A catalyst, a method for preparing the same, and a method for preparing 1,3-propanediol

Abstract

The present application relates to a kind of catalyst and its preparation method and the method for preparing 1,3-propylene glycol, the catalyst includes carrier, first active component and second active component supported on the carrier;The carrier is micro-intermediate hierarchical pore molecular sieve, the first active component is tungsten oxide, and the second active component is nano-alloy;The nano-alloy is PtSn nano-alloy and / or PtLa nano-alloy.The present application also relates to the preparation method of the above-mentioned catalyst, the preparation method includes: S1, using the solution containing nano-alloy impregnation is loaded with tungsten oxide micro-intermediate hierarchical pore molecular sieve, then first solid-liquid separation is carried out, and first solid material is obtained;S2, the first solid material is carried out first drying and first calcination.The present application also relates to a kind of method for preparing 1,3-propylene glycol, which comprises: glycerol is contacted with the catalyst as described above under hydrogenation conditions.The catalyst prepared by the present application has the characteristics of high 1,3-propylene glycol selectivity and high glycerol conversion activity.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and in particular to a catalyst and a preparation method thereof, and a method for preparing 1,3-propylene glycol. Background Art

[0002] Glycerol is the main by-product of bio-jet fuel production, accounting for about 10%. The further high-value-added utilization of glycerol is an issue worth considering. Among them, the selective synthesis of high-value-added 1,3-propylene glycol from glycerol is one of its optimized routes. 1,3-propylene glycol is an important monomer for the production of poly(1,3-propylene terephthalate) (PTT). PTT combines the advantages of polyethylene terephthalate (PET) and polybutylene terephthalate (PBTE) and can be used to produce high-end plastic products. Therefore, the path to synthesize high-value-added 1,3-propylene glycol using glycerol obtained as a by-product of bio-jet fuel is proposed.

[0003] Currently, the industrial production methods of 1,3-propanediol include the ethylene oxide carbonylation hydrogenation method of Shell Company and the acrolein hydration hydrogenation method of Degussa and Dupont Company. However, the above production processes are complex, the reaction conditions are harsh, and the environmental pollution is serious. A generation path of converting glycerol into 1,3-propanediol through biological fermentation is reported in the literature (Appl. Microbiol. Biotechnol. 1992, 36, 592-597), however, the conversion efficiency is low due to the influence of biological metabolic activity, and the product contains vitamins, salts and other impurities, so that the separation energy consumption is very high. Based on this, the direct hydrogenolysis of glycerol to 1,3-propanediol has attracted unprecedented attention. At present, the path of glycerol producing 1,3-propanediol has been paid attention to, but there are still many problems, so this path has not been industrialized. CN201010262066.X discloses a Pt / WO3 / TiO2-SiO2 catalyst for preparing 1,3-propanediol by hydrogenation of glycerol; CN201110026988.5 discloses a catalyst for preparing 1,3-propanediol by direct hydrogenation of glycerol, which contains at least Pt, W, Ti, SiO2, and at least one of La, Ce, Sn, Re, Zr, Zn, Cu, Rh and Ru; CN201310637597.6 discloses a catalyst for preparing 1,3-propanediol by hydrogenation of glycerol, which uses SiO2 or HZSM-5 molecular sieve as the carrier and Re and Ir as the main active components, the glycerol conversion rate is less than 59%, and the 1,3-propanediol selectivity is up to 53%; CN201510933866.2 discloses a catalyst for preparing 1,3-propanediol by hydrogenolysis of glycerol, which includes a tungsten oxide-aluminum oxide (WO3-Al2O3) composite carrier and noble metal active components and transition metal components; CN201611127797.7 discloses a catalyst composed of a tungsten oxide carrier doped with transition metals such as Nb and Ta, and active components Pt, Pd or auxiliary metal; CN201710242714.7 discloses a catalyst for synthesizing 1,3-propanediol, which loads Pt nanoparticles on a composite carrier WO3-Al2O3-SiO2, the glycerol conversion rate is less than 50%, and the 1,3-propanediol selectivity is up to 56%; CN201710411402.4 discloses a catalyst loaded with Pt and WOx on SAPO-34, the glycerol conversion rate is less than 50%, and the 1,3-propanediol selectivity is less than 20%; CN201710499695.6 discloses a supported mesoporous molecular sieve catalyst Pt / W-Al-SBA-15; similar catalysts are also reported in the literature to different degrees.The literature (ACS Catal. 2020, 10, 15217-15226) reported a Pt / W / β (Beta) catalyst with an optimal glycerol conversion of 84% and an optimal 1,3-propylene glycol selectivity of 46%.

[0004] However, current catalysts still suffer from low conversion and selectivity. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of low conversion rate and low selectivity of existing catalysts, and to provide a catalyst and a preparation method thereof, and a method for preparing 1,3-propylene glycol.

[0006] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a catalyst, which includes a carrier, a first active component and a second active component loaded on the carrier; the carrier is a micro-meso-multilevel pore molecular sieve, the first active component is tungsten oxide, and the second active component is a nano-alloy; the nano-alloy is PtSn nano-alloy and / or PtLa nano-alloy; the mass ratio of the nano-alloy, tungsten oxide and micro-meso-multilevel pore molecular sieve is 1:(1-14):(25-200).

[0007] Optionally, the mass ratio of the nano alloy, tungsten oxide and micro-meso-hierarchical pore molecular sieve is preferably 1: (5-10): (50-100); in the PtSn nano alloy, the molar ratio of Pt to Sn is 1: (0.1-2); in the PtLa nano alloy, the molar ratio of Pt to La is 1: (0.1-2); the size of the nano alloy is 0.5-8 nm, preferably 2-6 nm; the specific surface area of ​​the micro-meso-hierarchical pore molecular sieve is 150-500 m 2 / g, a silicon-aluminum ratio of 5-100, and a pore size of 0.5-20nm; the micro-meso-hierarchical pore molecular sieve includes at least one of micro-meso-hierarchical pore Beta molecular sieve, micro-meso-hierarchical pore ZSM-5 molecular sieve, micro-meso-hierarchical pore Y molecular sieve and micro-meso-hierarchical pore mordenite.

[0008] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising:

[0009] S1. Impregnating a micro-meso-hierarchical pore molecular sieve loaded with tungsten oxide with a solution containing a nano-alloy, and then performing a first solid-liquid separation to obtain a first solid material; the nano-alloy is a PtSn nano-alloy and / or a PtLa nano-alloy; and the mass ratio of the nano-alloy, tungsten oxide, and micro-meso-hierarchical pore molecular sieve is 1:(1-14):(25-200);

[0010] S2. performing a first drying and a first calcination on the first solid material.

[0011] Optionally, in step S1, the mass ratio of the nanoalloy, tungsten oxide and micro-mesoporous molecular sieve is preferably 1:(5-10):(50-100); in the PtSn nanoalloy, the molar ratio of Pt to Sn is 1:(0.1-2); in the PtLa nanoalloy, the molar ratio of Pt to La is 1:(0.1-2); the size of the nanoalloy is 0.5-8nm, preferably 2-6nm; the solvent of the solution containing the nanoalloy is ethanol aqueous solution; in the ethanol aqueous solution, the volume fraction of ethanol is 80-99%; the pH value of the solution containing the nanoalloy is 8-11; in the solution containing the nanoalloy, the content of the nanoalloy is 0.1-2% by mass; in step S2, the first calcination temperature is 300-550°C, and the time is 2-8h.

[0012] Optionally, the method further includes: mixing a Pt source, an auxiliary metal source, a surfactant, an organic solvent, a base and water and heating and refluxing to prepare the nanoalloy; the auxiliary metal source includes a Sn source and / or a La source; relative to 100mL of water, the amount of the Pt source is 0.1-1g, the amount of the auxiliary metal source is 0.1-1g, the amount of the surfactant is 0.2-2g, the amount of the organic solvent is 20-500mL, and the amount of the base is 0.1-2g; the heating temperature is 100-200°C, and the reflux time is 1-5h.

[0013] Preferably, the Pt source is one of chloroplatinic acid solution, tetraammineplatinum nitrate, platinum chloride and platinum nitrate; the Sn source is at least one of stannous chloride dihydrate, tin tetrachloride, bis(acetylacetonate)tin dichloride and butyltin trichloride; the La source is at least one of lanthanum chloride, lanthanum nitrate hexahydrate, lanthanum carbonate and lanthanum sulfate; the surfactant is at least one of PVP, CTAB, oleylamine and sodium acetate; the organic solvent is at least one of ethanol, methanol, propanol and ethylene glycol; the alkali is at least one of sodium hydroxide, ammonia water, potassium hydroxide and sodium carbonate.

[0014] Optionally, the method further includes: impregnating the micro-meso-hierarchical pore molecular sieve with an aqueous solution of a tungsten-containing precursor and then performing a second solid-liquid separation to obtain a second solid material, and performing a second drying and a second calcination on the second solid material to prepare the micro-meso-hierarchical pore molecular sieve loaded with tungsten oxide; the tungsten-containing precursor is selected from at least one of sodium tungstate, ammonium paratungstate and ammonium metatungstate; the second calcination temperature is 400-700°C, and the time is 1-6h; the concentration of the tungsten-containing precursor in the aqueous solution of the tungsten-containing precursor is 1-20% by mass.

[0015] Optionally, the method further comprises: homogeneously reacting the microporous molecular sieve with an alkaline solution, then performing a third solid-liquid separation to obtain a third solid material, and performing a third drying and a third calcination on the third solid material to prepare the micro-meso-hierarchical pore molecular sieve;

[0016] The specific surface area of ​​the microporous molecular sieve is 200-650m 2 / g, a silicon-aluminum ratio of 5-100, a pore size of 0.3-1nm; the specific surface area of ​​the micro-meso-hierarchical pore molecular sieve is 150-500m 2 / g, a silicon-aluminum ratio of 5-100, and a pore size of 0.5-20nm; the microporous molecular sieve includes at least one of microporous Beta molecular sieve, microporous ZSM-5 molecular sieve, microporous Y molecular sieve and microporous mordenite; the micro-meso-hierarchical pore molecular sieve includes at least one of micro-meso-hierarchical pore Beta molecular sieve, micro-meso-hierarchical pore ZSM-5 molecular sieve, micro-meso-hierarchical pore Y molecular sieve and micro-meso-hierarchical pore mordenite;

[0017] The mass ratio of the microporous molecular sieve to the alkaline solution is 1:(10-50); the homogeneous reaction temperature is 50-150° C., and the reaction time is 6-36 hours; the third calcination temperature is 300-600° C., and the reaction time is 1-6 hours; the alkali in the alkaline solution is at least one of sodium hydroxide, potassium hydroxide, tetrapropylammonium hydroxide, and tetraethylammonium hydroxide; and the concentration of the alkali in the alkaline solution is 0.5-5% by mass.

[0018] The third aspect of the present invention provides a catalyst prepared by the method provided by the second aspect of the present invention.

[0019] A fourth aspect of the present invention provides a method for preparing 1,3-propylene glycol, comprising: contacting glycerol with the catalyst described in the third aspect of the present invention under hydrogenation conditions.

[0020] Optionally, the mass ratio of glycerol to the catalyst is 1:(0.01-0.3), preferably 1:(0.02-0.1); the hydrogenation conditions include: hydrogen pressure of 1-8 MPa, preferably 2-5 MPa, reaction temperature of 140-200°C, preferably 150-180°C, and reaction time of 6-24 h; glycerol is used in the form of a glycerol aqueous solution with a mass fraction of 5-90%, preferably in the form of a glycerol aqueous solution with a mass fraction of 10-50%.

[0021] Through the above technical solution, the catalyst of the present invention uses a structurally stable, water-resistant and high-temperature resistant molecular sieve as a carrier, which is subjected to mesoporous treatment, enhancing both stability and activity during the reaction. Unlike existing methods that use Pt salts as precursors for loading, the catalyst of the present invention is prepared through a series of pretreatment steps to synthesize PtSn and / or PtLa nanoalloys with narrow distributions, which are then loaded. This greatly enhances their hydrogen overflow capacity, improves activity and target product selectivity. In addition, the use of alkaline ethanol aqueous solution as a solvent during the nanoalloy loading process enhances the binding of the two active components, improving stability and enhancing activity.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a TEM image of the catalyst prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0026] The first aspect of the present invention provides a catalyst, which includes a carrier, a first active component loaded on the carrier, and a second active component; the carrier is a micro-meso-multilevel pore molecular sieve, the first active component is tungsten oxide, and the second active component is a nano-alloy; the nano-alloy is PtSn nano-alloy and / or PtLa nano-alloy; the mass ratio of the nano-alloy, tungsten oxide and micro-meso-multilevel pore molecular sieve is 1:(1-14):(25-200).

[0027] According to the present invention, optionally, the size of the nano alloy is 0.5-8 nm, preferably 2-6 nm. The catalytic activity of the nano alloy of suitable size is significantly higher than that of other sizes.

[0028] According to the present invention, optionally, the specific surface area of ​​the micro-meso-hierarchical pore molecular sieve can be 150-500m 2 / g, the silicon-aluminum ratio can be 5-100, and the pore size can be 0.5-20nm; the micro-meso-hierarchical pore molecular sieve includes at least one of micro-meso-hierarchical pore Beta molecular sieve, micro-meso-hierarchical pore ZSM-5 molecular sieve, micro-meso-hierarchical pore Y molecular sieve and micro-meso-hierarchical pore mordenite.

[0029] The inventors of the present invention discovered that by using a structurally stable, water-resistant, and high-temperature resistant microporous molecular sieve as a carrier and subjecting it to mesoporation, the resulting treated molecular sieve has micro-meso-multilevel pores. This not only stabilizes the Pt nanoparticles, but also enhances the contact probability between the two components, creating more Pt-W interfaces, while also enhancing stability during the reaction process and its activity. This makes the catalyst prepared using this carrier particularly suitable for catalyzing glycerol hydrogenation reactions, effectively improving the selectivity of the target product. The first active component, tungsten oxide, has strong aerobic properties, and highly dispersed tungsten oxide can efficiently and selectively activate secondary CO bonds in glycerol. The second active component, PtSn nanoalloy and / or PtLa nanoalloy, has a uniform nanometer size. The alloy components can improve the stability of the metal in high-temperature hydrothermal reaction environments and have a higher ability to activate hydrogen.

[0030] According to the present invention, the ratio of the support, the first active component, and the second active component optionally has a certain influence on the catalytic activity of the catalyst. In the present invention, the mass ratio of the nano-alloy, tungsten oxide, and micro-mesoporous molecular sieve is preferably 1:(5-10):(50-100). The above embodiment provides the catalyst with good catalytic activity.

[0031] According to the present invention, optionally, the molar ratio of Pt to Sn in the PtSn nanoalloy can be 1:(0.1-2); and the molar ratio of Pt to La in the PtLa nanoalloy can be 1:(0.1-2). The above embodiment can produce PtSn and / or PtLa nanoalloys with a narrow particle size distribution, enhance their hydrogen overflow capacity, and improve activity and target product selectivity.

[0032] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising:

[0033] S1. Impregnating a micro-meso-hierarchical pore molecular sieve loaded with tungsten oxide with a solution containing a nano-alloy, and then performing a first solid-liquid separation to obtain a first solid material; the nano-alloy is a PtSn nano-alloy and / or a PtLa nano-alloy; and the mass ratio of the nano-alloy, tungsten oxide, and micro-meso-hierarchical pore molecular sieve is 1:(1-14):(25-200);

[0034] S2. performing a first drying and a first calcination on the first solid material.

[0035] According to the present invention, optionally, in step S1, the mass ratio of the nano alloy, tungsten oxide and micro-meso-hierarchical pore molecular sieve can vary within a certain range. For example, the mass ratio of the nano alloy, tungsten oxide and micro-meso-hierarchical pore molecular sieve is preferably 1:(5-10):(50-100); in the PtSn nano alloy, the molar ratio of Pt to Sn can be 1:(0.1-2); in the PtLa nano alloy, the molar ratio of Pt to La can be 1:(0.1-2); the size of the nano alloy is 0.5-8 nm, preferably 2-6 nm.

[0036] According to the present invention, optionally, in step S1, the specific surface area of ​​the micro-meso-hierarchical pore molecular sieve can be 150-500m 2 / g, the silicon-aluminum ratio can be 5-100, and the pore size can be 0.5-20nm; the micro-meso-hierarchical pore molecular sieve includes at least one of micro-meso-hierarchical pore Beta molecular sieve, micro-meso-hierarchical pore ZSM-5 molecular sieve, micro-meso-hierarchical pore Y molecular sieve and micro-meso-hierarchical pore mordenite.

[0037] According to the present invention, the solvent for the nanoalloy solution can optionally be an ethanol-water solution; the volume fraction of ethanol in the ethanol-water solution can be 80-99%, and the pH of the nanoalloy solution can be 8-11. Using an ethanol-water solution as a solvent under alkaline conditions enhances the binding of the two active components, improving stability and enhancing activity. The nanoalloy content in the nanoalloy solution can be 0.1-2% by mass; within this range, uniformly sized, monodispersed nanoparticles can be synthesized.

[0038] According to the present invention, optionally, the first drying and first calcining are conventional steps for preparing the catalyst and are not particularly limited in the present invention. For example, in step S2, the conditions for the first drying can be: a temperature of 80-120°C and a time of 1-8 hours. The conditions for the first calcining can be: a temperature of 300-550°C and a time of 1-8 hours. Calcination can remove the surfactant from the outer layer of the PtSn nanoalloy and / or PtLa nanoalloy.

[0039] According to the present invention, optionally, the method further comprises: mixing a Pt source, an auxiliary metal source, a surfactant, an organic solvent, an alkali and water and heating and refluxing the mixture to prepare the nano alloy; the auxiliary metal source comprises a Sn source and / or a La source.

[0040] According to the present invention, optionally, relative to 100 mL of water, the amount of the Pt source can be 0.1-1 g, the amount of the auxiliary metal source can be 0.1-1 g, the amount of the surfactant can be 0.2-2 g, the amount of the organic solvent can be 20-500 mL, and the amount of the base can be 0.1-2 g; the heating temperature can be 100-200 ° C, and the reflux time can be 1-5 h; within the above conditions, nano-alloy particles of uniform size can be obtained.

[0041] According to the present invention, optionally, the Pt source can be one of chloroplatinic acid solution, tetraammineplatinum nitrate, platinum chloride and platinum nitrate. In a preferred embodiment, the Pt source is chloroplatinic acid solution; the Sn source can be at least one of stannous chloride dihydrate, tin tetrachloride, bis(acetylacetonate)tin dichloride and butyltin trichloride. In a preferred embodiment, the Sn source is stannous chloride dihydrate; the La source can be at least one of lanthanum chloride, lanthanum nitrate hexahydrate, lanthanum carbonate and lanthanum sulfate. In a preferred embodiment, the La source is lanthanum chloride. The surfactant is known in the art, for example, the surfactant can be at least one of PVP, CTAB, oleylamine and sodium acetate. In a preferred embodiment, the surfactant can be PVP; the organic solvent can be one known to those skilled in the art, for example, it can be at least one of ethanol, methanol, propanol and ethylene glycol. The present invention is preferably ethanol; the alkali is at least one of sodium hydroxide, ammonia water, potassium hydroxide and sodium carbonate. In a preferred embodiment, the alkali is sodium hydroxide. In the above embodiment, chloroplatinic acid solution is used as a Pt source, tin chloride dihydrate is used as a Sn source, and lanthanum chloride is used as a La source. The metal can be used as an oxidant and an organic solvent can be used as a reducing agent to synthesize PtSn and / or PtLa nanoalloys. The use of a surfactant can make the size of the synthesized nanoalloy particles uniform, which is beneficial to enhancing activity.

[0042] According to the present invention, optionally, the method further comprises: impregnating the micro-meso-hierarchical pore molecular sieve with a tungsten-containing precursor aqueous solution and then performing a second solid-liquid separation to obtain a second solid material, and performing a second drying and a second calcination on the second solid material to prepare the micro-meso-hierarchical pore molecular sieve loaded with tungsten oxide.

[0043] According to the present invention, the concentration of the tungsten-containing precursor in the aqueous tungsten-containing precursor solution can optionally be 1-20% by mass. Within this range, the loaded tungsten species can be more dispersed. The tungsten-containing precursor is selected from at least one of sodium tungstate, ammonium paratungstate, and ammonium metatungstate. In a preferred embodiment, the tungsten-containing precursor can be selected from sodium tungstate. The second calcination temperature can be 400-700°C, and the time can be 1-6 hours.

[0044] According to the present invention, optionally, the method further comprises: homogeneously reacting the microporous molecular sieve with an alkaline solution, then performing a third solid-liquid separation to obtain a third solid material, and performing a third drying and a third calcination on the third solid material to prepare the micro-mesoporous multi-level molecular sieve.

[0045] According to the present invention, optionally, the specific surface area of ​​the microporous molecular sieve can be 200-650m 2 / g, the silicon-aluminum ratio can be 5-100, the pore size can be 0.3-1nm; the specific surface area of ​​the micro-meso-hierarchical pore molecular sieve can be 150-500m 2 / g, the silicon-aluminum ratio can be 5-100, and the pore size can be 0.5-20nm; the microporous molecular sieve includes at least one of microporous Beta molecular sieve, microporous ZSM-5 molecular sieve, microporous Y molecular sieve and microporous mordenite; the micro-meso-multilevel pore molecular sieve includes at least one of micro-meso-multilevel pore Beta molecular sieve, micro-meso-multilevel pore ZSM-5 molecular sieve, micro-meso-multilevel pore Y molecular sieve and micro-meso-multilevel pore mordenite.

[0046] According to the present invention, optionally, the mass ratio of the microporous molecular sieve to the alkaline solution can vary within a certain range. In order to give full play to the optimal performance of the microporous molecular sieve, a suitable ratio of mesoporous conditions is provided. For example, the mass ratio of the microporous molecular sieve to the alkaline solution can be 1: (10-50). The alkali in the alkaline solution is at least one of sodium hydroxide, potassium hydroxide, tetrapropylammonium hydroxide and tetraethylammonium hydroxide; in the alkaline solution, the concentration of the alkali is 0.5-5% by mass. By treating the microporous molecular sieve with alkali, micro-meso-multilevel pores can be introduced into the microporous molecular sieve pore system, which not only enhances the stability during the reaction, but also enhances its activity. The homogeneous reaction temperature is 50-150°C and the time is 6-36h; the third drying and the third calcination are conventional steps for preparing molecular sieves, and the present invention has no special limitations. For example, the third drying temperature can be 80-150°C and the time is 4-18h; the third calcination temperature can be 300-600°C and the time is 1-6h.

[0047] The third aspect of the present invention provides a catalyst prepared by the method provided by the second aspect of the present invention.

[0048] A fourth aspect of the present invention provides a method for preparing 1,3-propylene glycol, comprising: contacting glycerol with the catalyst described in the third aspect of the present invention under hydrogenation conditions.

[0049] According to the present invention, the contacting can optionally be carried out in any reactor sufficient to allow the glycerol-containing feedstock to contact the catalyst under hydrogenation conditions for reaction, such as a fixed bed reactor or an autoclave reactor. The glycerol is used in the form of a 5-90% by mass glycerol aqueous solution, preferably a 10-50% by mass glycerol aqueous solution. The mass ratio of glycerol to the catalyst is 1:(0.01-0.3), preferably 1:(0.02-0.1). The hydrogenation conditions can be based on existing techniques. Taking the evaluation of an autoclave reactor as an example, the hydrogenation conditions may include: a hydrogen pressure of 1-8 MPa, preferably 2-5 MPa; a reaction temperature of 140-200°C, preferably 150-180°C; and a reaction time of 6-24 hours.

[0050] The catalyst of the present invention has high catalytic activity and 1,3-propylene glycol selectivity when used for preparing 1,3-propylene glycol. The glycerol conversion rate is 40-95%, and the 1,3-propylene glycol selectivity is 50-70%.

[0051] The present invention is further illustrated below by way of examples, but the present invention is not limited thereto.

[0052] Example 1

[0053] Weigh 6g of microporous Beta molecular sieve (specific surface area of ​​536m 2 / g, Si / Al ratio of 40, pore size of 0.7nm) was placed in a 100mL hydrothermal kettle, and 60mL of 0.15mol·L -1 NaOH solution, placed in a homogeneous reactor at 60 ° C for 6 hours, taken out and centrifuged, dried at 110 ° C for 8 hours, and then calcined at 550 ° C for 2 hours to obtain micro-meso-hierarchical pore Beta molecular sieve (specific surface area of ​​468m 2 / g, Si / Al ratio of 50, pore size of 3.8 nm), prepared in advance. 100 mL of water and 400 mL of ethanol were measured into a 1 L round-bottom flask, 0.16 g of 8% chloroplatinic acid solution, 0.12 g of stannous chloride dihydrate, 1.12 g of PVP, and 0.5 g of NaOH were weighed, stirred for 5 minutes, and then heated to 100°C, and refluxed for 3 hours under an argon atmosphere to obtain a PtSn nanometer alloy solution. Then, 100 mL of 1M hydrochloric acid solution was added, and after centrifugal separation, the product was washed with acetone and n-hexane three times and then separated for use. 1.07 g of sodium tungstate was dissolved in 5 mL of water to prepare a sodium tungstate aqueous solution, and then 6 g of micro-meso hierarchical pore Beta zeolite was added, stirred for 6 hours, dried at 80°C for 12 hours, and calcined at 600°C for 3 hours to obtain micro-meso hierarchical pore Beta zeolite loaded with 14% by weight of tungsten oxide. 0.09 g of PtSn nanometer alloy was dispersed in an ethanol / water (volume ratio of 9:1) solution by ultrasonic dispersion, 6 g of micro-meso hierarchical pore Beta zeolite loaded with 14% by weight of tungsten oxide was added, the pH of the solution was adjusted to 9 with ammonia water, stirred for 3 hours, and then centrifugally filtered, and then dried at 80°C for 8 hours and calcined at 500°C for 3 hours to obtain a final PtSn-WOx-Beta catalyst. The composition of the catalyst was 1.5% by weight of PtSn / 14% by weight of W-Beta on a dry basis, based on the metal elements, and the Pt:Sn atomic ratio in the PtSn alloy was 4:1, and the size of the PtSn alloy was 3 nm.

[0054] Example 2

[0055] The catalyst was prepared in the same manner as in Example 1, except that the amount of sodium tungstate was 0.54 g, and micro-meso hierarchical pore Beta zeolite loaded with 7% by weight of tungsten oxide was obtained. The composition of the catalyst was 1.5% by weight of PtSn / 7% by weight of W-Beta on a dry basis, based on the metal elements.

[0056] Example 3

[0057] The catalyst was prepared in the same manner as in Example 1, except that the amount of PtSn nanometer alloy was 0.18 g, and the composition of the catalyst was 3% by weight of PtSn / 14% by weight of W-Beta on a dry basis, based on the metal elements.

[0058] Example 4

[0059] The catalyst was prepared in the same manner as in Example 1, except that the amount of sodium tungstate was 0.8 g, and micro-meso hierarchical pore Beta zeolite loaded with 10% by weight of tungsten oxide was obtained. The amount of PtSn nanometer alloy was 0.12 g, and the composition of the catalyst was 2% by weight of PtSn / 10% by weight of W-Beta on a dry basis, based on the metal elements.

[0060] Example 5

[0061] The catalyst was prepared by the same method as in Example 1, except that the auxiliary metal source used was La source, the amount of chloroplatinic acid solution used was 0.18 g, the amount of lanthanum chloride used was 0.13 g, the Pt:La atomic ratio in the PtLa alloy was 9:1, and the size of the PtLa alloy was 3 nm.

[0062] Example 6

[0063] The catalyst was prepared by the same method as in Example 1, except that the micro-meso-hierarchical pore molecular sieve used was ZSM-5 (specific surface area of ​​450 m 2 / g, a silicon-aluminum ratio of 25, and a pore size of 4.2nm). Calculated as metal elements and based on the dry weight of the catalyst, the composition of the catalyst is 1.5 wt% PtSn / 14 wt% W-ZSM-5.

[0064] Example 7

[0065] The catalyst was prepared by the same method as in Example 1, except that when the PtSn alloy was loaded, the solvent used was a neutral anhydrous ethanol solution, and the size of the PtSn alloy was 5 nm.

[0066] Comparative Example 1

[0067] The catalyst was prepared by the same method as in Example 1, except that the Pt loading method was a conventional equal volume impregnation method.

[0068] Comparative Example 2

[0069] The catalyst was prepared by the same method as in Example 1, except that the microporous Beta molecular sieve carrier used was not subjected to mesoporation treatment.

[0070] Comparative Example 3

[0071] The catalyst was prepared using the same method as in Example 1, except that 5.35 g of sodium tungstate was used to obtain a micro-meso-hierarchical pore Beta molecular sieve loaded with 70 wt% tungsten oxide. The amount of PtSn nanoalloy used was 0.3 g. The catalyst composition, calculated as metal element and based on the dry weight of the catalyst, was 5 wt% PtSn / 70 wt% W-Beta.

[0072] Test Case

[0073] The catalytic activities of the catalysts prepared in Examples 1 to 7 and Comparative Examples 1 to 3 for preparing 1,3-propylene glycol were tested.

[0074] The catalysts obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were weighed separately and placed in a 50 mL autoclave reactor. 20 g of 10 wt% glycerol was added. The reaction temperature was set at 160° C. and the mixture was reacted for 12 h before centrifugation. The supernatant was taken and analyzed by gas chromatography. The test results are shown in Table 1.

[0075] Table 1

[0076]

[0077]

[0078] According to the above examples and comparative examples, the catalyst for preparing 1,3-propylene glycol by hydrogenolysis of glycerol synthesized by the present invention has the characteristics of high unit Pt space-time yield and high selectivity for 1,3-propylene glycol compared with the catalyst synthesized by the existing method, and has good industrial application value in the industrial synthesis of 1,3-propylene glycol from glycerol.

[0079] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0080] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0081] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A catalyst, characterized in that The catalyst comprises a carrier, a first active component supported on the carrier, and a second active component; the carrier is a micro-meso-hierarchical pore molecular sieve, the first active component is tungsten oxide, and the second active component is a nano alloy; the nano alloy is a PtSn nano alloy and / or a PtLa nano alloy; the mass ratio of the nano alloy, tungsten oxide, and micro-meso-hierarchical pore molecular sieve is 1:(1-14):(25-200); In the PtSn nanoalloy, the molar ratio of Pt to Sn is 1:(0.1-2); in the PtLa nanoalloy, the molar ratio of Pt to La is 1:(0.1-2); The size of the nano alloy is 0.5-8 nm; The specific surface area of ​​the micro-meso-hierarchical pore molecular sieve is 150-500m 2 / g, silicon-aluminum ratio of 5-100, pore size of 0.5-20nm; The microporous molecular sieve is homogeneously reacted with an alkaline solution, and then a third solid-liquid separation is performed to obtain a third solid material. The third solid material is subjected to a third drying and a third calcination to prepare the micro-meso-hierarchical pore molecular sieve.

2. The catalyst according to claim 1, wherein The mass ratio of the nano alloy, tungsten oxide and micro-meso-hierarchical pore molecular sieve is 1: (5-10): (50-100); The size of the nano alloy is 2-6 nm; The micro-meso-hierarchical pore molecular sieve includes at least one of micro-meso-hierarchical pore Beta molecular sieve, micro-meso-hierarchical pore ZSM-5 molecular sieve, micro-meso-hierarchical pore Y molecular sieve and micro-meso-hierarchical pore mordenite.

3. A method for preparing the catalyst according to any one of claims 1 to 2, characterized in that: The method includes: S1. impregnating a tungsten oxide-loaded micro-mesoporous molecular sieve with a solution containing a nano-alloy, and then performing a first solid-liquid separation to obtain a first solid material; homogeneously reacting the microporous molecular sieve with an alkaline solution, then performing a third solid-liquid separation to obtain a third solid material, and performing a third drying and a third calcination on the third solid material to prepare the micro-meso-hierarchical pore molecular sieve; The specific surface area of ​​the microporous molecular sieve is 200-650m 2 / g, silicon-aluminum ratio of 5-100, pore size of 0.3-1nm; S2. performing a first drying and a first calcination on the first solid material.

4. The method according to claim 3, wherein: In step S1, the solvent of the solution containing the nanoalloy is an ethanol aqueous solution; the volume fraction of ethanol in the ethanol aqueous solution is 80-99%; the pH value of the solution containing the nanoalloy is 8-11; the content of the nanoalloy in the solution containing the nanoalloy is 0.1-2% by mass; In step S2, the first calcination temperature is 300-550°C and the time is 2-8 hours.

5. The method according to claim 3 or 4, wherein: The method further comprises: mixing a Pt source, an auxiliary metal source, a surfactant, an organic solvent, an alkali and water and heating and refluxing the mixture to prepare the nano alloy; the auxiliary metal source comprises a Sn source and / or a La source; Relative to 100 mL of water, the amount of the Pt source is 0.1-1 g, the amount of the auxiliary metal source is 0.1-1 g, the amount of the surfactant is 0.2-2 g, the amount of the organic solvent is 20-500 mL, and the amount of the base is 0.1-2 g; The heating temperature is 100-200°C and the reflux time is 1-5h; The Pt source is one of chloroplatinic acid solution, tetraammineplatinum nitrate, platinum chloride and platinum nitrate; the Sn source is at least one of stannous chloride dihydrate, tin tetrachloride, bis(acetylacetonate)tin dichloride and butyltin trichloride; the La source is at least one of lanthanum chloride, lanthanum nitrate hexahydrate, lanthanum carbonate and lanthanum sulfate; the surfactant is at least one of PVP, CTAB, oleylamine and sodium acetate; the organic solvent is at least one of ethanol, methanol, propanol and ethylene glycol; and the alkali is at least one of sodium hydroxide, ammonia water, potassium hydroxide and sodium carbonate.

6. The method according to claim 3, wherein: The method further includes: impregnating the micro-meso-hierarchical pore molecular sieve with a tungsten-containing precursor aqueous solution and then performing a second solid-liquid separation to obtain a second solid material, and performing a second drying and a second calcination on the second solid material to prepare the micro-meso-hierarchical pore molecular sieve loaded with tungsten oxide; The tungsten-containing precursor is selected from at least one of sodium tungstate, ammonium paratungstate and ammonium metatungstate; the second calcination temperature is 400-700° C., and the time is 1-6 hours; the concentration of the tungsten-containing precursor in the tungsten-containing precursor aqueous solution is 1-20% by mass.

7. The method according to claim 3, wherein: The microporous molecular sieve comprises at least one of microporous Beta molecular sieve, microporous ZSM-5 molecular sieve, microporous Y molecular sieve and microporous mordenite; The mass ratio of the microporous molecular sieve to the alkaline solution is 1:(10-50); the homogeneous reaction temperature is 50-150°C, and the time is 6-36 hours; the third calcination temperature is 300-600°C, and the time is 1-6 hours; The alkali in the alkaline solution is at least one of sodium hydroxide, potassium hydroxide, tetrapropylammonium hydroxide and tetraethylammonium hydroxide; and the concentration of the alkali in the alkaline solution is 0.5-5% by mass.

8. A method for preparing 1,3-propylene glycol, characterized in that: The method comprises: contacting glycerol with the catalyst according to any one of claims 1 to 2 under hydrogenation conditions.

9. The method according to claim 8, wherein The mass ratio of glycerol to the catalyst is 1:(0.01-0.3); the hydrogenation conditions include: hydrogen pressure of 1-8 MPa, reaction temperature of 140-200° C., and reaction time of 6-24 hours; Glycerol is used in the form of a glycerol aqueous solution with a mass fraction of 5 to 90%.

10. The method according to claim 9, wherein: The mass ratio of glycerol to the catalyst is 1:(0.02-0.1); the hydrogen pressure is 2-5 MPa, and the reaction temperature is 150-180°C; Glycerol is used in the form of a 10 to 50% by mass glycerol aqueous solution.

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