Catalyst for ethylene glycol production, method of making and use of biomass to produce ethylene glycol

Abstract

The application provides a catalyst for preparing ethylene glycol, and belongs to the technical field of catalysts.The catalyst comprises a noble metal component, a tungsten-containing active component and a carrier, and further comprises a first additive and a second additive; the first additive contains at least one transition metal element, and the second additive contains at least one element of group IIIA; preferably, the molar ratio of the carrier to the noble metal element, the tungsten element, the transition metal element and the element of group IIIA is 1:(0.0018-0.009):(0.0036-0.018):(0.024-0.064):(0.003-0.01). The application can make the yield of ethylene glycol higher than 45%, and solves the technical problem of low selectivity of ethylene glycol in the process of preparing ethylene glycol from biomass.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a catalyst for the preparation of ethylene glycol, a method for its preparation, and its use in the preparation of ethylene glycol from biomass. Background Technology

[0002] Ethylene glycol is an important bulk chemical with a wide range of applications. It can be used to produce polyethylene terephthalate, polyethylene naphthalate, automotive antifreeze, unsaturated polyester resins, nonionic surfactants, plasticizers, and more.

[0003] Currently, the main technological route for industrial ethylene glycol production is the ethylene oxide hydration method, while the coal-to-ethylene glycol method has also seen rapid development in recent years. It is reported that the ethylene oxide method currently accounts for approximately 56% of ethylene glycol production capacity, and the coal-to-ethylene glycol method accounts for approximately 35%. Both routes rely on fossil resources, but fossil resources are finite and non-renewable. With the depletion of fossil resources and the increasing prominence of environmental problems, there is an urgent need to develop a sustainable route for ethylene glycol production to supplement existing methods, increase ethylene glycol output, and reduce dependence on fossil resources to some extent. Biomass is the only renewable organic carbon source that can provide chemicals for humans. Using biomass to produce ethylene glycol has advantages such as abundant raw material resources, flexible process routes, energy conservation and emission reduction, and green and low-carbon characteristics. Therefore, developing a highly efficient catalytic system for converting biomass feedstock into ethylene glycol is of great significance.

[0004] According to current research, there are multiple routes for producing ethylene glycol from biomass feedstocks. Among them, the route of producing ethylene glycol from cellulose / hemicellulose, starch, sugars, etc. by direct catalytic hydrogenation cracking has fewer steps, higher selectivity for the target product ethylene glycol, and is more efficient and energy-saving, which has attracted increasing attention. In particular, the conversion of non-edible cellulose is the focus of current research.

[0005] In 2008, researchers at the Dalian Institute of Chemical Physics first reported that nickel-promoted tungsten carbide catalysts could be used to directly catalyze the conversion of cellulose into ethylene glycol (Angew. Chem. Int. Ed. 2008, 47, 8510-8513).

[0006] CN101735014B discloses a method for preparing ethylene glycol from polyhydroxy compounds. The method uses polyhydroxy compounds as reactants and a multi-metal catalyst composed of metallic states, carbides, nitrides, and phosphides of group 8, 9, and 10 transition metals (iron, cobalt, nickel, ruthenium, rhodium, palladium, iridium, platinum, molybdenum, and tungsten) as catalytic active components. The process involves a one-step catalytic conversion at 120-300℃ and a hydrogen pressure of 1-13 MPa, achieving efficient, highly selective, and high-yield preparation of ethylene glycol from polyhydroxy compounds.

[0007] CN101768050B discloses a method for producing ethylene glycol and 1,2-propanediol. The method involves hydrolyzing cellulose under hot water conditions (200-250℃), and introducing WO3, supported WO3 and Ru / C catalysts to provide acidity and promote cellulose hydrolysis, while converting the hydrolysis intermediates into low-carbon substances, which are then hydrogenated to obtain ethylene glycol and 1,2-propanediol.

[0008] CN106795079A discloses a method for preparing ethylene glycol from sugars, comprising pyrolyzing monosaccharides and hydrogenating the product composition in the presence of a catalyst and a solvent.

[0009] CN109896922B provides a method for the efficient separation and full utilization of lignocellulose, achieving highly selective conversion from primary biomass to ethylene glycol. The catalyst used is a composite catalyst, comprising catalyst A and catalyst B. The active component of catalyst A is one or more of the transition metals from Groups 8, 9, and 10: iron, cobalt, nickel, ruthenium, rhodium, palladium, iridium, and platinum. Catalyst B is one or more of tungstic acid, ammonium metatungstate, tungsten oxide, and tungsten bronze. The reaction is carried out in a stirred reactor. Hydrogen gas is introduced into the reactor before the reaction, the reaction temperature is ≥120℃, and the reaction time is not less than 5 minutes.

[0010] CN113083299A discloses a Yolk Shell-structured bifunctional catalysts and their application in the catalytic hydrogenolysis of glucose to prepare ethylene glycol.

[0011] However, the above methods for preparing ethylene glycol from biomass still suffer from the problem of low ethylene glycol selectivity. Summary of the Invention

[0012] The purpose of this invention is to solve the technical problem of low ethylene glycol selectivity in existing biomass-to-ethylene glycol processes.

[0013] To achieve the above objectives, in a first aspect, the present invention provides a catalyst for the preparation of ethylene glycol, the catalyst comprising: a noble metal component, a tungsten-containing active component and a support, the catalyst further comprising a first promoter and a second promoter; wherein the first promoter comprises at least one transition metal element and the second promoter comprises at least one group IIIA element.

[0014] As a specific embodiment of the present invention, the molar ratio of the above-mentioned carrier to the noble metal element, group IIIA element, tungsten element and transition metal element is 1:(0.0018~0.0090):(0.0036~0.0180):(0.0240~0.0640):(0.0030~0.0100).

[0015] As a specific embodiment of the present invention, the molar ratio of the above-mentioned carrier to the noble metal element, group IIIA element, tungsten element and transition metal element is 1: (0.0018~0.0048): (0.0036~0.0096): (0.0240~0.0360): (0.0030~0.0600).

[0016] As a specific embodiment of the present invention, the molar ratio of the above-mentioned carrier to the noble metal element, group IIIA element, tungsten element and transition metal element is 1:0.0048:0.0096:0.036:0.006.

[0017] As a specific embodiment of the present invention, the XRD diffraction pattern of the catalyst for preparing ethylene glycol has one or more characteristic peaks of 2θ selected from 23.12±0.15, 23.95±0.15, 32.93±0.15, 33.60±0.20, 40.70±0.20, and 47.70±0.20.

[0018] As a specific embodiment of the present invention, the XRD diffraction pattern of the above catalyst does not include one or more characteristic peaks of 2θ at 23.46±0.15, 28.60±0.15, 41.55±0.15, and 50.05±0.20.

[0019] As a specific embodiment of the present invention, the XRD diffraction pattern of the above catalyst does not include the characteristic peak of 2θ at 36.95±0.15.

[0020] As a specific embodiment of the present invention, the above-mentioned catalyst for ethylene glycol preparation has WO3 content. 3-x The specific component, where x = 0.05-0.10, and W is a variable valence state, exhibiting a corresponding characteristic peak, whereas the existing technology uses WO3. The aforementioned second auxiliary agent is used as a protective ligand, which introduces the noble metal component and the first auxiliary agent through coordination, forming a structure with WO3. 3-xThe catalyst with specific components not only improves the catalyst activity but also enhances the selectivity of ethylene glycol.

[0021] As a specific embodiment of the present invention, the above-mentioned tungsten-containing active component is an inorganic compound of tungsten.

[0022] As a specific embodiment of the present invention, the above-mentioned tungsten-containing active component is tungstic acid or metatungstate.

[0023] As a specific embodiment of the present invention, the tungsten-containing active component is ammonium metatungstate.

[0024] As a specific embodiment of the present invention, the above-mentioned noble metal component contains at least one group VIII metal element.

[0025] As a specific embodiment of the present invention, the above-mentioned noble metal component includes Ru or Pd.

[0026] In a specific embodiment of the present invention, the aforementioned transition metal element is cobalt.

[0027] The amount of transition metal element added as the first auxiliary agent should not be too high. When the content of transition metal element such as cobalt is too high, it will affect the selectivity of the catalyst.

[0028] As a specific embodiment of the present invention, the aforementioned Group IIIA element is a boron compound.

[0029] As a specific embodiment of the present invention, the above-mentioned boron compound is selected from any one of pyridine-3-boronic acid, pyridine-4-boronic acid, 2-methoxypyridyl-3-boronic acid, and quinoline-3-boronic acid.

[0030] As a specific embodiment of the present invention, the above-mentioned carrier is at least one of silicon oxide, alumina, zirconium oxide, and titanium oxide.

[0031] As a specific embodiment of the present invention, the above-mentioned silicon-containing oxide is any one of silicon oxide, SBA-15 molecular sieve, and MCM-41 molecular sieve.

[0032] In a specific embodiment of the present invention, the carrier is silicon oxide.

[0033] Secondly, the present invention provides a method for preparing a catalyst for ethylene glycol preparation, comprising the following steps: 1) The precious metal component, the second auxiliary agent, and the solvent are mixed to obtain material 1; preferably, the solvent is acetone; 2) Mix material 1 with the carrier and dry to obtain material 2; preferably, dry in an oven at 50-80℃; most preferably, dry in an oven at 60℃; 3) Mix the tungsten-containing active component, the first auxiliary agent, and water to obtain material 3; 4) Mix material 2 and material 3, evaporate the water, dry and then calcine to reduce, to obtain the catalyst for preparing ethylene glycol.

[0034] As a specific embodiment of the present invention, the drying temperature is 30-75°C.

[0035] As a specific embodiment of the present invention, the drying temperature is 40-60°C; As a specific embodiment of the present invention, the above-mentioned calcination and reduction step includes: 1) The calcination atmosphere is air, the temperature is programmed to rise to the range of 450~600℃, the heating rate is 2~3℃ / min, and the calcination time is 2~4h; 2) Replace the atmosphere with nitrogen and cool to room temperature; 3) The reducing atmosphere is a mixture of hydrogen and nitrogen, with hydrogen comprising 40% to 60% of the total gas volume. The temperature is programmed to rise to 250 to 350°C at a rate of 2 to 5°C / min, and the reduction time is 2 to 4 hours.

[0036] Thirdly, the present invention provides a catalyst for preparing ethylene glycol according to the above preparation method.

[0037] Fourthly, the present invention provides a catalyst for preparing ethylene glycol according to the above description or the application of the catalyst for preparing ethylene glycol in the preparation of ethylene glycol from biomass.

[0038] As a specific embodiment of the present invention, the biomass is selected from at least one of cellulose, starch, hemicellulose, fructan, xylan and disaccharides; most preferably, the cellulose is microcrystalline cellulose.

[0039] Fifthly, the present invention provides a method for preparing ethylene glycol, the method comprising the steps of: contacting biomass with the above-mentioned catalyst for preparing ethylene glycol or the above-mentioned catalyst for preparing ethylene glycol in a closed environment filled with hydrogen gas.

[0040] Compared with the prior art, the present invention has at least the following advantages: (1) In the process of preparing ethylene glycol from biomass raw materials, the present invention introduces a noble metal component and a second auxiliary agent through coordination. Due to the good dispersion of the noble metal component, the first auxiliary agent and the tungsten-containing active component are introduced to form a product containing WO3. 3-x Specific component catalyst, this WO 3-x The structure is an unsaturated W oxide state. By adjusting the proportion and type of each component, the catalytic performance can be modified, thereby improving the selectivity of ethylene glycol.

[0041] (2) The present invention divides the roasting step of the mixture into two stages. The first stage is carried out in an air atmosphere at a higher temperature, and then roasting and reduction are carried out in an atmosphere of hydrogen and nitrogen mixture at a relatively lower temperature. Through the reduction step, a product with WO3 is obtained. 3-x The final catalyst with this structure, the reduction step allows for full utilization of the precious metal; this preparation method results in a catalyst with higher selectivity than that prepared by reduction in air alone, and further enables a higher ethylene glycol yield. Attached Figure Description

[0042] Figure 1 The XRD diffraction patterns are those of the catalysts obtained in Example 1, Comparative Example 1, and Comparative Example 2 of this invention. Detailed Implementation

[0043] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0044] Unless otherwise specified, all operations in the examples and comparative examples are performed at room temperature.

[0045] In this invention, the reaction products are quantitatively determined by high-performance liquid chromatography (Waters Alliance e2695), and signal detection is performed by a refractive index detector (RID). The chromatographic column used is an SC1011 column, with water as the mobile phase, a flow rate of 0.7 mL / min, and a column temperature of 80 °C.

[0046] In this invention, the X-ray diffraction (XRD) is measured using a Bruker AXS D8 Avance X-ray diffractometer with a scanning range of 10° to 80°.

[0047] X-ray photoelectron spectroscopy (XPS) was measured using the Nexsa™ X-ray photoelectron spectrometer from Thermo Fisher Scientific.

[0048] Calculate the carbohydrate conversion rate, ethylene glycol selectivity, and yield using the following formulas:

[0049]

[0050]

[0051] Example 1: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.143g of ruthenium acetylacetonate, 0.088g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60°C oven to obtain material 2. Mix 1.224g ammonium metatungstate, 0.175g cobalt nitrate, and 20ml water to obtain material 3; Material 2 and material 3 were mixed and stirred at 60°C until the moisture evaporated, then dried overnight at 110°C and calcined. The calcination conditions were as follows: first, calcined in air at a programmed temperature of 2°C / min to 450°C for 4 hours; then, the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas fraction of 40%, the temperature was increased to 350°C at a programmed temperature of 5°C / min for 2 hours to obtain catalyst C1.

[0052] Figure 1 The XRD diffraction pattern of the prepared catalyst C1 is shown, wherein the XRD diffraction pattern has 2θ characteristic peaks at 23.12±0.15, 23.95±0.15, 32.93±0.15, 33.60±0.20, 40.70±0.20, and 47.70±0.20, which belong to WO 3-x Crystal form.

[0053] Example 2: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.717g of ruthenium acetylacetonate, 0.442g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60°C oven to obtain material 2. Mix 1.224g ammonium metatungstate, 0.175g cobalt nitrate, and 20ml water to obtain material 3; Material 2 and material 3 were mixed and stirred at 60°C until the moisture evaporated, then dried overnight at 110°C and calcined. The calcination conditions were as follows: first, calcined in air at a programmed temperature of 2°C / min to 450°C for 4 hours; then, the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas fraction of 40%, the temperature was increased to 350°C at a programmed temperature of 5°C / min for 2 hours to obtain catalyst C2.

[0054] Example 3: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.143g of ruthenium acetylacetonate, 0.088g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 3.264g of ammonium metatungstate, 0.175g of cobalt nitrate, and 20ml of water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, dry overnight at 110°C, and then calcine. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min for 2 hours to obtain catalyst C3.

[0055] Example 4: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.143g of ruthenium acetylacetonate, 0.088g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.224g ammonium metatungstate, 0.582g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, then dry at 110°C overnight. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst C4.

[0056] Example 5: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.141g of platinum acetylacetonate, 0.088g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.224g ammonium metatungstate, 0.175g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, then dry at 110°C overnight. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas fraction of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst C5.

[0057] Example 6: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.382 g of ruthenium acetylacetonate, 0.236 g of pyridine-3-boronic acid, and 20 ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.224g ammonium metatungstate, 0.175g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, then dry at 110°C overnight. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min for 2 hours to obtain catalyst C6.

[0058] Example 7: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.382 g of ruthenium acetylacetonate, 0.236 g of pyridine-3-boronic acid, and 20 ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.836g ammonium metatungstate, 0.175g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, then dry at 110°C overnight. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas fraction of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst C7.

[0059] Example 8: A method for preparing a catalyst for ethylene glycol preparation The steps of this method include: 0.382 g of ruthenium acetylacetonate, 0.236 g of pyridine-3-boronic acid, and 20 ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.836g ammonium metatungstate, 0.349g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, then dry at 110°C overnight. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min for 2 hours to obtain catalyst C8.

[0060] Comparative Example 1: A method for preparing a catalyst for ethylene glycol preparation The only difference in this comparative example is the roasting conditions; everything else is the same as in Example 1.

[0061] The calcination conditions for the catalyst were as follows: calcination was carried out in air at a programmed temperature increase of 2℃ / min to 450℃ for 4 hours to obtain catalyst D1.

[0062] Figure 1 The XRD diffraction pattern of the prepared catalyst D1 is shown, wherein the XRD diffraction pattern has 2θ characteristic peaks at 23.46±0.15, 28.60±0.15, 41.55±0.15, and 50.05±0.20, which belongs to the crystal form of WO3.

[0063] Comparative Example 2: A method for preparing a catalyst for ethylene glycol preparation In this comparative example, the tungsten content is low and the cobalt content is high, which is not within the specified range. The total active component content is consistent, and everything else is the same as in Example 1.

[0064] The preparation method of this catalyst includes: 0.143g of ruthenium acetylacetonate, 0.088g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 0.612g ammonium metatungstate, 0.873g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, dry overnight at 110°C, and then calcine. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst D2.

[0065] Figure 1The XRD diffraction pattern of the prepared catalyst D2 is shown, wherein the XRD diffraction pattern has a 2θ characteristic peak at 36.95±0.15, which is attributed to the characteristic peak of Co3O4.

[0066] Comparative Example 3: A method for preparing a catalyst for ethylene glycol preparation This comparative example does not include pyridine-3-boronic acid (a second auxiliary agent) containing B ligand; otherwise, it is the same as in Example 1.

[0067] The preparation method of this catalyst includes: 0.143g of ruthenium acetylacetone was mixed with 20ml of acetone and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.224g ammonium metatungstate, 0.175g cobalt nitrate, and 20ml water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, dry overnight at 110°C, and then calcine. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst D3.

[0068] Comparative Example 4: A method for preparing a catalyst for ethylene glycol preparation This comparative example does not include cobalt nitrate (the first auxiliary agent), but is otherwise the same as Example 1.

[0069] The preparation method of this catalyst includes: 0.143g of ruthenium acetylacetonate, 0.088g of pyridine-3-boronic acid, and 20ml of acetone were mixed and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.224g of ammonium metatungstate with 20ml of water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, dry overnight at 110°C, and then calcine. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas fraction of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst D4.

[0070] Comparative Example 5: A method for preparing a catalyst for ethylene glycol preparation This comparative example does not include the two additives pyridine-3-boronic acid and cobalt nitrate; otherwise, it is the same as Example 1.

[0071] The preparation method of this catalyst includes: 0.143g of ruthenium acetylacetone was mixed with 20ml of acetone and refluxed at 40 degrees Celsius for 2 hours to obtain material 1; Material 1 was mixed with 12g of silicon dioxide, dried at room temperature, and then dried overnight in a 60-degree oven to obtain material 2. Mix 1.224g of ammonium metatungstate with 20ml of water to obtain material 3; Mix material 2 and material 3, stir at 60°C until the moisture evaporates, dry overnight at 110°C, and then calcine. The calcination conditions were as follows: first, calcination was carried out in air at a programmed temperature of 2℃ / min to 450℃ for 4 hours; the atmosphere was replaced with nitrogen and cooled to room temperature; then, in a hydrogen-nitrogen mixture with a hydrogen gas integral of 40%, the temperature was increased to 350℃ at a programmed temperature of 5℃ / min and the reduction time was 2 hours to obtain catalyst D5.

[0072] Test Example 1: Method for preparing ethylene glycol from cellulose via catalytic conversion The catalysts prepared in Examples 1-8 and Comparative Examples 1-5 were evaluated for their catalytic performance under the same conditions. The reaction for the catalytic conversion of cellulose to ethylene glycol was carried out in a closed reactor.

[0073] The catalytic conversion process includes: weighing 2.0 g of microcrystalline cellulose and 1.0 g of catalyst and adding them to a high-pressure reactor (100 mL) containing 40 mL of water. The reactor is then sealed, and hydrogen gas is introduced to purge the mixture three times. The pressure is then increased to 5 MPa, and the temperature is raised to 220 °C. The reaction is allowed to proceed for 60 minutes. After the reaction is complete, the temperature is lowered, and the solid and reaction liquid (reaction products) are separated by filtration.

[0074] The liquid products were analyzed by high-performance liquid chromatography (HPLC), and the conversion rate of cellulose and the yield of ethylene glycol were calculated according to the formulas described above. The evaluation results are shown in Table 1.

[0075] Table 1. Cellulose conversion and ethylene glycol yield in the presence of different catalysts.

[0076] As shown in Table 1, the catalyst prepared by this invention can achieve a cellulose conversion rate as high as 93.7%. The two-stage calcination method, compared with a single-stage calcination method, results in a catalyst with higher selectivity, increasing the cellulose conversion rate from 45.6% to 89.4%, and consequently improving the ethylene glycol yield, increasing it from 5.29% to 40.05%, demonstrating high selectivity.

[0077] Furthermore, without further reduction, the catalyst cannot obtain WO3. 3-x The structure is flawed, and the role of precious metals cannot be fully utilized.

[0078] 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 catalyst for the preparation of ethylene glycol, the catalyst comprising: The catalyst comprises a noble metal component, a tungsten-containing active component, and a support, characterized in that the catalyst further comprises a first promoter and a second promoter; wherein the first promoter comprises cobalt, and the second promoter comprises boron; The molar ratio of the carrier to the noble metal element, boron, tungsten, and cobalt is 1:(0.0018~0.0090):(0.0036~0.0180):(0.0240~0.0640):(0.0030~0.0100). The catalyst for ethylene glycol preparation contains WO3. 3-x Specific components, where x = 0.05~0.

10.

2. The catalyst for ethylene glycol preparation according to claim 1, characterized in that, The molar ratio of the carrier to the noble metal element, boron, tungsten and cobalt is 1:(0.0018~0.0048):(0.0036~0.0096):(0.0240~0.0360):(0.0030~0.0600).

3. The catalyst for ethylene glycol preparation according to claim 2, characterized in that, The molar ratio of the carrier to the precious metal element, boron, tungsten, and cobalt is 1:0.0048:0.0096:0.036:0.

006.

4. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The XRD diffraction pattern of the catalyst for preparing ethylene glycol has one or more characteristic peaks of 2θ selected from 23.12±0.15, 23.95±0.15, 32.93±0.15, 33.60±0.20, 40.70±0.20, and 47.70±0.

20.

5. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The tungsten-containing active component is an inorganic compound of tungsten.

6. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The precursor of the tungsten-containing active component is tungstic acid or metatungstate.

7. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The precursor of the tungsten-containing active component is ammonium metatungstate.

8. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The precious metal component contains at least one group VIII metal element.

9. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The noble metal component contains Ru or Pd.

10. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The precursor of the boron compound is selected from any one of pyridine-3-boronic acid, pyridine-4-boronic acid, 2-methoxypyridyl-3-boronic acid, and quinoline-3-boronic acid.

11. The catalyst for preparing ethylene glycol according to any one of claims 1-3, characterized in that, The carrier is at least one of silicon oxide, alumina, zirconium oxide, and titanium oxide.

12. The catalyst for ethylene glycol preparation according to claim 11, characterized in that, The silicon-containing oxide is either SBA-15 molecular sieve or MCM-41 molecular sieve.

13. The catalyst for ethylene glycol preparation according to any one of claims 1-3, characterized in that, The carrier is silicon dioxide.

14. A method for preparing a catalyst for ethylene glycol preparation, characterized in that, The preparation method includes the following steps: 1) The precious metal component, the second auxiliary agent, and the solvent are mixed to obtain material 1; 2) Mix material 1 with the carrier and dry to obtain material 2; 3) Mix the tungsten-containing active component, the first auxiliary agent, and water to obtain material 3; 4) Mix material 2 and material 3, evaporate the water, dry and then calcine and reduce to obtain the catalyst for preparing ethylene glycol; Wherein, the first auxiliary agent contains cobalt, and the second auxiliary agent contains boron; The molar ratio of the carrier to the noble metal element, boron, tungsten and cobalt is 1:(0.0018~0.0090):(0.0036~0.0180):(0.0240~0.0640):(0.0030~0.0100).

15. The preparation method according to claim 14, characterized in that, The solvent is acetone; And / or, in step 2), dry in an oven at 50-80°C; And / or, the calcination reduction step includes: 1) The calcination atmosphere is air, the temperature is programmed to rise to the range of 450~600℃, the heating rate is 2~3℃ / min, and the calcination time is 2~4h; 2) Replace the atmosphere with nitrogen and cool to room temperature; 3) The reducing atmosphere is a mixture of hydrogen and nitrogen, with hydrogen comprising 40% to 60% of the total gas volume. The temperature is programmed to rise to 250 to 350°C at a rate of 2 to 5°C / min, and the reduction time is 2 to 4 hours.

16. The preparation method according to claim 14, characterized in that, In step 2), the product is dried in an oven at 60°C.

17. A catalyst for preparing ethylene glycol prepared according to any one of claims 14-16.

18. The use of a catalyst for preparing ethylene glycol according to any one of claims 1-13 or the catalyst for preparing ethylene glycol according to claim 17 in the preparation of ethylene glycol from biomass.

19. The application according to claim 18, characterized in that, The biomass is selected from at least one of cellulose, starch, hemicellulose, fructan, xylan and disaccharides.

20. The application according to claim 19, characterized in that, The cellulose is microcrystalline cellulose.

21. A method for preparing ethylene glycol, characterized in that, The preparation method includes the following steps: in a closed environment filled with hydrogen, contacting biomass with the ethylene glycol preparation catalyst according to any one of claims 1-13 or the ethylene glycol preparation catalyst according to claim 17.

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