A catalyst for glycerol synthesis of 1,3-propanediol, its preparation method and application

Abstract

The present disclosure relates to a catalyst for glycerol synthesis of 1,3-propanediol, and a preparation method and application thereof, the catalyst has a core-shell structure, the shell comprises a SiO2 nano-coating film, the core comprises a carrier and an active component supported on the carrier; the carrier comprises mesoporous WO x , 2≤x≤3; the active component comprises nano-Pt and / or nano-PtSn alloy; the average particle size of the nano-Pt is 2-8 nm, and the average particle size of the nano-PtSn alloy is 2-8 nm. The catalyst has a stable structure, the SiO2 nano-coating film can avoid aggregation and loss of the active component, and when it is applied to a reaction of glycerol hydrogenolysis to prepare 1,3-propanediol, high 1,3-propanediol selectivity and high stability can be achieved at low Pt content.

Description

Technical Field

[0001] This disclosure relates to the field of catalyst material synthesis, specifically to a catalyst for the synthesis of 1,3-propanediol from glycerol, its preparation method, and its application. Background Technology

[0002] As my country's economic, technological, and cultural influence continues to rise internationally, the requirements for green environmental protection and sustainable development have been placed on the agenda, attracting nationwide attention. Glycerin is a major byproduct of the production of bio-jet fuel from renewable animal and vegetable oils, accounting for as much as 10%. The effective utilization of glycerin, such as its use in the production of high-value-added high-end chemicals, is a good choice from the perspectives of economy, environmental protection, and resource recycling. Among these, the selective synthesis of high-value-added 1,3-propanediol from glycerin is one of the most economically promising and socially valuable pathways. 1,3-Propanediol is an important monomer for the production of poly(1,3-propanediol) terephthalate (PTT). PTT combines the advantages of easy processing of polyethylene terephthalate (PET) and high performance of polybutylene terephthalate (PBT), enabling the production of high-end plastic products and textiles. Therefore, utilizing glycerin, a byproduct of bio-jet fuel production, to synthesize high-value-added 1,3-propanediol aligns perfectly with my country's advocacy of a green, environmentally friendly, and sustainable development path.

[0003] Industrial production methods for 1,3-propanediol include Shell's ethylene oxide carbonylation hydrogenation method and Degussa and DuPont's acrolein hydration hydrogenation method. However, these methods suffer from complex processes, harsh reaction conditions, and severe environmental pollution. A literature report (Appl. Microbiol. Biotechnol. 1992, 36, 592-597) describes a method for the biochemical conversion of glycerol to 1,3-propanediol using Clostridiurn bacteria. However, this method is affected by the biochemical metabolic activity, resulting in low production efficiency and complex products containing vitamins, salts, and other impurities. Separation energy consumption accounts for a significant portion of the production cost. Therefore, the direct hydrogenolysis of glycerol to 1,3-propanediol offers a more optimized method and pathway for high-value-added conversion and upgrading.

[0004] However, current catalysts for the direct hydrogenolysis of glycerol to 1,3-propanediol still have the following problems: (1) The catalysts with good activity all use Pt as the main active component. In the reported catalysts, the Pt content is 2% to achieve a good catalytic effect. However, Pt is expensive. Reducing the Pt content in the catalyst without reducing the selectivity of 1,3-propanediol is of great importance to promoting its industrial application; (2) Both the active components W and Pt have the disadvantage of insufficient stability. The W component is easily leached under hydrothermal reaction conditions to form H. 2x WO 3-x Pt is a species that is prone to agglomeration and loss under hydrothermal reaction conditions, resulting in catalyst deactivation. Currently, publicly available and reported catalysts have problems with high Pt content and poor stability. Summary of the Invention

[0005] The purpose of this disclosure is to provide a catalyst for the synthesis of 1,3-propanediol from glycerol, its preparation method, and its application. The catalyst has good catalytic activity and high stability, and the product 1,3-propanediol has high selectivity.

[0006] To achieve the above objectives, the first aspect of this disclosure provides a catalyst for the synthesis of 1,3-propanediol from glycerol, the catalyst having a core-shell structure, the shell comprising a SiO2 nanofilm coating, and the core comprising a support and an active component loaded on the support;

[0007] The carrier includes mesoporous WO3 x , 2≤x≤3; the active component includes nano-Pt and / or nano-PtSn alloy;

[0008] The average particle size of the nano-Pt is 2-8 nm, and the average particle size of the nano-PtSn alloy is 2-8 nm.

[0009] Optionally, the thickness of the SiO2 nano-coated film is 5-100 nm, and the SiO2 nano-coated film has mesopores and / or micropores.

[0010] Optionally, the WO x The average particle size is 0.2-5 μm, and the specific surface area is 30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8cm³. 3 / g, the pore volume of the micropores is 0.1-0.4cm³. 3 / g, total pore volume is 0.2-1.2cm³ 3 / g.

[0011] Optionally, the catalyst has an average particle size of 0.2-5 μm and a specific surface area of ​​30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8cm³.3 / g, the pore volume of the micropores is 0.1-0.4cm³. 3 / g, total pore volume is 0.2-1.2cm³ 3 / g.

[0012] Optionally, the average particle size of the nano-Pt is 2-4 nm;

[0013] The average particle size of the nano-PtSn alloy is 2-4 nm.

[0014] Optionally, the content of the support is 50-95% by weight relative to the total weight of the catalyst;

[0015] In the catalyst, the content of Pt element is 0.5-4 wt% and the content of Sn element is 0-4 wt% relative to the total weight of the support.

[0016] A second aspect of this disclosure provides a method for preparing a catalyst for the synthesis of 1,3-propanediol from glycerol, the method comprising the following steps:

[0017] (1) The surface of the carrier was treated with aminosilane to obtain the treated carrier;

[0018] (2) Load the active component onto the treated carrier to obtain the first product;

[0019] (3) The first product, template agent, base source, silicon source and first solvent are subjected to a first contact reaction to obtain the second product;

[0020] (4) Heat treatment is performed on the second product;

[0021] The carrier includes mesoporous WO3 x , 2≤x≤3, the active component includes nano Pt and / or nano PtSn alloy.

[0022] Optionally, step (1) includes: subjecting the support, the aminosilane, and the second solvent to a second contact reaction to obtain the treated support;

[0023] The conditions for the second contact reaction include: a temperature of 60-120℃ and a time of 1-6 hours;

[0024] The second solvent includes one or more of ethanol, n-propanol, and isopropanol;

[0025] The aminosilane includes one or more of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and N-[3-(trimethoxysilyl)propyl]ethylenediamine, preferably 3-aminopropyltrimethoxysilane;

[0026] The weight ratio of the carrier, the aminosilane, and the second solvent is (0.5-1):(0.1-0.5):(50-300), preferably (0.8-1):(0.3-0.5):(100-200).

[0027] Optionally, step (2) includes: subjecting the treated carrier, the active component, and a third solvent to a third contact reaction to obtain the first product;

[0028] The duration of the third contact reaction is 1-8 hours;

[0029] The third solvent is a mixture of alcohol and water, wherein the volume ratio of alcohol to water is 1:(0.1-1);

[0030] The alcohol includes one or more of methanol, ethanol, propanol, and ethylene glycol;

[0031] The amount of the third solvent used is 20-200 mL relative to 1 g of the treated carrier;

[0032] The amount of the active component, calculated as Pt, is 0.5-4% by weight relative to the total weight of the treated carrier.

[0033] Optionally, in step (3), the weight ratio of the first product, the silicon source (based on silicon element), the template agent, the alkali source, and the first solvent is 1:(0.1-5):(0.2-2):(0.5-5):(20-200).

[0034] Optionally, the silicon source includes tetraethyl orthosilicate and / or methyl orthosilicate;

[0035] The alkaline source includes one or more of ammonia, sodium hydroxide, and potassium hydroxide;

[0036] The template agent includes one or more of the quaternary ammonium bromide salts having 15-20 carbon atoms;

[0037] Preferably, the template agent comprises hexadecyltrimethylammonium bromide and / or tetradecyltrimethylammonium bromide;

[0038] The first solvent includes one or more of water and saturated monohydric alcohols having 1-3 carbon atoms.

[0039] Optionally, the WO x The average particle size is 0.2-5 μm, and the specific surface area is 30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8cm³. 3 / g, the pore volume of the micropores is 0.1-0.4cm³. 3 / g, total pore volume is 0.2-1.2cm³3 / g.

[0040] Optionally, in step (3), the conditions for the first contact reaction include: a time of 1-12 hours and a temperature of 20-60°C.

[0041] Optionally, in step (4), the heat treatment method is calcination, and the calcination conditions include: a temperature of 300-600℃ and a time of 1-8h.

[0042] The third aspect of this disclosure provides a catalyst prepared using the method described in the second aspect of this disclosure.

[0043] The fourth aspect of this disclosure provides a method for synthesizing 1,3-propanediol from glycerol, the method comprising: reacting hydrogen, glycerol, with a catalyst as described in the first or third aspect of this disclosure.

[0044] Optionally, the method includes: contacting hydrogen, an aqueous glycerol solution, and the catalyst in a reactor at a reaction temperature of 120-200°C, a hydrogen pressure of 1-6 MPa, and a concentration of 5-90% by weight for the aqueous glycerol solution.

[0045] Optionally, the reactor is a batch reactor, the reaction time is 6-24 h, and the mass ratio of the catalyst to the glycerol is 1:(0.2-5); or,

[0046] The reactor is a fixed-bed reactor, and the weight hourly space velocity (WHSV) is 0.1-5 h⁻¹ based on the total weight of the glycerol. -1 The hydrogen flow rate is 50-200 mL / min.

[0047] Through the above technical solution, the catalyst disclosed herein is a mesoporous WO3 x Using nano-Pt and / or nano-PtSn alloys with specific average particle sizes as the active components, the catalyst has a more stable structure. The catalyst is coated and modified with SiO2 nanofilm to avoid aggregation and loss of active components. When applied to the reaction of glycerol hydrogenolysis to 1,3-propanediol, it can achieve high 1,3-propanediol selectivity and high stability at low Pt content.

[0048] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0049] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0050] Figure 1The images show TEM characterizations of the SiO2-coated catalyst prepared in Example 3 of this disclosure before and after coating. Detailed Implementation

[0051] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0052] The first aspect of this disclosure provides a catalyst for the synthesis of 1,3-propanediol from glycerol, the catalyst having a core-shell structure, the shell comprising a SiO2 nanofilm coating, and the core comprising a support and an active component loaded on the support;

[0053] The carrier includes mesoporous WO3 x , 2≤x≤3; the active component includes nano-Pt and / or nano-PtSn alloy;

[0054] The average particle size of the nano-Pt is 2-8 nm, and the average particle size of the nano-PtSn alloy is 2-8 nm.

[0055] In this disclosure, "mesoporous WO" x "Refers to WO with a mesoporous structure" x Furthermore, the pore volume of the mesopore is 0.05 cm³. 3 / g or above, WO x It may or may not have micropores.

[0056] The catalyst disclosed herein is a mesoporous WO3 x Using nano-Pt and / or nano-PtSn alloys as the active components makes the catalyst structure more stable; and using a SiO2 nano-coating film to coat the outer layer modifies the catalyst, which can prevent the aggregation and loss of active components and improve the stability of the catalyst under hydrothermal reaction conditions.

[0057] According to one embodiment of this disclosure, in order to obtain a catalyst with good cycle stability and good catalytic performance, the thickness of the SiO2 nano-coated film is 5-100 nm, preferably 10-50 nm, and more preferably 10-25 nm. The above thickness is measured by TEM. The SiO2 nano-coated film has mesopores and / or micropores.

[0058] According to this disclosure, the average particle size of nano-Pt is 2-4 nm, and the average particle size of nano-PtSn alloy is 2-4 nm. Pt nanoparticles and / or nano-PtSn of this size exhibit high catalytic activity and selectivity for the target product 1,3-propanediol.

[0059] According to this disclosure, the carrier WO xThe average particle size is 0.2-5 μm, and the specific surface area is 30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8cm³. 3 / g, the pore volume of the micropores is 0.1-0.4cm³. 3 / g, total pore volume is 0.2-1.2cm³ 3 / g; preferably, WO x The average particle size is 0.3-2 μm, and the specific surface area is 100-200 m². 2 / g, the pore volume of the mesoporous tissue is 0.2-0.5cm³. 3 / g, the pore volume of the micropores is 0.15-0.3cm³. 3 / g, total pore volume is 0.35-0.8cm³ 3 / g.

[0060] According to one embodiment of this disclosure, in the catalyst, the content of Pt element is 0.5-4 wt% and the content of Sn element is 0-4 wt% relative to the total weight of the support; the content of Pt element is preferably 0.5-3 wt%, more preferably 0.9-2 wt%; the content of Sn element is preferably 0.2-3 wt%, more preferably 0.5-2 wt%. The catalyst having the above element contents has the advantage of high selectivity for 1,3-propanediol.

[0061] According to one embodiment of this disclosure, in the catalyst, the content of the support is 50-95% by weight, preferably 60-80% by weight, relative to the total weight of the catalyst.

[0062] According to one embodiment of this disclosure, the catalyst has an average particle size of 0.2-5 μm and a specific surface area of ​​30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8cm³. 3 / g, the pore volume of the micropores is 0.1-0.4-cm³. 3 / g, total pore volume is 0.2-1.2cm³ 3 / g; preferably, the catalyst has an average particle size of 0.3-2μm and a specific surface area of ​​100-200m². 2 / g, the pore volume of the mesoporous tissue is 0.2-0.5cm³. 3 / g, the pore volume of the micropores is 0.15-0.3cm³. 3 / g, total pore volume is 0.35-0.8cm³ 3 / g.

[0063] A second aspect of this disclosure provides a catalyst for the synthesis of 1,3-propanediol from glycerol, the method comprising the following steps:

[0064] (1) The surface of the carrier was treated with aminosilane to obtain the treated carrier;

[0065] (2) Load the active component onto the treated carrier to obtain the first product;

[0066] (3) The first product, template agent, base source, silicon source and first solvent are subjected to a first contact reaction to obtain the second product;

[0067] (4) Heat treatment is performed on the second product;

[0068] The carrier includes mesoporous WO3 x , 2≤x≤3, the active component includes nano Pt and / or nano PtSn alloy.

[0069] According to one embodiment of this disclosure, mesoporous WO x (2≤x≤3) can be prepared using the following steps:

[0070] S1 mixes a tungsten source, porous silicon (KIT-6), and a fourth solvent;

[0071] Tungsten sources include one or more of phosphotungstic acid, sodium tungstate, and ammonium metatungstate;

[0072] The fourth solvent includes one or more of water, ethanol, and propanol;

[0073] The molar ratio of tungsten source, KIT-6 and fourth solvent, calculated as tungsten element, is 1:(10-200):(1000-20000);

[0074] S2 After drying the mixture obtained in step S1, heat it to 300-600℃ at a heating rate of 1-5℃ / min and calcine it for 1-8 hours. The drying method is conventional in the art, such as drying in a forced-air drying oven at a temperature of 80-120℃ for 6-12 hours.

[0075] S3. The product obtained in step S2 is cooled to room temperature (25±5℃), and then heated to 100-400℃ in an H2 / Ar atmosphere (H2 content is 4% by volume) at a heating rate of 1-5℃ / min, and calcined for 1-12h.

[0076] S4. The product obtained in step S3 is etched using an HF dilution solution (concentration of 0.1-1 mol / L) to obtain a mesoporous support WO. x (2≤x≤3).

[0077] According to one embodiment of this disclosure, nano-PtSn alloys and nano-Pt can be prepared using the following steps:

[0078] a. Mix the metal source, polyvinylpyrrolidone (PVP), and the fifth solvent, and stir until homogeneous;

[0079] The metal source is a platinum source and a tin source; or, the metal source is a platinum source; the platinum source includes one or more of chloroplatinic acid, platinum nitrate imine and potassium chloroplatinate. When the platinum source is chloroplatinic acid, it can be added in the form of an aqueous solution. The mass fraction of chloroplatinic acid is 0.5-5%. When the platinum source is added in the form of an aqueous solution, the weight of the platinum source is based on the weight of the platinum element in the platinum-containing substance.

[0080] Tin sources include stannous dichloride and / or stannous isooctanoate;

[0081] The fifth solvent can be a mixture of alcohol and water, with a volume ratio of alcohol to water of 1:(0.1-1). The alcohol can be one or more of methanol, ethanol, propanol, and ethylene glycol.

[0082] The metal sources are platinum and tin, with the weight ratio of platinum source (calculated as platinum element), tin source (calculated as tin element), polyvinylpyrrolidone, and the fifth solvent being 1:(0.1-1):(1-50):(5000-30000); or,

[0083] The metal source is a platinum source, and the weight ratio of platinum source, polyvinylpyrrolidone and fifth solvent, calculated as platinum element, is 1:(1-50):(5000-30000);

[0084] b. Reflux the mixture obtained in step a under an argon atmosphere for 0.5-6 hours at a temperature of 80-160℃ to obtain a solution containing the active component and the fifth solvent.

[0085] According to one embodiment of the present disclosure, step (1) includes: subjecting the support, aminosilane and a second solvent to a second contact reaction to obtain the treated support;

[0086] The conditions for the second contact reaction include: a temperature of 60-120℃ and a time of 1-6 hours;

[0087] The second solvent includes one or more of saturated monohydric alcohols having 1-3 carbon atoms, preferably one or more of ethanol, n-propanol and isopropanol.

[0088] The weight ratio of the carrier, aminosilane and the second solvent is (0.5-1):(0.1-0.5):(50-300), preferably (0.8-1):(0.3-0.5):(100-200).

[0089] According to one embodiment of the present disclosure, step (1) further includes: performing solid-liquid separation on the mixture obtained from the second contact reaction, and washing and drying the obtained solid to obtain the processed carrier; the solid-liquid separation method is conventional in the art, such as centrifugation or filtration; the drying method is conventional in the art, such as drying in a blower drying oven at a temperature of 80-120°C for 6-12 hours.

[0090] According to one embodiment of the present disclosure, step (2) includes: subjecting the treated carrier, the active component, and a third solvent to a third contact reaction to obtain the first product;

[0091] The conditions for the third contact reaction include: a time of 1-8 hours; and no specific restrictions on the temperature of the third contact reaction, for example, room temperature (25±5℃).

[0092] The third solvent can be a mixture of alcohol and water, with a volume ratio of alcohol to water of 1:(0.1-1). The alcohol can be one or more of methanol, ethanol, propanol, and ethylene glycol.

[0093] The amount of the third solvent used is 20-200 mL relative to 1 g of the treated carrier;

[0094] The amount of active component, calculated as Pt, is 0.5-4 wt%, 0.5-3 wt%, or more preferably 0.9-2 wt%, relative to the total weight of the treated carrier.

[0095] According to one embodiment of the present disclosure, step (2) includes: mixing the treated carrier with a solution containing the active component and a fifth solvent to carry out a third contact reaction to obtain a first product; at this time, the fifth solvent is the third solvent.

[0096] According to one embodiment of the present disclosure, step (2) further includes: performing solid-liquid separation on the mixture obtained from the third contact reaction, washing the obtained solid, and obtaining the first product; the solid-liquid separation method is conventional in the art, such as centrifugation; the drying method is conventional in the art, such as drying in a forced-air drying oven at a temperature of 80-120°C for 6-12 hours.

[0097] According to one embodiment of this disclosure, in step (3), the weight ratio of the first product, silicon source (based on silicon element), template agent, base source, and first solvent is 1:(0.1-5):(0.2-2):(0.5-5):(20-200); preferably 1:(1.5-4):(0.5-1):(1-2):(50-100). When the above range is met, the prepared catalyst can have a SiO2 nanofilm of suitable thickness, so that it can have both high cycling stability and high catalytic activity when applied to the reaction of glycerol to 1,3-propanediol.

[0098] In this disclosure, the template agent includes, but is not limited to, a template agent for forming mesopores, such as one or more of quaternary ammonium bromide salts having 15-20 carbon atoms. Preferably, the template agent includes hexadecyltrimethylammonium bromide and / or tetradecyltrimethylammonium bromide.

[0099] In this disclosure, the silicon source is conventional in the art and may include, for example, tetraethyl orthosilicate and / or methyl orthosilicate.

[0100] In this disclosure, the alkali source is used to hydrolyze the silicon source and can be conventional in the art, such as one or more of ammonia, sodium hydroxide, and potassium hydroxide. Sodium hydroxide and potassium hydroxide can be added as compounds or as aqueous solutions. When the alkali source is added in the form of an aqueous solution, the amount of alkali source added is based on the weight of the solute. For example, if the alkali source is ammonia, the amount of alkali source added is based on NH3.

[0101] According to one embodiment of this disclosure, the first solvent includes one or more of water and saturated monohydric alcohols having 1-3 carbon atoms.

[0102] According to one embodiment of this disclosure, in step (3), the conditions for the first contact reaction include: a time of 1-12 hours, preferably 4-6 hours; and a temperature of 20-60°C, preferably 20-40°C. Under these conditions, the synthesized shell has a uniform thickness and high catalyst activity.

[0103] According to one embodiment of the present disclosure, step (3) further includes: performing solid-liquid separation on the mixture obtained from the first contact reaction, and washing and drying the obtained solid to obtain a second product; the solid-liquid separation method is conventional in the art, such as centrifugation; the solvent used for washing is, for example, ethanol; the drying method is conventional in the art, such as drying in a forced-air drying oven at a temperature of 80-120°C for 6-12 hours.

[0104] According to one embodiment of this disclosure, in step (4), the heat treatment is calcination, and the calcination conditions include: a temperature of 300-600℃, preferably 400-500℃; and a time of 1-8h, preferably 2-3h. These treatment conditions can remove the existing template agent and aminosilane, and enhance the interaction between the active component and the support, thereby increasing the catalyst activity.

[0105] This disclosure provides a third aspect of a catalyst prepared using the method described in the second aspect of this disclosure. The catalyst described above has the same characteristics as the catalyst described in the first aspect of this disclosure, and will not be repeated here.

[0106] The fourth aspect of this disclosure provides a method for preparing 1,3-propanediol from glycerol, the method comprising: reacting hydrogen, glycerol, and a catalyst as described in the first or third aspect of this disclosure.

[0107] According to one embodiment of this disclosure, the method includes: contacting hydrogen, an aqueous glycerol solution, and a catalyst in a reactor at a reaction temperature of 120-200°C, preferably 120-180°C, more preferably 150-160°C; a hydrogen pressure of 1-6 MPa, preferably 2-4 MPa; and a glycerol aqueous solution concentration of 5-90% by weight, preferably 10-60% by weight, more preferably 30-50% by weight.

[0108] According to one embodiment of this disclosure, the reactor is a batch reactor, the reaction time is 6-24h, preferably 12-24h; the mass ratio of catalyst to glycerol is 1:(0.2-5), preferably 1:(1-2).

[0109] According to one embodiment of this disclosure, the reactor is a fixed-bed reactor, and the weight hourly space velocity (WHSV) is 0.1-5 h⁻¹ based on the total weight of glycerol. -1 Preferably 0.5-2h -1 The hydrogen flow rate is 50-200 mL / min, preferably 80-150 mL / min.

[0110] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0111] All raw materials used in the examples and comparative examples were obtained commercially and, unless otherwise specified, were of analytical grade.

[0112] Methods and instruments for measuring average particle size: transmission electron microscopy (TEM).

[0113] Methods and instruments for testing specific surface area: N2 adsorption-desorption analysis (fully automated specific surface area and pore adsorption instrument).

[0114] Methods, instruments and conditions for pore volume testing: N2 adsorption-desorption analysis (fully automated specific surface area and pore adsorption instrument).

[0115] Methods and instruments for measuring the thickness of SiO2 nanofilms: transmission electron microscopy (TEM).

[0116] Methods and instruments for testing elemental and component content: X-ray fluorescence spectroscopy (XRF).

[0117] Example 1

[0118] Catalyst A1 was prepared using the following steps:

[0119] (1) Dissolve phosphotungstic acid in ethanol (60 mL) and add KIT-6 while stirring; dry the mixture at 100 °C for 8 h, then heat it to 550 °C at a heating rate of 1 °C / min and calcine for 3 h; cool the obtained solid to room temperature, then heat it to 400 °C at a heating rate of 1 °C / min and calcine for 3 h in an H2 / Ar atmosphere (H2 content is 4 vol%); etch the obtained solid with 50 mL of 0.5 mol / L HF dilution solution to obtain mesoporous WO3. x (2≤x≤3);

[0120] The molar ratio of phosphotungstic acid, KIT-6 and ethanol, calculated as tungsten, is 1:50:1000;

[0121] (2) Measure 100 mL of water and 400 mL of ethanol as a mixed solvent and place them in a 1 L round bottom flask. Weigh 8% chloroplatinic acid solution, stannous chloride dihydrate and PVP (polyvinylpyrrolidone), stir for 5 min, then heat to 100 °C and reflux for 3 h under argon atmosphere to obtain a solution containing nano PtSn alloy.

[0122] The weight ratio of platinum source (calculated as platinum element), tin source (calculated as tin element), polyvinylpyrrolidone, and mixed solvent is 1:1:1.2:8000;

[0123] In the mixed solvent, the volume ratio of ethanol to water is 1:0.25;

[0124] (3) Take 5g of the mesoporous WO3 prepared in step (1) x The carrier was dispersed in isopropanol, and aminosilane (3-aminopropyltrimethoxysilane) was added. The mixture was then heated to 80°C, stirred for 2 hours, filtered, and dried at 100°C for 8 hours to obtain the treated carrier.

[0125] Mesoporous WO x The weight ratio of 3-aminopropyltrimethoxysilane to isopropanol is 1:0.4:100;

[0126] (4) Mix 5g of the treated carrier with the PtSn nano-alloy solution prepared in step (2), stir at room temperature for 3h, centrifuge, and dry at 100℃ for 6h to obtain the first product;

[0127] The amount of active component, calculated as Pt, is 1% by weight relative to the total weight of the treated carrier.

[0128] The volume of the mixed solvent used is 100 mL relative to 1 g of the treated carrier;

[0129] (5) The first product was dispersed in ethanol, and then hexadecyltrimethylammonium bromide, tetraethyl orthosilicate (TEOS) and ammonia were added. The mixture was stirred at room temperature (25°C) for 4.5 h, filtered to obtain a solid and washed three times with ethanol. The solid was then dried at 120°C for 12 h and calcined at 500°C for 3 h to obtain catalyst A1 with nano-PtSn alloy as active component.

[0130] The weight ratio of the first product, silicon source (calculated as silicon element), template agent, base source, and ethanol is 1:1.8:1:1.5:100.

[0131] Weigh 2g of the catalyst A1 obtained above and place it in a 50mL batch reactor. Add 10g of 20% glycerol aqueous solution. Under the conditions of reaction temperature of 160℃ and hydrogen pressure of 4MPa, after 24h of reaction, centrifuge and separate the supernatant. Perform gas chromatography analysis. The reaction results are listed in Table 1.

[0132] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 1.

[0133] Example 2

[0134] Catalyst A2, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted to produce 1,3-propanediol from glycerol. The difference was that in step (3), the amount of active component, calculated as Pt element, was 0.8% by weight relative to the total weight of the treated support. The catalyst parameters and reaction results are listed in Table 1.

[0135] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 1.

[0136] Example 3

[0137] The catalyst with nano-Pt as the active component was prepared by the method of Example 1, and A3 was used to prepare 1,3-propanediol from glycerol. The difference was that no tin source was added in step (2). The parameters and results of the catalyst are listed in Table 1.

[0138] The TEM characterization results of the catalyst in Example 3 before (left) and after (right) SiO2 coating are as follows: Figure 1 As shown.

[0139] Example 4

[0140] Catalyst A4, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The difference was that the amount of tetraethyl orthosilicate added was half that of Example 1. The catalyst parameters and reaction results are listed in Table 1.

[0141] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 1.

[0142] Example 5

[0143] Catalyst A5, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The difference was that the amount of tetraethyl orthosilicate added was 2.5 times that of Example 1. The catalyst parameters and reaction results are listed in Table 1.

[0144] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 1.

[0145] Example 6

[0146] Catalyst A6, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The difference was that ethanol in step (2) was replaced with an equal weight of methanol. The catalyst parameters and reaction results are listed in Table 1.

[0147] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 1.

[0148] Example 7

[0149] The reaction to prepare 1,3-propanediol from glycerol was carried out using the catalyst A1 and method of Example 1. The difference was that 1g of the catalyst A1 obtained above was weighed and placed in a 50mL batch reactor, and 20g of 10% glycerol aqueous solution was added. The reaction was carried out at a temperature of 170°C and a hydrogen pressure of 2MPa for 18 hours. After centrifugation, the supernatant was collected and analyzed by gas chromatography. The reaction results are listed in Table 2.

[0150] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0151] Example 8

[0152] The reaction for preparing 1,3-propanediol from glycerol was carried out using catalyst A1 from Example 1. The specific steps were as follows: 1 g of catalyst was placed in a fixed-bed reactor, and the reaction was carried out at 160°C, 4 MPa pressure, and 50% (w / w) glycerol aqueous solution for 1 hour. -1 The reaction was carried out under conditions of weight hourly space velocity and hydrogen flow rate of 100 mL / min. The sample was collected after 8 h of reaction and analyzed by gas chromatography. The reaction results are listed in Table 2.

[0153] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0154] Example 9

[0155] Catalyst A7, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted to produce 1,3-propanediol from glycerol. The difference was that in step (5), the calcination temperature was 600℃ and the time was 8h. The parameters of the catalyst and the reaction results are listed in Table 2.

[0156] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0157] Example 10

[0158] Catalyst A8, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The parameters of the catalyst and the reaction results are listed in Table 2. The difference is that in step (4), the amount of active component based on Pt element was 3.5% by weight relative to the total weight of the treated support, and the mass ratio of platinum source based on Pt element to tin source based on Sn element was 1:0.30.

[0159] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0160] Example 11

[0161] Catalyst A9, with nano-PtSn alloy as the active component, was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The catalyst parameters and reaction results are listed in Table 2. The difference is that step (3) is: the mesoporous WO3 prepared in step (1) is used as the catalyst. x Dispersed in ethanol, 3-aminopropyltrimethoxysilane was added and heated to 60°C, stirred for 6 h, filtered, and dried at 120°C for 6 h to obtain the treated carrier;

[0162] Mesoporous WO x The weight ratio of 3-aminopropyltrimethoxysilane to ethanol is 1:0.3:80.

[0163] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0164] The silica coating of the catalysts prepared in Examples 1-11 has mesopores and micropores.

[0165] Comparative Example 1

[0166] Catalyst D1 was prepared using the method of Example 1 and reacted to prepare 1,3-propanediol from glycerol. The difference was that in step (4), the active component was loaded using the equal volume impregnation method, and step (5) was not performed. The parameters of the catalyst and the reaction results are listed in Table 2.

[0167] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0168] Comparative Example 2

[0169] Catalyst D2, with nano-Pt as the active component, was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The difference was that step (5) was not performed. The parameters of the catalyst and the reaction results are listed in Table 2.

[0170] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0171] Comparative Example 3

[0172] Catalyst D3 with nano-Pt as the active component was prepared using the method of Example 1 and reacted with glycerol to produce 1,3-propanediol. The difference was that the surface treatment of the support in step (3) was not performed. The parameters of the catalyst and the reaction results are listed in Table 2.

[0173] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0174] Comparative Example 4

[0175] Catalyst D4, with nano-Pt as the active component, was prepared using the method in Example 1 and then reacted with glycerol to produce 1,3-propanediol. The difference was that in step (1), KIT-6 was not added and the etching step with HF dilution solution was not performed. The resulting support was microporous WO4. x (2≤x≤3), the catalyst parameters and reaction results are listed in Table 2.

[0176] After the reaction was completed, the catalyst was removed, washed and dried, and a second reaction was carried out under the same conditions. The results are listed in Table 2.

[0177] Table 1

[0178]

[0179]

[0180]

[0181] Table 2

[0182]

[0183]

[0184]

[0185] As can be seen from the data in Tables 1 and 2, the reaction of glycerol to 1,3-propanetriol using the embodiments of this disclosure can achieve a high conversion rate and 1,3-propanediol selectivity, and can still achieve high catalytic activity when recycled.

[0186] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0187] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0188] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A catalyst for the synthesis of 1,3-propanediol from glycerol, characterized in that, The catalyst has a core-shell structure, wherein the shell comprises a SiO2 nanofilm coating, and the core comprises a support and an active component loaded on the support; The carrier includes mesoporous WO3 x , 2≤x≤3; the active component includes nano-Pt and / or nano-PtSn alloy; The average particle size of the nano-Pt is 2-8 nm, and the average particle size of the nano-PtSn alloy is 2-8 nm. The SiO2 nano-coating film has mesopores and / or micropores.

2. The catalyst according to claim 1, wherein, The thickness of the SiO2 nanofilm is 5-100 nm.

3. The catalyst according to claim 1, wherein, The WO x The average particle size is 0.2-5 μm, and the specific surface area is 30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8 cm³. 3 / g, the pore volume of the micropores is 0.1-0.4 cm³. 3 / g, total pore volume is 0.2-1.2cm³ 3 / g.

4. The catalyst according to claim 1, wherein, The catalyst has an average particle size of 0.2-5 μm and a specific surface area of ​​30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8cm³. 3 / g, the pore volume of the micropores is 0.1-0.4cm³. 3 / g, total pore volume is 0.2-1.2cm³ 3 / g.

5. The catalyst according to claim 1, wherein, The average particle size of the nano-Pt is 2-4 nm; The average particle size of the nano-PtSn alloy is 2-4 nm.

6. The catalyst according to claim 1, wherein, The content of the support is 50-95% by weight relative to the total weight of the catalyst. In the catalyst, the content of Pt element is 0.5-4 wt% and the content of Sn element is 0-4 wt% relative to the total weight of the support.

7. A method for preparing the catalyst for the synthesis of 1,3-propanediol from glycerol according to any one of claims 1 to 6, characterized in that, The method includes the following steps: (1) The surface of the carrier is treated with aminosilane to obtain the treated carrier; (2) The active component is loaded onto the treated support to obtain the first product; (3) The first product, template agent, base source, silicon source and first solvent are subjected to a first contact reaction to obtain the second product; (4) Heat treatment is performed on the second product.

8. The method according to claim 7, wherein, Step (1) includes: subjecting the support, the aminosilane, and a second solvent to a second contact reaction to obtain the treated support; The conditions for the second contact reaction include: a temperature of 60-120℃ and a time of 1-6 hours; The second solvent includes one or more of ethanol, n-propanol, and isopropanol; The aminosilane includes one or more of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-[3-(trimethoxysilyl)propyl]ethylenediamine; The weight ratio of the carrier, the aminosilane, and the second solvent is (0.5-1):(0.1-0.5):(50-300).

9. The method according to claim 7, wherein, The aminosilane is 3-aminopropyltrimethoxysilane.

10. The method according to claim 8, wherein, The weight ratio of the carrier, the aminosilane, and the second solvent is (0.8-1):(0.3-0.5):(100-200).

11. The method according to claim 7, wherein, Step (2) includes: subjecting the treated carrier, the active component, and a third solvent to a third contact reaction to obtain the first product; The duration of the third contact reaction is 1-8 hours; The third solvent is a mixture of alcohol and water, wherein the volume ratio of alcohol to water is 1:(0.1-1). The alcohol includes one or more of methanol, ethanol, propanol, and ethylene glycol; The amount of the third solvent used is 20-200 mL relative to 1 g of the treated carrier; The amount of the active component, calculated as Pt, is 0.5-4% by weight relative to the total weight of the treated carrier.

12. The method according to claim 7, wherein, In step (3), the weight ratio of the first product, the silicon source (based on silicon element), the template agent, the alkali source and the first solvent is 1:(0.1-5):(0.2-2):(0.5-5):(20-200).

13. The method according to claim 7, wherein, The silicon source includes tetraethyl orthosilicate and / or methyl orthosilicate; The alkaline source includes one or more of ammonia, sodium hydroxide, and potassium hydroxide; The template agent includes one or more of the quaternary ammonium bromide salts having 15-20 carbon atoms; The first solvent includes one or more of water and saturated monohydric alcohols having 1-3 carbon atoms.

14. The method according to claim 7, wherein, The template agent comprises hexadecyltrimethylammonium bromide and / or tetradecyltrimethylammonium bromide.

15. The method according to claim 7, wherein, The WO x The average particle size is 0.2-5 μm, and the specific surface area is 30-300 m². 2 / g, the pore volume of the mesoporous tissue is 0.1-0.8 cm³. 3 / g, the pore volume of the micropores is 0.1-0.4 cm³. 3 / g, total pore volume is 0.2-1.2 cm³ 3 / g.

16. The method according to claim 7, wherein, In step (3), the conditions for the first contact reaction include: a time of 1-12 hours and a temperature of 20-60°C.

17. The method according to claim 7, wherein, In step (4), the heat treatment method is calcination, and the calcination conditions include: temperature of 300-600℃ and time of 1-8h.

18. A method for synthesizing 1,3-propanediol from glycerol, characterized in that, The method includes reacting hydrogen, glycerol, and the catalyst described in any one of claims 1-6.

19. The method according to claim 18, wherein, The method includes: contacting hydrogen, an aqueous glycerol solution, and the catalyst in a reactor for reaction at a reaction temperature of 120-200°C, a hydrogen pressure of 1-6 MPa, and a concentration of 5-90% by weight of the aqueous glycerol solution.

20. The method according to claim 19, wherein, The reactor is a batch reactor, the reaction time is 6-24 hours, and the mass ratio of the catalyst to the glycerol is 1:(0.2-5); or, The reactor is a fixed-bed reactor, and the weight hourly space velocity (WHSV) is 0.1-5 h⁻¹ based on the total weight of the glycerol. -1 The hydrogen flow rate is 50-200 mL / min.

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