Catalyst for hydrogenolysis of glycerol and method for its preparation and use

Abstract

The application provides a preparation method of a supported catalyst and belongs to the field of catalyst preparation. The preparation method comprises the following steps: loading tungsten and niobium on a carrier by using a hydrothermal method, and washing and drying to obtain a catalyst intermediate body loaded with NbO x and WO x ; loading a platinum precursor on the catalyst intermediate body, drying and calcining to obtain the catalyst. The application adopts the hydrothermal method to prepare the NbO x -WO x / Y catalyst intermediate body, which can not only uniformly disperse NbO x and WO x on the surface of the carrier and make the particle size very small, but also can reduce the Pt salt into metal Pt in the calcination process by using the carbon-based compounds with reducing property generated by the reducing agent under the hydrothermal condition, so that the obtained catalyst does not need to be reduced after calcination and can be directly used in the glycerol hydrogenolysis reaction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalyst preparation, and particularly relates to a catalyst for preparing 1,3-propanediol by glycerol hydrogenolysis, and a preparation method and application thereof. BACKGROUND

[0002] Biodiesel is a clean and renewable liquid biofuel, as an important low-carbon and environmentally friendly energy, it enjoys a variety of policy support in the world, and thus develops vigorously. However, 1 ton of glycerol by-product is produced for every 10 tons of diesel, resulting in a large excess of glycerol. If it can be effectively utilized, not only the economy of the biodiesel industry can be improved, but also the dependence on petrochemical products can be reduced. One of the hydrogenolysis products of glycerol is 1,3-propanediol, which is a raw material for producing unsaturated polyester, plasticizer, surfactant, emulsifier and demulsifier; in the polyurethane industry, it is often used as a raw material for polyester polyol, a starter for polyether polyol and a polyurethane chain extender, etc.; in the organic chemical industry, it is also an important monomer and intermediate, and the most important use is as a polymer monomer to synthesize polytrimethylene terephthalate (PTT). PTT, as a new type of biodegradable polyester, overcomes the shortcomings of too hard polyethylene terephthalate (PET) and too soft polybutylene terephthalate (PBT), and has excellent resilience, easy dyeability and biodegradability, and thus has great development potential in the carpet, textile, engineering plastic and other industries. The economy of synthesizing PTT is limited by 1,3-propanediol.

[0003] At present, the production methods of 1,3-propanediol include propenal hydration hydrogenation method, ethylene oxide carbonylation method, biological fermentation method and glycerol hydrogenolysis method, etc. The Chinese patent CN93114516.3 applied by Degussa Company discloses a method for preparing 1,3-propanediol by propenal hydration, in which solid acid is used as catalyst, gaseous glycerol is dehydrated to generate propenal, then 3-hydroxypropionaldehyde is generated by hydration under the action of acid catalyst, and 1,3-propanediol is generated by hydrogenation. The Chinese patent (CN96198050.8) applied by Shell Company discloses a method for preparing 1,3-propanediol by using cobalt-based compound as catalyst, in which ethylene oxide and synthesis gas are reacted to generate 3-hydroxypropionaldehyde, and then 3-hydroxypropionaldehyde is hydrogenated to generate 1,3-propanediol under the action of hydrogenation catalyst. The patent (CN96195288.1) of Dupont Company provides a production process for preparing 1,3-propanediol by using microbial fermentation method, in which raw material (sugar of glucose or starch) is first reacted to generate intermediate product glycerol under the action of yeast, and then glycerol is converted into 1,3-propanediol under the action of biological strain. In the propenal hydration hydrogenation method, the selectivity of product 3-hydroxypropionaldehyde is low in the process of propenal hydration, and 3-hydroxypropionaldehyde is extremely unstable and prone to produce acetal, which is not conducive to separation; in addition, propenal itself is a highly toxic, flammable and explosive chemical. The ethylene oxide carbonylation method has large equipment investment and high reaction pressure. The biological fermentation method has the disadvantages of low conversion rate of raw material and low concentration of product, many by-products, high separation cost of product and strain, and the like. The glycerol hydrogenolysis method has the advantages of short process flow, low toxicity of reaction raw material, mild reaction condition, reaction in water phase, small environmental pollution and the like, and is a green synthesis route.

[0004] The supported Pt-W catalyst is a catalyst system which is frequently studied in the glycerol hydrogenolysis reaction, and the tungsten precursor is usually loaded on the surface of the carrier by impregnation, and WO3 / support is obtained after high-temperature calcination; then the platinum precursor is loaded on the surface of the WO3 / support, and (as shown in the patent CN111389397A) is obtained after calcination and reduction. Although this preparation method is simple, it is difficult to control the size of the W species, and the crystalline WO3 which does not contribute to the activity of the catalyst is generated after high-temperature calcination. SUMMARY

[0005] The purpose of the present application is to provide a catalyst for preparing 1,3-propanediol by glycerol hydrogenolysis and a preparation method thereof, and the feature is that the NbO x -WO x / Y catalyst intermediate (Y represents the carrier) is prepared by hydrothermal method in the presence of a reducing agent, and then Pt is loaded by impregnation to obtain the supported Pt / NbO x -WO x / Y catalyst.

[0006] According to one aspect of the present application, there is provided a method for preparing a supported catalyst, comprising:

[0007] (1) loading Nb and W on a support by a hydrothermal method, and after washing and drying, obtaining a catalyst intermediate supported with NbO x and WO x ;

[0008] (2) loading a platinum precursor on the catalyst intermediate, and after drying and calcining, obtaining the catalyst.

[0009] Optionally, in step (1), the hydrothermal method comprises: preparing an aqueous solution containing a tungsten source, a niobium source, a reducing agent and an additive, adding the support, stirring I, adding hydrochloric acid dropwise, stirring II, and performing a hydrothermal reaction.

[0010] Optionally, in step (2), the loading comprises: adding the catalyst intermediate into an aqueous solution containing the platinum precursor, stirring III, and water-bath evaporation.

[0011] Optionally, the loading amount of platinum is 1wt%-5wt% of the catalyst intermediate, preferably 2wt%-4wt%.

[0012] Optionally, the stirring time of stirring I and stirring II is independently 10-60min.

[0013] Optionally, the rotation speed of the hydrothermal reaction is 100-400rpm, the temperature is 120-180℃, and the time is 12-24 hours.

[0014] Optionally, the stirring time of stirring III is 2-8h.

[0015] Optionally, the temperature of the water-bath evaporation is 60-90℃.

[0016] Optionally, the molar ratio of the tungsten source calculated based on tungsten, the niobium source calculated based on niobium, the reducing agent, the additive, and the support is 1:0.1-1.0:3-10:1-5:15-75, preferably 1:0.3-0.5:4-6:1-3:20-50.

[0017] Optionally, the concentration of the hydrochloric acid is 3-12mol / L, and the added amount is 2-6ml.

[0018] Optionally, the added amount of the hydrochloric acid is within the range of the hydrogen ion concentration of the aqueous solution in the hydrothermal reaction.

[0019] Optionally, after adding the hydrochloric acid dropwise, the hydrogen ion concentration of the aqueous solution is 0.1-1mol / L, preferably 0.1-0.5mol / L.

[0020] Optionally, the tungsten source is selected from at least one of ammonium metatungstate, ammonium paratungstate, sodium tungstate, potassium tungstate, ammonium tungstate, sodium phosphotungstate, phosphotungstic acid and silicotungstic acid, preferably sodium tungstate, potassium tungstate and ammonium metatungstate, more preferably sodium tungstate and ammonium metatungstate.

[0021] Optionally, the niobium source is selected from at least one of ammonium niobate oxalate hydrate, potassium niobate, sodium niobate and niobium oxalate, preferably potassium niobate, sodium niobate, more preferably sodium niobate.

[0022] Optionally, the reducing agent is selected from at least one of glucose, fructose and sucrose, preferably glucose.

[0023] Optionally, the additive is selected from at least one of citric acid, oxalic acid, tartaric acid and nitric acid, preferably citric acid.

[0024] Optionally, the platinum precursor is selected from at least one of chloroplatinic acid, tetraammineplatinum chloride, tetraammineplatinum nitrate and platinum nitrate.

[0025] Optionally, in step (1), the drying temperature is 30-100°C, preferably 40-60°C.

[0026] Optionally, in step (2), the drying condition is 80-120°C drying for 8-15h; the calcination condition is 250-500°C calcination for 2-8h.

[0027] Optionally, the carrier is selected from at least one of SiO2, Al2O3, ZrO2, TiO2, preferably Al2O3.

[0028] Optionally, the specific surface area of Al2O3 is 50-500m2 / g, preferably 100-400m2 / g, more preferably 150-300m2 / g. 2 2 2

[0029] According to an aspect of the present application, there is provided a catalyst prepared by the above method.

[0030] Optionally, the loading of WO x is 1wt%-10wt% based on the mass of the carrier, preferably 4wt%-9wt%.

[0031] Optionally, the loading of Nb is 0.2wt%-2wt% based on the mass of the carrier, preferably 0.4wt%-1wt%.

[0032] Optionally, the surface density of Nb atoms on the carrier is 0.1-1, preferably 0.2-0.8, more preferably 0.2-0.4.

[0033] ​​​Optionally, the surface density of W atoms on the carrier is 0.1-3, preferably 0.2-2, and more preferably 0.4-1.

[0034] In the present application, the surface density of W atoms and the surface density of Nb atoms refer to the number of tungsten atoms or niobium atoms per square nanometer of the surface of the carrier.

[0035] Optionally, the molar ratio of Nb to W is 0.1-1, preferably 0.3-0.7, and more preferably 0.3-0.5.

[0036] Optionally, the loading of platinum is 1wt%-5wt% based on the catalyst intermediate, preferably 2wt%-4wt%.

[0037] As a specific embodiment of the present application, a method for preparing a catalyst for preparing 1,3-propanediol by hydrogenolysis of glycerol, a tungsten source, a niobium source, a reducing agent, and an additive are dissolved in water, Al2O3 is added, and stirring is performed for 10-60 min. Hydrochloric acid is added dropwise, and stirring is continued for 10-60 min. A hydrothermal kettle is kept at a rotation speed of 100-400 rpm and a temperature of 120-180°C for 12-24 hours. The obtained mixture is washed with water, washed with alcohol, and dried in vacuum or left at room temperature to obtain NbO x -WO x / Al2O3 powder; the NbO x -WO x / Al2O3 powder is added to a water solution of platinum precursor, stirring is performed at room temperature for 2-8 h, water bath evaporation is performed at 60-90°C, drying is performed at 80-120°C for 8-15 h, and calcination is performed at 250-500°C for 2-8 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0038] According to still another aspect of the present application, a method for preparing 1,3-propanediol by hydrogenolysis of glycerol is provided, in which the glycerol is reacted with hydrogen gas in the presence of a catalyst to produce 1,3-propanediol; and the catalyst is selected from at least one of the above-mentioned catalysts and the catalyst prepared by the above-mentioned preparation method.

[0039] Optionally, the initial pressure of hydrogen gas is 1-8 MPa, and preferably 2-6 MPa.

[0040] Optionally, the reaction temperature is 100-200°C, preferably 120-180°C, and more preferably 150-180°C.

[0041] Optionally, the reaction time is 3-24 h, and preferably 6-24 h.

[0042] The catalyst described herein is used in the hydrogenolysis of glycerol to produce 1,3-propylene glycol. The reaction is carried out in a high-pressure reactor using a 10 wt% aqueous glycerol solution and hydrogen. The air in the reactor is first replaced with pure hydrogen, then hydrogen is introduced. The reaction is stirred for 12 hours at 180°C and an initial pressure of 5 MPa. The catalyst activity was evaluated using these reaction conditions, but the reaction conditions are not limited thereto.

[0043] The present invention provides a method for preparing NbO by a hydrothermal method. x -WO x / Y catalyst intermediate, which can make NbO x and WO x It is evenly dispersed on the surface of the carrier with a very small particle size. At the same time, the reducing agent produces a reducing carbon-based compound under hydrothermal conditions, which can reduce the Pt salt to metallic Pt during the calcination process. Therefore, the resulting catalyst does not need to be reduced after calcination and can be directly used in the glycerol hydrogenolysis reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 NbO obtained by hydrothermal method and impregnation method x -WO x / Al2O3 Raman characterization results. DETAILED DESCRIPTION

[0045] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0046] Example 1

[0047] 0.66g sodium tungstate, 0.10g sodium niobate, 1.80g glucose, 0.58g citric acid were dissolved in 60ml water, and 10g Al2O3 (specific surface area 159m 2 / g), stirred for 30min, 6ml of 6M hydrochloric acid solution was added dropwise, and stirring was continued for 30min. Then, the mixture was transferred to a high-pressure reactor, and maintained at 400r / min, 120℃, for 24h. After cooling, the mixture was centrifuged, washed with water, washed with alcohol, and dried at room temperature to obtain NbO x -WO x / Al2O3. 3.05g platinum solution (0.03930g Pt / g) was diluted with water to 10g, and 3g of the above NbO x -WO x / Al2O3, stirred at room temperature for 5 h, evaporated to dryness in a water bath at 80 °C, dried in an oven at 100 °C for 8 h, and calcined at 450 °C for 5 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0048] Take 0.5 g of the above catalyst, disperse in 30 g of glycerol aqueous solution (10 wt%), transfer the catalyst and reaction liquid to a 100 mL autoclave. After 5 times of replacement at room temperature under H2 pressure of 3 MPa, fill hydrogen to 5 MPa, stirring speed 650 r / min, reaction temperature 180°C, stop stirring after reaction for 12 h. After cooling to room temperature, centrifugal separation, filter with 0.25 μm filter membrane, collect the aqueous phase sample, analyze the product composition by gas chromatography.

[0049] Glycerol conversion rate: 53.34%; 1,3-propanediol selectivity: 58.01%; 1,3-propanediol yield: 30.94%.

[0050] Example 2

[0051] Dissolve 0.49 g of ammonium metatungstate, 0.14 g of sodium niobate, 1.80 g of glucose, and 0.58 g of citric acid in 60 ml of water, add 8 g of Al2O3 (specific surface area 159 m 2 / g), stir for 15 min, add 2 ml of 12M hydrochloric acid solution dropwise, continue to stir for 10 min, transfer to a high-pressure reaction kettle, 250 r / min, 180°C, keep for 12 h. After cooling, centrifugal separation, water washing, alcohol washing, vacuum drying at 60°C, obtain NbO x -WO x / Al2O3. Dilute 3.05 g of platinum solution (0.03930 g Pt / g) to 10 g with water, add 3 g of the above NbO x -WO x / Al2O3, after stirring at room temperature for 6 h, evaporate to dryness in a water bath at 75°C, dry in an oven at 90°C for 15 h, calcine at 400°C for 6 h, obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0052] Take 0.5 g of the above catalyst, disperse in 30 g of glycerol aqueous solution (10 wt%), transfer the catalyst and reaction liquid to a 100 mL autoclave. After 5 times of replacement at room temperature under H2 pressure of 3 MPa, fill hydrogen to 5 MPa, stirring speed 650 r / min, reaction temperature 180°C, stop stirring after reaction for 12 h. After cooling to room temperature, centrifugal separation, filter with 0.25 μm filter membrane, collect the aqueous phase sample, analyze the product composition by gas chromatography.

[0053] Glycerol conversion rate: 50.21%; 1,3-propanediol selectivity: 57.13%; 1,3-propanediol yield: 28.68%.

[0054] Example 3

[0055] 0.66 g sodium tungstate, 0.14 g sodium niobate, 1.80 g glucose, 0.58 g citric acid were dissolved in 60 ml water, 5.3 g Al2O3 (specific surface area 292 m 2 / g) was added, stirred for 60 min, 6 ml 3.5 M hydrochloric acid solution was added dropwise, and stirring was continued for 60 min. It was transferred into a high-pressure reactor, 100 r / min, 150°C, and maintained for 15 h. After cooling, centrifugal separation, water washing, alcohol washing, and vacuum drying at 40°C, NbO x -WO x / Al2O3 was obtained. 3.05 g platinum solution (0.03930 g Pt / g) was diluted with water to 10 g, and 3 g of the above NbO x -WO x / Al2O3 was added. After stirring at room temperature for 2 h, it was evaporated to dryness in a water bath at 65°C, and dried in an oven at 80°C for 12 h, and calcined at 400°C for 6 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0056] 0.5 g of the above catalyst was dispersed in 30 g of aqueous glycerol solution (10%), and the catalyst and reaction solution were transferred together into a 100 ml high-pressure reactor. After 5 times of replacement at room temperature under a hydrogen pressure of 3 MPa, hydrogen was filled to 5 MPa, the stirring speed was 650 r / min, the reaction temperature was 180°C, and stirring was stopped after 12 h of reaction. After cooling to room temperature, centrifugal separation was performed, the water phase sample was collected after filtration with a 0.25 μm filter membrane, and the product composition was analyzed by gas chromatography.

[0057] Glycerol conversion rate: 47.48%; 1,3-propanediol selectivity: 54.01%; 1,3-propanediol yield: 25.64%.

[0058] Example 4

[0059] 0.49 g ammonium metatungstate, 0.14 g sodium niobate, 1.52 g glucose, 0.45 g citric acid were dissolved in 60 ml water, 8 g Al2O3 (specific surface area 159 m 2 / g) was added, stirred for 30 min, 2 ml 12 M hydrochloric acid solution was added dropwise, and stirring was continued for 30 min. It was transferred into a high-pressure reactor, 400 r / min, 150°C, and maintained for 16 h. After cooling, centrifugal separation, water washing, alcohol washing, and vacuum drying at 60°C, NbO x -WO x / Al2O3 was obtained. 2.29 g platinum solution (0.03930 g Pt / g) was diluted with water to 10 g, and 3 g of the above NbO x -WO x / Al2O3, stirred at room temperature for 6 hours, evaporated to dryness in a water bath at 90℃, dried in an oven at 90℃ for 15 hours, and calcined at 400℃ for 6 hours to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0060] 0.65g of the above catalyst was dispersed in 30g of a 10% aqueous glycerol solution. The catalyst and reaction mixture were transferred to a 100mL autoclave. After five H2 displacements at room temperature with a pressure of 3MPa, hydrogen was introduced to 5MPa. The reaction was stirred at 650 rpm and 180°C for 12 hours before stirring was stopped. After cooling to room temperature, the mixture was centrifuged and filtered through a 0.25μm filter membrane. The aqueous phase was sampled and the product composition was analyzed by gas chromatography.

[0061] Glycerol conversion rate: 40.05%; 1,3-propylene glycol selectivity: 56.90%; 1,3-propylene glycol yield: 22.79%.

[0062] Example 5

[0063] 0.66g sodium tungstate, 0.14g sodium niobate, 2.01g glucose, 0.58g citric acid were dissolved in 60ml water, and 8g Al2O3 (specific surface area 222m 2 / g), stirred for 30min, 2ml of 3M hydrochloric acid solution was added dropwise, and stirring was continued for 30min. Then the mixture was transferred to a high-pressure reactor, and kept at 400r / min, 180℃, for 12h. After cooling, the mixture was centrifuged, washed with water, washed with alcohol, and dried in vacuum at 40℃ to obtain NbO x -WO x / Al2O3. 1.53g platinum solution (0.03930g Pt / g) was diluted with water to 10g, and 3g of the above NbO x -WO x / Al2O3, stirred at room temperature for 2h, evaporated to dryness in a water bath at 75℃, dried in an oven at 80℃ for 12h, and calcined at 400℃ for 6h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0064] 1.0 g of the above catalyst was dispersed in 30 g of a 10% aqueous glycerol solution. The catalyst and reaction mixture were transferred to a 100 mL autoclave. After five H2 displacements at room temperature with a pressure of 3 MPa, hydrogen was introduced to 5 MPa. The reaction was stirred at 650 rpm and 180°C for 12 hours before stirring was stopped. After cooling to room temperature, the mixture was centrifuged and filtered through a 0.25 μm filter membrane. The aqueous phase was sampled and the product composition was analyzed by gas chromatography.

[0065] Glycerol conversion: 34.11%; 1,3-propanediol selectivity: 57.00%; 1,3-propanediol yield: 19.44%.

[0066] Example 6

[0067] 0.49 g ammonium metatungstate, 0.09 g sodium niobate, 1.8 g glucose, 1.0 g citric acid were dissolved in 60 ml water, 8 g Al2O3 (specific surface area 159 m2 / g) was added, stirred for 30 min, 2 ml 12 M hydrochloric acid solution was added dropwise, stirring was continued for 30 min, transferred into a high-pressure reactor, 400 r / min, 120°C, maintained for 24 h. After cooling, centrifugal separation, water washing, alcohol washing, vacuum drying at 60°C, NbO-WO-Al2O3 was obtained. 2 / g), stirred for 30 min, 2 ml 12 M hydrochloric acid solution was added dropwise, stirring was continued for 30 min, transferred into a high-pressure reactor, 400 r / min, 120°C, maintained for 24 h. After cooling, centrifugal separation, water washing, alcohol washing, vacuum drying at 60°C, NbO-WO-Al2O3 was obtained. x -WO x / Al2O3. 1.53 g platinum solution (0.03930 g Pt / g) was diluted with water to 10 g, 3 g of the above NbO-WO-Al2O3 was added, stirred at room temperature for 6 h, evaporated to dryness in a water bath at 90°C, dried in an oven at 90°C for 15 h, calcined at 280°C for 8 h, to obtain the catalyst Pt / NbO-WO-Al2O3. x -WO x / Al2O3, after stirring at room temperature for 6 h, evaporated to dryness in a water bath at 90°C, dried in an oven at 90°C for 15 h, calcined at 280°C for 8 h, to obtain the catalyst Pt / NbO-WO-Al2O3. x -WO x / Al2O3.

[0068] 1.0 g of the above catalyst was taken and dispersed in 30 g of glycerol aqueous solution (10%), the catalyst and the reaction liquid were transferred together into a 100 ml high-pressure reactor. After 5 times of replacement at room temperature under H2 pressure of 3 MPa, hydrogen was filled to 5 MPa, the stirring speed was 650 r / min, the reaction temperature was 180°C, after 12 h of reaction, the stirring was stopped. After cooling to room temperature, centrifugal separation, filtration with 0.25 μm filter membrane, the aqueous phase sample was collected, and the product composition was analyzed by gas chromatography.

[0069] Glycerol conversion: 34.11%; 1,3-propanediol selectivity: 57.00%; 1,3-propanediol yield: 19.44%.

[0070] Comparative Example 1

[0071] 0.66 g sodium tungstate, 0.10 g sodium niobate, 1.80 g glucose, 0.58 g citric acid were dissolved in 60 ml water, 10 g Al2O3 (specific surface area 159 m2 / g) was added, stirred for 30 min, 6 ml 6 M hydrochloric acid solution was added dropwise, stirring was continued for 30 min, transferred into a high-pressure reactor, 400 r / min, 120°C, maintained for 24 h. After cooling, centrifugal separation, water washing, alcohol washing, drying at room temperature, NbO-WO-Al2O3 was obtained. 2 -WO x / Al2O3, after stirring at room temperature for 6 h, evaporated to dryness in a water bath at 90°C, dried in an oven at 90°C for 15 h, calcined at 280°C for 8 h, to obtain the catalyst Pt / NbO-WO-Al2O3. x / Al203. 3.05 g platinum solution (0.03930 g Pt / g) was diluted with water to 10 g, and 3 g of the above NbO x -WO x / Al203, stirred at room temperature for 5 h, evaporated to dryness in a water bath at 80 °C, dried in an oven at 100 °C for 10 h, calcined at 450 °C for 5 h, and reduced in hydrogen at 250 °C for 3 h to obtain the catalyst Pt / NbO x -WO x / Al203.

[0072] 0.5 g of the above catalyst was dispersed in 30 g of an aqueous glycerol solution (10%), and the catalyst and reaction solution were transferred together into a 100 mL autoclave. After replacement with H2at 3 MPa for 5 times at room temperature, hydrogen was filled to 5 MPa, the stirring speed was 650 rpm, the reaction temperature was 180 °C, and the stirring was stopped after reaction for 12 h. After cooling to room temperature, centrifugal separation was performed, the aqueous phase sample was collected after filtration through a 0.25 μm filter membrane, and the product composition was analyzed by gas chromatography.

[0073] Glycerol conversion: 54.40%; 1,3-propanediol selectivity: 58.31%; 1,3-propanediol yield: 31.72%.

[0074] Comparative Example 2

[0075] 0.49 g of ammonium metatungstate and 0.14 g of sodium niobate were dissolved in 10 g of water, and 8 g of Al203(bet surface area 159 m 2 / g) was added, stirred at room temperature for 5 h, evaporated to dryness in a water bath at 60 °C, dried in an oven at 120 °C for 8 h, calcined at 550 °C for 4 h to obtain NbO x -WO x / Al203. 3.05 g platinum solution (0.03930 g Pt / g) was diluted with water to 10 g, and 3 g of the above NbO x -WO x / Al203, stirred at room temperature for 5 h, evaporated to dryness in a water bath at 80 °C, dried in an oven at 120 °C for 8 h, calcined at 450 °C for 3 h, and reduced in hydrogen at 250 °C for 3 h to obtain the catalyst Pt / NbO x -WO x / Al203.

[0076] 0.5 g of the above catalyst was dispersed in 30 g of an aqueous glycerol solution (10%), and the catalyst and reaction solution were transferred together into a 100 mL autoclave. After replacement with H2at 3 MPa for 5 times at room temperature, hydrogen was filled to 5 MPa, the stirring speed was 650 rpm, the reaction temperature was 180 °C, and the stirring was stopped after reaction for 12 h. After cooling to room temperature, centrifugal separation was performed, the aqueous phase sample was collected after filtration through a 0.25 μm filter membrane, and the product composition was analyzed by gas chromatography.

[0077] Glycerol conversion: 32.45%; 1,3-propanediol selectivity: 55.27%; 1,3-propanediol yield: 17.94%.

[0078] Comparative Example 3

[0079] 0.66 g sodium tungstate, 1.80 g glucose, 0.58 g citric acid were dissolved in 60 ml water, 10 g Al2O3 (specific surface area 159 m2 / g) was added, stirred for 30 min, 6 ml 6M hydrochloric acid solution was added dropwise, stirring was continued for 30 min, it was transferred into a high-pressure reactor, 400 r / min, 120°C, and maintained for 24 h. After cooling, centrifugal separation, water washing, alcohol washing, and drying at room temperature, WO 2 / Al2O3 was obtained. 3.05 g platinum solution (0.03930 g Pt / g) was diluted to 10 g with water, and 3 g of the above WO x / Al2O3 was added, stirred at room temperature for 5 h, then evaporated to dryness in a water bath at 80°C, dried in an oven at 100°C for 10 h, and calcined at 450°C for 5 h to obtain the catalyst Pt / WO x / Al2O3. x

[0080] 0.5 g of the above catalyst was taken and dispersed in 30 g of an aqueous glycerol solution (10%), and the catalyst and the reaction solution were transferred together into a 100 ml high-pressure reactor. After 5 times of replacement at room temperature under a hydrogen pressure of 3 MPa, hydrogen was filled to 5 MPa, the stirring speed was 650 r / min, the reaction temperature was 180°C, and after 12 h of reaction, stirring was stopped. After cooling to room temperature, centrifugal separation, filtration with a 0.25 μm filter membrane, and collection of the aqueous phase sample, the product composition was analyzed by gas chromatography.

[0081] Glycerol conversion: 51.16%; 1,3-propanediol selectivity: 56.49%; 1,3-propanediol yield: 28.90%.

[0082] Comparative Example 4

[0083] 0.66 g sodium tungstate, 0.19 g sodium niobate, 1.80 g glucose, 0.58 g citric acid were dissolved in 60 ml water, 10 g Al2O3 (specific surface area 159 m2 / g) was added, stirred for 30 min, 6 ml 6M hydrochloric acid solution was added dropwise, stirring was continued for 30 min, it was transferred into a high-pressure reactor, 400 r / min, 120°C, and maintained for 24 h. After cooling, centrifugal separation, water washing, alcohol washing, and drying at room temperature, NbO 2 -WO x / Al2O3 was obtained. 3.05 g platinum solution (0.03930 g Pt / g) was diluted to 10 g with water, and 3 g of the above NbO x -WO x / Al2O3 was added, stirred at room temperature for 5 h, then evaporated to dryness in a water bath at 80°C, dried in an oven at 100°C for 10 h, and calcined at 450°C for 5 h to obtain the catalyst Pt / WO x ​Pt / NbOx / Al2O3, stirring at room temperature for 5 h, evaporating water at 80 °C, drying in an oven at 100 °C for 10 h, and calcining at 450 °C for 5 h to obtain the catalyst Pt / NbOx / Al2O3 x -WO x / Al2O3.

[0084] Take 0.5 g of the above catalyst and disperse it in 30 g of an aqueous glycerol solution (10%). Transfer the catalyst and the reaction solution to a 100 mL autoclave. After 5 times of replacement at room temperature under a hydrogen pressure of 3 MPa, fill hydrogen to 5 MPa, and stir at a speed of 650 r / min. The reaction temperature is 180 °C, and the stirring is stopped after 12 h of reaction. After cooling to room temperature, centrifugal separation is performed, and the water phase sample is collected after filtration with a 0.25 μm filter membrane. The product composition is analyzed by gas chromatography.

[0085] Glycerol conversion rate: 50.31%; 1,3-propanediol selectivity: 56.17%; 1,3-propanediol yield: 28.26%.

[0086] The catalyst preparation conditions of Example 1 and Comparative Example 1 are almost completely the same, and the difference between the two is that the catalyst of Example 1 is directly used for glycerol hydrogenolysis reaction after calcination, and the catalyst of Comparative Example 1 is reduced and then used for glycerol hydrogenolysis reaction after calcination. It can be seen from the reaction results that whether or not to reduce after calcination has little effect on the activity of the catalyst, indicating that the carbon-based substances produced in the hydrothermal process of the reducing agent can reduce the platinum salt to metallic platinum in the calcination process.

[0087] Example 2 uses the hydrothermal method to load NbOxand WOx x and WO x on the carrier, and Comparative Example 2 uses the impregnation method to load NbOxand WOx x and WO x on the carrier. It can be seen from the comparison of the reaction results that the catalyst obtained by the hydrothermal method has higher activity than the catalyst obtained by the impregnation method. Figure 1 Example 2 uses the hydrothermal method to load NbOxand WOx x -WO x / Al2O3sample Raman characterization results, the sample obtained by the impregnation method has two peaks near 705 cm -1 and 800 cm -1 , which correspond to the stretching vibration of the crystal phase tungsten oxide W-O-W bond, while the two peaks do not appear in the sample obtained by the hydrothermal method, indicating that the hydrothermal method can disperse NbOxand WOx x and WO x with smaller particles more uniformly on the surface of the carrier.

[0088] Comparative Example 3 differs from Example 1 in that Example 1 added element Nb. As can be seen from the reaction results, moderate addition of Nb can improve the glycerol conversion rate and 1,3-propanediol selectivity, and in turn improve the 1,3-propanediol yield.

[0089] Comparative Example 4 differs from Example 1 in the amount of element Nb added. As can be seen from the reaction results, excessive addition of Nb can decrease the glycerol conversion rate and 1,3-propanediol selectivity.

[0090] Any numerical values recited herein include all values from the lower value and up to the upper value. Values that are near to or fall within a range provided in the written description should be considered to be within the range. For example, if a range is stated as 50-90, it is intended that all individual values, such as 51-89, 52-88, etc., within the range are specifically recited. For values which are less than one, one unit in the disclosed range is considered to be equivalent to one unit and thus it is a matter of interpretation within the skilled in the art, how many units are added. To the extent that particular numerical values of the Cited Examples are recited herein, those values are exemplary. It is contemplated to have values outside of this range. For example, if a numerical value is stated as 50-90, it is intended that values such as 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, etc. are within the scope of this application. For non-integral values, it is contemplated that values such as 0.1, 0.01, 0.001, or 0.0001 are within the scope of this application. These are merely some specific examples. In a similar manner, all stated numerical values are "approximate", meaning that the value of the quantity is roughly in the

[0091] It is to be understood that the embodiments which have been described are merely illustrative of the present application and that modifications of structure, arrangement, proportions, materials, and components and additionally the use of alternatives, known or unknown equivalents, are intended to be comprehended within the philosophy of the present application. The above description is that of current embodiments of the application. Various modifications and changes can be made thereto without departing from the spirit of the application, and it is intended to embrace all such modifications and changes as fall within the scope of the application. Although the present application has been described in detail with reference to particular embodiments, it should be understood that various other adaptations and modifications can be made within the scope of the present application and without departing from the true spirit and scope of the application. While the preferred embodiments have been described above, it is to be understood that assorted modifications and enhancements can be made to the preferred embodiments that are within the scope of the underlying principles of the preferred embodiments. For example, certain steps in the processes described above can be performed in a different order. Additionally, variations in the components, equipment, and arrangements can be implemented. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A method for preparing a supported catalyst, characterized in that: include: (1) Nb and W are loaded on the carrier by hydrothermal method, and NbO is obtained after washing and drying. x and WO x Catalyst intermediates; (2) loading the platinum precursor onto the catalyst intermediate, drying, and calcining to obtain the catalyst; In step (1), the hydrothermal method comprises: preparing an aqueous solution containing a tungsten source, a niobium source, a reducing agent and an additive, adding a carrier, stirring I, adding hydrochloric acid dropwise, stirring II, and performing a hydrothermal reaction; The molar ratio of tungsten source calculated as tungsten: niobium source calculated as niobium: reducing agent: additive: carrier is 1:0.1~1.0:3~10:1~5:15~75; The loading amount of the platinum is 1 wt% to 5 wt% based on the catalyst intermediate.

2. The preparation method according to claim 1, characterized in that In step (2), the loading comprises adding the catalyst intermediate to an aqueous solution containing a platinum precursor, stirring III, and evaporating to dryness in a water bath; And / or, the loading amount of the platinum is 2 wt% to 4 wt% based on the catalyst intermediate.

3. The preparation method according to claim 2, characterized in that The stirring time of said stirring I and stirring II is independently 10 to 60 minutes; And / or, the hydrothermal reaction is carried out at a speed of 100-400 rpm, a temperature of 120-180° C., and a time of 12-24 hours; And / or, the stirring time of III is 2 to 8 hours; And / or, the temperature of the water bath evaporation is 60-90°C.

4. The preparation method according to claim 1, characterized in that The molar ratio of tungsten source calculated as tungsten: niobium source calculated as niobium: reducing agent: additive: carrier is 1:0.3~0.5:4~6:1~3:20~50; and / or, after the hydrochloric acid is added dropwise, the hydrogen ion concentration in the aqueous solution is 0.1 to 1 mol / L.

5. The preparation method according to claim 4, characterized in that After adding hydrochloric acid, the hydrogen ion concentration in the aqueous solution is 0.1~0.5mol / L.

6. The preparation method according to any one of claims 1 to 5, characterized in that The tungsten source is selected from at least one of ammonium metatungstate, ammonium paratungstate, sodium tungstate, potassium tungstate, ammonium tungstate, sodium phosphotungstate, phosphotungstic acid and silicotungstic acid; and / or, the niobium source is selected from at least one of ammonium niobate oxalate hydrate, potassium niobate, sodium niobate and niobium oxalate; and / or, the reducing agent is selected from at least one of glucose, fructose and sucrose; and / or, the additive is selected from at least one of citric acid, oxalic acid, tartaric acid and nitric acid; And / or, the platinum precursor is selected from at least one of chloroplatinic acid, tetraammonium platinum chloride, tetraammine platinum nitrate and platinum nitrate.

7. The preparation method according to any one of claims 1 to 5, characterized in that In step (1), the drying temperature is 30-100°C; And / or, in step (2), the drying condition is 80-120°C for 8-15 hours; the calcination condition is 250-500°C for 2-8 hours; And / or, the carrier is selected from at least one of SiO2, Al2O3, ZrO2, and TiO2.

8. The preparation method according to claim 7, characterized in that In step (1), the drying temperature is 40-60°C; And / or, the carrier is Al2O3.

9. The preparation method according to claim 7, characterized in that The specific surface area of ​​Al2O3 is 50~500m 2 / g.

10. The preparation method according to claim 9, characterized in that The specific surface area of ​​Al2O3 is 100~400m 2 / g.

11. The preparation method according to claim 10, characterized in that: The specific surface area of ​​Al2O3 is 150~300m 2 / g.

12. A catalyst prepared by the preparation method according to any one of claims 1 to 11.

13. The catalyst according to claim 12, characterized in that The WO x The loading amount is 1wt%~10wt% based on the mass of the carrier; and / or, the NbO x The loading amount is 0.2wt%~2wt% based on the mass of the carrier; and / or, the surface density of Nb atoms on the support is 0.1 to 1; and / or, the surface density of W atoms on the carrier is 0.1 to 3; And / or, the molar ratio of Nb to W is 0.1-1.

14. The catalyst according to claim 13, characterized in that The WO x The loading amount is 4wt%~9wt% based on the mass of the carrier; and / or, the NbO x The loading amount is 0.4wt%~1wt% based on the mass of the carrier; and / or, the surface density of Nb atoms on the support is 0.2 to 0.8; and / or, the surface density of W atoms on the carrier is 0.2 to 2; And / or, the molar ratio of Nb to W is 0.3-0.

7.

15. The catalyst according to claim 14, characterized in that The surface density of Nb atoms on the support is 0.2~0.4; and / or, the surface density of W atoms on the carrier is 0.4 to 1; And / or, the molar ratio of Nb to W is 0.3-0.

5.

16. A method for preparing 1,3-propylene glycol by hydrogenolysis of glycerol, characterized in that: The glycerol reacts with hydrogen in the presence of a catalyst to produce 1,3-propylene glycol; the catalyst is selected from at least one of the catalysts prepared by the preparation method according to any one of claims 1 to 11 and the catalysts according to any one of claims 12 to 15.

17. The method according to claim 16, characterized in that The initial hydrogen pressure is 1-8 MPa; and / or the reaction temperature is 100-200° C.; and / or the reaction time is 3-24 h.

18. The method according to claim 17, characterized in that The initial hydrogen pressure is 2-6 MPa; and / or the reaction temperature is 120-180° C.; and / or the reaction time is 6-24 h.

19. The method according to claim 18, characterized in that The reaction temperature is 150~180℃.

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