Catalyst, preparation method and application in preparing 1,4-butanediol by hydrogenation of succinic acid

Abstract

The present invention provides a catalyst, a preparation method and an application thereof in preparing 1,4-butanediol by hydrogenation of succinic acid, belonging to the field of catalyst preparation technology. The expression of the catalyst is Co-X-M / SiO2, wherein SiO2 is a carrier, X is selected from one or both of Cu, Ni, Fe, Zn, Mn, Mo, V or Cr metal elements, and M is selected from one of alkali metal oxides and alkaline earth metal oxides. The present invention also provides a preparation method of the above-mentioned catalyst, and the present invention also provides the application of the catalyst in preparing 1,4-butanediol by hydrogenation of succinic acid. The present invention uses a non-precious metal catalyst, which is simple to prepare, low in price, and has high catalytic activity, good selectivity for 1,4-butanediol, and can be obtained at a lower reaction temperature, a moderate hydrogen pressure, and a shorter reaction time. 1,4-butanediol can be obtained in a yield of more than 95%.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation, and in particular relates to a catalyst, a preparation method and application in the preparation of 1,4-butanediol by hydrogenation of succinic acid. Background Art

[0002] 1,4-Butanediol is an important raw material for the industrial production of chemicals such as tetrahydrofuran and N-vinylpyrrolidone. It is also a basic raw material for the production of polybutylene terephthalate (PBTE) engineering plastics and fibers, and is widely used in pesticides, pharmaceuticals, and cosmetics. In recent years, as a core raw material for the production of biodegradable plastics such as butylene adipate and polybutylene succinate, demand for 1,4-butanediol has increased significantly, leading to a significant price increase. There are four main industrial production methods for 1,4-butanediol: the acetylene aldehyde method, the butadiene method, the propylene oxide method, and the maleic anhydride method. The acetylene aldehyde method is a more traditional method. While widely used, it is difficult to prepare raw materials and is costly. It also carries significant safety risks and has a significant impact on the environment. The butadiene method offers abundant raw materials and milder reaction conditions, but it uses precious metal catalysts, requires a longer process, and requires high overall investment and energy consumption. The propylene oxide method uses reusable catalysts with a long lifespan, and the yield of 1,4-butanediol can be adjusted, but the isomerized product, allyl alcohol, is somewhat toxic. The maleic anhydride method utilizes inexpensive raw materials and has low production costs, but its acid-based production process requires high corrosion resistance from the equipment. Currently, all of these methods utilize fossil resources as raw materials and present various challenges. With the development of the chemical industry and the increasing demand for 1,4-butanediol, further development of green and renewable synthesis processes for 1,4-butanediol is needed.

[0003] Succinic acid is an important renewable biomass-based platform molecule and a potential raw material for the production of renewable 1,4-butanediol. In recent years, China has gradually increased its efforts to develop and utilize renewable resources such as biomass. Succinic acid can be produced from lignocellulosic biomass, and bioproduction of succinic acid has been achieved on an industrial scale. Therefore, the development of effective technologies for producing 1,4-butanediol from succinic acid is necessary, feasible, and of great research and application value. Le et al. prepared a Cu-Pd / HAP catalyst using a co-impregnation method for the hydrogenation of succinic acid to 1,4-butanediol. Cu and Pd exhibit a synergistic effect during alloying, and a fine alloy structure with a high Cu content is beneficial for the preparation of 1,4-butanediol. When the Cu and Pd contents are 8 wt.% and 2 wt.%, respectively, at 200°C and 8 MPa hydrogen pressure, the conversion of succinic acid and the selectivity for 1,4-butanediol reach 100% and 82%, respectively (ACS Sustainable Chemistry & Engineering, 2019, 7:18483-18492). Tapin et al. prepared a Re-Pd / TiO2 catalyst using a continuous impregnation and catalytic reduction method, achieving a 1,4-butanediol yield of 80-90% at 160°C and 15 MPa hydrogen pressure (Materials Chemistry and Physics, 2020, 252:123-225). Di et al. prepared a Re-Ru / C bimetallic catalyst for succinic acid hydrogenation using microwave pyrolysis. The Re-Ru bimetallic interaction alters the adsorption and activation of active components on the catalyst surface, resulting in a 1,4-butanediol yield of 70.1% at 160°C and 8 MPa hydrogen pressure (Industrial & Engineering Chemistry Research, 2017, 56:4672-4683). Vardon et al. prepared a Ru-Sn / AC catalyst using an impregnation method for aqueous succinic acid hydrogenation. A 1:1 metal ratio of Ru to Sn yielded the best catalytic activity, achieving an 82% 1,4-butanediol yield at 180°C and 10 MPa hydrogen pressure (ACS Catalysis, 2017, 7:6207-6219). Mou et al. also used a Pt-Fe bimetallic catalyst to prepare 1,4-butanediol via succinic acid hydrogenation. At 180°C and 5 MPa hydrogen pressure for 5, 10, and 30 hours, the yields of 1,4-butanediol were 22%, 40.7%, and 90.7%, respectively (CN 104368358 A). In these studies, it is generally believed that γ-butyrolactone is an intermediate in the hydrogenation of succinic acid to produce 1,4-butanediol, and that γ-butyrolactone and tetrahydrofuran are the main byproducts in the production of 1,4-butanediol.A US patent reports the vapor-phase hydrogenation of γ-butyrolactone over a magnesium silicate-supported Cu-Pd-KOH catalyst. When the mass percentages of Cu, Pd, and KOH are 12, 0.5, and 2%, respectively, at 160°C and 6.2 MPa hydrogen pressure, the γ-butyrolactone conversion reaches 96.5%, with a 1,4-butanediol selectivity of 99.0% (US 4797382). In a Japanese patent, Fuchigami et al. reported the hydrogenation of γ-butyrolactone to 1,4-butanediol using a Pd / C catalyst in the presence of tetrabutylammonium rhenium oxide in a water and ethanol mixture. At 180°C and 10 MPa hydrogen pressure for 16 hours, the γ-butyrolactone conversion and 1,4-butanediol selectivity reached 98% and 88.6%, respectively (JP 7082188).

[0004] In summary, the production of 1,4-butanediol from succinic acid primarily utilizes precious metal catalysts, reaction temperatures of 160-200°C, and hydrogen pressures of 5-15 MPa, achieving 1,4-butanediol yields of 80%-90%. These conditions are relatively demanding, generally requiring high hydrogen pressures and long reaction times. Given the high cost of precious metal catalysts, this can significantly increase production costs. Therefore, developing and applying non-precious metal catalysts to catalyze the hydrogenation of succinic acid to 1,4-butanediol at lower temperatures and hydrogen pressures is an effective approach to achieving industrial application of this reaction. Summary of the Invention

[0005] The present invention aims to provide a catalyst, a preparation method and application in the preparation of 1,4-butanediol by hydrogenation of succinic acid. The catalyst can produce 1,4-butanediol under relatively low temperature and hydrogen pressure conditions and in a short reaction time.

[0006] To achieve the above objectives, the technical solution of the present invention is:

[0007] The present invention first provides a catalyst, the expression of the catalyst is Co-XM / SiO2, wherein SiO2 is a carrier, X is selected from one or two metal elements of Cu, Ni, Fe, Zn, Mn, Mo, V or Cr, and M is selected from one of alkali metal oxides and alkaline earth metal oxides.

[0008] Preferably, in the catalyst, the content of the SiO2 carrier is 60-89wt.%, the content of the Co component is 5-30wt.%, the content of the X component is 1-15wt.%, and the content of the M component is 5-20wt.%.

[0009] Preferably, M is selected from Li2O, MgO or CaO.

[0010] The present invention also provides a method for preparing a catalyst, comprising:

[0011] Step 1: impregnate a metal solution of an alkali metal or alkaline earth metal into a SiO2 carrier, and obtain an M / SiO2 catalyst after drying and calcining;

[0012] Step 2: impregnate the mixed metal solution of Co and metal component X into the M / SiO2 prepared in step 1 according to the method of step 1, and obtain the catalyst Co-XM / SiO after drying, calcination and reduction. 2。

[0013] Preferably, the impregnation described in step 1 is specifically as follows: adding the metal solution of alkali metal or alkaline earth metal dropwise and evenly onto the surface of SiO2, evaporating the solution under tungsten lamp at 65-75°C, stirring SiO2 until it is dry and uniform, and then adding the next drop, and repeating this process until the metal solution is exhausted.

[0014] Preferably, the calcination temperature of step 1 is 200-800° C. and the calcination time is 1-6 hours, and the calcination temperature of step 2 is 200-600° C. and the calcination time is 1-6 hours.

[0015] Preferably, the reduction temperature in step 2 is 200-600° C., and the reduction time is 0.5-4 h.

[0016] The present invention also provides use of the catalyst in preparing 1,4-butanediol by hydrogenating succinic acid.

[0017] Preferably, the method for preparing 1,4-butanediol by hydrogenating succinic acid comprises:

[0018] Succinic acid hydrogenation reaction is carried out using H2 as a hydrogen source. The reduced Co-XM / SiO2 catalyst, succinic acid, and solvent are added into a reactor to react and produce 1,4-butanediol.

[0019] Preferably, the reaction temperature is 140-200° C., the hydrogen pressure is 3-10 MPa, and the reaction time is 1-28 h.

[0020] Beneficial effects of the present invention

[0021] The present invention provides a catalyst, a preparation method, and an application thereof in preparing 1,4-butanediol by hydrogenating succinic acid. By adding two components, X and M, to a Co-based catalyst, the catalytic activity can be greatly improved, and 1,4-butanediol can be prepared under relatively low temperature and hydrogen pressure conditions and in a shorter reaction time. Compared with the prior art, the present invention does not use precious metals but adopts a Co-based non-precious metal catalyst, which can greatly reduce the catalyst cost and is low in cost. The preparation method is simple, does not contain toxic and harmful components, and is environmentally friendly. The use and dependence on fossil raw materials in the production of 1,4-butanediol can be reduced. At the same time, the prepared 1,4-butanediol has high selectivity and relatively mild reaction conditions. 1,4-butanediol can be prepared under relatively low temperature and hydrogen pressure conditions, which can facilitate the subsequent separation process in industrial production and reduce the difficulty and energy consumption of the separation process. DETAILED DESCRIPTION

[0022] The present invention first provides a catalyst expressed as Co-XM / SiO2, wherein Co is the main metal component, SiO2 is the carrier, X and M represent two other components respectively, X is selected from one or two metal elements of Cu, Ni, Fe, Zn, Mn, Mo, V or Cr, and M is selected from one of alkali metal oxides and alkaline earth metal oxides, preferably Li2O, MgO or CaO.

[0023] According to the present invention, in the catalyst, the content of SiO2 carrier is preferably 60-89wt.%, the content of Co component is 5-30wt.%, the content of X component is 1-15wt.%, and the content of M component is 5-20wt.%. More preferably, the content of SiO2 carrier is preferably 65-70wt.%, the content of Co component is 15-22wt.%, the content of X component is 3-10wt.%, and the content of M component is 5-10wt.%.

[0024] The present invention also provides a method for preparing a catalyst, comprising:

[0025] Step 1: impregnating a metal solution of an alkali metal or an alkaline earth metal into a SiO2 carrier, wherein the impregnation is preferably performed by uniformly dropping the metal solution of the alkali metal or alkaline earth metal dropwise onto the surface of the SiO2, adding a small amount each time, evaporating the solution at 65-75°C under tungsten lamp irradiation, stirring the SiO2 until it is uniform after drying, and then adding the next drop, repeating this process until the metal solution is exhausted, and then drying, wherein the drying is preferably performed at 110°C overnight, and then calcining to obtain the M / SiO2 catalyst; the calcination temperature is preferably 200-800°C, more preferably 400-600°C, and the calcination time is preferably 1-6h, more preferably 3-4h;

[0026] The alkali metal or alkaline earth metal metal solution is a nitrate solution or acetate solution of an alkali metal or alkaline earth metal, and the concentration of the metal solution is preferably 0.03-0.15 g / ml; the mass ratio of the metal solution to the SiO2 carrier is preferably 5-30:1;

[0027] Step 2: impregnating the mixed metal solution of Co and metal component X into the M / SiO2 prepared in step 1 according to the method of step 1, and then drying, wherein the drying is preferably drying at 110°C overnight, and then calcining, wherein the calcination temperature is preferably 200-600°C, more preferably 300-500°C, and the calcination time is preferably 1-6h, more preferably 3-4 hours. Before use, the calcined catalyst is reduced in a hydrogen atmosphere to obtain a Co-XM / SiO2 catalyst, and the reduction temperature in the hydrogen atmosphere is preferably 200-600°C, more preferably 300-500°C, and the reduction time is preferably 0.5-4h, more preferably 1-2 hours;

[0028] The mixed metal solution of Co and metal component X is a nitrate solution or acetate solution of Co and metal component X. The concentration of the mixed metal solution is preferably 0.03-0.15 g / ml; the mass ratio of the mixed metal solution to the SiO2 carrier is preferably 5-30:1.

[0029] The present invention also provides use of the catalyst in preparing 1,4-butanediol by hydrogenating succinic acid.

[0030] The method for preparing 1,4-butanediol by hydrogenating succinic acid preferably comprises:

[0031] Succinic acid hydrogenation reaction is carried out using H2 as a hydrogen source, and the reduced Co-XM / SiO2 catalyst, succinic acid, and solvent are added to a reactor for reaction. The reaction temperature is preferably 140-200°C, more preferably 160-180°C, the hydrogen pressure is preferably 3-10MPa, more preferably 5-7MPa, and the reaction time is preferably 1-28h, more preferably 4-8h, to produce 1,4-butanediol.

[0032] According to the present invention, the solvent is preferably selected from 1,4-dioxane, water and alcohol solvents. The mass ratio of the solvent to succinic acid is preferably 1-50:1, and the mass ratio of succinic acid to catalyst is preferably 1-40:1.

[0033] The present invention will be further described below with reference to specific examples, which however do not limit the scope of protection of the present invention.

[0034] Comparative Example 1

[0035] 4g of a SiO2 support with an average pore size of 10nm was weighed using an analytical balance and placed in an evaporating dish. The SiO2 support was purchased from Fuji Silycia Chemical Ltd. 4.26g of cobalt nitrate hexahydrate was added to a volumetric flask, followed by 25ml of distilled water to prepare a cobalt nitrate aqueous solution. The solution was then ultrasonically shaken for 30 minutes. The crucible was placed under a 375W tungsten lamp and the SiO2 surface temperature was adjusted to approximately 70°C. 25ml of the prepared cobalt nitrate aqueous solution was added dropwise onto the SiO2 surface, with each drop adding approximately 0.3ml of solution. Once the SiO2 surface was completely dry, the SiO2 support was stirred evenly before the next drop was added. This cycle was repeated until the cobalt nitrate aqueous solution was added. The impregnated catalyst was dried at 110°C for 12h and then calcined at 300°C for 3h. Prior to the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1h. After cooling, a Co / SiO2 catalyst sample with a Co loading of 25wt.% was prepared.

[0036] Comparative Example 2

[0037] Weigh 4g of SiO2 carrier with an average pore size of 10nm using an analytical balance and place it in an evaporating dish. Add 1.23g of lithium nitrate to a volumetric flask, then add 25ml of distilled water to prepare a lithium nitrate aqueous solution, and ultrasonically vibrate for 30 minutes. Place the crucible under a 375W tungsten lamp and adjust the SiO2 surface temperature to approximately 70°C. Add the prepared 25ml lithium nitrate aqueous solution dropwise to the SiO2 surface, with the volume of the solution added each time being approximately 0.3ml. After the SiO2 surface is completely dry, stir the SiO2 carrier evenly and then add the next drop. Repeat this cycle until the lithium nitrate aqueous solution is added. The impregnated catalyst is dried at 110°C for 12h and then calcined at 500°C for 3h to produce Li2O / SiO2. Weigh 4g of the prepared Li2O / SiO2 using an analytical balance and place it in an evaporating dish. Add 4.26g of cobalt nitrate hexahydrate to a volumetric flask, then add 25ml of distilled water to prepare a cobalt nitrate aqueous solution for secondary impregnation. Ultrasonicate for 30 minutes. Place the crucible under a 375W tungsten lamp and adjust the Li2O / SiO2 surface temperature to approximately 70°C. Add 25ml of the prepared cobalt nitrate aqueous solution dropwise onto the Li2O / SiO2 surface, with each drop adding approximately 0.3ml of solution. Once the surface is completely dry, stir the Li2O / SiO2 mixture thoroughly before adding the next drop. Repeat this process until the cobalt nitrate aqueous solution has been added. The impregnated catalyst is dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Prior to the reaction, the catalyst is reduced at 400°C under a hydrogen atmosphere for 1 hour. After cooling, a Co-Li2O / SiO2 catalyst sample with Co and Li2O loadings of 25 wt.% and 10 wt.%, respectively, is prepared.

[0038] Example 1

[0039] Li2O / SiO2 was prepared using the same method as in Comparative Example 2. 4 g of the prepared Li2O / SiO2 was weighed using an analytical balance and placed in an evaporating dish. 3.52 g of cobalt nitrate hexahydrate and 0.35 g of copper nitrate were added to a volumetric flask, and then 25 ml of distilled water was added to prepare a mixed solution of cobalt nitrate and copper nitrate for secondary impregnation, and ultrasonically shaken for 30 minutes. The secondary impregnation was carried out using the same method as in Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1 hour, and after cooling, a Co-Cu-Li2O / SiO2 catalyst sample with Co, Cu and Li2O loadings of 22 wt.%, 3 wt.% and 10 wt.%, respectively, was obtained.

[0040] Example 2

[0041] Li2O / SiO2 was prepared using the same method as in Comparative Example 2. 4 g of the prepared Li2O / SiO2 was weighed using an analytical balance and placed in an evaporating dish. 3.20 g of cobalt nitrate hexahydrate and 1.12 g of ferric nitrate nonahydrate were added to a volumetric flask, and then 25 ml of distilled water was added to prepare a mixed solution of cobalt nitrate and ferric nitrate for secondary impregnation, and ultrasonically shaken for 30 minutes. The secondary impregnation was carried out using the same method as in Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 500°C under a hydrogen atmosphere for 1 hour, and after cooling, a Co-Fe-Li2O / SiO2 catalyst sample with Co, Fe and Li2O loadings of 20 wt.%, 5 wt.% and 10 wt.%, respectively, was obtained.

[0042] Example 3

[0043] Li2O / SiO2 was prepared using the same method as in Comparative Example 2. 4 g of the prepared Li2O / SiO2 was weighed using an analytical balance and placed in an evaporating dish. 3.20 g of cobalt nitrate hexahydrate and 0.99 g of nickel nitrate hexahydrate were added to a volumetric flask, and 25 ml of distilled water was added to prepare a mixed solution of cobalt nitrate and nickel nitrate for secondary impregnation, and ultrasonic vibration was applied for 30 minutes. The secondary impregnation was carried out using the same method as in Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 400°C under hydrogen atmosphere for 1 hour, and after cooling, a Co-Ni-Li2O / SiO2 catalyst sample with Co, Ni and Li2O loadings of 20 wt.%, 5 wt.% and 10 wt.%, respectively, was obtained.

[0044] Example 4

[0045] Li2O / SiO2 was prepared using the same method as in Comparative Example 2. 4 g of the prepared Li2O / SiO2 was weighed using an analytical balance and placed in an evaporating dish. 3.52 g of cobalt nitrate hexahydrate and 0.60 g of nickel nitrate hexahydrate were added to a volumetric flask, and 25 ml of distilled water was added to prepare a mixed solution of cobalt nitrate and nickel nitrate for secondary impregnation, and ultrasonic vibration was applied for 30 minutes. The secondary impregnation was carried out using the same method as in Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1 hour, and after cooling, a Co-Ni-Li2O / SiO2 catalyst sample with Co, Ni and Li2O loadings of 22 wt.%, 3 wt.% and 10 wt.%, respectively, was obtained.

[0046] Example 5

[0047] Li2O / SiO2 was prepared using the same method as in Comparative Example 2. 4 g of the prepared Li2O / SiO2 was weighed using an analytical balance and placed in an evaporating dish. 2.40 g of cobalt nitrate hexahydrate and 2.00 g of nickel nitrate hexahydrate were added to a volumetric flask, and 25 ml of distilled water were added to prepare a mixed solution of cobalt nitrate and nickel nitrate for secondary impregnation, and ultrasonically shaken for 30 minutes. The secondary impregnation was carried out using the same method as in Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1 hour, and after cooling, a Co-Ni-Li2O / SiO2 catalyst sample with Co, Ni and Li2O loadings of 15 wt.%, 10 wt.% and 10 wt.%, respectively, was obtained.

[0048] Example 6

[0049] Weigh 4g of SiO2 carrier using an analytical balance and place it in an evaporating dish. Add 0.62g of lithium nitrate to a volumetric flask, then add 25ml of distilled water to prepare a lithium nitrate aqueous solution, and ultrasonically vibrate for 30 minutes. Place the crucible under a 375W tungsten lamp and adjust the SiO2 surface temperature to about 70°C. Add the prepared 25ml of lithium nitrate aqueous solution dropwise to the SiO2 surface, with the volume of the solution added each time being about 0.3ml. After the SiO2 surface is completely dry, stir the SiO2 carrier evenly, then add the next drop, and repeat this cycle until the lithium nitrate aqueous solution is added. The impregnated catalyst is dried at 110°C for 12h, and then calcined at 500°C for 3h to produce Li2O / SiO2. Add 3.20g of cobalt nitrate hexahydrate and 0.99g of nickel nitrate hexahydrate to a volumetric flask, then add 25ml of distilled water to prepare a mixed solution of cobalt nitrate and nickel nitrate for secondary impregnation, and ultrasonically vibrate for 30min. The secondary impregnation is carried out using the same method as Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1 hour and cooled to produce Co-Ni-Li2O / SiO2 catalyst samples with Co, Ni, and Li2O loadings of 20 wt.%, 5 wt.%, and 5 wt.%, respectively.

[0050] Example 7

[0051] Weigh 4g of the SiO2 carrier using an analytical balance and place it in an evaporating dish. Add 1.48g of magnesium nitrate to a volumetric flask, then add 25ml of distilled water to create a magnesium nitrate aqueous solution, and ultrasonically vibrate for 30 minutes. Place the crucible under a 375W tungsten lamp and adjust the SiO2 surface temperature to approximately 70°C. Add 25ml of the prepared magnesium nitrate aqueous solution dropwise to the SiO2 surface, with each drop adding approximately 0.3ml of solution. Once the SiO2 surface is completely dry, stir the SiO2 carrier evenly and then add the next drop. Repeat this cycle until the magnesium nitrate aqueous solution has been added. The impregnated catalyst is dried at 110°C for 12 hours and then calcined at 500°C for 3 hours to produce MgO / SiO2. Add 3.20g of cobalt nitrate hexahydrate and 0.99g of nickel nitrate hexahydrate to a volumetric flask, then add 25ml of distilled water to create a mixed solution of cobalt nitrate and nickel nitrate for a second impregnation, and ultrasonically vibrate for 30 minutes. The second impregnation is carried out using the same method as Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Before the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1 hour and cooled to produce Co-Ni-MgO / SiO2 catalyst samples with Co, Ni, and MgO loadings of 20 wt.%, 5 wt.%, and 10 wt.%, respectively.

[0052] Example 8

[0053] Weigh 4g of the SiO2 support using an analytical balance and place it in an evaporating dish. Add 1.68g of tetrahydrate and calcium nitrate to a volumetric flask, then add 25ml of distilled water to prepare a calcium nitrate aqueous solution. Ultrasonicate for 30 minutes. Place the crucible under a 375W tungsten lamp and adjust the SiO2 surface temperature to approximately 70°C. Add 25ml of the prepared calcium nitrate aqueous solution dropwise onto the SiO2 surface, with each drop adding approximately 0.3ml of solution. Once the SiO2 surface is completely dry, stir the SiO2 support evenly before adding the next drop. Repeat this process until the calcium nitrate aqueous solution has been added. The impregnated catalyst is dried at 110°C for 12h and then calcined at 500°C for 3h to produce CaO / SiO2. Add 3.20g of cobalt nitrate hexahydrate and 0.99g of nickel nitrate hexahydrate to a volumetric flask, then add 25ml of distilled water to prepare a mixed solution of cobalt nitrate and nickel nitrate for a second impregnation. Ultrasonicate for 30 minutes. A secondary impregnation was performed using the same method as in Comparative Example 2. The catalyst after secondary impregnation was dried at 110°C for 12 hours and then calcined at 300°C for 3 hours. Prior to the reaction, the catalyst was reduced at 400°C under a hydrogen atmosphere for 1 hour and cooled to produce Co-Ni-CaO / SiO2 catalyst samples with Co, Ni, and CaO loadings of 20 wt.%, 5 wt.%, and 10 wt.%, respectively.

[0054] Reaction Example

[0055] Comparative Example 3

[0056] 20g of a 5wt% succinic acid solution in 1,4-dioxane and 1g of the catalyst prepared in Comparative Example 1 were added to a 25ml reactor and reacted at 200°C and 5MPa hydrogen pressure for 12h. After the reaction, the reaction liquid was centrifuged and filtered to separate the catalyst from the reaction liquid. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion rate and selectivity of each product were calculated. The reaction results are shown in Table 1. Under these reaction conditions, the succinic acid conversion rate was 98.8%, and the selectivity and yield of 1,4-butanediol were 35.3% and 34.8%, respectively. (See Table 1).

[0057] Comparative Example 4

[0058] 20g of a 5wt% succinic acid solution in 1,4-dioxane and 1g of the catalyst prepared in Comparative Example 2 were added to a 25ml reactor and reacted at 180°C under 5MPa hydrogen pressure for 12 hours. After the reaction, the reaction liquid was centrifuged and filtered to separate the catalyst from the reaction solution. The reaction solution was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity of each product were calculated. Under these reaction conditions, the succinic acid conversion was 91.6%, and the selectivity and yield of 1,4-butanediol were 42.6% and 39.0%, respectively. Table 1 shows this.

[0059] Example 9

[0060] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 1 g of the catalyst prepared in Example 1 were added to a 25 ml reactor and reacted at 180°C under 5 MPa hydrogen pressure for 8 hours. After the reaction, the catalyst was separated from the reaction liquid by centrifugation and filtration. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity for each product were calculated. Under these reaction conditions, the succinic acid conversion was 78.8%, and the selectivity and yield of 1,4-butanediol were 72.5% and 57.1%, respectively. Table 1 shows this.

[0061] Example 10

[0062] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 1 g of the catalyst prepared in Example 2 were added to a 25 ml reactor and reacted at 180°C under 5 MPa hydrogen pressure for 8 hours. After the reaction, the reaction liquid was centrifuged and filtered to separate the catalyst from the reaction liquid. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity for each product were calculated. Under these reaction conditions, the succinic acid conversion was 72.5%, and the selectivity and yield of 1,4-butanediol were 52.4% and 38.0%, respectively. Table 1 shows this.

[0063] Example 11

[0064] 20g of a 5wt% succinic acid solution in 1,4-dioxane and 0.5g of the catalyst prepared in Example 3 were added to a 25ml reactor and reacted at 180°C under 5MPa hydrogen pressure for 4 hours. After the reaction, the reaction solution was centrifuged and filtered to separate the catalyst from the reaction solution. The reaction solution was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity of each product were calculated. Under these reaction conditions, the succinic acid conversion was 88.9%, and the selectivity and yield of 1,4-butanediol were 96.5% and 85.8%, respectively. Extending the reaction time to 8 hours resulted in a succinic acid conversion of 99.8%, and a 1,4-butanediol selectivity and yield of 96.1% and 94.2%, respectively. These results are shown in Table 1.

[0065] Example 12

[0066] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 0.5 g of the catalyst prepared in Example 4 were added to a 25 ml reactor and reacted at 180°C under 5 MPa hydrogen pressure for 4 hours. After the reaction, the catalyst was separated from the reaction liquid by centrifugation and filtration. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity of each product were calculated. Under these reaction conditions, the succinic acid conversion was 82.3%, and the selectivity and yield of 1,4-butanediol were 90.4% and 74.4%, respectively. Table 1 shows this.

[0067] Example 13

[0068] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 0.5 g of the catalyst prepared in Example 5 were added to a 25 ml reactor and reacted at 180°C under 5 MPa hydrogen pressure for 4 hours. After the reaction, the reaction liquid was centrifuged and filtered to separate the catalyst from the reaction liquid. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity for each product were calculated. Under these reaction conditions, the succinic acid conversion was 83.0%, and the selectivity and yield of 1,4-butanediol were 93.5% and 77.6%, respectively. Table 1 shows this.

[0069] Example 14

[0070] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 0.5 g of the catalyst prepared in Example 6 were added to a 25 ml reactor and reacted at 180°C under 5 MPa hydrogen pressure for 4 hours. After the reaction, the catalyst was separated from the reaction solution by centrifugation and filtration. The reaction solution was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity for each product were calculated. Under these reaction conditions, the succinic acid conversion was 62.6%, and the selectivity and yield of 1,4-butanediol were 78.2% and 49.0%, respectively. Table 1 shows this.

[0071] Example 15

[0072] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 0.5 g of the catalyst prepared in Example 7 were added to a 25 ml reactor and reacted at 180°C under a hydrogen pressure of 5 MPa for 8 hours. After the reaction, the catalyst was separated from the reaction liquid by centrifugation and filtration. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity of each product were calculated. Under these reaction conditions, the succinic acid conversion was 75.3%, and the selectivity and yield of 1,4-butanediol were 58.2% and 43.8%, respectively. Table 1 shows this.

[0073] Example 16

[0074] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 0.5 g of the catalyst prepared in Example 8 were added to a 25 ml reactor and reacted at 180°C under 5 MPa hydrogen pressure for 8 hours. After the reaction, the catalyst was separated from the reaction liquid by centrifugation and filtration. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity of each product were calculated. Under these reaction conditions, the succinic acid conversion was 69.4%, and the selectivity and yield of 1,4-butanediol were 49.1% and 34.1%, respectively. Table 1 shows this.

[0075] Example 17

[0076] 20 g of a 5 wt.% succinic acid solution in 1,4-dioxane and 0.5 g of the catalyst prepared in Example 3 were added to a 25 ml reactor and reacted at 160°C under 7 MPa hydrogen pressure for 6 hours. After the reaction, the reaction liquid was centrifuged and filtered to separate the catalyst from the reaction liquid. The reaction liquid was quantitatively analyzed by gas chromatography, and the succinic acid conversion and selectivity for each product were calculated. Under these reaction conditions, the succinic acid conversion was 96.2%, and the selectivity and yield of 1,4-butanediol were 98.8% and 95.0%, respectively. Table 1 shows this.

[0077] Table 1

[0078]

[0079] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A catalyst, characterized in that The catalyst is expressed as Co-XM / SiO2, wherein SiO2 is a carrier, X is selected from one or two metal elements of Cu, Ni, Fe, Zn, Mn, Mo, V or Cr, and M is selected from one of alkali metal oxides and alkaline earth metal oxides; in the catalyst, the content of the SiO2 carrier is 60-89wt.%, the content of the Co component is 5-30wt.%, the content of the X component is 1-15wt.%, and the content of the M component is 5-20wt.%.

2. A catalyst according to claim 1, characterized in that M is selected from Li2O, MgO or CaO.

3. The method for preparing a catalyst according to claim 1, wherein: include: Step 1: impregnate a metal solution of an alkali metal or alkaline earth metal into a SiO2 carrier, and obtain an M / SiO2 catalyst after drying and calcining; Step 2: impregnate the mixed metal solution of Co and metal component X into the M / SiO2 prepared in step 1 according to the method of step 1, and obtain the catalyst Co-XM / SiO2 after drying, calcination and reduction.

4. The method for preparing a catalyst according to claim 3, wherein: The impregnation described in step 1 is specifically as follows: the metal solution of alkali metal or alkaline earth metal is added dropwise and evenly onto the surface of SiO2, the solution is evaporated at 65-75°C under tungsten lamp irradiation, SiO2 is stirred until it is uniform after drying, and then the next drop is added, and this process is repeated until the metal solution is exhausted.

5. The method for preparing a catalyst according to claim 3, wherein: The calcination temperature of step 1 is 200-800° C. and the calcination time is 1-6 hours. The calcination temperature of step 2 is 200-600° C. and the calcination time is 1-6 hours.

6. The method for preparing a catalyst according to claim 3, characterized in that: The reduction temperature of step 2 is 200-600° C., and the reduction time is 0.5-4 h.

7. Use of the catalyst according to claim 1 in preparing 1,4-butanediol by hydrogenation of succinic acid.

8. Use of the catalyst according to claim 7 in preparing 1,4-butanediol by hydrogenation of succinic acid, characterized in that: A method for preparing 1,4-butanediol by hydrogenating succinic acid, comprising: Succinic acid hydrogenation reaction is carried out using H2 as a hydrogen source. The reduced Co-XM / SiO2 catalyst, succinic acid, and solvent are added into a reactor to react and produce 1,4-butanediol.

9. Use of the catalyst according to claim 8 in preparing 1,4-butanediol by hydrogenation of succinic acid, characterized in that The reaction temperature is 140-200°C, the hydrogen pressure is 3-10 MPa, and the reaction time is 1-28 hours.

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