Process for the preparation of a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol, catalyst and use

Abstract

The application relates to the technical field of catalyst preparation, and discloses a preparation method of a catalyst for preparing 1,3-propanediol through glycerol hydrogenolysis, the catalyst and application. The preparation method of the catalyst for preparing 1,3-propanediol through glycerol hydrogenolysis comprises the following steps: (1) an excessive impregnation method is adopted to contact tungsten oxide precursors, a solvent and gamma-Al2O3, and after water bath evaporation, first drying and first calcination treatment, a composite oxide WO3 / Al2O3 is obtained; the tungsten oxide precursors are tungsten hexachloride; (2) the composite oxide WO3 / Al2O3, water and a precursor of Pt are contacted, and after water bath evaporation, second drying, second calcination and reduction treatment, a catalyst Pt / WO3 / Al2O3 is obtained. The preparation method can convert the oxide precursors into WO3 at a lower temperature, and reduces the energy consumption in the catalyst preparation process.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, specifically to a method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol, as well as the catalyst and its application. Background Technology

[0002] 1,3-Propanediol, one of the hydrogenolysis products of glycerol, is a raw material for the production of unsaturated polyesters, plasticizers, surfactants, emulsifiers, and demulsifiers. In the polyurethane industry, it is commonly used as a raw material for polyester polyols, an initiator for polyether polyols, and a polyurethane chain extender. In the organic chemical industry, it is also an important monomer and intermediate, primarily used as a polymer monomer in the synthesis of polypropylene terephthalate (PTT). PTT, as a novel biodegradable polyester, overcomes the shortcomings of polyethylene terephthalate (PET) being too rigid and polybutylene terephthalate (PBT) being too soft, while possessing excellent resilience, dyeability, and biodegradability. It has enormous development potential in the carpet, textile, and engineering plastics industries. The economic viability of synthesizing PTT is limited by 1,3-propanediol.

[0003] Currently, the production methods for 1,3-propanediol include acrolein hydration hydrogenation, ethylene oxide carbonylation, bio-fermentation, and glycerol hydrogenolysis.

[0004] In the acrolein hydration hydrogenation process, the product 3-hydroxypropanal exhibits low selectivity and is extremely unstable, readily forming acetals, which is detrimental to separation. Furthermore, acrolein itself is a highly toxic, flammable, and explosive chemical. The ethylene oxide carbonylation method requires significant equipment investment and involves high reaction pressures. Biofermentation methods suffer from low feed conversion rates and product concentrations, numerous byproducts, and high costs associated with separating the product from the microbial strain. In contrast, the glycerol hydrogenolysis method not only has a short process flow and uses low-toxicity reactants under mild reaction conditions, but also allows the reaction to proceed in an aqueous phase, resulting in less environmental pollution and making it a green synthetic route.

[0005] Pt-W catalysts are the most studied catalyst systems for the hydrogenolysis of glycerol.

[0006] Pt-W can exist alone. CN102728380A discloses a catalyst for the hydrogenolysis of glycerol to prepare 1,3-propanediol, its preparation and application. The catalyst support is a mesoporous tungsten oxide support, and the active component is one or more of the following metals: platinum, rhodium, ruthenium, yttrium, palladium, nickel and copper. CN113262783A discloses a catalyst for the directional hydrogenolysis of glycerol to propanediol and its preparation method. The catalyst is prepared by loading single-atom Pt onto an oxygen-vacancy-rich tungsten oxide support using atomic layer deposition (ALD) technology.

[0007] Pt-W can also be supported on a support, commonly including alumina, zirconium oxide, and silicon dioxide; CN112169795A discloses an optimized activation method for polyol hydrogenolysis catalysts, and prepares a catalyst Pt / WO3 / Al2O3 with alumina as the support.

[0008] CN112044435A discloses a Pt-W catalyst and its preparation method for the selective hydrogenolysis of glycerol to 1,3-propanediol. A catalyst, Pt / WO3 / TiO2, supported on titanium oxide, was prepared. When applied to the hydrogenolysis of glycerol, it was found that the catalyst supported on rutile phase titanium oxide exhibited significantly higher catalytic activity and 1,3-propanediol selectivity than the catalyst supported on anatase phase titanium oxide, with the yield of the target product, 1,3-propanediol, increasing by nearly 38 times. This demonstrates that the support plays a crucial role not only in dispersing the active component but also influencing the catalyst's activity through its physical and chemical properties. Furthermore, in most patents and literature, the tungsten oxide precursor is often selected from polyacid salts such as ammonium metatungstate or ammonium paratungstate, which typically require relatively high temperatures to completely convert the polyacid salts to WO3.

[0009] Therefore, researching and developing optimized carrier properties is of great significance. Summary of the Invention

[0010] The purpose of this invention is to overcome the problem that existing methods for preparing catalysts for the hydrogenolysis of glycerol to 1,3-propanediol require high temperatures to convert oxide precursors into WO3. This invention provides a method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol, as well as the catalyst and its application. This method can convert oxide precursors into WO3 at lower temperatures, reducing energy consumption in the catalyst preparation process.

[0011] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol, wherein the preparation method comprises:

[0012] (1) The tungsten oxide precursor, solvent and γ-Al2O3 are contacted by the excess impregnation method, and after water bath evaporation, first drying and first calcination treatment, the composite oxide WO3 / Al2O3 is obtained; the tungsten oxide precursor is tungsten hexachloride;

[0013] (2) The composite oxide WO3 / Al2O3, water and Pt precursor are brought into contact, and after being dried in a water bath, dried a second time, calcined a second time and reduced, the catalyst Pt / WO3 / Al2O3 is obtained.

[0014] A second aspect of the present invention provides a catalyst for the hydrogenolysis of glycerol to prepare 1,3-propanediol prepared by the aforementioned preparation method.

[0015] A third aspect of the present invention provides the application of the aforementioned catalyst for the hydrogenolysis of glycerol to 1,3-propanediol in the hydrogenolysis of glycerol to 1,3-propanediol.

[0016] The present invention provides a method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol using tungsten hexachloride as a tungsten oxide precursor, which can be converted into the promoter WO3 at a relatively low temperature. By selecting γ-alumina with suitable physical properties as a support, the dispersibility of tungsten oxide can be improved, thereby increasing the content of tungsten oxide components that contribute to catalytic activity; the platinum-tungsten atomic ratio is optimized to improve catalyst activity. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] As previously stated, the first aspect of this invention provides a method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol, wherein the preparation method includes:

[0019] (1) The tungsten oxide precursor, solvent and γ-Al2O3 are contacted by the excess impregnation method, and after water bath evaporation, first drying and first calcination treatment, the composite oxide WO3 / Al2O3 is obtained; the tungsten oxide precursor is tungsten hexachloride;

[0020] (2) The composite oxide WO3 / Al2O3, water and Pt precursor are brought into contact, and after being dried in a water bath, dried a second time, calcined a second time and reduced, the catalyst Pt / WO3 / Al2O3 is obtained.

[0021] In this invention, it should be noted that in the composite oxide WO3 / Al2O3, Al2O3 is the carrier and WO3 is the active component.

[0022] According to the present invention, the solvent is selected from one or more of diethyl ether, ethanol, benzene, and carbon tetrachloride; preferably ethanol. In this invention, the solvent specifically chosen has the advantages of being non-toxic and having moderate volatility.

[0023] According to the present invention, the contact conditions include: stirring at room temperature to 90°C for 2-8 hours; preferably, stirring at room temperature for 2-8 hours; preferably, the contact is carried out under stirring conditions, wherein the stirring conditions include: a stirring rate of 100-600 rpm.

[0024] According to the present invention, the conditions for the water bath evaporation include a temperature of 40-90°C; preferably, the temperature is 50-90°C.

[0025] According to the present invention, the conditions for the first drying include: a temperature of 60-100°C and a time of 6-12 hours; preferably, the temperature is 80-100°C and the time is 8-12 hours.

[0026] According to the present invention, the conditions for the second drying include: a temperature of 80-120°C and a time of 6-12 hours; preferably, a temperature of 100-120°C and a time of 8-12 hours.

[0027] According to the present invention, the conditions for the first calcination include: calcination at a temperature of 250-450°C for 4-10 hours; preferably, calcination at a temperature of 250-350°C for 6-10 hours.

[0028] According to the present invention, the conditions for the second calcination include: calcination at a temperature of 250-400℃ for 2-8 hours; preferably, calcination at a temperature of 250-350℃ for 4-8 hours.

[0029] The method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol provided by this invention uses tungsten hexachloride as a tungsten oxide precursor, which can be converted into the auxiliary agent WO3 at a relatively low temperature.

[0030] According to the present invention, the reduction conditions include: a temperature of 200-400°C and a time of 1-4 hours; preferably, a temperature of 250-300°C and a time of 2-3 hours.

[0031] In this invention, the reduction conditions are gas-phase reduction, the reducing gas is hydrogen, and the hydrogen content is 1-100%, preferably 10-100%, with the remainder being nitrogen. The reducing gas flow rate is 10-100 ml / min, preferably 10-50 ml / min. Reduction is preferably carried out at atmospheric pressure.

[0032] According to the present invention, the specific surface area of ​​the γ-Al₂O₃ is ≥50 m². 2 / g, preferably 50-500m 2 / g, more preferably 100-400m 2 / g, more preferably 150-300m 2 / g.

[0033] According to the present invention, the pore size of the γ-Al2O3 is ≥5nm, preferably 5-30nm, and more preferably 6-15nm.

[0034] According to the present invention, the Pt precursor includes one or more of chloroplatinic acid, tetraammineplatinum chloride, tetraammineplatinum nitrate, and platinum nitrate, preferably chloroplatinic acid.

[0035] According to the present invention, in step (1), the amount of the tungsten oxide precursor is 0.5-1.5g relative to 3g of the γ-Al2O3; preferably, the amount of the tungsten oxide precursor is 0.5-1.3g relative to 3g of the γ-Al2O3.

[0036] According to the present invention, in step (2), the amount of the precursor of Pt is 0.24-0.4g relative to 3g of the WO3 / Al2O3; preferably, the amount of the precursor of Pt is 0.24-0.32g relative to 3g of the WO3 / Al2O3.

[0037] The second aspect of the present invention provides a catalyst for the hydrogenolysis of glycerol to prepare 1,3-propanediol, prepared by the aforementioned preparation method.

[0038] According to the present invention, the catalyst comprises a composite oxide WO3 / Al2O3 and an active component Pt supported on the composite oxide WO3 / Al2O3, wherein the surface density of tungsten atoms is 1-5 atoms / nm. 2 Preferably 1-3 per nm 2 More preferably, it is 1.5-2.5 per nm. 2 A further preferred value is 1.73-2.57 per nm. 2 In this invention, if the surface density of tungsten atoms is too high, WO3, a crystalline phase that does not contribute to catalyst activity, will be formed, and the number of polytungstate species that contribute to catalyst activity will be reduced. If the surface density of tungsten atoms is too low, Pt and tungsten oxide will not be able to contact effectively, thus reducing catalyst activity.

[0039] According to the present invention, the platinum-tungsten atomic ratio is 0.01-1, preferably 0.05-0.8, and more preferably 0.16-0.67. In the present invention, if the platinum-tungsten atomic ratio is too high, the platinum dispersion will be reduced, which will not only be detrimental to improving catalyst activity but also increase catalyst cost; if the platinum-tungsten atomic ratio is too low, the number of active sites will be reduced.

[0040] In this invention, it should be noted that "surface density of tungsten atoms" refers to the number of tungsten atoms per square nanometer of the carrier surface.

[0041] "Platinum-tungsten atomic ratio" refers to the molar ratio of platinum to tungsten.

[0042] According to the present invention, based on the total weight of the catalyst, the content of WO3 is 8-25% by weight and the content of Pt is 2.9-5% by weight; preferably, based on the total weight of the catalyst, the content of WO3 is 8.5-21.7% by weight and the content of Pt is 2.9-4.8% by weight; more preferably, based on the total weight of the catalyst, the content of WO3 is 9-20% by weight and the content of Pt is 3-4% by weight.

[0043] According to the present invention, the catalyst has a specific surface area of ​​110-230 m². 2 The catalyst has a pore volume of 0.4-1.1 ml / g and a most probable pore size of 7-16 nm; preferably, the catalyst has a specific surface area of ​​113-225 m² / g. 2 / g, pore volume is 0.4-1ml / g, and most probable pore size is 7.9-15.4nm.

[0044] A third aspect of the present invention provides the application of the aforementioned catalyst for the hydrogenolysis of glycerol to 1,3-propanediol in the hydrogenolysis of glycerol to 1,3-propanediol.

[0045] According to the present invention, the catalyst is used for the hydrogenolysis of glycerol to prepare 1,3-propanediol. The reaction is carried out in a high-pressure reactor. The raw materials are an aqueous solution of glycerol and hydrogen. The air in the reactor is first replaced with pure hydrogen, and then hydrogen is introduced. The reaction is stirred at a certain temperature.

[0046] According to the present invention, the glycerol aqueous solution has a mass fraction of 1-50%, preferably 3-30%.

[0047] According to the present invention, the mass ratio of Pt to glycerol is 0.001-0.015, preferably 0.005-0.01.

[0048] According to the present invention, the initial pressure of the hydrogen gas is 1-8 MPa, preferably 2-6 MPa.

[0049] According to the present invention, the reaction temperature is 100-200°C, preferably 120-180°C, and more preferably 150-180°C.

[0050] According to the present invention, in a preferred embodiment, the reaction temperature is 150-180°C, resulting in a high yield of 1,3-propanediol.

[0051] According to the present invention, the reaction time is 3-24h, preferably 6-24h.

[0052] The present invention will be described in detail below through embodiments.

[0053] In the following examples and comparative examples:

[0054] Specific surface area, pore volume, and pore size distribution were measured using an Autosorb-iQ (Konta Corporation, USA) gas adsorption analyzer.

[0055] The contents of products and raw materials were determined by gas chromatography (Agilent, 7890A);

[0056] The raw material, glycerin, is a commercially available product from Innochem.

[0057] Example 1

[0058] This embodiment illustrates the catalyst prepared by the method of the present invention for the hydrogenolysis of glycerol to 1,3-propanediol and its application.

[0059] (1) Dissolve 1.02g of WCl6 in 50ml of ethanol, and add 3g of aluminum oxide (specific surface area: 222.5m²). 2 / g, pore volume: 0.54ml / g, most probable pore diameter: 7.4nm), at room temperature, under stirring at a stirring rate of 450 rpm for 5h, then evaporated to dryness in a water bath at 50℃, dried in an oven at 100℃ for 8h, and calcined at 250℃ for 10h to obtain WO3 / Al2O3.

[0060] (2) Dissolve 0.32g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 80℃, dry in an oven at 120℃ for 8h, calcine at 350℃ for 3h, and reduce with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0061] The surface density of tungsten atoms was measured to be 2.32 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.29;

[0062] Based on the total weight of the catalyst, the content of WO3 is 16% by weight and the content of Pt is 3.9% by weight.

[0063] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​162 m². 2 / g, pore volume is 0.49ml / g, and most probable pore size is 7.9nm.

[0064] (3) Take 0.5 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 30 g of glycerol aqueous solution (10%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 5 MPa, stir at 650 rpm, and react at 180 °C for 12 h. Stop stirring afterward. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0065] Glycerol conversion: 69.8%; 1,3-propanediol selectivity: 51.1%; 1,3-propanediol yield: 35.7%.

[0066] Example 2

[0067] This embodiment illustrates the catalyst prepared by the method of the present invention for the hydrogenolysis of glycerol to 1,3-propanediol and its application.

[0068] (1) Dissolve 0.51g WCl6 in 50ml of ethanol, then add 3g of aluminum oxide (specific surface area: 146.5m²). 2 / g, pore volume: 0.43ml / g, most probable pore diameter: 8.7nm), at room temperature, under stirring at a stirring rate of 150 rpm for 8 hours, then evaporated to dryness in a water bath at 70℃, dried in an oven at 80℃ for 10 hours, and calcined at 350℃ for 4 hours to obtain WO3 / Al2O3.

[0069] (2) Dissolve 0.28g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 8h, evaporate to dryness in a water bath at 60℃, dry in an oven at 80℃ for 10h, calcine at 250℃ for 8h, and reduce with hydrogen (10%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0070] The surface density of tungsten atoms was measured to be 1.76 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.46;

[0071] Based on the total weight of the catalyst, the content of WO3 is 8.7% by weight and the content of Pt is 3.4% by weight.

[0072] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​120 m². 2 / g, pore volume is 0.41ml / g, and most probable pore size is 9.2nm.

[0073] (3) Take 0.65 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 15 g of glycerol aqueous solution (3%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 4 MPa, stir at 650 rpm, and react at 155 °C for 6 h. Stop stirring after reaction. After cooling to room temperature, centrifuge, filter through a 0.25 μm filter membrane, collect the aqueous phase sample, and analyze the product composition by gas chromatography.

[0074] Glycerol conversion: 70.1%; 1,3-propanediol selectivity: 50.3%; 1,3-propanediol yield: 35.3%.

[0075] Example 3

[0076] This embodiment illustrates the catalyst prepared by the method of the present invention for the hydrogenolysis of glycerol to 1,3-propanediol and its application.

[0077] (1) Dissolve 1.28g of WCl6 in 50ml of ethanol, then add 3g of aluminum oxide (specific surface area: 286.3m²). 2 / g, pore volume: 0.78ml / g, most probable pore diameter: 7.6nm), at room temperature, under stirring at a stirring rate of 600 rpm for 2h, then evaporated to dryness in a water bath at 55℃, dried in an oven at 120℃ for 12h, and calcined at 300℃ for 8h to obtain WO3 / Al2O3.

[0078] (2) Dissolve 0.24g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 2h, evaporate to dryness in a water bath at 90℃, dry in an oven at 100℃ for 12h, calcine at 300℃ for 5h, and reduce with hydrogen (50%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0079] The surface density of tungsten atoms was measured to be 2.26 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.18;

[0080] Based on the total weight of the catalyst, the content of WO3 is 19.4% by weight and the content of Pt is 2.9% by weight.

[0081] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​219 m². 2 / g, pore volume is 0.71ml / g, and most probable pore size is 8.2nm.

[0082] (3) Take 0.5 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 10 g of glycerol aqueous solution (30%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 6 MPa, stir at 650 rpm, and react at 180 °C for 24 h. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the composition of the product by gas chromatography.

[0083] Glycerol conversion: 67.5%; 1,3-propanediol selectivity: 49.8%; 1,3-propanediol yield: 33.6%.

[0084] Example 4

[0085] This embodiment illustrates the catalyst prepared by the method of the present invention for the hydrogenolysis of glycerol to 1,3-propanediol and its application.

[0086] (1) Dissolve 0.50g WCl6 in 50ml ethanol, add 3g aluminum oxide (specific surface area: 146.5m²) 2 / g, pore volume: 0.43ml / g, most probable pore diameter: 8.7nm), at room temperature, under stirring at a stirring rate of 250 rpm for 5h, then evaporated to dryness at 55℃, dried in an oven at 80℃ for 12h, and calcined at 400℃ for 6h to obtain WO3 / Al2O3.

[0087] (2) Dissolve 0.40g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 90℃, dry in an oven at 100℃ for 12h, calcine at 300℃ for 5h, and reduce with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0088] The surface density of tungsten atoms was measured to be 1.73 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.67;

[0089] Based on the total weight of the catalyst, the content of WO3 is 8.5% by weight and the content of Pt is 4.8% by weight.

[0090] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​113 m². 2 / g, pore volume is 0.4ml / g, and most probable pore size is 9.5nm.

[0091] (3) Take 0.6 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 30 g of glycerol aqueous solution (12%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 4 MPa, stir at 650 rpm, and react at 180 °C for 10 h. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0092] Glycerol conversion: 66.4%; 1,3-propanediol selectivity: 48.8%; 1,3-propanediol yield: 32.4%.

[0093] Example 5

[0094] This embodiment illustrates the catalyst prepared by the method of the present invention for the hydrogenolysis of glycerol to 1,3-propanediol and its application.

[0095] (1) Dissolve 1.48g of WCl6 in 50ml of ethanol, and add 3g of aluminum oxide (specific surface area: 291.5m²). 2 / g, pore volume: 1.18ml / g, most probable pore diameter: 14.6nm), at room temperature, under stirring at a stirring rate of 500 rpm for 5h, then evaporated to dryness in a water bath at 50℃, dried in an oven at 100℃ for 8h, and calcined at 450℃ for 4h to obtain WO3 / Al2O3.

[0096] (2) Dissolve 0.24g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 80℃, dry in an oven at 120℃ for 8h, calcine at 400℃ for 3h, and reduce with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0097] The surface density of tungsten atoms was measured to be 2.57 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.16;

[0098] Based on the total weight of the catalyst, the content of WO3 is 21.7% by weight and the content of Pt is 2.9% by weight.

[0099] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​225 m². 2 / g, pore volume is 1ml / g, and most probable pore size is 15.4nm.

[0100] (3) Take 1.0 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 15 g of glycerol aqueous solution (30%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 6 MPa, stir at 650 rpm, and react at 170 °C for 20 h. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0101] Glycerol conversion: 65.9%; 1,3-propanediol selectivity: 47.7%; 1,3-propanediol yield: 31.4%.

[0102] Example 6

[0103] This embodiment illustrates the catalyst prepared by the method of the present invention for the hydrogenolysis of glycerol to 1,3-propanediol and its application.

[0104] (1) Dissolve 1.02g of WCl6 in 50ml of ethanol, and add 3g of aluminum oxide (specific surface area: 222.5m²). 2 / g, pore volume: 0.54ml / g, most probable pore diameter: 7.4nm), at room temperature, under stirring at a stirring rate of 400 rpm for 5h, then evaporated to dryness in a water bath at 50℃, dried in an oven at 100℃ for 8h, and calcined at 250℃ for 10h to obtain WO3 / Al2O3.

[0105] (2) Dissolve 0.32g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 80℃, dry in an oven at 120℃ for 8h, calcine at 400℃ for 3h, and reduce with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0106] The surface density of tungsten atoms was measured to be 2.32 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.29;

[0107] Based on the total weight of the catalyst, the content of WO3 is 15.9% by weight and the content of Pt is 3.8% by weight.

[0108] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​165 m². 2 / g, pore volume is 0.48ml / g, and most probable pore size is 8.1nm.

[0109] (3) Take 1.5g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 20g of glycerol aqueous solution (10%). Transfer the catalyst and reaction solution together to a 100mL autoclave. After purging with H2 at 3MPa for 5 times at room temperature, introduce hydrogen gas to 4MPa, stir at 650 rpm, and react at 160℃ for 8h. Stop stirring after 8h. After cooling to room temperature, centrifuge, filter through a 0.25μm filter membrane and collect the aqueous phase sample. Analyze the composition of the product by gas chromatography.

[0110] Glycerol conversion: 64.3%; 1,3-propanediol selectivity: 48.0%; 1,3-propanediol yield: 30.9%.

[0111] Comparative Example 1

[0112] (1) Dissolve 0.64g of ammonium metatungstate in 10g of water, and add 3g of γ-Al2O3 (specific surface area: 222.5m²). 2 / g, pore volume: 0.54ml / g, most probable pore diameter: 7.4nm), at room temperature, under stirring at a stirring rate of 600 rpm for 5h, then evaporated to dryness in a water bath at 60℃, dried in an oven at 120℃ for 8h, and calcined at 550℃ for 4h to obtain WO3 / Al2O3.

[0113] (2) Dissolve 0.32g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 80℃, dry in an oven at 120℃ for 8h, calcine at 400℃ for 3h, and reduce with hydrogen (100%) at 250℃ for 3h to obtain catalyst Pt / WO3 / Al2O3.

[0114] The surface density of tungsten atoms was measured to be 2.32 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.29;

[0115] Based on the total weight of the catalyst, the content of WO3 is 15.9% by weight and the content of Pt is 3.9% by weight.

[0116] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​167 m². 2 / g, pore volume is 0.48ml / g, and most probable pore size is 8.1nm.

[0117] (3) Take 0.5 g of the above catalyst and disperse it in 30 g of glycerol aqueous solution (10%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 5 MPa, stir at 650 rpm, and react at 180 °C for 12 h. Stop stirring afterward. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0118] Glycerol conversion: 67.2%; 1,3-propanediol selectivity: 50.2%; 1,3-propanediol yield: 33.7%.

[0119] Comparative Example 2

[0120] (1) Dissolve 1.54g of WCl6 in 50ml of ethanol, then add 3g of aluminum oxide (specific surface area: 222.5m²). 2 / g, pore volume: 0.54ml / g, most probable pore diameter: 7.4nm), at room temperature, under stirring at a stirring rate of 500 rpm for 5h, then evaporated to dryness in a water bath at 50℃, dried in an oven at 100℃ for 8h, and calcined at 250℃ for 10h to obtain WO3 / Al2O3.

[0121] (2) Dissolve 0.16g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 80℃, dry in an oven at 120℃ for 8h, calcine at 400℃ for 3h, and reduce with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0122] The surface density of tungsten atoms was measured to be 3.5 atoms / nm.2 The atomic ratio of platinum to tungsten is 0.1;

[0123] Based on the total weight of the catalyst, the content of WO3 is 22.6% by weight and the content of Pt is 2% by weight.

[0124] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​134 m². 2 / g, pore volume is 0.39ml / g, and most probable pore size is 9nm.

[0125] (3) Take 0.5 g of the above catalyst and disperse it in 30 g of glycerol aqueous solution (10%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 5 MPa, stir at 650 rpm, and react at 180 °C for 12 h. Stop stirring afterward. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0126] Glycerol conversion: 43.7%; 1,3-propanediol selectivity: 45.9%; 1,3-propanediol yield: 20.1%.

[0127] Comparative Example 3

[0128] 0.26 WCl6 was dissolved in 35 ml of ethanol, and 3 g of aluminum oxide (specific surface area: 146.5 m²) was added. 2 / g, pore volume: 0.43ml / g, most probable pore size: 8.7nm), at room temperature, with a stirring rate of 600 rpm, an aqueous ethanol solution (0.24g water + 15ml ethanol) was added dropwise at a rate of 0.12ml / min while stirring. After the addition was completed, stirring was continued for 5h, the solution was evaporated to dryness in a water bath at 40℃, dried in an oven at 100℃ for 8h, and calcined at 250℃ for 10h to obtain WO3 / Al2O3;

[0129] (2) Dissolve 0.24g of chloroplatinic acid in 10ml of water, add 3g of the above WO3 / Al2O3, stir at room temperature for 5h, evaporate to dryness in a water bath at 80℃, dry in an oven at 120℃ for 8h, calcine at 400℃ for 3h, and reduce with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / WO3 / Al2O3.

[0130] The surface density of tungsten atoms was measured to be 0.9 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.74;

[0131] Based on the total weight of the catalyst, the content of WO3 is 4.7% by weight and the content of Pt is 2.9% by weight.

[0132] The catalyst Pt / WO3 / Al2O3 has a specific surface area of ​​124 m². 2 / g, pore volume is 0.41ml / g, and most probable pore size is 8.8nm.

[0133] (3) Take 0.5 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 30 g of glycerol aqueous solution (10%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 5 MPa, stir at 650 rpm, and react at 180 °C for 12 h. Stop stirring afterward. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0134] Glycerol conversion: 34.6%; 1,3-propanediol selectivity: 47.7%; 1,3-propanediol yield: 16.5%.

[0135] Comparative Example 4

[0136] (1) Dissolve 0.32g of chloroplatinic acid in 10ml of water, then add 3g of aluminum oxide (specific surface area: 286.3m²). 2 / g, pore volume: 0.78ml / g, most probable pore size: 7.6nm), stirred at room temperature for 5h, evaporated to dryness in a water bath at 80℃, dried in an oven at 120℃ for 8h, calcined at 350℃ for 3h, and reduced with hydrogen (100%) at 250℃ for 2h to obtain catalyst Pt / Al2O3.

[0137] (2) Take 0.5 g of the above catalyst Pt / WO3 / Al2O3 and disperse it in 30 g of glycerol aqueous solution (10%). Transfer the catalyst and reaction solution together to a 100 mL autoclave. After purging with H2 at 3 MPa five times at room temperature, introduce hydrogen gas to 5 MPa, stir at 650 rpm, and react at 180 °C for 12 h. Stop stirring afterward. After cooling to room temperature, centrifuge and filter through a 0.25 μm filter membrane to collect the aqueous phase sample. Analyze the product composition by gas chromatography.

[0138] Glycerol conversion: 5.9%; 1,3-propanediol selectivity: 95.3%; 1,3-propanediol yield: 5.6%.

[0139] Comparative Example 1 shows that ammonium metatungstate is a commonly used tungsten source in the Pt-W catalyst system. The catalyst obtained using ammonium metatungstate as the tungsten source exhibits a conversion rate of 67.2% in the glycerol hydrogenolysis reaction, a 1,3-propanediol selectivity of 50.2%, and a yield of 33.7%. The catalyst obtained using tungsten hexachloride as the tungsten source achieves a glycerol conversion rate of 69.8%, a 1,3-propanediol selectivity of 51.1%, and a yield of 35.7%. Comparing the two catalysts, the latter has slightly higher activity than the former, and the decomposition temperature using ammonium metatungstate as the tungsten source is higher than that using tungsten hexachloride.

[0140] Comparative Examples 2 and 3 show that a low Pt content or a low surface tungsten atom density is detrimental to improving the yield of 1,3-propanediol.

[0141] Comparative Example 4 shows that without WO3, the catalyst has very low activity for the glycerol hydrogenolysis reaction, indicating that WO3 is an essential component of a highly active glycerol hydrogenolysis catalyst, and its content is crucial to the catalyst activity.

[0142] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a catalyst for the hydrogenolysis of glycerol to 1,3-propanediol, characterized in that, The preparation method includes: (1) The tungsten oxide precursor, solvent and γ-Al2O3 are contacted by the excess impregnation method, and then evaporated in a water bath. After the first drying and first calcination treatment, the composite oxide WO3 / Al2O3 is obtained; the tungsten oxide precursor is tungsten hexachloride; the conditions for the first calcination include: temperature of 250-450℃. (2) The composite oxide WO3 / Al2O3, water and Pt precursor are brought into contact, dried by water bath, dried a second time, calcined a second time and reduced to obtain catalyst Pt / WO3 / Al2O3; the conditions for the second calcination include: temperature of 250-400℃; The catalyst comprises a composite oxide WO3 / Al2O3 and an active component Pt supported on the composite oxide WO3 / Al2O3, wherein the surface density of tungsten atoms is 1-5 atoms / nm. 2 The platinum-tungsten atomic ratio is 0.01-1; wherein, the surface density of tungsten atoms refers to the number of tungsten atoms per square nanometer of the carrier surface, and the platinum-tungsten atomic ratio refers to the platinum-tungsten molar ratio; Based on the total weight of the catalyst, the content of WO3 is 8-25% by weight, and the content of Pt is 2.9-5% by weight. The catalyst has a specific surface area of ​​110-230 m². 2 / g, pore volume is 0.4-1.1ml / g, and most probable pore size is 7-16nm.

2. The preparation method according to claim 1, characterized in that, The solvent is selected from one or more of diethyl ether, ethanol, benzene, and carbon tetrachloride.

3. The preparation method according to claim 1, characterized in that, The first drying conditions include: a temperature of 60-100℃ and a time of 6-12 hours; And / or, the conditions for the second drying include: a temperature of 80-120°C and a time of 6-12 hours; And / or, the conditions for the first calcination include: a calcination time of 4-10 hours; And / or, the conditions for the second calcination include: a calcination time of 2-8 hours; And / or, the reduction conditions include: a temperature of 200-400℃ and a time of 1-4h.

4. The preparation method according to claim 3, characterized in that, The conditions for the first roasting include: a temperature of 250-350℃ and a roasting time of 6-10h; And / or, the conditions for the second calcination include: a temperature of 250-350℃ and a calcination time of 4-8h; And / or, the reduction conditions are gas-phase reduction, the reducing gas is hydrogen, the hydrogen content is 1-100%, and the remainder is nitrogen; the reducing gas flow rate is 10-100 mL / min.

5. The preparation method according to claim 4, characterized in that, The hydrogen content is 10-100%, and the reducing gas flow rate is 10-50 mL / min.

6. The preparation method according to claim 1, characterized in that, The specific surface area of ​​the γ-Al2O3 is ≥50m². 2 / g; the pore size of the γ-Al2O3 is ≥5nm.

7. The preparation method according to claim 6, characterized in that, The specific surface area of ​​the γ-Al2O3 is 50-500 m². 2 / g; the pore size of the γ-Al2O3 is 5-30nm.

8. The preparation method according to claim 7, characterized in that, The specific surface area of ​​the γ-Al₂O₃ is 100-400 m². 2 / g; the pore size of the γ-Al2O3 is 6-15nm.

9. The preparation method according to claim 8, characterized in that, The specific surface area of ​​the γ-Al2O3 is 150-300 m². 2 / g.

10. The preparation method according to claim 1, characterized in that, The Pt precursor includes one or more of chloroplatinic acid, tetraammineplatinum chloride, tetraammineplatinum nitrate, and platinum nitrate.

11. The preparation method according to claim 10, characterized in that, The Pt precursor is chloroplatinic acid.

12. The preparation method according to claim 1, characterized in that, The surface density of tungsten atoms is 1-3 per nm. 2 The atomic ratio of platinum to tungsten is 0.05-0.

8.

13. The preparation method according to claim 12, characterized in that, The surface density of tungsten atoms is 1.5-2.5 atoms / nm. 2 The atomic ratio of platinum to tungsten is 0.16-0.

67.

14. The preparation method according to claim 1, characterized in that, Based on the total weight of the catalyst, the content of WO3 is 8.5-21.7% by weight and the content of Pt is 2.9-4.8% by weight.

15. The use of a catalyst prepared by the preparation method according to any one of claims 1-14 in the hydrogenolysis of glycerol to prepare 1,3-propanediol.