A supported catalyst with MgO as carrier, preparation method and application thereof

Abstract

The invention discloses a kind of MgO as a supported catalyst and its preparation method and application as a carrier, comprising the following steps: a soluble magnesium salt and a precipitant are reacted under the action of a surface modifier, and a liquid phase reaction is used to prepare a precursor by precipitation, and then the MgO carrier with strong interface anchoring on the surface is pyrolyzed at a specific temperature, and loaded on the MgO carrier by an isometric impregnation method, and gradient temperature rises and roasts under an air atmosphere after drying, and then gradient temperature rises and reduces under a hydrogen atmosphere to obtain a supported catalyst for MgO as a carrier. The obtained catalyst is catalytically hydrogenated 5 hydroxymethylfurfural to prepare 2,5 furandimethanol under a hydrogen atmosphere. The present invention prepares a supported catalyst process for MgO as a carrier, which is simple, safe and reliable. At the same time, when the metal supported catalyst is used to prepare 2,5 furandimethanol, the reaction activity is strong, the selectivity is high, the reusability is strong, the reproducibility is good, and it is safe and pollution-free.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and particularly relates to a supported catalyst with MgO as a carrier, a preparation method and an application thereof. Background Art

[0002] In recent years, the preparation of new materials using biomass raw materials with many advantages such as "green, environmentally friendly, renewable, and with a wide range of raw material sources" has ushered in a development boom.

[0003] 5-Hydroxymethylfurfural (HMF), derived from biomass-derived sugars through dehydration, contains furan rings, hydroxyl groups, and aldehyde groups. Through chemical reactions such as oxidation, hydrogenation, esterification, halogenation, and polymerization, HMF can be used to produce polymer monomers, liquid fuels, and green solvents, and can also be converted into pharmaceuticals, fuel intermediates, and other high-value chemicals. For this reason, HMF has been designated one of the top ten key bio-based platform compounds by the U.S. Department of Energy.

[0004] 2,5-Furan dimethanol (BHMF), as an important chemical intermediate derived from the selective hydrogenation of 5-hydroxymethylfurfural (HMF), has the common properties of general diols and can be used as a raw material to synthesize pharmaceutical intermediates, nucleoside derivatives, crown ethers and other compounds, as well as polymer materials such as polyesters and polyurethanes. It can also be used as a solvent, wetting agent, adhesive, surfactant, artificial receptor, etc.

[0005] At present, the most reported method is to use precious metals (Pt, Au, Pd) as catalysts to catalyze the transfer hydrogenation of 5-hydroxymethylfurfural to prepare 2,5-furan dimethanol. Although it has considerable yield and selectivity, its industrial development is restricted by the complex preparation process and high cost. Non-precious metals (Cu, Ni, Co) are used as catalysts to directly hydrogenate hydrogen to prepare 2,5-furan dimethanol. Although it has low cost and simple preparation process, it has low selectivity and low reaction substrate concentration. At the same time, the metal loaded on the catalyst is easy to fall off, the catalyst is easy to deactivate, difficult to regenerate, and has poor reuse rate, which has become a restriction on the research of its downstream derivative synthesis and limited its further industrial application. Summary of the Invention

[0006] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0007] Beneficial effects of the present invention:

[0008] (1) The method for preparing 2,5-furan dimethanol provided by the present invention can be industrially scaled up because the raw material 5-hydroxymethylfurfural can be prepared from sufficient renewable sources (such as fructose, sucrose, glucose, straw, etc.), has a wide source, is inexpensive, and conforms to technical and economic production methods. At the same time, it is based on bio-based raw materials from renewable sources, is easy to post-process, and is environmentally friendly and clean.

[0009] (2) The surface of the MgO carrier prepared by the present invention is modified, and the surface has strong interface anchoring, which enhances the adsorption of metal particles on the carrier. At the same time, a specific roasting method and reduction method are adopted to further effectively anchor the metal particles on the MgO carrier, so that the MgO-based supported catalyst is less likely to fall off during multiple reactions under long-term high-temperature conditions than traditional supported catalysts, and the performance remains the same after high-temperature regeneration, which can effectively reduce costs and facilitate industrialization; the method for preparing the catalyst of the present invention uses an organic solvent as a solvent for dissolving metal salts to load onto the carrier, which can effectively avoid physical and chemical reactions between the carrier and the solvent during the loading process. Chemical reactions (such as changes in some alkaline supports and water systems) affect the support pore size and morphology, metal particle loading, and ultimately the selectivity and yield of 2,5-furan dimethanol. Furthermore, the selectivity of BHMF is affected by the surface acidity of the support. Weak acid sites and low acid content favor hydrogenation reactions while inhibiting etherification and polymerization reactions. The advantage of using MgO as a supported support to catalyze the preparation of BHMF from HMF in the present invention is that MgO, as an alkaline metal support, can effectively prevent side reactions such as polymerization of HMF at the acidic sites on the support. The mild conditions ensure the specific selectivity of HMF hydrogenation.

[0010] (3) The method for preparing the catalyst of the present invention has a simple loading method, is easy to operate, can be adaptively adjusted according to actual conditions, has strong operability, is low in price, is simple to synthesize, is safe and reliable, and has uniformly dispersed loaded particles. The selectivity and yield of 2,5-furan dimethanol prepared by catalytic hydrogenation reduction are greatly improved. Compared with traditional loaded catalysts, the catalyst prepared by the present invention has good reusability, is not easy to deactivate, has very high selectivity, strong specificity, and good regeneration. The catalyst after the reaction is re-calcined and reduced, and the performance effect remains the same, which reduces the cost of use and has good application prospects.

[0011] (3) The reaction process for preparing 2,5-furan dimethanol according to the present invention has a very high conversion rate, is controllable (by changing different reaction condition parameters), has a very strong selectivity, avoids interference from various intermediates, effectively improves the yield of the reaction, reduces the difficulty of separation, increases the yield, and is easy to implement on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort. Among them:

[0013] Figure 1 is a transmission electron microscope scanning (TEM) image of the carrier MgO;

[0014] Figure 2 Transmission electron microscopy (TEM) images of MgO supports prepared under different conditions;

[0015] Figure 3 This is the XPS characterization diagram of the valence state of the supported metal (Cu) of the supported catalyst with MgO as the carrier;

[0016] Figure 4 TEM characterization of the supported catalyst with MgO as the carrier;

[0017] Figure 5 TEM particle size distribution analysis diagram of the supported catalyst with MgO as the carrier;

[0018] Figure 6 is the XRD pattern of the supported catalyst with MgO as the carrier;

[0019] Figure 7 This is the TEM particle size distribution analysis diagram of the regenerated MgO-supported supported catalyst. DETAILED DESCRIPTION

[0020] In the present invention, "HMF" is an abbreviation for 5-hydroxymethylfurfural, and "BHMF" is an abbreviation for 2,5-furan dimethanol.

[0021] The term "renewable source" as used herein specifically refers to materials that are capable of self-replenishment from living organisms. Fossil materials that have been transformed by geological processes (e.g., coal, petroleum, etc.) are not renewable sources. More specifically, renewable sources include biomass derived from living materials (e.g., plant matter, or components isolated from plant matter, such as lignocellulose, cellulose, starch, or glucose).

[0022] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0023] The analysis method in the embodiment of the present invention is as follows:

[0024] The products of the 5-hydroxymethylfurfural synthesis reaction were analyzed using an Agilent LC1260 high-performance liquid chromatograph and quantified using the external standard method. Qualitative analysis of the products of the 5-hydroxymethylfurfural synthesis reaction was performed using a time-of-flight mass spectrometer (TOF). X-ray powder diffractometer (XRD) was used to qualitatively analyze the prepared MgO-supported supported catalyst. Transmission electron microscopy (TEM) was used to characterize the morphology of the prepared MgO support and the metal particles supported on the MgO-supported supported catalyst. X-ray photoelectron spectroscopy (XPS) was used to qualitatively and quantitatively analyze the chemical state of the metal particles supported on the prepared MgO-supported supported catalyst. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to qualitatively and quantitatively analyze the metal loading of the prepared MgO-supported supported catalyst. Specific surface area of ​​the prepared MgO-supported supported catalyst was qualitatively and quantitatively analyzed using a specific surface area adsorption analyzer.

[0025] The calculation method in the embodiments of the present application is as follows:

[0026] The calculation formulas for catalyst selectivity, 5-hydroxymethylfurfural conversion rate and 2,5-furan dimethanol yield are as follows:

[0027] 2,5-furandimethanol yield = (mass of 2,5-furandimethanol in the product / theoretical mass of 2,5-furandimethanol produced) × 100%;

[0028] 5-Hydroxymethylfurfural conversion rate = (mass of 5-Hydroxymethylfurfural actually involved in the reaction / mass of 5-Hydroxymethylfurfural in the raw material) × 100%;

[0029] Catalyst selectivity = (2,5-furan dimethanol yield / 5-hydroxymethylfurfural conversion rate) × 100%.

[0030] Example 1

[0031] (1) Add 18g of sodium sulfate and 150g of water to a 250ml beaker, stir thoroughly, then add 0.44g of sodium laureth sulfate, heat to 50°C and stir for 10 minutes until the surface modifier is fully dispersed.

[0032] (2) Add 31.8 g of sodium carbonate and 150 g of water into a three-necked flask, stir mechanically until fully uniform, then add 1.31 g of sodium dodecyl sulfate, heat to 50 °C and stir for 10 min until the surface modifier is fully dispersed.

[0033] (3) The precipitant prepared in step (1) was added to the reaction solution of step (2) at a constant rate (the flow rate was controlled at 3 ml / min) to carry out precipitation reaction. After the addition was completed, the mass of the composite surface modifier in the system accounted for 0.5% of the total system. The system temperature was controlled at 70±5°C. After continuous stirring for 20 minutes, the reaction solution was cooled to room temperature.

[0034] (4) The reaction solution was filtered, washed with ethanol 3-5 times, washed with water 3-5 times, and dried at 80° C. for 6 h to obtain a precursor of the MgO carrier.

[0035] (5) The precursor is placed in a muffle furnace and subjected to gradient pyrolysis. The temperature is raised from room temperature to 110°C at a heating rate of 5°C / min, maintained for 1 hour, and then raised from 110°C to a specific pyrolysis temperature of 500°C at a heating rate of 2°C / min. The specific pyrolysis temperature is maintained for 10 minutes to obtain the MgO carrier, which is recorded as 1#.

[0036] The morphology of sample 1# was scanned by transmission electron microscope (TEM), and the results showed that Figure 1 shown.

[0037] Example 2

[0038] Compared with Example 1, this example is different in that the stirring time of the liquid phase reaction is different, specifically, the continuous stirring in step (3) is changed from 20 minutes to 70 minutes, and the MgO carrier is obtained, which is recorded as 2#.

[0039] The morphology of sample 2# was scanned by transmission electron microscope (TEM), and the results showed that Figure 2 shown.

[0040] The morphology presented by the transmission electron microscope scan shows that the different stirring times of the liquid phase reaction in this embodiment lead to the uneven and irregular morphology of the final generated MgO carrier. Figure 1 and Figure 2 It can be seen that during the precipitation reaction of the MgO support precursor, the extended stirring time will break up the original crystal morphology, causing the crystal morphology to change from large to small. MgO prepared under these conditions is used as a support to prepare a supported catalyst.

[0041] Example 3

[0042] Compared with Example 1, this embodiment differs in that the flow rate of adding the precipitant is different. Specifically, the flow rate of adding the precipitant in step (3) is changed from 3 ml / min in Example 1 to 1 ml / min, and a MgO carrier can be obtained, which is recorded as 3#.

[0043] Example 4

[0044] Compared with Example 1, this embodiment differs in that the pyrolysis heating rate is changed. Specifically, the difference is that in step (5), the heating rate from 110°C to the specific pyrolysis temperature of 500°C at a heating rate of 2°C / min in Example 1 is changed to the heating rate from 110°C to the specific pyrolysis temperature of 500°C at a heating rate of 10°C / min, to obtain an MgO carrier, which is recorded as 4#.

[0045] Example 5

[0046] Compared with Example 1, this embodiment differs in that the specific pyrolysis temperature is changed, so that the specific pyrolysis temperature becomes smaller. Specifically, the difference is that the heating rate from 110°C to the specific pyrolysis temperature of 500°C at a heating rate of 2°C / min in Example 1 is changed to the heating rate from 110°C to the specific pyrolysis temperature of 300°C at a heating rate of 2°C / min, to obtain a MgO carrier, which is recorded as 5#.

[0047] Example 6

[0048] Compared with Example 1, this embodiment is different in that no surface modifier is added. The specific difference is:

[0049] (1) Add 18g sodium sulfate and 150g water to a 250ml beaker, heat to 50℃, and stir thoroughly.

[0050] (2) Add 31.8 g of sodium carbonate and 150 g of water to a three-necked flask, heat to 50°C, stir mechanically to mix thoroughly, and then add the precipitant prepared in step (1) at a constant rate (flow rate controlled at 3 ml / min) to carry out precipitation reaction. After the addition is completed, control the system temperature to 70±5°C, continue stirring for 20 minutes, and then cool the reaction solution to room temperature.

[0051] (3) After the reaction solution is filtered, it is washed with ethanol for 3-5 times, then washed with water for 3-5 times, and dried at 80° C. for 6 h to obtain a precursor of the MgO support without surface modification.

[0052] Other conditions were the same as those in Example 1, and an MgO carrier without surface modification was obtained, which was designated as 6#.

[0053] Example 7

[0054] The difference between this embodiment and embodiment 1 is that during the carrier preparation process, only one anionic surfactant is added for surface modification, and the added amount is the same as the compound amount in embodiment 1, specifically:

[0055] (1) Add 18g of sodium sulfate and 150g of water to a 250ml beaker, stir thoroughly, then add 1.75g ​​of sodium laureth sulfate, heat to 50℃ and stir for 10min until the surface modifier is fully dispersed.

[0056] (2) Add 31.8 g of sodium carbonate and 150 g of water to a three-necked flask, heat to 50° C., stir mechanically until fully uniform, and then add the precipitant prepared in step (1) at a constant rate (the flow rate is controlled at 3 ml / min) to carry out precipitation reaction. After the addition is completed, the mass of the surface modifier in the system accounts for 0.5% of the total system. Control the system temperature at 70±5° C., continue stirring for 20 minutes, and then cool the reaction solution to room temperature.

[0057] Other conditions were the same as those in Example 1, and a MgO carrier surface-modified with a single anionic surfactant was obtained, which was designated as 7#.

[0058] Example 8

[0059] The difference between this embodiment and embodiment 1 is that during the preparation of the carrier, only one anionic surfactant is added to the precipitant for surface modification, and the amount added is the same as the compound amount in embodiment 1:

[0060] (1) Add 18g of sodium sulfate and 150g of water to a 250ml beaker, heat to 50℃, and stir thoroughly.

[0061] (2) Add 31.8 g of sodium carbonate and 150 g of water to a three-necked flask, stir mechanically to make it fully uniform, then add 1.75 g of sodium dodecyl sulfate, heat to 50 ° C and stir for 10 min until the surface modifier is fully dispersed, then add the precipitant prepared in step (1) at a constant rate (flow rate controlled at 3 ml / min) to carry out precipitation reaction. After the addition is completed, the mass of the surface modifier in the system accounts for 0.5% of the total system. Control the system temperature at 70 ± 5 ° C, continue stirring for 20 min, and then cool the reaction solution to room temperature.

[0062] The other conditions are the same as those in Example 1 to obtain a MgO carrier surface-modified with a single anionic surfactant, which is designated as 8#.

[0063] Example 9

[0064] Compared with Example 1, this embodiment differs in that an anionic surfactant is added for surface modification, and the added amount is increased in proportion to the total system:

[0065] (1) Add 18g of sodium sulfate and 150g of water to a 250ml beaker, heat to 50℃, and stir thoroughly.

[0066] (2) Add 31.8 g of sodium carbonate and 150 g of water to a three-necked flask, stir mechanically to make it fully uniform, then add 8.75 g of sodium dodecyl sulfate, heat to 50 ° C and stir for 10 min until the surface modifier is fully dispersed, then add the precipitant prepared in step (1) at a constant rate (flow rate controlled at 3 ml / min) to carry out precipitation reaction. After the addition is completed, the mass of the surface modifier in the system accounts for 2.5% of the total system. Control the system temperature at 70 ± 5 ° C, continue stirring for 20 min, and then cool the reaction solution to room temperature.

[0067] Other conditions were the same as those in Example 1, and a surface-modified MgO carrier was obtained, which was designated as 9#.

[0068] Example 10

[0069] Compared with Example 1, this example is different in that the proportion of the surface modifier is changed:

[0070] (1) Add 18g of sodium sulfate and 150g of water to a 250ml beaker, stir thoroughly, then add 0.30g of sodium laureth sulfate, heat to 50℃ and stir for 10min until the surface modifier is fully dispersed.

[0071] (2) Add 31.8 g of sodium carbonate and 150 g of water into a three-necked flask, stir mechanically until fully uniform, then add 1.45 g of sodium dodecyl sulfate, heat to 50 °C and stir for 10 min until the surface modifier is fully dispersed.

[0072] Other conditions are the same as those in Example 1, and a MgO carrier can be obtained, which is marked as 10#.

[0073] Example 11

[0074] Compared with Example 1, this embodiment differs in that the type of surface modifier compound is changed:

[0075] (1) Add 18g of sodium sulfate and 150g of water to a 250ml beaker, stir thoroughly, then add 0.44g of sodium hexadecylbenzenesulfonate, heat to 50℃ and stir for 10min until the surface modifier is fully dispersed.

[0076] (2) Add 31.8 g of sodium carbonate and 150 g of water to a three-necked flask, stir mechanically until fully uniform, then add 1.31 g of sodium lauryl sulfate, heat to 50 °C and stir for 10 min until the surface modifier is fully dispersed.

[0077] Other conditions were the same as in Example 1 to obtain a MgO carrier, which was designated as 11#.

[0078] Example 12

[0079] Prepared 1#MgO carrier for loading:

[0080] (1) Determination of saturated adsorption capacity: Place 10g of dried 1# MgO carrier in a beaker and slowly and evenly add ethanol solution dropwise until the 10g MgO carrier is saturated with adsorption and the surface of the MgO carrier is just soaked with solvent. The amount of ethanol solvent adsorbed by the MgO carrier at this point is the saturated adsorption capacity of the carrier, and the saturated adsorption capacity is 10ml of ethanol solution.

[0081] (2) Add 10 ml of ethanol solvent and 1.92 g of copper nitrate trihydrate to a beaker and dissolve thoroughly to prepare a Cu(NO3)2 solution. Using the equal volume impregnation method, slowly pour 10 g of 1# MgO carrier particles into the prepared Cu(NO3)2 solution to mix the liquid and powder evenly. Then, leave it open in the air for 48 hours until the surface is completely dry.

[0082] (3) The sample was then placed in an oven and dried until completely dry. Finally, the sample was placed in a muffle furnace and calcined at a gradient temperature. The temperature was increased from room temperature at a rate of 2°C / min to 110°C, and calcined for 2 hours. The temperature was then increased from 110°C to 480°C at a rate of 3°C / min, and calcined at this specific temperature for 8 hours. After cooling, the sample was taken out to obtain a supported catalyst with oxidized MgO as the supported catalyst.

[0083] (4) Then, the temperature was gradually increased in a tubular furnace under a hydrogen atmosphere to 110°C at a heating rate of 2°C / min, maintained for 1 hour, and then increased from 110°C to 500°C at a heating rate of 3°C / min. The catalyst was reduced at this specific temperature for 4 hours to obtain a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-1#.

[0084] XPS valence characterization of sample 1-1# showed that Figure 3 As shown. TEM scanning of sample 1-1# shows the following Figure 4 As shown in the particle size analysis diagram Figure 5 shown.

[0085] Example 13

[0086] The prepared 2#MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-2#.

[0087] Example 14

[0088] The prepared 3# MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-3#.

[0089] Example 15

[0090] The prepared 4# MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-4#.

[0091] Example 16

[0092] The prepared 5# MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-5#.

[0093] Example 17

[0094] Compared with Example 12, this example changes the metal loading amount of the supported catalyst. The specific differences are:

[0095] In step (2), the amount of copper nitrate trihydrate added was 0.384 g, and the other conditions were the same as in Example 12, to obtain a Cu-MgO supported catalyst with a Cu content of 1% wt, recorded as 2-1#.

[0096] The oxidation state of sample 2-1# was characterized by XRD, and the results showed that Figure 6 shown.

[0097] Example 18

[0098] Compared with Example 12, the supported catalyst prepared in this example changes the type of metal supported. The specific differences are:

[0099] In step (2), copper nitrate trihydrate was replaced by nickel nitrate hexahydrate. Other conditions were the same as those in Example 12 to prepare a Ni-MgO supported catalyst with a Ni content of 5% wt, designated as 3-1#.

[0100] Example 19

[0101] Select the prepared 1#MgO carrier as the load

[0102] (1) Add 10 ml of ethanol solvent and 0.96 g of copper nitrate trihydrate to a beaker and dissolve them thoroughly to prepare a Cu(NO3)2 solution. Using the equal volume impregnation method, slowly pour 10 g of 1# MgO carrier particles into the prepared Cu(NO3)2 solution to mix the liquid and powder evenly. Leave it in the open air for 48 hours until the surface is completely dry. Then, place the sample in an oven at 100°C for 2 hours until it is completely dry and then crush it for preparation.

[0103] (2) Add 10 ml of ethanol solvent and 0.96 g of copper nitrate trihydrate to the beaker and dissolve thoroughly to prepare a Cu(NO3)2 solution. Using the equal volume standing method again, slowly pour the catalyst loaded once above into the prepared Cu(NO3)2 solution to mix the liquid and powder evenly. Leave the solution open to air for 48 hours until the surface is completely dry.

[0104] (3) The sample was then placed in an oven until completely dry, and finally placed in a muffle furnace for gradient calcination, with the temperature rising from room temperature at a rate of 2°C / min to 110°C, calcined for 2 hours, and then raised from 110°C to 480°C at a rate of 3°C / min, calcined at this specific temperature for 8 hours, and taken out after cooling to obtain a supported catalyst with oxidized MgO as the supported catalyst.

[0105] (4) Then, the temperature was gradually increased in a tubular furnace under a hydrogen atmosphere to 110°C at a heating rate of 2°C / min, maintained for 1 hour, and then increased from 110°C to 500°C at a heating rate of 3°C / min. The catalyst was reduced at this specific temperature for 4 hours to obtain a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 4-1#.

[0106] The supported catalyst prepared in this example changed the loading method and adopted multiple equal volume impregnation methods for loading, with a pre-loading amount of 5%, and 2.5% loading each time, for a total of two loadings.

[0107] Example 20

[0108] Compared with Example 12, the prepared supported catalyst in this example changes the heating rate to a specific calcination temperature:

[0109] (3) The sample was then placed in an oven until completely dried. Finally, the sample was placed in a muffle furnace and calcined at a gradient temperature from room temperature at a heating rate of 2°C / min to 110°C, calcined for 2 hours, then raised from 110°C to 480°C at a heating rate of 10°C / min, calcined at this specific temperature for 8 hours, and taken out after cooling to obtain a supported catalyst with oxidized MgO as the support. Other conditions were the same as those in Example 12. A Cu-MgO supported catalyst was obtained, with a Cu content of 5% by weight, and was recorded as 5-1#.

[0110] Example 21

[0111] Compared with Example 12, the specific calcination temperature of the prepared supported catalyst was changed in this example:

[0112] (3) The sample was then placed in an oven until completely dry. Finally, the sample was placed in a muffle furnace and calcined at a gradient temperature from room temperature at a heating rate of 2°C / min to 110°C, calcined for 2 hours, then raised from 110°C to 750°C at a heating rate of 3°C / min, calcined at this specific temperature for 8 hours, and removed after cooling to obtain a supported catalyst with oxidized MgO as the support. Other conditions were the same as in Example 12, and a Cu-MgO supported catalyst was prepared, with a Cu content of 5% by weight, denoted as 6-1#.

[0113] Example 22

[0114] Compared with Example 12, in this example, the heating rate to a specific reduction temperature was changed during the reduction of the supported catalyst in a hydrogen atmosphere:

[0115] (4) Then, the catalyst was reduced by gradient temperature increase in a tubular furnace under a hydrogen atmosphere, with the temperature increased from room temperature to 110°C at a heating rate of 2°C / min, maintained for 1 hour, and then increased from 110°C to 500°C at a heating rate of 10°C / min, and reduced at this specific temperature for 4 hours; other conditions were the same as those in Example 12, and a Cu-MgO supported catalyst was obtained, with a Cu content of 5% by weight, recorded as 7-1#.

[0116] Example 23

[0117] Compared with Example 12, the specific reduction temperature of the supported catalyst prepared in this example was changed during reduction in a hydrogen atmosphere:

[0118] (4) Then, the catalyst was reduced by gradient temperature increase in a tubular furnace under a hydrogen atmosphere, with the temperature increased from room temperature to 110°C at a heating rate of 2°C / min, maintained for 1 hour, and then increased from 110°C to 800°C at a heating rate of 3°C / min, and reduced at this specific temperature for 4 hours; other conditions were the same as those in Example 12, and a Cu-MgO supported catalyst was obtained, with a Cu content of 5% by weight, recorded as 8-1#.

[0119] Example 24

[0120] The prepared 6# MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-6#.

[0121] Example 25

[0122] The prepared 7# MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-7#.

[0123] Example 26

[0124] The prepared 8#MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-8#.

[0125] Example 27

[0126] The prepared 9#MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5%wt, which was recorded as 1-9#.

[0127] Example 28

[0128] The prepared 10# MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-10#.

[0129] Example 29

[0130] The prepared 11#MgO carrier was selected as the support, and the same loading method as in Example 12 was adopted to prepare a Cu-MgO supported catalyst with a Cu content of 5% wt, which was recorded as 1-11#.

[0131] Example 30

[0132] Compared with Example 12, in the process of loading the metal on the prepared supported catalyst, the method of using water as the solvent to dissolve the supported metal was changed from using an organic solvent as the solvent to dissolve the supported metal:

[0133] (1) Add 10 ml of water and 1.92 g of copper nitrate trihydrate to a beaker and dissolve thoroughly to prepare a Cu(NO3)2 solution. Using the equal volume impregnation method, slowly pour 10 g of 1# MgO carrier particles into the prepared Cu(NO3)2 solution to mix the liquid and powder evenly. Then, leave it open to air for 48 hours until the surface is completely dry.

[0134] Other conditions were the same as those in Example 12 to prepare a Cu-MgO supported catalyst with a Cu content of 5% by weight, designated as 9-1#.

[0135] Example 31

[0136] (1) Add 30 ml of isopropanol and 1.5 g of HMF to a polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0137] (2) Then, 0.3 g of the prepared 1-1# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0138] (3) After the reaction was completed, the mixture was cooled to room temperature and the contents in the reaction solution were analyzed by LC. The results are shown in Table 1.

[0139] Table 1

[0140]

[0141]

[0142] Example 32

[0143] Compared with Example 31, the catalyst sample in this example was changed from 1-1# to 1-2#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 2.

[0144] Table 2

[0145] Example BHMF yield HMF conversion Catalyst selectivity 32 89 93 96

[0146] The extension of the stirring time of the liquid-phase reaction breaks up the original crystal morphology, causing the crystal morphology to change from large to small, resulting in an irregular morphology of the carrier crystal, which leads to uneven dispersion of the metal particles during the loading process. The final prepared catalyst affects its selectivity for HMF and the yield of BHMF during the catalytic reaction.

[0147] Example 33

[0148] Compared with Example 31, the catalyst sample used in Example 33 was changed from 1-1# to 1-3#. After the reaction was completed, the reaction solution was cooled to room temperature and the contents in the reaction solution were analyzed by LC. The results are shown in Table 3.

[0149] Table 3

[0150] Example BHMF yield HMF conversion Catalyst selectivity 33 80 87 92

[0151] The slower flow rate of the precipitant added resulted in agglomeration during the liquid-phase reaction crystallization nucleation process, which did not present a uniform lamellar structure. This led to low dispersion of the metal particles during loading, affecting the selectivity of the catalyst for HMF and the yield of BHMF during the catalytic reaction.

[0152] Example 34

[0153] Compared with Example 31, the catalyst sample used in Example 34 was changed from 1-1# to 1-4#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 4.

[0154] Table 4

[0155] Example BHMF yield HMF conversion Catalyst selectivity 34 57 75 76

[0156] During the preparation of the MgO support, the pyrolysis heating rate was altered, accelerating the rate at which the specific pyrolysis temperature was reached. All other preparation conditions remained unchanged. This resulted in uneven surface morphology during precursor formation, weakening the anchoring of metal particles onto the support during the loading process. This compromised the selectivity for HMF and the yield of BHMF in the resulting catalyst during the catalytic reaction.

[0157] Example 35

[0158] Compared with Example 31, the catalyst sample used in Example 35 was changed from 1-1# to 1-5#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 5.

[0159] Table 5

[0160] Example BHMF yield HMF conversion Catalyst selectivity 35 36 69 52

[0161] The low pyrolysis temperature affects the strong interfacial anchoring effect on the surface of the precursor during formation, resulting in weak anchoring of the metal loaded on the carrier during the loading process. The final prepared catalyst affects its selectivity for HMF and the yield of BHMF during the catalytic reaction.

[0162] Example 36

[0163] Compared with Example 31, the catalyst sample used in Example 36 was changed from 1-1# to 2-1#, that is, the metal loading amount was changed during the carrier loading process, and the other preparation conditions remained unchanged;

[0164] The contents of the reaction solution were analyzed by LC, and the results are shown in Table 6.

[0165] Table 6

[0166] Example BHMF yield HMF conversion Catalyst selectivity 36 42 90 47

[0167] As the metal loading decreases, the final BHMF yield significantly decreases. This indicates that the metal loading on the support influences the BHMF yield and selectivity. Excessive metal loading can easily lead to inefficiencies in the experimental economy, so an appropriate metal loading is essential for optimal experimental efficiency.

[0168] Example 37

[0169] Compared with Example 31, the catalyst sample used in Example 37 was changed from 1-1# to 3-1#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 7.

[0170] Table 7

[0171] Example BHMF yield HMF conversion Catalyst selectivity 37 87 91 96

[0172] When preparing the supported catalyst, the metal type was changed from Cu to Ni. All other preparation conditions remained unchanged, but the final BHMF yield decreased significantly. This indicates that the type of metal supported on the supported catalyst affects the final BHMF yield in the catalytic reaction.

[0173] Example 38

[0174] Compared with Example 31, the catalyst sample used in Example 38 was changed from 1-1# to 4-1#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 8.

[0175] Table 8

[0176] Example BHMF yield HMF conversion Catalyst selectivity 38 96 96 100

[0177] The loading method was changed from a single equal volume impregnation method to a multiple impregnation method, while the other preparation conditions remained unchanged. The final BHMF selectivity and yield did not change significantly. This shows that the loading method of the present invention is flexible and can be used in different impregnation methods according to the solubility of the metal salt in the organic solvent, and the catalytic ability of the resulting catalyst does not vary significantly.

[0178] Example 39

[0179] Compared with Example 31, the catalyst sample used in Example 39 was changed from 1-1# to 5-1#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 9.

[0180] Table 9

[0181] Example BHMF yield HMF conversion Catalyst selectivity 39 87 93 94

[0182] During the preparation of the supported catalyst, the heating rate to the specific calcination temperature was increased from 3°C / min to 10°C / min. All other preparation conditions remained unchanged, resulting in a significant decrease in BHMF selectivity and yield. This suggests that excessively fast heating rates can cause the metal particles on the support to agglomerate, thereby affecting the catalyst selectivity and BHMF yield in the final catalytic reaction.

[0183] Example 40

[0184] Compared with Example 31, the catalyst sample used in Example 40 was changed from 1-1# to 6-1#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 10.

[0185] Table 10

[0186] Example BHMF yield HMF conversion Catalyst selectivity 40 78 85 92

[0187] When the calcination temperature was increased from 480°C to 750°C, while the other preparation conditions remained unchanged, the final BHMF selectivity and yield decreased significantly. This shows that excessively high calcination temperature will cause the metal particles loaded on the carrier to agglomerate, thereby affecting the selectivity of the catalyst and the yield of BHMF in the final catalytic reaction.

[0188] Example 41

[0189] Compared with Example 31, Example 41 used a different catalyst sample from Example 1-1# to Example 7-1#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 11.

[0190] Table 11

[0191] Example BHMF yield HMF conversion Catalyst selectivity 37 83 93 90

[0192] It can be seen from this that when reducing in a hydrogen atmosphere, a too fast heating rate will cause the metal particles loaded on the carrier to agglomerate, thereby affecting the selectivity of the catalyst and the yield of BHMF in the final catalytic reaction.

[0193] Example 42

[0194] Compared with Example 31, Example 42 used a different catalyst sample from 1-1# to 8-1#. The contents in the reaction solution were analyzed by LC, and the results are shown in Table 12.

[0195] Table 12

[0196] Example BHMF yield HMF conversion Catalyst selectivity 42 17 32 53

[0197] It can be seen from this that too high a reduction temperature will cause the metal particles loaded on the carrier to agglomerate, thereby affecting the selectivity of the catalyst and the yield of BHMF in the final catalytic reaction.

[0198] Example 43

[0199] Compared with Example 31, the ratio of substrate to catalyst used in this example was changed, while the other conditions remained unchanged:

[0200] Subsequently, 0.5 g of the prepared 1-1# catalyst was added, resulting in a mass ratio of substrate HMF to catalyst of 3:1. The mixture was then transferred to a hydrogenation reactor. After three nitrogen replacements, hydrogen was introduced to 1 MPa. The rotational speed was adjusted to 800 rpm, and a temperature program was initiated, with the reaction temperature set at 100°C for 6 hours. LC analysis of the reaction solution was performed, and the results are shown in Table 13.

[0201] Table 13

[0202] Example BHMF yield HMF conversion Catalyst selectivity 47 97 99 98

[0203] As the ratio of substrate to catalyst used decreases, the contact between the catalyst and the raw material becomes more complete, resulting in an increase in yield and catalyst selectivity, and ultimately an increase in the yield of BHMF.

[0204] Example 44

[0205] Compared with Example 31, the ratio of substrate and catalyst used in this example has changed, and the other conditions are unchanged:

[0206] Subsequently, 0.1 g of the prepared 1-1# catalyst was added, resulting in a mass ratio of substrate HMF to catalyst of 15:1. The mixture was then transferred to a hydrogenation reactor. After three nitrogen replacements, hydrogen was introduced to 1 MPa. The rotational speed was adjusted to 800 rpm, and a temperature program was initiated, with the reaction temperature set at 100°C for 6 hours. LC analysis of the reaction solution was performed, and the results are shown in Table 14.

[0207] Table 14

[0208] Example BHMF yield HMF conversion Catalyst selectivity 48 82 89 92

[0209] As the ratio of substrate to catalyst increases, the catalyst content in the same system decreases significantly, resulting in incomplete conversion of HMF and intermediates during the reaction, ultimately leading to a serious shortage of BHMF yield. Therefore, it can be seen that an appropriate catalyst content to support the reaction is a necessary condition for the production of BHMF.

[0210] Example 45

[0211] Catalyst recycling experiment:

[0212] (1), (2), and (3) are the same as in Example 31.

[0213] (4) Filter out the catalyst, wash it three times with isopropanol, place it in a polytetrafluoroethylene liner and seal it with 15 ml of isopropanol (minimize the time of contact with air), then add 1.5 g of HMF and 15 ml of isopropanol solvent to the liner (maintain the amount of solvent in the system unchanged). At this time, the mass ratio of substrate HMF and catalyst is still 5:1, and it is transferred to the hydrogenation reactor. After three times of nitrogen replacement of air, hydrogen is introduced to 1 MPa, the speed is adjusted to 800 rpm, and the temperature is programmed to 100 ° C and the reaction time is 6 h;

[0214] (5) After the reaction is completed, the mixture is cooled to room temperature and the contents of the reaction solution of the second reaction are analyzed by LC.

[0215] (6) Repeat the steps (4) to (5) and recycle the catalyst for 5 times.

[0216] (7) The catalyst after five reactions was filtered out, washed three times with isopropanol, dried and stored temporarily, and then subjected to ICP-OES qualitative and quantitative analysis and TEM particle size test. The TEM particle size analysis of the catalyst is as follows: Figure 7 shown.

[0217] (8) The results of ICP and LC analysis are shown in Tables 15 and 16.

[0218] Table 15

[0219] Number of reactions BHMF yield HMF conversion Catalyst selectivity first 96 96 100 Second time 96 96 100 The third time 94 94 100 Fourth time 92 92 100 Fifth 88 88 100

[0220] Table 16

[0221] Sample stage Cu (wt%) <![CDATA[d Cu (nm)]]> Carbon deposit content (wt%) initial 4.98 2.64 0 5th 4.96 2.28 1.75

[0222] It was found that the selectivity of the catalyst subjected to five consecutive reactions did not change significantly during the reaction. Analysis of the initial catalyst and the catalyst after five replicate reactions revealed that the Cu loading of the metal particles on the supported catalyst could be calculated after deducting the amount of carbon deposits. The Cu content after each cycle was essentially the same as that of the initial reaction, with little change. Furthermore, the particle size distribution showed that the average size of the Cu particles on the catalyst surface after three replicate reactions remained essentially the same as that in the initial state, indicating that the migration and leaching of the Cu particles could be largely ignored.

[0223] These experiments demonstrate that the support prepared by this invention exhibits a strong interfacial anchoring effect on metal particles, exhibits high tolerance, and does not cause the supported metal particles to fall off even during repeated, prolonged reactions at high temperatures. Furthermore, it demonstrates exceptional specificity for the catalytic hydrogenation of HMF to produce BHMF. Therefore, it is inferred that the decrease in BHMF yield is due to the impact of accumulated carbon deposition from multiple biomass reactions on the catalyst.

[0224] Example 46

[0225] Catalyst regeneration:

[0226] (1) The catalyst temporarily stored after the five-time application reaction in Example 43 was washed three times with ethanol, washed three times with water, and then placed in an oven at 100°C for 2 hours until completely dry. Finally, the sample was placed in a muffle furnace and calcined by gradient heating. The temperature was increased from room temperature to 110°C at a heating rate of 2°C / min, and calcined for 2 hours. The temperature was then increased from 110°C to 480°C at a heating rate of 3°C / min, and calcined at this specific temperature for 8 hours. After cooling, the sample was taken out to obtain the oxidized catalyst after removing the carbon deposits.

[0227] (2) Then, the catalyst was reduced by gradient temperature increase in a tubular furnace under a hydrogen atmosphere. The temperature was increased from room temperature to 110°C at a rate of 2°C / min and maintained for 1 hour. The temperature was then increased from 110°C to 500°C at a rate of 3°C / min and reduced at this specific temperature for 4 hours to obtain a regenerated supported catalyst, which was recorded as 1-1-1#.

[0228] Verification reaction of regenerated catalyst

[0229] (3) Add 30 ml of isopropanol and 1.5 g of HMF to the polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0230] (4) Then, 0.3 g of regenerated 1-1-1# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was still 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0231] (5) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 17.

[0232] Table 17

[0233] Example BHMF yield HMF conversion Catalyst selectivity 52 96 96 100

[0234] The decrease in BHMF yield during the continuous catalyst reuse reaction was due to the cumulative carbon deposition from the multiple biomass reactions, which affected the catalyst. After calcination and reduction, the catalyst, after removing the carbon deposits, regained its excellent hydrogenation catalytic performance. This demonstrates the excellent reusability of the catalyst prepared by this invention, as well as the strong anchoring of the loaded metal particles, which resists detachment and deactivation, and exhibits excellent regeneration.

[0235] Example 47

[0236] The reaction of the unmodified MgO carrier after metal loading and regeneration were verified by experiments:

[0237] (1) Add 30 ml of isopropanol and 1.5 g of HMF to a polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0238] (2) Then, 0.3 g of the prepared 1-6# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0239] (3) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 24.

[0240] Catalyst regeneration

[0241] (4) After the reaction in step (3), the catalyst is regenerated using the same method as in Example 46.

[0242] Catalyst verification experiment after regeneration

[0243] (5) Add 30 ml of isopropanol and 1.5 g of HMF to the polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0244] (6) The regenerated supported catalyst was then added, with the mass ratio of substrate HMF to catalyst being 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of the air, hydrogen was introduced to 1 MPa, the speed was adjusted to 800 rpm, and a temperature program was started. The reaction temperature was 100°C and the reaction time was 6 h.

[0245] (7) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 18.

[0246] Table 18

[0247] Example 47 BHMF yield HMF conversion Catalyst selectivity Control reaction 89 89 100 After catalyst regeneration 67 78 86

[0248] In this example, no surface modifier was added to the support during the preparation of the 1-6# supported catalyst. All other loading and reaction conditions remained unchanged, resulting in significantly insufficient BHMF yield. Reaction data after catalyst regeneration indicate that the supported catalyst prepared in this example without surface modification exhibited poor regeneration. Following high-temperature calcination and regeneration, HMF conversion decreased, ultimately impacting BHMF yield.

[0249] Example 48

[0250] The reaction of MgO carrier surface modified by single anionic surfactant after loading metal and its application after regeneration are verified by experiments:

[0251] (1) Add 30 ml of isopropanol and 1.5 g of HMF to a polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0252] (2) Then, 0.3 g of the prepared 1-7# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0253] (3) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 25.

[0254] Catalyst regeneration:

[0255] (4) After the reaction in step (3), the catalyst is regenerated using the same method as in Example 46.

[0256] Verification experiment of the regenerated catalyst:

[0257] (6) Add 30 ml of isopropanol and 1.5 g of HMF to the polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration;

[0258] (7) The regenerated supported catalyst was then added, with the mass ratio of substrate HMF to catalyst being 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of the air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and a temperature program was started. The reaction temperature was 100°C and the reaction time was 6 h.

[0259] (8) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 19.

[0260] Table 19

[0261] Example 48 BHMF yield HMF conversion Catalyst selectivity Control reaction 90 90 100 After catalyst regeneration 75 84 89

[0262] The 1-7# supported catalyst used in the present embodiment is only added with a kind of anionic surfactant to make surface modification during the preparation of the carrier, and the addition ratio is unchanged, and the other loading conditions and reaction conditions are not changed. The BHMF yield prepared by it is slightly less than the effect of Example 45. It can be seen from the catalyst application reaction data after regeneration that the catalyst support of the present embodiment has improved catalyst performance after modification with a surface modifier. However, compared to the effect of the supported catalyst of Example 45 the present invention is still less than. It will still affect its selectivity to HMF and the yield of BHMF after calcination regeneration at high temperature.

[0263] Example 49

[0264] The reaction of MgO carrier surface modified by single anionic surfactant after loading metal and its application after regeneration are verified by experiments:

[0265] (1) Add 30 ml of isopropanol and 1.5 g of HMF to a polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0266] (2) Then, 0.3 g of the prepared 1-8# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0267] (3) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 26.

[0268] Catalyst regeneration:

[0269] (4) The catalyst after the reaction in step (3) was regenerated using the same method as in Example 52.

[0270] Catalyst verification experiment after regeneration

[0271] (5) Add 30 ml of isopropanol and 1.5 g of HMF to the polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0272] (6) The regenerated supported catalyst was then added, with the mass ratio of substrate HMF to catalyst being 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of the air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and a temperature program was started. The reaction temperature was 100°C and the reaction time was 6 h.

[0273] (7) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 20.

[0274] Table 20

[0275] Example 49 BHMF yield HMF conversion Catalyst selectivity Control reaction 92 92 100 After catalyst regeneration 79 88 90

[0276] The 1-8# loaded catalyst used in this embodiment was surface modified by adding an anionic surfactant in the precipitant during the preparation of the carrier. The addition ratio remained unchanged, and the remaining loading methods and reaction conditions remained unchanged. From the experimental data, different anionic surfactants showed differences in the surface modification of the magnesium oxide carrier. From the catalyst regeneration reaction data, it can be seen that the loaded catalyst used in this embodiment has improved catalyst performance after being modified by a surface modifier. However, compared to the effect of the loaded catalyst of Example 45 of the present invention, it is still insufficient. And it will still affect its selectivity to HMF and the yield of BHMF after calcination and regeneration at high temperature.

[0277] Example 50

[0278] Experimental verification of the reaction of MgO carrier loaded with metals and its application after regeneration by increasing the dosage of single anionic surfactant for surface modification

[0279] (1) Add 30 ml of isopropanol and 1.5 g of HMF to a polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0280] (2) Then, 0.3 g of the prepared 1-9# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0281] (3) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 27.

[0282] Catalyst regeneration

[0283] (4) The catalyst after the reaction in step (3) was regenerated using the same method as in Example 46.

[0284] Catalyst verification experiment after regeneration

[0285] (5) Add 30 ml of isopropanol and 1.5 g of HMF to the polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0286] (6) The regenerated supported catalyst was then added, with the mass ratio of substrate HMF to catalyst being 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of the air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and a temperature program was started. The reaction temperature was 100°C and the reaction time was 6 h.

[0287] (7) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 21.

[0288] Table 21

[0289] Example 50 BHMF yield HMF conversion Catalyst selectivity Control reaction 92 92 100 After catalyst regeneration 81 89 91

[0290] During the preparation of the carrier for the 1-9# supported catalyst used in this example, an anionic surfactant was added in an increased amount for surface modification, while the other loading methods and reaction conditions remained unchanged. Experimental data revealed that the modified effect on the carrier was not significantly improved, so the appropriate addition amount is crucial for carrier modification.

[0291] Example 51

[0292] (1) Add 30 ml of isopropanol and 1.5 g of HMF to a polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0293] (2) Then, 0.3 g of the prepared 1-10# catalyst was added. At this time, the mass ratio of substrate HMF to catalyst was 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and the temperature was programmed to 100°C for 6 h.

[0294] (3) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 28.

[0295] Catalyst regeneration

[0296] (4) After the reaction in step (3), the catalyst is regenerated using the same method as in Example 46.

[0297] Verification experiment of the regenerated catalyst:

[0298] (5) Add 30 ml of isopropanol and 1.5 g of HMF to the polytetrafluoroethylene liner and stir thoroughly to ensure that the raw materials are evenly dispersed and stably distributed in the reaction system. At this point, the concentration of HMF in the solution system is 396 mM. Take a sample as the initial reaction concentration.

[0299] (6) The regenerated supported catalyst was then added, with the mass ratio of substrate HMF to catalyst being 5:1, and the mixture was transferred to the hydrogenation reactor. After three nitrogen replacements of the air, hydrogen was introduced to 1 MPa, the rotation speed was adjusted to 800 rpm, and a temperature program was started. The reaction temperature was 100°C and the reaction time was 6 h.

[0300] (7) After the reaction was completed, the mixture was cooled to room temperature and the contents of the reaction solution were analyzed by LC. The results are shown in Table 22.

[0301] Table 22

[0302] Example 51 BHMF yield HMF conversion Catalyst selectivity Control reaction 90 90 100 After catalyst regeneration 79 85 93

[0303] During the preparation of the carrier for the 1-10# supported catalyst used in this example, the surface modifier ratio was varied, while the other loading methods and reaction conditions remained unchanged. The experimental data showed that the modified carrier effect was not significantly improved, indicating that the appropriate surface modifier ratio is key to improving carrier performance.

[0304] Example 52

[0305] Based on Example 51, catalyst #1-10 was replaced with catalyst #1-11, and other conditions were the same.

[0306] The contents of the reaction solution were analyzed by LC. The results are shown in Table 29.

[0307] Table 29

[0308] Example 52 BHMF yield HMF conversion Catalyst selectivity Control reaction 91 91 100 After catalyst regeneration 75 84 89

[0309] From this, we can see that in the process of preparing the carrier, different raw materials need to screen the appropriate types and ratios of surface modifiers to modify the carrier surface during the precipitation reaction in order to achieve outstanding results.

[0310] Example 53

[0311] Performance verification of the catalyst prepared by using water as solvent during the metal loading process:

[0312] Compared with Example 31, the catalyst sample in this example was changed from 1-1# to 9-1#. The contents in the reaction liquid were analyzed by LC, and the results are shown in Table 30.

[0313] Table 30

[0314] Example BHMF yield HMF conversion Catalyst selectivity 59 0 0 0

[0315] It can be seen that during the process of loading the alkaline carrier with water as the solvent, physical and chemical reactions occur between the water and the carrier, affecting the pore size and morphology of the carrier, the loading of metal particles, and ultimately affecting the selectivity and yield of 2,5-furan dimethanol.

[0316] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the present invention.

Claims

1. A method for preparing a supported catalyst using MgO as a carrier, characterized in that: include, A soluble magnesium salt and a precipitant react in a liquid phase under the action of a surface modifier to prepare a precursor, which is then thermally decomposed at a specific temperature to generate an MgO carrier with a strong interface anchor on the surface. The surface modifier is a composite surface modifier composed of 1.31g of sodium dodecyl sulfate and 0.44g of sodium laureth sulfate, and the mass of the composite surface modifier accounts for 0.01% to 5% of the total system mass ratio. The order of adding the materials in the liquid phase reaction is as follows: the surface modifier sodium dodecyl sulfate is dissolved in a 2mol / L sodium carbonate aqueous solution, heated to 50°C and thoroughly mixed, and then a 1mol / L magnesium sulfate aqueous solution containing the surface modifier sodium laureth sulfate at the same temperature of 50°C is quickly added under mechanical stirring for precipitation reaction. The flow rate of the precipitant mixture is 3ml / min, the liquid phase reaction temperature is 60-80°C, the reaction time is 10-80min, and the mechanical stirring speed is 300rpm. The ratio of magnesium ion concentration to precipitant concentration in the liquid phase reaction is 1:

2. The pyrolysis of the MgO precursor adopts a gradient temperature increase method, which is from room temperature to 110°C at a heating rate of 1-10°C / min, maintained for 60 minutes, and then from 110°C to a specific pyrolysis temperature of 500°C at a heating rate of 2°C / min, and maintained at the specific pyrolysis temperature for 10-60 minutes. The particle size of the carrier MgO is 40nm-60nm, and the crystal shape is tetragonal flakes. The saturated adsorption capacity of the prepared MgO support is measured, and then a metal salt is dissolved in an organic solvent having the saturated adsorption capacity, and loaded onto the MgO support by an equal volume impregnation method; wherein the metal loaded in the catalyst is selected from a transition metal element, wherein the transition metal element is Cu, and the mass content of Cu is 5wt%, and the organic solvent for dissolving the metal salt includes one of methanol, ethanol, n-propanol, isopropanol, and n-butanol; After drying, the catalyst is calcined at a specific temperature by gradient heating in an air atmosphere, and then reduced at a specific temperature by gradient heating in a hydrogen atmosphere to obtain a supported catalyst with MgO as a carrier; wherein the calcination method adopts a gradient heating method, the calcination temperature is increased from room temperature to 110°C at a heating rate of 1-10°C / min, calcined for 1-5 hours, then increased from 110°C to a specific calcination temperature of 480°C at a heating rate of 3°C / min, and the calcination time at the specific calcination temperature is 1 hour to 20 hours; the reduction in a hydrogen atmosphere adopts a gradient heating method, the reduction temperature is increased from room temperature to 110°C at a heating rate of 1-10°C / min, reduced for 1-5 hours, then increased from 110°C to a specific reduction temperature of 500°C at a heating rate of 3°C / min, and the reduction time at the specific reduction temperature is 1 hour to 30 hours.

2. Use of a supported catalyst containing MgO as a carrier, prepared by the preparation method according to claim 1, in the preparation of 2,5-furan dimethanol.

3. The use according to claim 2, characterized in that: The method comprises the following steps: using 5-hydroxymethylfurfural as a raw material, an organic solvent as a reaction solvent, adding a supported catalyst with MgO as a carrier, and producing the 2,5-furan dimethanol through a catalytic hydrogenation reaction under a hydrogen pressure atmosphere; The concentration of 5-hydroxymethylfurfural in the reaction solution is 0.1~3000mM; The hydrogen pressure is 0.1MPa~8MPa; The reaction temperature is 50-200°C and the reaction time is 0.5-10h; The organic solvent is one of methanol, ethanol, n-propanol, isopropanol, and n-butanol; The mass ratio of the 5-hydroxymethylfurfural to the supported catalyst with MgO as the carrier is 1:1-30:1.

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