Supported hydrogenation catalyst, process for its preparation and use thereof

Abstract

The application relates to the technical field of catalyst preparation, and discloses a supported hydrogenation catalyst and a preparation method and application thereof. The catalyst comprises a group VIII metal element, at least one group VIB metal element and an organic silicon surface modifier, the content of the group VIII metal element is 0.5-2% of the carrier mass in terms of elements, the content of the group VIB metal element is 0.5-1% of the carrier mass in terms of elements, and the content of the organic silicon surface modifier is 1-10% of the carrier mass. The catalyst has good reaction activity and selectivity, and the catalyst is especially suitable for glycerol hydrogenation refining reaction, and can effectively improve the catalytic efficiency of the catalyst and the selectivity of the target product.

Description

Technical Field

[0001] This invention relates to the technical field of catalyst preparation, specifically to a supported catalyst, its preparation method, and its application. Background Technology

[0002] With the rapid development of new energy vehicles, sales of refined oil products are gradually reaching their peak. Given the overcapacity in oil refining, the trend of thinning profits is inevitable, making the shift towards producing high-end chemical products an inevitable development trend.

[0003] In 1995, Shell Chemical Company in the United States successfully developed a new type of polyester fiber material, polypropylene terephthalate (PTT), through the polycondensation of 1,3-propanediol and terephthalic acid. Due to the "unique carbon effect" of 1,3-propanediol, the fibers are arranged in a helical shape, giving PTT fibers good elasticity, dyeing properties, and processability, classifying them as high-end chemical products. Thanks to its excellent performance, global demand for PTT fibers has been increasing year by year; however, limited by the production capacity of 1,3-propanediol, the market has consistently been in a state of supply shortage. The production of biodiesel produces a large amount of glycerol as a byproduct, and the high-value utilization of glycerol has always been a focus. Using glycerol as a raw material to produce 1,3-propanediol via chemical methods has become a research hotspot in recent years because, compared to the lower production capacity of biological methods, chemical methods can significantly increase the yield of 1,3-propanediol. Among the chemical methods for producing 1,3-propanediol, the glycerol hydrogenation route has advantages such as mild conditions and simple steps. However, the catalysts required for this route are expensive due to the use of the precious metal Pt and their low activity, preventing them from reaching industrial application levels. Improving catalyst selectivity is one effective way to reduce catalyst costs, which depends on a deep understanding of the reaction mechanism of glycerol hydrogenolysis to 1,3-propanediol. Therefore, developing a technology for selective glycerol hydrogenation to 1,3-propanediol has high economic benefits. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of poor activity and selectivity of glycerol selective hydrogenation catalysts in the prior art, and to provide a supported hydrogenation catalyst, its preparation method and application. This catalyst is used in the hydrogenation of glycerol to 1,3-propanediol to improve the selectivity of the glycerol selective hydrogenation reaction.

[0005] To achieve the above objectives, a first aspect of the present invention provides a supported hydrogenation catalyst, wherein the catalyst comprises a support and at least one Group VIII metal element, at least one Group VIB metal element, and an organosilicon surface modifier supported on the support; wherein the content of the Group VIII metal element is 0.5-2% of the mass of the support, the content of the Group VIB metal element is 0.5-1% of the mass of the support, and the content of the organosilicon surface modifier is 1-10% of the mass of the support.

[0006] Preferably, the relative hydrophilicity parameter n of the catalyst is 0.6-0.95, and more preferably 0.7-0.95.

[0007] A second aspect of the present invention provides a method for preparing the supported hydrogenation catalyst described in the first aspect, wherein the method comprises:

[0008] (1) The precursors of Group VIII and Group VIB metal elements were introduced into the support by impregnation, followed by drying and calcination to obtain the catalyst precursor;

[0009] (2) The catalyst precursor was impregnated with an organosilicon surface modifier solution and then modified to obtain the catalyst.

[0010] The third aspect of this invention provides the application of the supported hydrogenation catalyst described in the first aspect in the selective hydrogenation purification reaction of glycerol.

[0011] Preferably, the selective hydrogenation purification reaction of glycerol is a selective hydrogenation reaction of glycerol to 1,3-propanediol.

[0012] The supported hydrogenation catalyst provided by this invention exhibits excellent reactivity, slight hydrophobicity, and stability. When used in the hydrogenation refining reaction of glycerol (preferably the selective hydrogenation refining of glycerol to 1,3-propanediol), the addition of an organosilicon surface modifier, along with the support and Group VIII and Group VIB metal elements, allows the catalyst to adjust the adsorption mode of glycerol molecules on the catalyst surface during the reaction, effectively improving the catalytic efficiency and the selectivity of the target product. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of in-situ infrared characterization of Embodiment 1 of the present invention;

[0014] Figure 2 This is a schematic diagram of the in-situ infrared characterization of Comparative Example 1 of the present invention. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] The first aspect of the present invention provides a supported hydrogenation catalyst, wherein the catalyst comprises a support and at least one Group VIII metal element, at least one Group VIB metal element, and an organosilicon surface modifier supported on the support; wherein the content of the Group VIII metal element is 0.5-2% of the mass of the support, the content of the Group VIB metal element is 0.5-1% of the mass of the support, and the content of the organosilicon surface modifier is 1-10% of the mass of the support.

[0017] In a preferred embodiment, the content of the Group VIII metal element, calculated as an element, is 1-2% of the carrier mass; the content of the Group VIB metal element, calculated as an element, is 0.5-0.75% of the carrier mass; and the content of the organosilicon surface modifier is 1-6% of the carrier mass. The advantage of this preferred embodiment is that it balances the micro-hydrophobic properties of the catalyst surface with the hydrophilic properties required for reactant adsorption on the catalyst surface, improves the adsorption-desorption behavior of the reaction product, and enhances the selectivity and yield of the target product, 1,3-propanediol.

[0018] In this invention, the contents of Group VIII and Group VIB metal elements are measured by X-ray fluorescence spectrometry. The specific test conditions are as follows: (1) Start the instrument, turn on the water-cooled circulation box, and preheat for about 30 minutes until the instrument is stable; (2) Turn on the computer and operating software, set the gas pressure at the gas cylinder pressure reducing valve to 0.25 bar, and set the flow rate of the argon-methane mixture to 6 mL / min; (3) Select the established standard curve corresponding method, put the powder sample into the sample introduction device after sample preparation, and start the analysis.

[0019] In a preferred embodiment, the relative hydrophilicity parameter n of the catalyst is preferably 0.6-0.95, more preferably 0.7-0.95, and can be, for example, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or any value between any two sets of data. The advantage of this preferred embodiment is that precise control of the degree of micro-hydrophobicity can promote product desorption and inhibit secondary transformation of the reaction products.

[0020] In this invention, the relative hydrophilicity parameter n = the hydrophilicity parameter of the modified catalyst / the hydrophilicity parameter of the unmodified catalyst. It is understood that the catalyst prepared according to the method in Comparative Example 1 (i.e., the unmodified catalyst) is defined as the reference sample, and the relative hydrophilicity parameter n is calculated accordingly. The hydrophilicity parameters of the modified and unmodified catalysts refer to the hydroxyl peaks observed at a wavelength of 3745 nm as determined by in-situ infrared characterization, and the peak area is measured.

[0021] Specifically, the conditions for in-situ infrared characterization include: (1) weighing 0.02g of catalyst and performing tableting; (2) placing the catalyst tablet sample in the original infrared sample cell for vacuum treatment; (3) heating to 450℃ in 30 minutes and maintaining a negative pressure state for 4 hours; (4) performing sampling operations to collect data.

[0022] In a preferred embodiment, the support comprises at least one of molecular sieve and heat-resistant inorganic oxide.

[0023] In a preferred embodiment, the support comprises a molecular sieve and optionally a heat-resistant inorganic oxide.

[0024] In this invention, the type of molecular sieve is not particularly limited. Preferably, the molecular sieve is a silica-alumina molecular sieve, and more preferably, at least one of Beta molecular sieve, Y-type molecular sieve, and ZSM-5 molecular sieve. The advantage of this preferred embodiment is that the unique pore structure and large specific surface area of ​​the molecular sieve support facilitate the dispersion of active metals and the attack of active hydrogen species on active metals and adsorbed glycerol molecules, thereby improving the activity of the catalyst.

[0025] In a preferred embodiment, the silicon-to-aluminum molar ratio of the molecular sieve is 0-200, preferably 15-100. It should be understood that the silicon-to-aluminum molar ratio refers to the silicon-to-aluminum atomic ratio in this invention.

[0026] In this invention, there is no particular limitation on the type of heat-resistant inorganic oxide; all heat-resistant inorganic oxide matrices conventionally defined in the art are applicable to this invention. Preferably, the heat-resistant inorganic oxide is selected from at least one of alumina, magnesium oxide, titanium oxide, and zirconium oxide.

[0027] In this invention, there is no particular limitation on the content of each substance in the carrier. Preferably, based on the total amount of the carrier, the content of the silica-alumina molecular sieve is not less than 70% by mass, and the content of the heat-resistant inorganic oxide is 0-30% by mass.

[0028] In a preferred embodiment, the carrier is a silica-alumina molecular sieve.

[0029] In this invention, the use of silica-alumina molecular sieves as a support enables the catalyst to achieve high hydrothermal stability.

[0030] In this invention, there is no particular limitation on the specific types of Group VIII metal elements; all Group VIII metals conventionally defined in the art are applicable to this invention. Preferably, the Group VIII metal element is a noble metal, more preferably Pt and / or Pd, and even more preferably Pt. The advantages of this preferred embodiment are its strong ability to dissociate hydrogen at low temperatures and its strong ability to activate non-noble metals using the overflow hydrogen effect.

[0031] In this invention, there is no particular limitation on the specific types of Group VIB metal elements; all Group VIB metals conventionally defined in the art are applicable to this invention. Preferably, the Group VIB metal element is Mo and / or W, and more preferably W.

[0032] In a preferred embodiment, the organosilicon surface modifier is selected from at least one organosilicon compound.

[0033] In a preferred embodiment, the silicon atoms in the organosilicon compound are directly bonded to at least one alkoxy group and at least one hydrocarbon group; more preferably, the silicon atoms in the organosilicon compound are directly bonded to 1-3 alkoxy groups and 1-3 hydrocarbon groups. The advantage of this preferred embodiment is that it ensures sufficient bonding between the organosilicon compound and the catalyst surface during the dissociation process.

[0034] In a preferred embodiment, the hydrocarbon group is a heteroatom-substituted or unsubstituted aliphatic hydrocarbon group, wherein the heteroatom is selected from S and / or N. It is understood in this invention that heteroatom substitution refers to a mixture in which the heteroatom S and / or N unsaturated bonds are located on the terminal carbon atom of the hydrocarbon group.

[0035] In a preferred embodiment, the hydrocarbon group is a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain aliphatic hydrocarbon group with 1-12 carbon atoms. The advantage of this preferred embodiment is that it ensures a certain degree of hydrophobicity.

[0036] In a preferred embodiment, the alkoxy group is an alkoxy group having 1-8 carbon atoms, preferably an alkoxy group having 1-4 carbon atoms.

[0037] In a preferred embodiment, the organosilicon compound has the structural formula shown in formula (1);

[0038] R-(CH2)n-Si-(OR 1 (OR) 2 (OR) 3 Equation (1);

[0039] Where n = 1-10, R is an alkyl or amino group, R 1R 2 R 3 Each is independently selected from C1-C8 aliphatic alkyl groups, preferably C1-C4 straight-chain aliphatic alkyl groups.

[0040] In this invention, there is no particular limitation on the specific type of organosilicon compound, as long as it can meet the performance requirements of the catalyst. Preferably, the organosilicon compound is selected from at least one of n-octyltrimethoxysilane, n-octyltriethoxysilane, n-dodecyltrimethoxysilane, hexadecyltrimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, and trimethylethoxysilane. More preferably, it is selected from at least one of n-octyltrimethoxysilane, n-octyltriethoxysilane, methyltrimethoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0041] In this invention, by selecting organosilicon surface modifiers with different structures to modify the surface of the catalyst, precise control of micro-hydrophobicity is achieved, which can significantly improve the activity, stability and selectivity of the catalyst and the target product.

[0042] A second aspect of the present invention provides a method for preparing the supported hydrogenation catalyst described in the first aspect, wherein the method comprises:

[0043] (1) The precursors of Group VIII and Group VIB metal elements were introduced into the support by impregnation, followed by drying and calcination to obtain the catalyst precursor;

[0044] (2) The catalyst precursor was impregnated with an organosilicon surface modifier solution and then modified to obtain the catalyst.

[0045] In this invention, the types and contents of Group VIII metal elements, Group VIB metal elements, and organosilicon surface modifiers have been described in the first aspect and will not be repeated here.

[0046] In this invention, there is no particular limitation on the types of precursors for Group VIII and Group VIB metal elements. Preferably, the Group VIII and Group VIB metal element precursors are each independently selected from their soluble salts or chlorides.

[0047] In a preferred embodiment, the Group VIII metal precursor is selected from at least one of chloroplatinic acid, palladium nitrate, and palladium chloride.

[0048] In a preferred embodiment, the Group VIB metal precursor is preferably selected from at least one of sodium tungstate, ammonium tungstate, ammonium heptamolybdate, ammonium molybdate, ammonium phosphomolybdate, ammonium metatungstate, and ethyl metatungstate.

[0049] In this invention, the impregnation method is not specifically limited, and conventional impregnation methods in the art are applicable to this invention. Examples include co-impregnation, stepwise impregnation, saturated impregnation, and supersaturated impregnation. In a preferred embodiment, stepwise impregnation is used in this invention. In a more preferred embodiment, in step (1), the impregnation method includes: first introducing a Group VIB metal element precursor into the carrier, then performing an aging treatment, followed by a first drying and a first calcination, then introducing a Group VIII metal element precursor, followed by a second drying and a second calcination. The advantage of this preferred embodiment is that it can meet the preparation conditions required for bimetallic synergistic effects, and stepwise calcination facilitates sufficient contact between metals and between the metal and the carrier.

[0050] In this invention, the selection range for aging treatment conditions is relatively wide. Preferably, the aging treatment conditions include: a temperature of 80-160℃ and a time of 4-24h; more preferably, a temperature of 100-140℃ and a time of 12-24h. The advantage of this preferred embodiment is that the metal precursor can fully adsorb onto the skeletal structure of the carrier, ensuring uniformity under a small metal loading condition.

[0051] In this invention, the selection range for the conditions of the first drying and the second drying is relatively wide. Preferably, the conditions for the first drying and the second drying each independently include: a temperature of 80-120°C and a time of 2-12 hours.

[0052] In this invention, the selection range for the conditions of the first roasting is relatively wide. Preferably, the conditions of the first roasting include: a temperature of 500-600℃ and a time of 2-12h; more preferably, a temperature of 550-600℃ and a time of 2-6h.

[0053] In this invention, the selection range for the conditions of the second calcination is relatively wide. Preferably, the conditions of the second calcination include: a temperature of 300-550℃ and a time of 2-12h; more preferably, a temperature of 350-500℃ and a time of 2-6h.

[0054] In a preferred embodiment, the first calcination temperature is higher than the second calcination temperature. This preferred embodiment is more conducive to the formation of a stronger oxidized metal-support coordination structure of the supported metal at the first calcination temperature, enhancing the support-metal interaction and ensuring that the metal does not undergo secondary agglomeration at the second calcination temperature.

[0055] In this invention, the concentration of the organosilicon surface modifier solution is not particularly limited. Preferably, the concentration of the organosilicon surface modifier solution is 1-10% by mass, more preferably 1-6% by mass, and even more preferably 1-4% by mass.

[0056] In this invention, there is no particular limitation on the type of solvent for the organosilicon surface modifier solution. Preferably, the solvent for the organosilicon surface modifier solution is selected from at least one of ethanol, isopropanol, and n-propanol, and more preferably ethanol.

[0057] In a preferred embodiment, the modification treatment includes a first modification treatment and a second modification treatment. It is understood that in this invention, the first modification treatment is carried out under stirring conditions, and the second modification treatment is carried out under static conditions.

[0058] In a preferred embodiment, the first modification treatment is carried out under stirring conditions.

[0059] In this invention, the selection range of conditions for the first modification treatment is relatively wide. Preferably, the conditions for the first modification treatment include: a stirring speed of 300-1200 r / min, a temperature of 0-80℃, and a time of 4-36 h. More preferably, the stirring speed is 400-800 r / min, the temperature is 15-40℃, and the time is 8-24 h.

[0060] In this invention, the selection range of conditions for the second modification treatment is relatively wide. Preferably, the conditions for the second modification treatment include: a temperature of 120-170℃ and a time of 4-36h; more preferably, a temperature of 120-150℃ and a time of 4-12h.

[0061] In the preferred embodiment, the first modification treatment and the second modification treatment are carried out under different conditions. This preferred embodiment is more conducive to the precise control of the surface micro-hydrophobicity.

[0062] The above modification treatment can adjust the adsorption mode of glycerol molecules and promote the formation of the target product. On the other hand, it can also promote the desorption of reaction products and by-products, thus solving the problem of decreased catalyst activity caused by competitive adsorption.

[0063] The third aspect of this invention provides the application of the supported hydrogenation catalyst described in the first aspect in the selective hydrogenation purification reaction of glycerol.

[0064] In a preferred embodiment, the selective hydrogenation purification reaction of glycerol is a selective hydrogenation reaction of glycerol to 1,3-propanediol.

[0065] In this invention, the raw materials for the selective hydrogenation refining reaction of glycerol are not particularly limited. Preferably, the raw material for the selective hydrogenation refining reaction of glycerol is a 10-30% by mass aqueous solution of glycerol.

[0066] In a preferred embodiment, the selective hydrogenation refining reaction of glycerol is carried out in at least one of a slurry bed reactor, a fixed bed reactor, and a moving bed reactor, more preferably in a slurry bed reactor.

[0067] In this invention, the reaction conditions for the selective hydrogenation purification of glycerol are selected over a wide range. Preferably, the reaction conditions include: a catalyst-to-oil mass ratio of 0.02-0.1, a pressure of 2-4 MPa, a temperature of 150-170°C, and a time of 12-24 h. More preferably, the catalyst-to-oil mass ratio is 0.04-0.06, the pressure is 2-3 MPa, the temperature is 150-160°C, and the time is 15-18 h. In this invention, the catalyst-to-oil mass ratio refers to the ratio of the mass of the catalyst to the mass of the glycerol aqueous solution.

[0068] The inventors of this invention discovered that in the hydrogenation reaction of glycerol, glycerol molecules need to be adsorbed onto catalytically active sites. Hydrogen gas is adsorbed and dissociated by noble metals, and active hydrogen species attack the primary or secondary hydroxyl groups of glycerol molecules through hydrogen spillover, generating the corresponding products. Based on this, by selecting specific catalysts and adjusting the adsorption mode of glycerol molecules on the catalyst surface, the catalytic efficiency of the catalyst and the selectivity of the target product can be effectively improved.

[0069] The present invention will be described in detail below through examples. In the following examples, the process is carried out in a slurry bed reactor.

[0070] The hydrophilic parameters of the catalyst were measured using the method described above, and the relative hydrophilic parameters were calculated using the following formula:

[0071] The relative hydrophilicity parameter n = the hydrophilicity parameter of the modified catalyst / the hydrophilicity parameter of the unmodified catalyst.

[0072] Example 1

[0073] A supported hydrogenation catalyst contains Pt, W, a support, and a surface modifier, wherein the loading of Pt is 2% of the mass of the support, the loading of W is 0.5% of the mass of the support, and the loading of the surface modifier is 2% of the mass of the support, wherein the support is a Beta molecular sieve.

[0074] Supported hydrogenation catalysts are prepared by the following methods:

[0075] (1) The Beta molecular sieve (silicon-aluminum molar ratio of 25) was dispersed in sodium tungstate solution, aged at 120°C for 24 hours, dried at 100°C for 4 hours, and then calcined at 600°C for 3 hours.

[0076] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 100°C for 4 hours and then calcined at 350°C for 3 hours.

[0077] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of n-octyltrimethoxysilane with a concentration of 2% by mass, and modified by stirring at 400 r / min at 25 °C for 12 h, and then modified at 120 °C for 36 h to obtain the catalyst. The in-situ infrared spectrum of the catalyst is as follows. Figure 1 As shown.

[0078] Example 2

[0079] A supported hydrogenation catalyst contains Pt, W, a support, and a surface modifier, wherein the loading of Pt is 2% of the mass of the support, the loading of W is 0.75% of the mass of the support, and the loading of the surface modifier is 2% of the mass of the support, wherein the support is a Y-type molecular sieve.

[0080] Supported hydrogenation catalysts are prepared by the following methods:

[0081] (1) Y-type molecular sieve (silicon-aluminum molar ratio of 50) was dispersed in sodium tungstate solution, aged at 140℃ for 18h, dried at 120℃ for 4h and calcined at 550℃ for 5h.

[0082] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 100°C for 4 hours and then calcined at 400°C for 3 hours.

[0083] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of methyltrimethoxysilane with a concentration of 2% by mass, and modified by stirring at 500 r / min at 15 °C for 12 h, and then modified at 120 °C for 24 h to obtain the catalyst.

[0084] Example 3

[0085] A supported hydrogenation catalyst contains Pt, W, a support, and a surface modifier. The loading of Pt is 1% of the mass of the support, the loading of W is 0.5% of the mass of the support, and the loading of the surface modifier is 1% of the mass of the support. The support is a Y-type molecular sieve (specifically, type Y).

[0086] Supported hydrogenation catalysts are prepared by the following methods:

[0087] (1) Y-type molecular sieve (silicon-aluminum molar ratio of 15) was dispersed in sodium tungstate solution, aged at 120℃ for 24h, dried at 110℃ for 6h and calcined at 550℃ for 5h.

[0088] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 110°C for 2 hours and then calcined at 450°C for 4 hours.

[0089] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of dimethyldiethoxysilane with a concentration of 1% by mass, and modified by stirring at 400 r / min at 20 °C for 12 h, and then modified at 150 °C for 24 h to obtain the catalyst.

[0090] Example 4

[0091] A supported hydrogenation catalyst contains Pt, W, a molecular sieve support, and a surface modifier. The loading of Pt is 2% of the support mass, the loading of W is 0.5% of the support mass, and the loading of the surface modifier is 4% of the support mass. The support is a Beta molecular sieve.

[0092] Supported hydrogenation catalysts are prepared by the following methods:

[0093] (1) The Beta molecular sieve (silicon-aluminum molar ratio of 25) was dispersed in sodium tungstate solution, aged at 120°C for 24 h, dried at 120°C for 4 h, and then calcined at 600°C for 3 h.

[0094] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 100°C for 4 hours and then calcined at 450°C for 3 hours.

[0095] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of n-dodecyltrimethoxysilane with a concentration of 4% by mass, and modified by stirring at 20°C and 400 r / min for 24 h, and then modified at 150°C for 24 h to obtain the catalyst.

[0096] Example 5

[0097] A supported hydrogenation catalyst contains Pt, W, a molecular sieve support, and a surface modifier. The loading of Pt is 2% of the support mass, the loading of W is 0.5% of the support mass, and the loading of the surface modifier is 6% of the support mass. The support is a Beta molecular sieve.

[0098] Supported hydrogenation catalysts are prepared by the following methods:

[0099] (1) The Beta molecular sieve (silicon-aluminum molar ratio of 100) was dispersed in sodium tungstate solution, aged at 120°C for 24 hours, dried at 90°C for 6 hours, and then calcined at 500°C for 6 hours.

[0100] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 90°C for 6 hours and then calcined at 500°C for 2 hours.

[0101] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of hexadecyltrimethoxysilane with a concentration of 6% by mass, and modified by stirring at 25°C and 600 r / min for 36 h, and then modified at 120°C for 36 h to obtain the catalyst.

[0102] Example 6

[0103] A supported hydrogenation catalyst contains Pt, W, a support (70% by mass molecular sieve + 30% by mass alumina) and a surface modifier, wherein the loading of Pt is 2% by mass of the support, the loading of W is 1% by mass of the support, and the loading of the surface modifier is 4% by mass of the support, wherein the support is a Beta molecular sieve.

[0104] Supported hydrogenation catalysts are prepared by the following methods:

[0105] (1) Beta molecular sieve (silicon-aluminum molar ratio of 100) and alumina were dispersed in sodium tungstate solution, aged at 80°C for 12 h, dried at 80°C for 6 h, and then calcined at 500°C for 6 h.

[0106] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 100°C for 6 hours and then calcined at 500°C for 2 hours.

[0107] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of n-octyltriethoxysilane with a concentration of 4% by mass, and modified by stirring at 600 r / min at 40 °C for 36 h, and then modified at 120 °C for 36 h to obtain the catalyst.

[0108] Example 7

[0109] A supported hydrogenation catalyst contains Pd, W, a support, and a surface modifier, wherein the loading of Pd is 2% of the mass of the support, the loading of W is 0.5% of the mass of the support, and the loading of the surface modifier is 1% of the mass of the support, wherein the support is a Y-type molecular sieve.

[0110] Supported hydrogenation catalysts are prepared by the following methods:

[0111] (1) Y-type molecular sieve (silicon-aluminum molar ratio of 50) was dispersed in sodium tungstate solution, aged at 150℃ for 24h, dried at 100℃ for 6h and calcined at 500℃ for 4h.

[0112] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 100°C for 4 hours and then calcined at 450°C for 6 hours.

[0113] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of dimethyldiethoxysilane with a concentration of 1% by mass, and modified by stirring at 600 r / min at 20 °C for 12 h, and then modified at 140 °C for 24 h to obtain the catalyst.

[0114] Example 8

[0115] A supported hydrogenation catalyst contains Pt, W, a molecular sieve, and a surface modifier. The loading of Pt is 0.5% of the support mass, the loading of W is 1% of the support mass, and the loading of the surface modifier is 2% of the support mass. The support is a Beta molecular sieve.

[0116] Supported hydrogenation catalysts are prepared by the following methods:

[0117] (1) The Beta molecular sieve (silicon-aluminum molar ratio of 50) was dispersed in sodium tungstate solution, aged at 150°C for 24 hours, dried at 80°C for 6 hours, and then calcined at 600°C for 3 hours.

[0118] (2) The intermediate product obtained in (1) was immersed in chloroplatinic acid solution, dried at 80°C for 6 hours and then calcined at 450°C for 3 hours.

[0119] (3) The intermediate product obtained in (2) was dispersed in an ethanol solution of 3-aminopropyltrimethoxysilane with a concentration of 2% by mass, and modified by stirring at 500 r / min at 40 °C for 24 h, and then modified at 150 °C for 24 h to obtain the catalyst.

[0120] Comparative Example 1

[0121] A supported hydrogenation catalyst comprising Pt, W and a support, wherein the loading of Pt is 2% of the mass of the support, the loading of W is 0.75% of the mass of the support, and no surface modifier is used, wherein the support is a Beta molecular sieve.

[0122] Supported hydrogenation catalysts are prepared by the following methods:

[0123] (1) The Beta molecular sieve (silicon-aluminum molar ratio of 25) was dispersed in sodium tungstate solution, aged at 140°C for 24 h, dried at 100°C for 4 h, and then calcined at 600°C for 6 h.

[0124] (2) The intermediate product obtained in (1) was impregnated in chloroplatinic acid solution, dried at 120°C for 4 hours, and then calcined at 500°C for 4 hours to obtain the catalyst. The in-situ infrared spectrum of the catalyst is shown below. Figure 2 As shown.

[0125] Comparative Example 2

[0126] A supported hydrogenation catalyst containing Pt, W and a support, wherein the loading of Pt is 2% of the mass of the support, the loading of W is 0.5% of the mass of the support, and no surface modifier is used, wherein the support is a Beta molecular sieve.

[0127] Supported hydrogenation catalysts are prepared by the following methods:

[0128] (1) The Beta molecular sieve (silicon-aluminum molar ratio of 50) was dispersed in sodium tungstate solution, aged at 140°C for 24 hours, dried at 80°C for 6 hours, and then calcined at 600°C for 4 hours.

[0129] (2) The intermediate product obtained in (1) is immersed in chloroplatinic acid solution, dried at 100°C for 6 hours and then calcined at 500°C for 4 hours to obtain the catalyst.

[0130] Performance testing

[0131] The catalysts prepared in the examples and comparative examples were used in the hydrogenation of glycerol to 1,3-propanediol under the following conditions: 1 g of catalyst was weighed and placed in 20 g of 10% glycerol aqueous solution (catalyst-to-oil mass ratio 0.05), and loaded into a high-pressure reactor. The reaction was carried out at a temperature of 160°C and a hydrogen pressure of 2.6 MPa for 16 h. After the reaction was completed, the sample was cooled to room temperature, and solid-liquid separation was performed using a centrifuge. The sample was then taken for quantitative analysis by gas chromatography, and the results were calculated according to the following formula. The results are listed in Table 1.

[0132] Glycerol conversion rate (%) = (molar amount of glycerol before reaction - molar amount of glycerol after reaction) / molar amount of glycerol before reaction × 100%;

[0133] 1,3-Propanediol selectivity (%) = molar amount of 1,3-propanediol / total molar amount of carbonaceous material produced × 100%;

[0134] 1,2-Propanediol selectivity (%) = molar amount of 1,2-propanediol / total molar amount of carbonaceous material produced × 100%;

[0135] n-Propanol selectivity (%) = molar amount of n-propanol / total molar amount of carbonaceous material produced × 100%;

[0136] Isopropanol selectivity (%) = molar amount of isopropanol / total molar amount of carbonaceous material produced × 100%.

[0137] Table 1. Performance test evaluation results of the examples and comparative examples.

[0138]

[0139] As can be seen from the results in Table 1, Examples 1 and 8 and the comparative examples, which use the surface modification technology of the present invention to regulate the surface micro-hydrophobic properties, have significantly better effects, and the selectivity of 1,3-propanediol is significantly improved.

[0140] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. Application of a supported hydrogenation catalyst in the selective hydrogenation purification reaction of glycerol; in, The catalyst comprises a support and at least one Group VIII metal element, at least one Group VIB metal element, and an organosilicon surface modifier supported on the support; the content of the Group VIII metal element is 0.5-2% of the mass of the support, the content of the Group VIB metal element is 0.5-1% of the mass of the support, and the content of the organosilicon surface modifier is 1-10% of the mass of the support.

2. The application according to claim 1, wherein, The content of the Group VIII metal element, calculated as an element, is 1-2% of the carrier mass; the content of the Group VIB metal element, calculated as an element, is 0.5-0.75% of the carrier mass; and the content of the organosilicon surface modifier is 1-6% of the carrier mass.

3. The application according to claim 1 or 2, wherein, The carrier includes at least one of molecular sieve and heat-resistant inorganic oxide.

4. The application according to claim 3, wherein, The carrier includes a molecular sieve and optionally a heat-resistant inorganic oxide; And / or, the molecular sieve is a silica-alumina molecular sieve; And / or, the silica-alumina molar ratio of the molecular sieve is 15-200; And / or, the heat-resistant inorganic oxide is selected from at least one of aluminum oxide, magnesium oxide, titanium oxide and zirconium oxide.

5. The application according to claim 4, wherein, The molecular sieve is selected from at least one of Beta molecular sieve, Y-type molecular sieve and ZSM-5 molecular sieve.

6. The application according to claim 4, wherein, Based on the total amount of carrier, the content of the silica-alumina molecular sieve is not less than 70% by mass, and the content of the heat-resistant inorganic oxide is 0-30% by mass.

7. The application according to claim 4, wherein, The carrier is a silica-alumina molecular sieve.

8. The application according to claim 1 or 2, wherein, The group VIII metals mentioned are noble metals; And / or, the Group VIB metal element is Mo and / or W.

9. The application according to claim 1 or 2, wherein, The Group VIII metallic elements are Pt and / or Pd.

10. The application according to claim 1 or 2, wherein, The organosilicon surface modifier is selected from at least one organosilicon compound.

11. The application according to claim 10, wherein, In the organosilicon compound, silicon atoms are directly bonded to at least one alkoxy group and at least one hydrocarbon group.

12. The application according to claim 11, wherein, In the organosilicon compound, silicon atoms are directly bonded to 1-3 alkoxy groups and 1-3 hydrocarbon groups.

13. The application according to claim 12, wherein, When the organosilicon compound has two or more alkoxy groups, the alkoxy groups may be the same or different alkoxy groups.

14. The application according to claim 12, wherein, When the organosilicon compound has two or more hydrocarbon groups, the hydrocarbon groups may be the same or different hydrocarbon groups.

15. The application according to claim 11, wherein, The hydrocarbon group is a heteroatom-substituted or unsubstituted aliphatic hydrocarbon group, wherein the heteroatom is selected from S and / or N.

16. The application according to claim 15, wherein, The hydrocarbon group is a straight-chain aliphatic hydrocarbon group.

17. The application according to claim 16, wherein, The hydrocarbon group is a straight-chain aliphatic hydrocarbon group with 1-12 carbon atoms.

18. The application according to claim 11, wherein, The alkoxy group is an alkoxy group with 1-8 carbon atoms.

19. The application according to claim 18, wherein, The alkoxy group is an alkoxy group with 1-4 carbon atoms.

20. The application according to claim 11, wherein, The structural formula of the organosilicon compound is shown in formula (1); R-(CH2)n-Si-(OR 1 )(OR 2 )(OR 3 ) Formula (1); Where n = 1-10, R is an alkyl or amino group, R 1 R 2 R 3 Each is independently selected from C1-C8 aliphatic alkyl groups.

21. The application according to claim 20, wherein, R 1 R 2 R 3 Each is independently selected from C1-C4 straight-chain aliphatic alkyl groups.

22. The application according to claim 21, wherein, The organosilicon compound is selected from at least one of n-octyltrimethoxysilane, n-octyltriethoxysilane, n-dodecyltrimethoxysilane, hexadecyltrimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

23. The application according to claim 1 or 2, wherein, The method for preparing the catalyst includes: (1) The precursors of Group VIII and Group VIB metal elements were introduced into the support by impregnation, followed by drying and calcination to obtain the catalyst precursor; (2) The catalyst precursor is impregnated with an organosilicon surface modifier solution and then modified to obtain the catalyst.

24. The application according to claim 23, wherein, In step (1), the impregnation method includes: introducing a Group VIB metal element precursor into the carrier, then performing an aging treatment, then performing a first drying and a first calcination, then introducing a Group VIII metal element precursor, and then performing a second drying and a second calcination.

25. The application according to claim 24, wherein, The aging treatment conditions include: a temperature of 80-160℃ and a time of 4-24h.

26. The application according to claim 25, wherein, The aging treatment conditions include: a temperature of 100-140℃ and a time of 12-24h.

27. The application according to claim 24, wherein, The conditions for the first drying and the second drying each independently include: a temperature of 80-120℃ and a time of 2-12h.

28. The application according to claim 24, wherein, The conditions for the first roasting include: a temperature of 500-600℃ and a time of 2-12h.

29. The application according to claim 28, wherein, The conditions for the first roasting include: a temperature of 550-600℃ and a time of 2-6 hours.

30. The application according to claim 24, wherein, The conditions for the second roasting include: a temperature of 300-550℃ and a time of 2-12 hours.

31. The application according to claim 30, wherein, The conditions for the second roasting include: a temperature of 350-500℃ and a time of 2-6 hours.

32. The application according to claim 24, wherein, In step (2), the concentration of the organosilicon surface modifier solution is 1-10 by mass.

33. The application according to claim 32, wherein, In step (2), the concentration of the organosilicon surface modifier solution is 1-6 by mass.

34. The application according to claim 33, wherein, The solvent for the organosilicon surface modifier solution is selected from at least one of ethanol, isopropanol, and n-propanol.

35. The application according to claim 24, wherein, The modification process includes a first modification process and a second modification process.

36. The application according to claim 35, wherein, The first modification treatment was carried out under stirring conditions.

37. The application according to claim 36, wherein, The conditions for the first modification treatment include: a stirring speed of 300-1200 r / min, a temperature of 0-80℃, and a time of 4-36 h.

38. The application according to claim 37, wherein, The conditions for the first modification treatment include: a stirring speed of 400-800 r / min, a temperature of 15-40℃, and a time of 8-24 h.

39. The application according to claim 35, wherein, The conditions for the second modification treatment include: a temperature of 120-170℃ and a time of 4-36h.

40. The application according to claim 39, wherein, The conditions for the second modification treatment include: a temperature of 120-150℃ and a time of 12-24h.

41. The application according to claim 1 or 2, wherein, The selective hydrogenation purification reaction of glycerol is a selective hydrogenation reaction of glycerol to 1,3-propanediol.

42. The application according to claim 1 or 2, wherein, The feedstock for the selective hydrogenation refining of glycerol is a 10-30% by mass aqueous solution of glycerol.

43. The application according to claim 1 or 2, wherein, The selective hydrogenation refining reaction of glycerol is carried out in at least one of a slurry bed reactor, a fixed bed reactor, and a moving bed reactor.

44. The application according to claim 42, wherein, The selective hydrogenation refining reaction of glycerol is carried out in a slurry bed reactor.

45. The application according to claim 1 or 2, wherein, The reaction conditions include: an agent-to-oil mass ratio of 0.02-0.1, a pressure of 2-4 MPa, a temperature of 150-170℃, and a time of 12-24 h.

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