Glycerin hydrogenolysis reaction catalyst as well as preparation method and application thereof

Abstract

The invention 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 adopting a hydrothermal method, washing and drying to obtain a catalyst intermediate loaded with NbOx and WOx; loading a platinum precursor on the catalyst intermediate, drying and roasting to obtain the catalyst. The NbOx-WOx / Y catalyst intermediate is prepared by adopting a hydrothermal method, NbOx and WOx can be uniformly dispersed on the surface of a carrier, the particle size is very small, a reductive carbon-based compound generated by a reducing agent under the hydrothermal condition can reduce Pt salt into metal Pt in the roasting process, so that the obtained catalyst does not need to be reduced after being roasted, and the preparation method is simple and convenient. And the catalyst can be directly used for glycerol hydrogenolysis reaction.

Description

Technical Field

[0001] The invention belongs to the field of catalyst preparation, and specifically relates to a catalyst for preparing 1,3-propylene glycol by hydrogenolysis of glycerol, and a preparation method and application thereof. Background Art

[0002] Biodiesel is a clean, renewable liquid biofuel. As an important low-carbon and environmentally friendly energy source, it enjoys a variety of policy supports around the world and has flourished. However, for every 10 tons of diesel produced, 1 ton of glycerol by-product is produced, resulting in a large surplus of glycerol. If it can be effectively utilized, it will not only improve the economic efficiency of the biodiesel industry, but also reduce dependence on petrochemical products. One of the products of glycerol hydrogenolysis, 1,3-propylene glycol, is a raw material for the production of unsaturated polyesters, plasticizers, surfactants, emulsifiers and demulsifiers; in the polyurethane industry, it is often used as a raw material for polyester polyols, a starter for polyether polyols and a polyurethane chain extender; in the organic chemical industry, it is also an important monomer and intermediate, and its main use is as a polymer monomer to synthesize polytrimethylene terephthalate (PTT). As a new type of biodegradable polyester, PTT overcomes the shortcomings of polyethylene terephthalate (PET) being too hard and polybutylene terephthalate (PBT) being too soft, and has excellent resilience, dyeability and biodegradability. It has great development potential in the carpet, textile, engineering plastics and other industries. The economic feasibility of synthesizing PTT is limited by 1,3-propylene glycol.

[0003] At present, the production methods of 1,3-propylene glycol include acrolein hydration hydrogenation method, ethylene oxide carbonylation method, biological fermentation method and glycerol hydrogenolysis method. The Chinese patent CN93114516.3 applied by Degussa Company discloses a method for preparing 1,3-propylene glycol by acrolein hydration, in which solid acid is used as a catalyst, gaseous glycerol is dehydrated to generate acrolein, and then hydrated under the action of an acidic catalyst to generate 3-hydroxypropanal, and then hydrogenated to generate 1,3-propylene glycol. The Chinese patent (CN96198050.8) applied by Shell Company discloses a method in which a cobalt-based compound is used as a catalyst, ethylene oxide and synthesis gas react to generate 3-hydroxypropanal, and then 3-hydroxypropanal is hydrogenated under the action of a hydrogenation catalyst to generate 1,3-propylene glycol. Dupont's patent (CN96195288.1) provides a production process for preparing 1,3-propylene glycol by microbial fermentation. The raw material (sugar of glucose or starch) first generates the intermediate product glycerol under the action of yeast, and then converts it into propylene glycol under the action of biological strains. In the process of acrolein hydration hydrogenation, the product 3-hydroxypropanal has low selectivity and is extremely unstable, and it is easy to produce acetal, which is not conducive to separation; moreover, acrolein itself is a highly toxic, flammable and explosive chemical. The ethylene oxide carbonylation method has large equipment investment and high reaction pressure. The disadvantages of the biological fermentation method are that the conversion rate of the raw materials and the concentration of the products are both low, there are many by-products, and the separation cost of the products and strains is high. The glycerol hydrogenolysis method not only has a short process flow, low toxicity of the reaction raw materials, mild reaction conditions, but also the reaction can be carried out in the aqueous phase, with little pollution to the environment, and is a green synthesis route.

[0004] The supported Pt-W catalyst is a catalyst system that has been widely studied for the hydrogenolysis reaction of glycerol. Usually, a tungsten precursor is loaded on the surface of a carrier by an impregnation method, and WO3 / carrier is obtained after high-temperature calcination; then a platinum precursor is loaded on the surface of WO3 / carrier, calcined, and reduced to obtain (as shown in patent CN 111389397A). Although this preparation method is simple, it is difficult to control the size of the W species, and after high-temperature calcination, a crystalline WO3 that does not contribute to the activity of the catalyst will be produced. Summary of the invention

[0005] The present invention aims to provide a catalyst for preparing 1,3-propylene glycol by hydrogenolysis of glycerol and a preparation method thereof, which is characterized in that NbO is prepared by a hydrothermal method in the presence of a reducing agent. x -WO x / Y catalyst intermediate (Y refers to the carrier), and then Pt is loaded by impregnation to obtain supported Pt / NbO x -WO x / Y catalyst, the catalyst of the present invention can be directly used in glycerol hydrogenolysis reaction without reduction after calcination.

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

[0007] (1) Nb and W are loaded on a carrier by a hydrothermal method, and after washing and drying, NbO is obtained. x and WO x Catalyst intermediates;

[0008] (2) The platinum precursor is loaded onto the catalyst intermediate, and then dried and calcined to obtain 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 a carrier, stirring I, adding hydrochloric acid dropwise, stirring II, and conducting a hydrothermal reaction.

[0010] Optionally, in step (2), the loading comprises adding the catalyst intermediate to an aqueous solution containing a platinum precursor, stirring, and evaporating to dryness in a water bath.

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

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

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

[0014] Optionally, the stirring time of III is 2 to 8 hours.

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

[0016] Optionally, the molar ratio of the tungsten source calculated as tungsten: the niobium source calculated as niobium: the reducing agent: the additive: the carrier 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 to 12 mol / L, and the amount added is 2 to 6 ml.

[0018] Optionally, the amount of hydrochloric acid added is based on the hydrogen ion concentration range of the aqueous solution in the hydrothermal reaction as the final standard.

[0019] Optionally, after the hydrochloric acid is added dropwise, the hydrogen ion concentration in the aqueous solution is 0.1 to 1 mol / L, preferably 0.1 to 0.5 mol / 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, and 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, tetraammonium platinum chloride, tetraammine platinum nitrate and platinum nitrate.

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

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

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

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

[0029] According to one aspect of the present invention, a catalyst prepared by the above preparation method is provided.

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

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

[0032] Optionally, the surface density of Nb atoms on the carrier is 0.1 to 1, preferably 0.2 to 0.8, and more preferably 0.2 to 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 invention, the W atom surface density and the Nb atom surface density refer to the number of tungsten atoms or niobium atoms per square nanometer on the surface of the carrier.

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

[0036] Optionally, the loading amount of the platinum is 1 wt% to 5 wt%, preferably 2 wt% to 4 wt%, calculated on the basis of the catalyst intermediate.

[0037] As a specific embodiment of the present invention, a method for preparing a catalyst for preparing 1,3-propylene glycol by hydrogenolysis of glycerol is provided, wherein a tungsten source, a niobium source, a reducing agent and an additive are dissolved in water, Al2O3 is added, stirred for 10 to 60 minutes, hydrochloric acid is added dropwise, and stirring is continued for 10 to 60 minutes, and the hydrothermal autoclave is maintained at 100 to 400 rpm and 120 to 180°C for 12 to 24 hours, and the obtained mixture is washed with water, washed with alcohol, and vacuum dried or placed at room temperature to obtain NbO x -WO x / Al2O3 powder; NbO x -WO x / Al2O3 powder is added to the platinum precursor aqueous solution, stirred at room temperature for 2-8h, evaporated to dryness in a water bath at 60-90℃, dried at 80-120℃ for 8-15h, and calcined at 250-500℃ for 2-8h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0038] According to another aspect of the present invention, a method for preparing 1,3-propylene glycol by hydrogenolysis of glycerol is provided, wherein 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 above catalysts and the catalysts prepared by the above preparation method.

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

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

[0041] Optionally, the reaction time is 3 to 24 hours, preferably 6 to 24 hours.

[0042] The catalyst of the present invention is used for the hydrogenolysis of glycerol to prepare 1,3-propylene glycol. The reaction is carried out in a high-pressure reactor. The raw materials are a glycerol aqueous solution (10wt%) and hydrogen. The air in the reactor is first replaced with pure hydrogen, and then hydrogen is filled in. The reaction is stirred for 12 hours at 180° C. and an initial pressure of 5MPa. The above reaction conditions are used as an example to examine the catalyst activity, but the reaction conditions are not limited thereto.

[0043] The 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 metal Pt during the calcination process. Therefore, the obtained 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, purposes 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 construed as limiting the applicable scope 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, added 6ml of 6M hydrochloric acid solution, continued stirring for 30min, transferred to a high-pressure reactor, 400r / min, 120℃, maintained for 24h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at room temperature to obtain NbO x -WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted to 10g with water, 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 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10wt%), transfer the catalyst and the reaction liquid into a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0050] Example 2

[0051] 0.49g ammonium metatungstate, 0.14g sodium niobate, 1.80g glucose, 0.58g citric acid were dissolved in 60ml water, and 8g Al2O3 (specific surface area 159m 2 / g), stirred for 15min, added 2ml of 12M hydrochloric acid solution, continued stirring for 10min, transferred to a high-pressure reactor, 250r / min, 180℃, maintained for 12h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at 60℃ in vacuum to obtain NbO x -WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted to 10g with water, and 3g of the above NbO x -WO x / Al2O3, stirred at room temperature for 6 h, evaporated to dryness in a water bath at 75 °C, dried in an oven at 90 °C for 15 h, and calcined at 400 °C for 6 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0052] Take 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0054] Example 3

[0055] 0.66g sodium tungstate, 0.14g sodium niobate, 1.80g glucose, 0.58g citric acid were dissolved in 60ml water, and 5.3g Al2O3 (specific surface area 292m 2 / g), stirred for 60min, added 6ml of 3.5M hydrochloric acid solution, continued stirring for 60min, transferred to a high-pressure reactor, 100r / min, 150℃, maintained for 15h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at 40℃ in vacuum to obtain NbO x -WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted to 10g with water, and 3g of the above NbO x -WO x / Al2O3, stirred at room temperature for 2 h, evaporated to dryness in a water bath at 65 °C, 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] Take 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0058] Example 4

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

[0060] Take 0.65g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, filter with 0.25μm filter membrane, collect water phase sample, and analyze product composition 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, added 2ml of 3M hydrochloric acid solution, continued stirring for 30min, transferred to a high-pressure reactor, 400r / min, 180℃, maintained for 12h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at 40℃ in vacuum to obtain NbO x -WO x / Al2O3. 1.53g of 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 2 h, evaporated to dryness in a water bath at 75 °C, 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.

[0064] Take 1.0g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

[0065] Glycerol conversion rate: 38.27%; 1,3-propylene glycol selectivity: 54.33%; 1,3-propylene glycol yield: 20.79%.

[0066] Example 6

[0067] 0.49g ammonium metatungstate, 0.09g sodium niobate, 1.8g glucose, 1.0g citric acid were dissolved in 60ml water, and 8g Al2O3 (specific surface area 159m 2 / g), stirred for 30min, added 2ml of 12M hydrochloric acid solution, continued stirring for 30min, transferred to a high-pressure reactor, 400r / min, 120℃, maintained for 24h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at 60℃ in vacuum to obtain NbO x -WO x / Al2O3. 1.53g of 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 6 hours, evaporated to dryness in a water bath at 90°C, dried in an oven at 90°C for 15 hours, and calcined at 280°C for 8 hours to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0068] Take 1.0g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0070] Comparative Example 1

[0071] 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, added 6ml of 6M hydrochloric acid solution, continued stirring for 30min, transferred to a high-pressure reactor, 400r / min, 120℃, maintained for 24h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at room temperature to obtain NbO x -WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted to 10g with water, 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 10 h, calcined at 450 °C for 5 h, and reduced with hydrogen at 250 °C for 3 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0072] Take 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0074] Comparative Example 2

[0075] 0.49g ammonium metatungstate, 0.14g sodium niobate, dissolved in 10g water, add 8g Al2O3 (specific surface area 159m 2 / g), stirred at room temperature for 5h, 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 NbO x -WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted to 10g with water, 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 120 °C for 8 h, calcined at 450 °C for 3 h, and reduced with hydrogen at 250 °C for 3 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0076] Take 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0078] Comparative Example 3

[0079] 0.66g sodium tungstate, 1.80g glucose, 0.58g citric acid were dissolved in 60ml water, and 10g Al2O3 (specific surface area 159m 2 / g), stirred for 30min, added 6ml of 6M hydrochloric acid solution, continued stirring for 30min, transferred to a high-pressure reactor, 400r / min, 120℃, maintained for 24h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at room temperature to obtain WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted with water to 10g, and 3g of the above 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 10 h, and calcined at 450 °C for 5 h to obtain the catalyst Pt / WO x / Al2O3.

[0080] Take 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

[0082] Comparative Example 4

[0083] 0.66g sodium tungstate, 0.19g 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, added 6ml of 6M hydrochloric acid solution, continued stirring for 30min, transferred to a high-pressure reactor, 400r / min, 120℃, maintained for 24h. After cooling, centrifuged, washed with water, washed with alcohol, and dried at room temperature to obtain NbO x -WO x / Al2O3. 3.05g of platinum solution (0.03930g Pt / g) was diluted to 10g with water, 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 10 h, and calcined at 450 °C for 5 h to obtain the catalyst Pt / NbO x -WO x / Al2O3.

[0084] Take 0.5g of the above catalyst and disperse it in 30g of glycerol aqueous solution (10%), transfer the catalyst and the reaction liquid to a 100mL autoclave. After H2 pressure 3MPa replacement 5 times at room temperature, fill with hydrogen to 5MPa, stir at 650 rpm, reaction temperature 180°C, and stop stirring after 12h of reaction. After cooling to room temperature, centrifuge, collect water phase samples after filtering with 0.25μm filter membrane, and analyze product composition by gas chromatography.

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

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

[0087] Example 2: Hydrothermal method was used to convert NbO x and WO x Loaded on the carrier, Comparative Example 2 uses the impregnation method to x and WO x Loaded on the carrier, comparison of the reaction results shows that the activity of the catalyst obtained by the hydrothermal method is higher than that of the catalyst obtained by the impregnation method. Figure 1 NbO is obtained by hydrothermal method and impregnation method. x -WO x / Al2O3 sample Raman characterization results, the sample obtained by impregnation method showed 705cm -1 Nearby and 800cm -1 The two peaks near the NbO2 bond correspond to the stretching vibration of the WOW bond of the crystalline tungsten oxide. These two peaks do not appear in the sample obtained by the hydrothermal method, indicating that the hydrothermal method can convert NbO2 x and WO x Smaller particles are dispersed more evenly on the carrier surface.

[0088] The difference between Comparative Example 3 and Example 1 is that the element Nb is added in Example 1. It can be seen from the reaction results that moderate addition of Nb can improve the glycerol conversion rate and 1,3-propylene glycol selectivity, thereby improving the 1,3-propylene glycol yield.

[0089] The difference between Comparative Example 4 and Example 1 lies in the amount of Nb added. From the reaction results, it can be seen that excessive addition of Nb will reduce the glycerol conversion rate and 1,3-propylene glycol selectivity.

[0090] Any numerical value mentioned in the present invention includes all values ​​that increase by one unit each time from the lowest value to the highest value if there is only an interval of two units between any minimum value and any maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, time, etc. is declared to be 50-90, in this specification it means that 51-89, 52-88... and 69-71 and 70-71 are specifically listed. For non-integer values, 0.1, 0.01, 0.001 or 0.0001 can be appropriately considered as a unit. These are just some specially specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed lowest and highest values ​​are considered to have been disclosed.

[0091] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for preparing a supported catalyst, characterized in that: include: (1) Nb and W are loaded on a carrier by a hydrothermal method, and after washing and drying, NbO is obtained. x and WO x Catalyst intermediates; (2) The platinum precursor is loaded onto the catalyst intermediate, and then dried and calcined to obtain the catalyst.

2. The preparation method according to claim 1, characterized in that: 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; and / or, 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 1 wt% to 5 wt%, preferably 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 rotation speed of the hydrothermal reaction is 100-400 rpm, the temperature is 120-180° C., and the time is 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 2 or 3, characterized in that: 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, preferably 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, preferably 0.1 to 0.5 mol / L.

5. The preparation method according to any one of claims 2 to 4, 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.

6. The preparation method according to any one of claims 1 to 5, characterized in that In step (1), the drying temperature is 30 to 100° C., preferably 40 to 60° C.; And / or, in step (2), the drying condition is 80-120° C. for 8-15 h; the calcination condition is 250-500° C. for 2-8 h; And / or, the carrier is selected from at least one of SiO2, Al2O3, ZrO2, TiO2, preferably Al2O3; Preferably, the specific surface area of ​​Al2O3 is 50 to 500 m 2 / g, preferably 100 to 400 m 2 / g, more preferably 150 to 300 m 2 / g.

7. A catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. The catalyst according to claim 7, characterized in that The WO x The loading amount is 1 wt% to 10 wt% based on the mass of the carrier, preferably 4 wt% to 9 wt%; and / or, the NbO x The loading amount is 0.2 wt% to 2 wt% based on the mass of the carrier, preferably 0.4 wt% to 1 wt%; and / or, the surface density of Nb atoms on the carrier is 0.1 to 1, preferably 0.2 to 0.8, more preferably 0.2 to 0.4; and / or, the surface density of W atoms on the carrier is 0.1 to 3, preferably 0.2 to 2, more preferably 0.4 to 1; and / or, the molar ratio of Nb to W is 0.1 to 1, preferably 0.3 to 0.7, more preferably 0.3 to 0.5; And / or, the loading amount of the platinum is 1 wt% to 5 wt%, preferably 2 wt% to 4 wt%, based on the catalyst intermediate.

9. A method for preparing 1,3-propylene glycol by hydrogenolysis of glycerol, characterized in that: The glycerol reacts with hydrogen under the action 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 6 and the catalysts according to claim 7 or 8.

10. The method according to claim 9, characterized in that The initial hydrogen pressure is 1-8 MPa, preferably 2-6 MPa; and / or the reaction temperature is 100-200° C., preferably 120-180° C., more preferably 150-180° C.; and / or the reaction time is 3-24 h, preferably 6-24 h.

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