solvent is one or more alcohol solvents with a carbon chain length of C1 to C10; further, the alcohol solvent is one or more of methanol, ethanol, and isopropanol, preferably methanol.

[0021] According to a preferred embodiment of the present invention, the ketone solvent is one or more ketone solvents with a carbon chain length of C3 to C10; further, the ketone solvent is one or more of acetone, butanone, and cyclohexanone, preferably acetone.

[0022] According to a preferred embodiment of the present invention, the ester solvent is one or more ester solvents with a carbon chain length of C2 to C10; further, the ester solvent is one or more ethyl formate and ethyl acetate, preferably ethyl formate.

[0023] According to a preferred embodiment of the present invention, the nitrile solvent is one or more nitrile solvents with a carbon chain length of C2 to C10; further, the nitrile solvent is one or more of acetonitrile, propionitrile, and butyronitrile, preferably acetonitrile.

[0024] According to a preferred embodiment of the present invention, the solvent is a mixed solvent of acetonitrile and methanol and / or acetone, and the acetonitrile content in the solvent is preferably 70-80 wt%.

[0025] In the present invention, the reaction can be carried out according to the above reaction. There is no special requirement for the content of each substance in the reaction system. The content can be selected according to the specific reaction conditions. The following is an exemplary description, but it does not limit the scope of the present invention.

[0026] According to a preferred embodiment of the present invention, based on the total weight of the materials in the reaction system at the start of the reaction, the mass content of the solvent in the system is 0-80% (the amount of the solvent does not include the amount of water introduced by hydrogen peroxide), preferably 5-75%, more preferably 50-75%, the mass content of the titanium silicon catalyst in the system is 1-25%, preferably 5-20%, the mass content of the organic base auxiliary is 0.5-5%, preferably 1-3%, and the mass content of hydrogen peroxide is 3-95%, preferably 5-90%, more preferably 5-40%.

[0027] In the present invention, the conditions for the contact reaction can be selected in a wide range and can be flexibly adjusted and selected. According to a preferred embodiment of the present invention, the reaction temperature is 25°C to 65°C, preferably 50°C to 65°C; the reaction time is 0.5h to 12h; and the reaction pressure is 0.1MPa to 2.0MPa.

[0028] In the present invention, under appropriate reaction conditions, the conversion rate of hydrogen peroxide can reach 96%, and the selectivity of glycolaldehyde dimer can reach 97%.

[0029] In the present invention, there are no special requirements for the separation step after the contact reaction. For example, solid-liquid separation can be performed to obtain the catalyst, and the separated catalyst is washed with water or a solvent, dried in an oven, and then reused.

[0030] As mentioned above, the titanium silicate catalyst can be a metal-loaded modified titanium silicate molecular sieve, preferably a gold-loaded modified titanium silicate molecular sieve, preferably Au / HTS and / or Au / TS-1, and more preferably the gold content in the gold-loaded modified titanium silicate molecular sieve is 0.1-5wt%, for example, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%. The gold content within the above range is applicable to the present invention, and the specific selection is based on the reaction requirements. In the embodiment of the present invention, 2wt% is used as an exemplary illustration.

[0031] In the present invention, there are no special requirements for the preparation method of the metal-modified titanium silicate molecular sieve. Various commonly used loading methods can be used in the present invention. The following exemplary description, but not limiting the scope of the present invention, takes the metal as Au as an example, and the preparation method includes:

[0032] A. Dissolve the gold precursor in deionized water and adjust the pH to 7-9 to obtain a gold-containing solution;

[0033] B. dispersing the titanium silicate molecular sieve in the above-mentioned gold-containing solution, aging at room temperature, solid-liquid separation, and washing to obtain a solid;

[0034] C. After the solid is dried, reduction is performed. The above method is also applicable to other metal modifications.

[0035] In the present invention, in step A, there are no special requirements for the pH regulator, and it can be various alkaline substances, preferably organic bases, such as one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide (TPAOH), and tetrabutylammonium hydroxide. In the embodiment, TPAOH is used as an example, but the scope of the present invention is not limited thereto.

[0036] In the present invention, in step B, the solid-liquid mass ratio of the titanium silicate molecular sieve to the gold-containing solution can be selected in a wide range, preferably a solid-liquid mass ratio of the titanium silicate molecular sieve to the gold-containing solution of 1:10-1:20.

[0037] In the present invention, in step B, the room temperature aging time can be selected in a wide range, preferably 12-24 hours.

[0038] In the present invention, the room temperature of room temperature aging refers to the ambient temperature during the experiment, which is generally 10-40°C.

[0039] In the present invention, there are no special requirements for the drying and reducing conditions in step C, and various commonly used drying and reducing conditions can be used.

[0040] According to a preferred embodiment of the present invention, the drying temperature is preferably 60° C.-80° C., and there is no special requirement for the drying time, which is generally sufficient to dry until constant weight.

[0041] In the present invention, the reduction conditions can be selected in a wide range, for example, the reduction is carried out in a hydrogen atmosphere, and the reduction temperature is, for example, 300°C-400°C.

[0042] According to a preferred embodiment of the present invention, reduction is carried out at 300° C.-400° C. in a H 2 / Ar atmosphere, and the hydrogen content in the H 2 / Ar atmosphere has a wide range, for example, 1-20 v %.

[0043] According to a preferred embodiment of the present invention, the metal-supported modified titanium silicalite, taking metal Au as an example, the preparation methods of Au / TS-1 and Au / HTS are as follows:

[0044] A. Dissolve the gold precursor HAuCl4·3H2O in deionized water and adjust the pH to 7-9 to promote the formation of Au(OH)3 or [Au(OH)4] - ;

[0045] B. Disperse molecular sieve TS-1 or HTS in the above solution (solid-to-liquid ratio 1:10-1:20), stir for 1-2 hours, age at room temperature for 12-24 hours, centrifuge and wash with deionized water;

[0046] C. After drying at 60°C-80°C, the catalyst was reduced at 300°C-400°C for 2h in a H2 / Ar (5% H2) atmosphere to obtain Au / TS-1 and Au / HTS supported catalysts, in which the mass content of gold was 0.1-5%.

[0047] The method of the invention uses ethylene as a raw material, hydrogen peroxide as an oxidant, a titanium silicon catalyst and an organic base auxiliary agent, and can catalyze the reaction to generate high-value-added glycolaldehyde dimer.

[0048] According to the method of the present invention, the raw material ethylene is easily available, the price of hydrogen peroxide is cheap, the supported titanium silicon molecular sieve is cheaper than the rhodium catalyst and is not easily deactivated, the solvent can be recycled, and the selectivity of the target product is high.

[0049] The production process of the present invention is simple, easy to operate, has mild reaction conditions, and is clean and environmentally friendly. DETAILED DESCRIPTION

[0050] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0051] The following specific embodiments are further detailed descriptions of the present invention. It should be noted that the following embodiments are illustrative, not restrictive, and the scope of protection of the present invention cannot be limited by the following embodiments, but should be limited by the claims.

[0052] In the following examples, catalysts Au / HTS and Au / TS-1 were prepared according to the following steps:

[0053] A. Dissolve the gold precursor HAuCl4·3H2O in deionized water and adjust the pH to 8 with TPAOH;

[0054] B. Disperse molecular sieve TS-1 or HTS in the above solution (solid-to-liquid ratio 1:15), stir for 2 hours, age at room temperature for 15 hours, centrifuge and wash with deionized water;

[0055] C. After drying at 70°C, the catalyst was reduced at 350°C for 2 h in a H2 / Ar (5% H2) atmosphere to obtain Au / TS-1 and Au / HTS supported catalysts, in which the mass content of gold was 2%.

[0056] TS-1 was prepared according to the method disclosed in US Pat. No. 4,410,501A, and had a titanium content of 2.24 wt%. HTS was a hollow titanium silicalite molecular sieve (brand ETG-1) produced by Hunan Jianchang Petrochemical Co., Ltd.

[0057] Catalyst Au / HTS* was prepared according to the steps of Au / HTS and Au / TS-1, except that step A was omitted. Other conditions were the same.

[0058] In the present invention, the solution after the reaction was analyzed by an Agilent gas chromatograph (GC-7890B).

[0059] Catalyst Au / HTS** was prepared according to the procedures of Au / HTS and Au / TS-1, except that ammonia was used in step A to adjust the pH to the same value. All other conditions were the same.

[0060] Example 1

[0061] 29 g of 7 wt% hydrogen peroxide, 4 g of methanol, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0062] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0063] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 78%, and the selectivity of glycolaldehyde dimer was 76%.

[0064] Example 2

[0065] 29 g of 7 wt% hydrogen peroxide, 4 g of acetone, 1.8 g of Au / HTS catalyst, and 0.5 g of additive TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0066] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0067] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 86%, and the selectivity of glycolaldehyde dimer was 82%.

[0068] Example 3

[0069] 29 g of 7 wt% hydrogen peroxide, 4 g of ethyl formate, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0070] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0071] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 80%, and the selectivity of glycolaldehyde dimer was 56%.

[0072] Example 4

[0073] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0074] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0075] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 90%, and the selectivity of glycolaldehyde dimer was 92%.

[0076] Example 5

[0077] 29 g of 7 wt% hydrogen peroxide, 4 g of a mixed solvent of methanol and acetonitrile (acetonitrile accounts for 70 wt%), 1.8 g of Au / HTS catalyst, and 0.5 g of an auxiliary agent TPAOH were added to a high-pressure closed reactor and mixed evenly.

[0078] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0079] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 96%, and the selectivity of glycolaldehyde dimer was 97%.

[0080] Example 6

[0081] 29 g of 7 wt% hydrogen peroxide, 4 g of a mixed solvent of acetone and acetonitrile (acetonitrile accounts for 80 wt%), 1.8 g of Au / HTS catalyst, and 0.5 g of an auxiliary agent TPAOH were added to a high-pressure closed reactor and mixed evenly.

[0082] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0083] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 95%, and the selectivity of glycolaldehyde dimer was 97%.

[0084] Example 7

[0085] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0086] Ethylene was added at 30°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0087] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 76%, and the selectivity of glycolaldehyde dimer was 89%.

[0088] Example 8

[0089] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0090] Ethylene was added at 40°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0091] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 84%, and the selectivity of glycolaldehyde dimer was 92%.

[0092] Example 9

[0093] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0094] Ethylene was added at 50°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was carried out for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0095] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 89%, and the selectivity of glycolaldehyde dimer was 95%.

[0096] Example 10

[0097] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0098] Ethylene was added at 60°C and 800 rpm to control the pressure to 0.5 MPa and the reaction was carried out for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0099] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 73%, and the selectivity of glycolaldehyde dimer was 88%.

[0100] Example 11

[0101] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0102] Ethylene was added at 60°C and 800 rpm to control the pressure to 1.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0103] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 78%, and the selectivity of glycolaldehyde dimer was 92%.

[0104] Example 12

[0105] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, 1.8 g of Au / HTS catalyst, and 0.5 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0106] Ethylene was added at 60°C and 800 rpm to control the pressure to 1.5 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0107] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 86%, and the selectivity of glycolaldehyde dimer was 94%.

[0108] Example 13

[0109] 13.6 g of 50 wt% hydrogen peroxide, 0.34 g of acetonitrile, 19.30 g of water, 0.4 g of Au / HTS catalyst, and 0.35 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0110] Ethylene was added at 60°C and 800 rpm to control the pressure to 1.5 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0111] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 60%, and the selectivity of glycolaldehyde dimer was 73%.

[0112] Example 14

[0113] 2.0 g of 50 wt% hydrogen peroxide, 6.8 g of acetonitrile, 17.4 g of water, 6.8 g of Au / HTS catalyst, and 1.0 g of auxiliary agent TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0114] Ethylene was added at 60°C and 800 rpm to control the pressure to 1.5 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0115] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 94%, and the selectivity of glycolaldehyde dimer was 92%.

[0116] Example 15

[0117] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, and 1.8 g of Au / TS-1 catalyst were added into a high-pressure closed reactor and mixed evenly.

[0118] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0119] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 68%, and the selectivity of glycolaldehyde dimer was 84%.

[0120] Example 16

[0121] The method of Example 1 was followed, except that the catalyst used was Au / HTS*, and the other conditions were the same.

[0122] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 69%, and the selectivity of glycolaldehyde dimer was 64%.

[0123] Example 17

[0124] The method of Example 1 was followed, except that the catalyst used was Au / HTS**, and the other conditions were the same.

[0125] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 60%, and the selectivity of glycolaldehyde dimer was 54%.

[0126] Comparative Example 1

[0127] 33 g of 6 wt% hydrogen peroxide, 1.8 g of Au / HTS catalyst, and 0.5 g of additive TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0128] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0129] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 56%, and the selectivity of glycolaldehyde dimer was 68%.

[0130] Comparative Example 2

[0131] 29 g of 7 wt% hydrogen peroxide, 4 g of acetonitrile, and 1.8 g of Au / HTS catalyst were added into a high-pressure closed reactor and mixed evenly.

[0132] Ethylene was added at 60°C and 800 rpm to control the pressure to 2.0 MPa and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0133] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 42%, and the selectivity of glycolaldehyde dimer was 58%.

[0134] Comparative Example 3

[0135] 29 g of 7 wt% hydrogen peroxide, 4 g of ethylene glycol, 1.8 g of Au / HTS catalyst, and 0.5 g of additive TPAOH were added into a high-pressure closed reactor and mixed evenly.

[0136] Nitrogen was added to control the pressure to 2.0 MPa at 50°C and 800 rpm, and the reaction was continued for 6 h. After the reaction was completed, the mixture was cooled to room temperature.

[0137] The slurry after the reaction was separated by centrifugation, and the clear liquid was analyzed by gas chromatography. The results showed that the conversion rate of hydrogen peroxide was 54%, and the selectivity of glycolaldehyde dimer was 93%.

[0138] Comparative Example 4

[0139] Comparative Example 4 is from the example in CN105618035A. The reaction is carried out by formylation reaction using formaldehyde as a raw material and a rhodium-based catalyst to obtain the result.

[0140] 20 mmol of paraformaldehyde, 0.001 mmol of bistriphenylphosphine carbonyl rhodium chloride, and 0.0495 mmol (containing 0.099 mmol of manganese) decacarbonyl manganese were added sequentially into a 100 mL high-pressure sealed reactor, and 20 mL of N,N-dimethylacetamide was added and mixed evenly (total metal ion concentration was 0.005 mol / L, and the molar ratio of rhodium to manganese was 1:99).

[0141] The reaction was carried out at 110°C with an initial pressure of 9 MPa of synthesis gas (CO to H2 volume ratio of 1:1) and 800 rpm for 4 h. After the reaction was completed, the mixture was cooled in a water bath to room temperature.

[0142] The solution after the reaction was analyzed by gas chromatography, and the yield of the target product glycolaldehyde was 17% and the selectivity was 94%.

[0143] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A method for preparing glycolaldehyde dimer by one-step oxidation of ethylene, characterized in that: The method comprises the following steps: In the presence of a titanium silicon catalyst and an organic base auxiliary, hydrogen peroxide, a solvent and ethylene are contacted to react.

2. The method according to claim 1, characterized in that The titanium silicate catalyst is one or more of titanium silicate molecular sieve and / or metal-supported modified titanium silicate molecular sieve; Preferably, The metal is Au; and / or The metal content in the metal-loaded modified titanium silicate is 0.1-5 wt%; and / or The titanium silicate molecular sieve is TS-1 and / or HTS.

3. The method according to claim 1 or 2, characterized in that The organic base is one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide, preferably tetrapropylammonium hydroxide.

4. The method according to claim 1 or 2, characterized in that The solvent is one or more of an alcohol solvent, a ketone solvent, an ester solvent, a nitrile solvent, and water, preferably one or more of an alcohol solvent, a ketone solvent, an ester solvent, and a nitrile solvent.

5. The method according to claim 4, characterized in that The alcohol solvent is one or more alcohol solvents with a carbon chain length of C1 to C10; further, the alcohol solvent is preferably one or more of methanol, ethanol, and isopropanol, and further, methanol is preferred; The ketone solvent is one or more ketone solvents with a carbon chain length of C3 to C10; further, the ketone solvent is preferably one or more of acetone, butanone, and cyclohexanone, and further, acetone is preferred; The ester solvent is one or more ester solvents with a carbon chain length of C2 to C10; further, the ester solvent is preferably one or more of ethyl formate and ethyl acetate, and further, ethyl formate is preferred. The nitrile solvent is one or more nitrile solvents with a carbon chain length of C2 to C10; further, the nitrile solvent is preferably one or more of acetonitrile, propionitrile, and butyronitrile, and further, acetonitrile is preferred.

6. The method according to claim 1 or 2, characterized in that Based on the total weight of the materials in the reaction system at the start of the reaction, the mass content of the solvent in the system is 0-80%, preferably 5-75%; the mass content of the titanium silicon catalyst in the system is 1-25%, preferably 5-20%; the mass content of the organic base auxiliary agent is 0.5-5%, preferably 1-3%; and the mass content of hydrogen peroxide is 3-95%, preferably 5-90%.

7. The method according to claim 1 or 2, characterized in that The conditions for contact reaction include: The reaction temperature is 25°C to 65°C, preferably 50°C to 65°C; The reaction time is 0.5h to 12h, preferably 5h to 7h; The reaction pressure is 0.1MPa~2.0MPa.

8. The method according to claim 1 or 2, characterized in that The titanium silicate catalyst is a gold-loaded modified titanium silicate molecular sieve, preferably Au / HTS and / or Au / TS-1, and the gold content in the gold-loaded modified titanium silicate molecular sieve is preferably 0.1-5wt%.

9. The method according to claim 8, characterized in that The preparation method of the gold-loaded modified titanium silicate molecular sieve comprises: A. dissolving a gold precursor in deionized water and adjusting the pH to 7-9 to obtain a gold-containing solution; B. dispersing the titanium silicate molecular sieve in the above-mentioned gold-containing solution, aging at room temperature, solid-liquid separation, and washing to obtain a solid; C. After the solid is dried, reduction is performed.

10. The method according to claim 9, characterized in that In step B, the solid-liquid mass ratio of the titanium silicate molecular sieve to the gold-containing solution is 1:10-1:20, and / or the aging time is 12-24 hours; and / or In step C, the drying conditions include: a temperature of 60° C.-80° C.; and / or the reduction conditions include: reduction at 300° C.-400° C. in a H 2 / Ar atmosphere.

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