Catalyst and preparation method therefor, and method for preparing 4-methyl-1-pentene by means of propylene dimerization by using catalyst

Abstract

The present invention relates to the technical field of catalysts. Disclosed are a catalyst and a preparation method therefor, a method for preparing 4-methyl-1-pentene by means of propylene dimerization by using the catalyst and the use thereof. The catalyst comprises a carrier, and an active metal component and an auxiliary metal component loaded on the carrier, wherein the carrier comprises at least one carrier matrix selected from an alkali metal carbonate and an alkali metal bicarbonate, and a binder; the active metal component is at least one selected from an alkali metal elementary substance; and the auxiliary metal component is at least one selected from the transition metal elementary substances in the sixth period. On the basis of the mass of the carrier, in terms of the metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%. The catalyst has good catalytic activity and stability during a propylene dimerization reaction.

Description

Catalyst and its preparation method, and method for preparing 4-methyl-1-pentene from propylene dimerization using the catalyst. Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a catalyst and its preparation method, a method for preparing 4-methyl-1-pentene from propylene dimerization using the catalyst, and its applications. Background Technology

[0002] 4-Methyl-1-pentene (4M1P) can form linear low-density polyethylene (LLDPE), high-performance polypropylene copolymers, and other polymer materials with ethylene and propylene. These polymers have excellent impact resistance, tensile tear strength, and dielectric properties, and are therefore widely used in industry. At the same time, it can also self-polymerize to obtain a thermoplastic plastic with strong advantages in density, transparency, heat resistance, and corrosion resistance—poly-4-methyl-1-pentene (PMP), which is the core material of extracorporeal membrane oxygenation (ECMO), an "artificial lung".

[0003] In the 1960s, California Research Corp. successfully developed alkali metal catalysts for the dimerization of propylene to produce 4M1P. BP pioneered its industrialization, building the world's first 2,000-ton / year production plant. In the 1970s, Mitsui Petrochemicals of Japan imported and improved upon BP's manufacturing technology, establishing a 2,500-ton / year production plant, which was increased to 25,000 tons / year in the early 1990s. Meanwhile, Phillips Chemicals of the United States built an industrial-scale plant in the early 1990s, reaching a capacity of 45,000 tons / year. Currently, global 4M1P production capacity is mainly concentrated in companies such as Mitsui Chemicals of Japan, using alkali metal catalyst systems as the active component and propylene dimerization under high temperature, high pressure, anhydrous, and oxygen-free conditions to produce 4M1P.

[0004] The low single-pass conversion rate of feedstock is a major challenge in the alkali metal-catalyzed propylene dimerization to 4M1P reaction. Therefore, current experiments typically employ methods such as increasing reaction temperature and pressure, and decreasing space velocity to attempt to overcome this limitation. However, while these operations improve feedstock conversion, they also prolong the contact time between reactants and catalyst, intensifying the polymerization reaction and increasing the proportion of isomerization byproducts in the product, thus creating new challenges for the subsequent industrial separation and purification of the product. Simulation studies of the product component distillation process show that 4M1P is the light key component in distillation, while 4-methyl-2-pentene (4M2P), with a similar boiling point, is the heavy key component. The ratio of these two components in the distillation feedstock significantly affects the scale and energy consumption of the distillation column. Therefore, their proportion in the product becomes one of the main evaluation indicators for the propylene dimerization reaction. Correspondingly, the selectivity of 4M1P is also an important factor influencing the industrial application potential of propylene dimerization catalysts. Furthermore, improving catalyst lifetime not only reduces production costs but also helps to reduce the cumbersome steps of loading water- and oxygen-sensitive catalysts and the risk of handling deactivated catalysts. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low single-pass conversion rate and poor stability of raw materials in the prior art, and to provide a catalyst and its preparation method, a method for preparing 4-methyl-1-pentene by using the catalyst from propylene dimerization and its uses. The catalyst exhibits excellent catalytic activity and stability in the reaction of propylene dimerization to prepare 4-methyl-1-pentene.

[0006] To achieve the above objectives, the inventors of this invention conducted in-depth research and discovered that by further combining an auxiliary metal with existing alkali metal catalysts, the resulting catalyst exhibits excellent catalytic activity and stability in the reaction of propylene dimerization to prepare 4-methyl-1-pentene.

[0007] More specifically, the present invention provides a catalyst, characterized in that the catalyst comprises a support and an active metal component and an auxiliary metal component supported on the support; wherein the support comprises at least one support matrix selected from alkali metal carbonates and alkali metal bicarbonates and a binder, the active metal component is at least one selected from alkali metal elements, the auxiliary metal component is at least one selected from sixth-period transition metal elements, and based on the mass of the support and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0008] Furthermore, the present invention provides a method for preparing a catalyst, characterized in that the preparation method includes the following steps:

[0009] (1) Mix at least one carrier matrix, binder and pore expander selected from alkali metal carbonates and alkali metal bicarbonates, optionally add solvent and then mold to obtain a mixture molded body;

[0010] (2) After the mixture is optionally crushed and / or sieved, the resulting carrier precursor is calcined to obtain the carrier.

[0011] (3) Loading the auxiliary metal component and the active metal component onto the carrier;

[0012] The active metal component is selected from at least one alkali metal element, and the auxiliary metal component is selected from at least one transition metal element of the sixth period. Based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0013] This invention provides a method for preparing a catalyst, characterized in that the preparation method includes the following steps:

[0014] (1') At least one carrier matrix, binder, pore expander and auxiliary metal component selected from alkali metal carbonate and alkali metal bicarbonate are mixed and then molded to obtain a mixture molded body;

[0015] (2') The mixture is optionally crushed and / or sieved, and then calcined to obtain a carrier loaded with auxiliary metal components;

[0016] (3') Load the active metal component onto the carrier obtained in step (2');

[0017] The active metal component is selected from at least one alkali metal element, and the auxiliary metal component is selected from at least one transition metal element of the sixth period. Based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0018] In another aspect, the present invention provides a method for preparing 4-methyl-1-pentene from propylene dimerization, the method comprising the following steps: contacting propylene with a catalyst under an inert gas atmosphere to carry out selective polymerization of propylene, wherein the catalyst is the catalyst of the present invention, or a catalyst prepared by the preparation method of the present invention.

[0019] In another aspect, the present invention provides the use of the catalyst of the present invention, or the catalyst prepared by the preparation method of the present invention, in a method for preparing 4-methyl-1-pentene by propylene dimerization.

[0020] Technical effect

[0021] The catalyst of this invention, with an alkali metal element as the active metal component and a transition metal element selected from the sixth period as the promoter metal component supported on a support, combined with the porous properties of the support, exhibits excellent catalytic activity in the propylene dimerization reaction. Compared with conventional alkali metal catalysts, the propylene single-component conversion rate is significantly improved. Furthermore, the catalyst performs admirably at a rapid deactivation temperature of 170°C, effectively slowing down the deactivation process and demonstrating good catalyst stability. Without any theoretical limitations, the inventors speculate that this is because the introduction of a specific promoter metal component, through its interaction with the active metal component and the specific support, promotes the adsorption of propylene molecules on the catalyst surface, lowers the energy barriers for reactant diffusion and adsorption at active sites in heterogeneous catalytic reactions, thereby improving the conversion rate and selectivity of the catalyst in the propylene dimerization reaction. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0023] 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.

[0024] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0025] When this specification uses the prefixes "known to those skilled in the art," "prior art," or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application's filing, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0026] In the context of this specification, except where expressly stated, any matters or issues not mentioned herein shall apply directly to those known in the art without any modification. Furthermore, any implementation described herein may be freely combined with one or more other implementations described herein, and any resulting technical solutions or concepts shall be considered part of the original disclosure or original record of this invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider such combination to be clearly unreasonable.

[0027] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight, unless being based on weight would not be in accordance with the common understanding of those skilled in the art.

[0028] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0029] In the context of this invention, unless otherwise specified, the physical properties of substances (such as boiling point) are measured at room temperature (25°C) and normal pressure (101325 Pa).

[0030] A first aspect of the present invention provides a catalyst, characterized in that the catalyst comprises a support and an active metal component and an auxiliary metal component supported on the support; wherein the support comprises at least one support matrix selected from alkali metal carbonates and alkali metal bicarbonates and a binder, the active metal component is at least one selected from alkali metal elements, the auxiliary metal component is at least one selected from sixth-period transition metal elements, and based on the mass of the support and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0031] The catalyst of this invention exhibits excellent catalytic activity in propylene dimerization under the synergistic effect of the support, the active metal supported on the support, and specific auxiliary metals. Compared with conventional alkali metal catalysts, the single conversion rate of propylene is significantly improved. Simultaneously, the catalyst possesses high stability and a long service life. Without any theoretical limitations, the inventors speculate that this is because the introduction of appropriate auxiliary metal components, through their interaction with the active metal components and the specific support, can promote the adsorption of propylene molecules on the catalyst surface, reducing the energy barriers for reactant diffusion and adsorption at active sites in heterogeneous catalytic reactions, thereby improving the conversion rate, selectivity, and stability of the catalyst in propylene dimerization.

[0032] In this invention, the carrier matrix, as one of the carrier components, is at least one selected from alkali metal carbonates and alkali metal bicarbonates. There are no special requirements regarding the source of the carrier matrix in this invention. Preferably, the carrier matrix is ​​potassium carbonate, more preferably anhydrous potassium carbonate, which can be commercially available or prepared using any method known in the art. In one embodiment of this invention, the carrier matrix is ​​a carrier matrix whose particle size distribution satisfies the Rosin-Rammler (RR) distribution obtained by sieving, grading, and mixing according to the Rosin-Rammler (RR) distribution disclosed in EP0083083A1.

[0033] In addition to the carrier matrix, the carrier of the present invention also includes an adhesive.

[0034] In one embodiment of the present invention, the binder is at least one selected from graphite and modified graphite, preferably at least one selected from graphite and fluorinated graphite.

[0035] In one embodiment of the present invention, the content of the adhesive is 0.02-10 wt% relative to the mass of the carrier matrix, preferably 0.1-5 wt%, and more preferably 0.2-3 wt%.

[0036] In one embodiment of the present invention, the content of the binder relative to the mass of the carrier matrix is ​​0.05 wt%, 0.15 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3.5 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or 9 wt%.

[0037] In one embodiment of the present invention, the carrier of the present invention is substantially composed of a carrier matrix and a binder. In another embodiment of the present invention, the carrier of the present invention contains only a carrier matrix and a binder.

[0038] In one embodiment of the present invention, the active metal component in the catalyst is at least one selected from alkali metals. Examples of alkali metals include lithium, sodium, potassium, rubidium, and cesium.

[0039] In one embodiment of the present invention, the active metal component in the catalyst is at least one selected from lithium, sodium, potassium, rubidium, and cesium, preferably sodium and potassium. When sodium and potassium are present, the mass ratio of sodium to potassium, based on the metal elements, is 1:5 to 5:1.

[0040] In one embodiment of the present invention, when the catalyst contains sodium and potassium, the mass ratio of sodium to potassium, calculated as metal elements, is 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, or 1:4.

[0041] With the composition of the carrier and active metal of the present invention, it is possible to further achieve a suitable propylene conversion rate and selectivity for 4-methyl-1-pentene.

[0042] According to the present invention, preferably, the active metal component exists in elemental form.

[0043] In the catalyst of the present invention, the promoter metal component is at least one selected from the sixth-period transition metal elements. In one embodiment of the present invention, the promoter metal component is at least one selected from iridium, platinum, and gold, preferably at least one selected from platinum and gold. In the above preferred embodiments, it is advantageous to further improve the catalytic activity and stability of the catalyst.

[0044] According to the present invention, preferably, the auxiliary metal component exists in elemental form.

[0045] In this invention, based on the mass of the carrier, the content of the active metal component, calculated by metal element, is 1-20 wt%, preferably 2-10 wt%.

[0046] In one embodiment of the present invention, based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.2 wt%, 2.5 wt%, 2.8 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, and 9.5 wt%.

[0047] In this invention, based on the mass of the carrier, the content of the auxiliary metal component, calculated by metal element, is 0.001-10 wt%, preferably 0.002-5 wt%.

[0048] In one embodiment of the present invention, based on the mass of the carrier and calculated by metal element, the content of the auxiliary metal component is 0.004 wt%, 0.008 wt%, 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, and 9.5 wt%.

[0049] In one embodiment of the present invention, the mass ratio of the active metal component to the auxiliary metal component, based on metal elements, is 1:(0.0001-2), preferably 1:(0.001-1).

[0050] In one embodiment of the present invention, the mass ratio of the active metal component to the auxiliary metal component, based on metal elements, is 1:0.0005, 1:0.0008, 1:0.0015, 1:0.002, 1:0.003, 1:0.005, 1:0.01, 1:0.02, 1:0.05, 1:0.08, 1:0.1, 1:0.2, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.5, or 1:1.8.

[0051] In the catalyst of this invention, when multiple active metal components are contained, the amount of each active metal component is calculated based on the total amount of all active metals. Similarly, when multiple auxiliary metal components are contained, the amount of each auxiliary metal component is calculated based on the total amount of all auxiliary metals.

[0052] Through the above-described preferred embodiments of the present invention, it is beneficial for the catalyst to maintain a high propylene conversion and 4M1P selectivity while having good flowability. Due to the water and oxygen sensitive characteristics of the catalyst, flowability is particularly important in the loading and transfer steps of industrial plants.

[0053] The support of the present invention is a porous support. In the preparation process of the catalyst of the present invention, a pore is formed in the support by using a pore-expanding agent.

[0054] In one embodiment of the present invention, the specific surface area (BET method) of the support in the catalyst is 0.15-20 m². 2 / g, preferably 0.2-5m 2 / g.

[0055] In one embodiment of the present invention, the specific surface area of ​​the support in the catalyst is 0.4 m². 2 / g, 0.8m 2 / g, 1.0m 2 / g, 1.5m 2 / g, 2.0m 2 / g, 2.5m 2 / g, 3.0m 2 / g, 3.5m 2 / g, 4.0m 2 / g, 4.5m 2 / g, 5.0m 2 / g, 5.5m 2 / g, 6.0m 2 / g, 6.5m 2 / g, 7.0m 2 / g, 7.5m 2 / g, 8.0m 2 / g, 8.5m 2 / g, 9.0m 2 / g, 9.5m 2 / g.

[0056] In one embodiment of the present invention, the pore volume (BET method) of the support in the catalyst of the present invention is 0.0002-0.05 mL / g, preferably 0.0003-0.02 mL / g.

[0057] In one embodiment of the present invention, the pore volume of the support in the catalyst of the present invention is 0.0004 mL / g, 0.0008 mL / g, 0.001 mL / g, 0.004 mL / g, 0.008 mL / g, 0.01 mL / g, 0.03 mL / g, or 0.04 mL / g.

[0058] In one embodiment of the present invention, the average pore size (BET method) of the support in the catalyst of the present invention is 4.5-60 nm, preferably 5-18 nm.

[0059] In one embodiment of the present invention, the average pore size of the support in the catalyst is 5.0 nm, 5.5 nm, 6.0 nm, 6.5 nm, 7.0 nm, 7.5 nm, 8.0 nm, 8.5 nm, 9.0 nm, 9.5 nm, 10.0 nm, 10.5 nm, 11.0 nm, 11.5 nm, 12.0 nm, 12.5 nm, 13.0 nm, 13.5 nm, 14.0 nm, 14.5 nm, 15.0 nm, 15.5 nm, 16.0 nm, 16.5 nm, 17.0 nm, and 17.5 nm.

[0060] In one embodiment of the present invention, the particle size of the support in the catalyst is 0.2-5.0 mm, preferably 0.3-3.0 mm.

[0061] In one embodiment of the present invention, the particle size of the support in the catalyst of the present invention is 0.25 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, or 4.5 mm.

[0062] A second aspect of the present invention provides a method for preparing a catalyst, characterized in that the preparation method includes the following steps:

[0063] (1) Mix at least one carrier matrix, binder and pore expander selected from alkali metal carbonates and alkali metal bicarbonates, optionally add solvent and then mold to obtain a mixture molded body;

[0064] (2) After the mixture is optionally crushed and / or sieved, the resulting carrier precursor is calcined to obtain the carrier.

[0065] (3) Loading the auxiliary metal component and the active metal component onto the carrier;

[0066] The active metal component is selected from at least one alkali metal element, and the auxiliary metal component is selected from at least one transition metal element of the sixth period. Based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0067] In the preparation method of the present invention, in step (1), the carrier matrix is ​​selected from at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0068] In the preparation method of the present invention, in step (1), the binder is at least one selected from graphite and modified graphite, preferably at least one selected from graphite and fluorinated graphite.

[0069] In the preparation method of the present invention, in step (1), the pore-expanding agent is at least one selected from polyethylene glycol, guar gum powder, and cellulose derivatives, preferably at least one selected from guar gum powder, methylcellulose, and carboxymethylcellulose.

[0070] In the preparation method of the present invention, in step (1), the content of the binder relative to the mass of the carrier matrix is ​​0.02-10 wt%, preferably 0.1-5 wt%, and more preferably 0.2-3 wt%.

[0071] In one embodiment of the present invention, in step (1), the content of the adhesive relative to the mass of the carrier matrix is ​​0.05wt%, 0.15wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.5wt%, 2wt%, 2.5wt%, 3.5wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, or 9wt%.

[0072] In the preparation method of the present invention, in step (1), the content of the pore-expanding agent is 0.1-20 wt% relative to the mass of the carrier matrix, preferably 1.0-10 wt%, and more preferably 2.0-5 wt%.

[0073] In one embodiment of the present invention, in step (1), the content of the pore-expanding agent relative to the mass of the carrier matrix is ​​0.5wt%, 1.5wt%, 2.5wt%, 3.0wt%, 3.5wt%, 4.0wt%, 4.5wt%, 5.0wt%, 5.5wt%, 6.0wt%, 6.5wt%, 7.0wt%, 7.5wt%, 8.0wt%, 8.5wt%, 9.0wt%, and 9.5wt%.

[0074] In the preparation method of the present invention, in step (1), no solvent is used. After mixing, the mixture is compressed into tablets to obtain a mixed molded body. Preferably, the conditions for the tablet compression are: pressure 10-30 MPa, holding pressure for 1-10 min.

[0075] In one embodiment of the present invention, in step (1), a reciprocating or circulating tablet press can also be used to perform the above-mentioned tableting.

[0076] In the preparation method of the present invention, in step (2), after the mixture is crushed and / or sieved, the obtained carrier precursor is calcined to obtain the carrier. Preferably, the particle size of the carrier precursor after crushing and / or sieving is 0.2-5.0 mm, and more preferably 0.3-3.0 mm.

[0077] In one embodiment of the present invention, in step (2), the particle size of the carrier precursor after crushing and / or sieving is 0.25mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm.

[0078] In this invention, the crushing and sieving can be carried out using conventional methods in the art, as long as the particle size of the carrier meets the above-mentioned range. By ensuring that the particle size of the carrier precursor is within the above-mentioned preferred range, the final carrier particle size can be controlled. This helps to balance the conversion rate of propylene dimerization and the product isomerization rate, achieving both suitable propylene conversion and 4M1P selectivity, while further improving the catalyst's flowability.

[0079] In the preparation method of the present invention, in step (2), the calcination conditions are: calcination temperature of 300-800℃, preferably 400-600℃, calcination time of 1-10h, preferably 2-8h, and calcination atmosphere of inert gas atmosphere or oxygen-containing atmosphere.

[0080] The carrier of the present invention can be obtained by step (2) of the preparation method of the present invention. The particle size of the carrier is 0.2-5.0 mm, preferably 0.3-3.0 mm.

[0081] In one embodiment of the present invention, in step (2), the particle size of the carrier particles is 0.25mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, or 4.5mm.

[0082] The specific surface area of ​​the carrier obtained by step (2) of the preparation method of the present invention is 0.15-20 m². 2 / g, preferably 0.2-5m 2 / g.

[0083] In one embodiment of the present invention, the specific surface area of ​​the carrier obtained by step (2) of the preparation method of the present invention is 0.4 m². 2 / g, 0.8m 2 / g, 1.0m 2 / g, 1.5m 2 / g, 2.0m 2 / g, 2.5m 2 / g, 3.0m 2 / g, 3.5m 2 / g, 4.0m 2 / g, 4.5m 2 / g, 5.0m 2 / g, 5.5m 2 / g, 6.0m 2 / g, 6.5m 2 / g, 7.0m 2 / g, 7.5m 2 / g, 8.0m 2 / g, 8.5m2 / g, 9.0m 2 / g, 9.5m 2 / g.

[0084] The pore volume of the carrier obtained by step (2) of the preparation method of the present invention is 0.0002-0.05 mL / g, preferably 0.0003-0.02 mL / g.

[0085] In one embodiment of the present invention, the pore volume of the carrier obtained by step (2) of the preparation method of the present invention is 0.0004 mL / g, 0.0008 mL / g, 0.001 mL / g, 0.004 mL / g, 0.008 mL / g, 0.01 mL / g, 0.03 mL / g, or 0.04 mL / g.

[0086] The average pore size of the carrier obtained by step (2) of the preparation method of the present invention is 4.5-60 nm, preferably 5-18 nm.

[0087] In one embodiment of the present invention, the average pore size of the carrier obtained by step (2) of the preparation method of the present invention is 5.0 nm, 5.5 nm, 6.0 nm, 6.5 nm, 7.0 nm, 7.5 nm, 8.0 nm, 8.5 nm, 9.0 nm, 9.5 nm, 10.0 nm, 10.5 nm, 11.0 nm, 11.5 nm, 12.0 nm, 12.5 nm, 13.0 nm, 13.5 nm, 14.0 nm, 14.5 nm, 15.0 nm, 15.5 nm, 16.0 nm, 16.5 nm, 17.0 nm, and 17.5 nm.

[0088] In the preparation method of the present invention, in step (3), the carrier and the auxiliary metal component are first mixed under an inert gas atmosphere to load the auxiliary metal component. Preferably, the first mixing conditions are: mixing temperature of 100-500℃, preferably 200-400℃; mixing time of 1-8h, preferably 2-4h; and the inert gas is at least one selected from nitrogen, argon, neon and helium.

[0089] In the preparation method of the present invention, the auxiliary metal component is at least one selected from the sixth-period transition metal elements. In one embodiment of the present invention, the auxiliary metal component is at least one selected from iridium, platinum, and gold, preferably at least one selected from platinum and gold. In the above preferred embodiments, it is beneficial to further improve the catalytic activity and stability of the catalyst.

[0090] In the catalyst prepared by the method of the present invention, based on the mass of the support and calculated by metal element, the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0091] In one embodiment of the present invention, the catalyst obtained by the preparation method of the present invention, based on the mass of the support and calculated by metal element, has the following content of auxiliary metal component: 0.004 wt%, 0.008 wt%, 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, and 9.5 wt%.

[0092] In the preparation method of the present invention, in step (3), the carrier and the active metal component are mixed for the second time under an inert gas to load the active metal component. Preferably, the second mixing conditions are: mixing temperature of 100-600℃, preferably 200-400℃; mixing time of 0.5-8h, preferably 1-6h; and the inert gas is at least one selected from nitrogen, argon, neon and helium.

[0093] In the preparation method of the present invention, the active metal component is at least one selected from alkali metals. Examples of alkali metals include lithium, sodium, potassium, rubidium, and cesium.

[0094] In the catalyst prepared by the method of the present invention, the content of the active metal component, based on the mass of the support and calculated as metal elements, is 1-20 wt%, preferably 2-10 wt%.

[0095] In one embodiment of the present invention, the catalyst obtained by the preparation method of the present invention, based on the mass of the support and calculated by metal element, has an active metal component content of 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.2 wt%, 2.5 wt%, 2.8 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, and 9.5 wt%.

[0096] In the preparation method of the present invention, in step (3), there is no particular limitation on the loading order of the active metal component and the auxiliary metal component. The auxiliary metal component can be loaded first, and then the active metal component can be loaded. Alternatively, the active metal component can be loaded first, and then the auxiliary metal component can be loaded. Or, the active metal component and the active metal component can be loaded together.

[0097] In the preparation method of the present invention, in step (3), the auxiliary metal component is selected from at least one of iridium, platinum and gold, preferably at least one of platinum and gold.

[0098] In the preparation method of the present invention, in step (3), the active metal component is at least one selected from lithium, sodium, potassium, rubidium, and cesium, preferably sodium and potassium. When sodium and potassium are present, the mass ratio of sodium to potassium, based on metal elements, is 1:5-5:1.

[0099] In one embodiment of the present invention, in step (3), when sodium and potassium are used simultaneously, the mass ratio of sodium to potassium, based on the metal elements, is 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, or 1:4.

[0100] In the preparation method of the present invention, in step (3), the mass ratio of the active metal component to the auxiliary metal component, based on metal elements, is 1:(0.0001-2), preferably 1:(0.001-1).

[0101] In one embodiment of the present invention, the mass ratio of the active metal component to the auxiliary metal component in the catalyst obtained by the preparation method of the present invention, based on metal elements, is 1:0.0005, 1:0.0008, 1:0.0015, 1:0.002, 1:0.003, 1:0.005, 1:0.01, 1:0.02, 1:0.05, 1:0.08, 1:0.1, 1:0.2, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.5, or 1:1.8.

[0102] In the preparation method of the catalyst of the present invention, when multiple active metal components are contained, the amount of the active metal components is calculated based on the total amount of all active metals. When multiple auxiliary metal components are contained, the amount of the auxiliary metal components is calculated based on the total amount of all auxiliary metals.

[0103] In one embodiment of the present invention, in the preparation method of the present invention, in step (1), the carrier matrix, binder, pore expander and auxiliary metal component are mixed and then shaped; in step (2), the shaped body is optionally crushed and / or sieved and then calcined to obtain a carrier loaded with metal component; in step (3), the active metal component is introduced.

[0104] In one embodiment of the present invention, the method for preparing the catalyst of the present invention includes the following steps:

[0105] (1') At least one carrier matrix, binder, pore expander and auxiliary metal component selected from alkali metal carbonate and alkali metal bicarbonate are mixed and then molded to obtain a mixture molded body;

[0106] (2') The mixture is optionally crushed and / or sieved, and then calcined to obtain a carrier loaded with metal components.

[0107] (3') Load the active metal component onto the carrier obtained in step (2');

[0108] The active metal component is selected from at least one alkali metal element, and the auxiliary metal component is selected from at least one transition metal element of the sixth period. Based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

[0109] In one embodiment of the present invention, the conditions and components in step (1') are the same as those described above.

[0110] In one embodiment of the present invention, the conditions in step (2') are the same as the conditions in steps (2) and (3) of the present invention described above. For example, the calcination conditions in step (2') correspond to the first mixing in step (3) described above.

[0111] In one embodiment of the present invention, the conditions for loading the active metal component in step (3') are the same as those in step (3) above.

[0112] A third aspect of the present invention provides a method for preparing 4-methyl-1-pentene from propylene dimerization, the method comprising the following steps: contacting propylene with a catalyst under an inert gas atmosphere to carry out selective polymerization of propylene;

[0113] The catalyst is either the catalyst described in the first aspect or the catalyst prepared by the preparation method described in the second aspect.

[0114] In the method for preparing 4-methyl-1-pentene from propylene dimerization of the present invention, the selection range for the contact conditions is relatively wide and can be chosen according to actual production needs. Preferably, the contact conditions include: a reaction pressure of 4-16 MPa, preferably 6-12 MPa; a reaction temperature of 110-180°C, preferably 120-160°C; and a liquid hourly space velocity of 0.2-6 h⁻¹. -1Preferably 0.6-3h -1 .

[0115] In the method for preparing 4-methyl-1-pentene from propylene dimerization of the present invention, the inert gas atmosphere is provided by an inert gas that does not participate in the reaction, and the inert gas is at least one selected from nitrogen, argon, neon and helium.

[0116] Preferably, the method for preparing 4-methyl-1-pentene from propylene dimerization according to the present invention further includes: subjecting the propylene to deoxygenation and dehydration treatment before the contact. The deoxygenation and dehydration treatment can be carried out using conventional methods in the art, which are well known to those skilled in the art and will not be described in detail here.

[0117] The fourth aspect of the present invention provides the use of the catalyst described in the first aspect of the present invention or the catalyst prepared by the preparation method described in the second aspect of the present invention in a method for preparing 4-methyl-1-pentene by propylene dimerization.

[0118] On the other hand, the present invention provides the following technical solutions.

[0119] Option 1: A catalyst, characterized in that the catalyst comprises a support and an active metal component and an auxiliary metal component supported on the support; wherein the support comprises potassium carbonate and a binder, the active metal component is selected from sodium and / or potassium, and the auxiliary metal component is selected from at least one of noble metals;

[0120] Based on the mass of the carrier, the content of the active metal component is 1-20 wt% and the content of the auxiliary metal component is 0.1-10 wt%, calculated by metal element.

[0121] Option 2: The catalyst according to Option 1, wherein the active metal includes sodium and potassium;

[0122] Preferably, in the active metal component, the mass ratio of sodium to potassium, calculated by element, is 1-5:5-1;

[0123] Preferably, the active metal component exists in elemental form.

[0124] Option 3: The catalyst according to Option 1 or 2, wherein the auxiliary metal component is selected from at least one of platinum, rhodium and palladium, preferably platinum;

[0125] Preferably, the auxiliary metal component exists in elemental form.

[0126] Option 4: The catalyst according to any one of Options 1-3, wherein, based on the mass of the support, the content of the active metal component is 2-10 wt% and the content of the auxiliary metal component is 0.5-2.5 wt%.

[0127] Preferably, the mass ratio of the active metal component to the auxiliary metal component, based on metal elements, is 1:(0.01-1), more preferably 1:(0.1-0.5).

[0128] Option 5: A method for preparing a catalyst, characterized in that the preparation method includes:

[0129] (1) Potassium carbonate, binder and guar gum powder are mixed and molded to obtain a carrier;

[0130] (2) Loading the active metal component and the auxiliary metal component onto the carrier;

[0131] The active metal component is selected from sodium and / or potassium, and the auxiliary metal component is selected from at least one of noble metals.

[0132] Based on the mass of the carrier, the loading of the active metal component is 1-20 wt% and the loading of the auxiliary metal component is 0.1-10 wt%, calculated by metal element.

[0133] Scheme 6: According to the preparation method described in Scheme 5, in step (1), based on the mass of potassium carbonate, the amount of binder is 0.5-5 wt%, preferably 0.75-3 wt%.

[0134] Preferably, in step (1), the amount of guar gum powder used is 0.1-20 wt%, preferably 1-10 wt%, based on the mass of potassium carbonate;

[0135] Preferably, in step (1), the molding method is tablet molding;

[0136] Preferably, step (1) further includes: optionally crushing and sieving the shaped product to a particle size of 250-500 nm, preferably 300-450 nm.

[0137] Option 7: The preparation method according to Option 5 or 6, wherein the molding and calcination is carried out in an oxygen-containing atmosphere;

[0138] Preferably, the molding and baking temperature is 100-800℃, more preferably 300-600℃;

[0139] Preferably, the molding and baking time is 1-10 hours, and more preferably 2-8 hours.

[0140] Scheme 8: The preparation method according to any one of Schemes 5-7, wherein step (2) includes:

[0141] (2-1) Under a protective atmosphere, the carrier and the auxiliary metal are first mixed;

[0142] (2-2) The product obtained in step (2-1) is mixed with the active metal in a second process;

[0143] Preferably, the temperature of the first mixing is 50-400℃, more preferably 100-300℃; the time is 1-8h, more preferably 2-4h.

[0144] Preferably, the temperature of the second mixing is 100-600℃, more preferably 200-400℃; and the time is 0.5-8h, more preferably 1-6h.

[0145] Preferably, the protective atmosphere is provided by at least one of nitrogen, argon, neon and helium.

[0146] Option 9: A method for preparing 4-methyl-1-pentene by propylene dimerization, the method comprising: contacting propylene with a catalyst under an inert atmosphere to carry out selective polymerization of propylene;

[0147] The catalyst is characterized in that it is a catalyst according to any one of the above schemes 1-4 or a catalyst prepared by any one of the above schemes 5-8.

[0148] Option 10: The method described in Option 9, wherein the contact conditions include: a reaction pressure of 4-16 MPa, preferably 6-12 MPa; a reaction temperature of 120-180°C, preferably 140-160°C; and a liquid hourly space velocity of 0.2-6 h⁻¹. -1 Preferably, it is 0.6-2.4h. -1 .

[0149] Example

[0150] The present invention will be described in detail below through embodiments.

[0151] All reagents used in the embodiments of the present invention are commercially available reagents.

[0152] Example 1

[0153] (1) Carrier treatment: Anhydrous potassium carbonate was sieved, graded, and mixed according to the Rosin-Rammler distribution (RR distribution) disclosed in patent EP0083083A1. Based on the mass of anhydrous potassium carbonate (RR distribution potassium carbonate), 1 wt% graphite and 2.5 wt% guar gum powder were added and mixed evenly. The mixture was then pressed into tablets using an electric tablet press at a pressure of 20 MPa and a holding time of 5 min. The pressed tablets were pulverized and sieved. Carrier particles of 0.30-0.45 mm were placed in a vacuum crucible furnace and baked at 500℃ and atmospheric pressure for 6 h to prepare catalyst carrier A1. The physicochemical properties of the carrier are shown in Table 1.

[0154] (2) Support loading: A certain amount of baked catalyst support was placed in a three-necked flask under an inert gas atmosphere, and 1 wt% of platinum powder relative to the support mass was added. The flask was dried at 350°C by mechanical stirring and electric heating. After the flask wall was free of water mist, the drying was maintained for 2 hours. After cooling, 2.2 wt% of metallic sodium and 2.8 wt% of metallic potassium relative to the support mass were added. The flask was then stirred at 350°C for 4 hours to prepare CAT-1, a propylene dimerization catalyst with silver-gray particles.

[0155] Example 2

[0156] (1) Carrier treatment: Anhydrous potassium carbonate was sieved, graded, and mixed according to the Rosin-Rammler distribution (RR distribution) disclosed in patent EP0083083A1. Based on the mass of anhydrous potassium carbonate (RR distribution potassium carbonate), 0.75 wt% graphite and 3 wt% guar gum powder were added and mixed evenly. The mixture was then pressed into tablets using an electric tablet press at a pressure of 20 MPa and a holding time of 5 min. The pressed tablets were pulverized and sieved. Carrier particles of 0.30-0.45 mm were placed in a vacuum crucible furnace and baked at 500℃ and atmospheric pressure for 6 h to prepare catalyst carrier A2. The physicochemical properties of the carrier are shown in Table 1.

[0157] (2) Support loading: A certain amount of baked catalyst support was placed in a three-necked flask under an inert gas atmosphere, and 1 wt% of platinum powder relative to the support mass was added. The flask was dried at 300°C by mechanical stirring and electric heating. After the flask wall was free of water mist, the drying was maintained for 4 hours. After cooling, 2 wt% of metallic sodium and 1 wt% of metallic potassium relative to the support mass were added. The mixture was then stirred at 350°C for 3 hours to prepare CAT-2, a propylene dimerization catalyst with silver-gray particles.

[0158] Example 3

[0159] The method is the same as in Example 1, except that in step (2), the amount of platinum powder added is 0.2 wt%.

[0160] The resulting propylene dimerization catalyst was designated CAT-3.

[0161] Example 4

[0162] The method of Example 1 is different in that the RR-distributed potassium carbonate, graphite and guar gum powder are mixed evenly and then pressed into tablets using a reciprocating electric tablet press. The tablet press parameters are adjusted to obtain a cylindrical support with a diameter of 3*3mm. The support is placed in a vacuum crucible furnace and baked with air at 500℃ and normal pressure for 6 hours to prepare the catalyst support. In step (2), the amount of platinum powder added is 0.01wt%.

[0163] The resulting propylene dimerization catalyst was designated CAT-4.

[0164] Example 5

[0165] The method is the same as in Example 1, except that in step (2), the amount of platinum powder added is 3 wt%.

[0166] The propylene dimerization catalyst obtained was designated CAT-5.

[0167] Example 6

[0168] The method of Example 1 is different in that, in step (1), 1 wt% of platinum powder based on the carrier mass and potassium carbonate, graphite and guar gum powder of RR distribution are mixed evenly, pressed into tablets, crushed and sieved to obtain mixed particles of 0.30-0.45 mm, and then placed into a vacuum crucible furnace and calcined at 500°C and normal pressure for 6 hours.

[0169] The catalyst was then placed in a three-necked flask under an inert gas atmosphere and dried at 350°C using mechanical stirring and electric heating. After the flask walls were free of water vapor, the temperature was maintained for 2 hours. After cooling, 2.2 wt% sodium metal and 2.8 wt% potassium metal were added based on the carrier mass. The mixture was then stirred at 350°C for 4 hours to prepare CAT-6, a propylene dimerization catalyst with silver-gray particles.

[0170] Example 7

[0171] The method is the same as in Example 1, except that in step (2), platinum powder is replaced with gold powder.

[0172] The propylene dimerization catalyst obtained was designated CAT-7.

[0173] Example 8

[0174] The method of Example 1 was followed, except that in step (1), graphite was replaced with fluorinated graphite to prepare catalyst support A3. The physicochemical properties of the support are shown in Table 1.

[0175] The resulting propylene dimerization catalyst was designated CAT-8.

[0176] Example 9

[0177] Following the method of Example 1, except that in step (1), guar gum powder was replaced with methylcellulose, and the amount added was 4.5 wt%, to prepare catalyst support A4. The physicochemical properties of the support are shown in Table 1.

[0178] The propylene dimerization catalyst obtained was designated CAT-9.

[0179] Example 10

[0180] The method of Example 1 was followed, except that in step (1), the amount of graphite added was 0.2 wt%, and catalyst support A5 was prepared. The physicochemical properties of the support are shown in Table 1.

[0181] The resulting propylene dimerization catalyst was designated CAT-10.

[0182] Comparative Example 1

[0183] (1) Carrier treatment: Anhydrous potassium carbonate was sieved, graded and mixed according to the Rosin-Rammler distribution (RR distribution) disclosed in patent EP0083083A1; based on the mass of anhydrous potassium carbonate (RR distribution potassium carbonate), 1 wt% graphite and 2.5 wt% guar gum powder were added and mixed evenly. Then, the mixture was pressed into tablets using an electric tablet press at a pressure of 20 MPa and a holding time of 5 min; the pressed tablets were crushed and sieved, and 0.30-0.45 mm carrier particles were placed in a vacuum crucible furnace and baked at 500℃ and normal pressure for 6 h to prepare catalyst carrier A1.

[0184] (2) Support loading: A certain amount of baked catalyst support was placed in a three-necked flask under an inert gas atmosphere and dried at 350°C by mechanical stirring and electric heating. After the flask wall was free of water mist, it was maintained for 2 hours. After cooling, 2.2 wt% sodium metal and 2.8 wt% potassium metal relative to the support mass were added. Then, the mixture was stirred at 350°C for 4 hours to prepare propylene dimerization catalyst DCAT-1 with silver-gray particles.

[0185] Comparative Example 2

[0186] (1) Carrier treatment: Anhydrous potassium carbonate was sieved, graded and mixed according to the Rosin-Rammler distribution (RR distribution) disclosed in patent EP0083083A1; based on the mass of anhydrous potassium carbonate (RR distribution potassium carbonate), 1 wt% graphite and 2.5 wt% guar gum powder were added and mixed evenly. Then, the mixture was pressed into tablets using an electric tablet press at a pressure of 20 MPa and a holding time of 5 min; the pressed tablets were crushed and sieved, and 0.30-0.45 mm carrier particles were placed in a vacuum crucible furnace and baked at 500℃ and normal pressure for 6 h to prepare catalyst carrier A1.

[0187] (2) Support loading: A certain amount of baked catalyst support was placed in a three-necked flask under an inert gas atmosphere, and copper powder of 1 wt% relative to the support mass was added. The flask was dried at 350°C by mechanical stirring and electric heating. After the flask wall was free of water mist, the drying was maintained for 2 hours. After cooling, sodium metal of 2.2 wt% relative to the support mass and potassium metal of 2.8 wt% were added. The flask was then stirred at 350°C for 4 hours to prepare propylene dimerization catalyst DCAT-2 with silver-gray particles.

[0188] Comparative Example 3

[0189] (1) Carrier treatment: Anhydrous potassium carbonate was sieved, graded and mixed according to the Rosin-Rammler distribution (RR distribution) disclosed in patent EP0083083A1; based on the mass of anhydrous potassium carbonate (RR distribution potassium carbonate), 1 wt% graphite and 2.5 wt% guar gum powder were added and mixed evenly. Then, the mixture was pressed into tablets using an electric tablet press at a pressure of 20 MPa and a holding time of 5 min; the pressed tablets were crushed and sieved, and 0.30-0.45 mm carrier particles were placed in a vacuum crucible furnace and baked at 250℃ and normal pressure for 4 h to prepare catalyst carrier DA.

[0190] (2) Support loading: A certain amount of baked catalyst support was placed in a three-necked flask under an inert gas atmosphere, and 1 wt% of platinum powder relative to the support mass was added. The flask was dried at 350°C by mechanical stirring and electric heating. After the flask wall was free of water mist, the drying was maintained for 2 hours. After cooling, 2.2 wt% of metallic sodium and 2.8 wt% of metallic potassium relative to the support mass were added. The flask was then stirred at 350°C for 4 hours to prepare the silver-gray propylene dimerization catalyst DCAT-3.

[0191] Table 1 Physicochemical properties of different carriers (BET method)

[0192] Test case

[0193] Under a nitrogen atmosphere, the catalysts prepared in the above examples and comparative examples were transferred to the reactor and connected to a high-pressure microreactor. The raw material propylene was fed into the reactor through a high-pressure constant flow pump and sequentially through a deoxygenation and dehydration pretreatment system to carry out the reaction of propylene dimerization to prepare 4-methyl-1-pentene. The polymerization reaction conditions are shown in Table 2. Part of the reaction product was split and entered into a gas chromatograph for online analysis through a six-way valve, while the remaining product was collected in a cold trap collection bottle.

[0194] Product analysis: Gas chromatography analysis of the products was performed using a PONA column (50m×200μm×0.5μm), detector temperature 300℃, injection port temperature 250℃, split ratio 1:200, and temperature programmed conditions: initial temperature 35℃, constant temperature for 15 min, then increased to 65℃ at 2℃ / min, and then increased to 250℃ at 20℃ / min; the product analysis results are listed in Table 2.

[0195] Table 2

[0196] Stability test:

[0197] The catalysts prepared in Example 1 and Comparative Example 1 were subjected to polymerization at a temperature of 170°C, a pressure of 11 MPa, and a space velocity of 1.0 h⁻¹. -1 Stability tests were conducted under these conditions. Timing began after the catalyst's polymerization performance stabilized under these conditions (approximately 12 hours). The high-temperature deactivation data obtained are shown in Table 3.

[0198] Table 3

[0199] As can be seen from the results of CAT-1 in Example 1 and the comparative example DCAT in Table 2, under the same polymerization conditions, the polymerization performance of the propylene dimerization catalyst prepared by the method of the present invention is more than doubled when the 4M1P selectivity is approximately the same. Comparing the data in the second and third columns of Table 2, it can be seen that CAT-1 has similar catalytic performance at different polymerization reaction temperatures and space velocities, providing multiple polymerization conditions for the subsequent industrial application of the catalyst. Meanwhile, according to the stability test data in Table 3, the propylene dimerization catalyst of the present invention can effectively slow down the deactivation process at high temperatures compared to the comparative example. At 170°C, the half-life increased from 100 min in the comparative example to 140 min, and the conversion rate after 160 min increased from 38% to 46% of the initial conversion rate. These data demonstrate that the catalyst of the present invention has superior high-temperature stability.

[0200] 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. A catalyst characterized in that, The catalyst comprises a support and an active metal component and an auxiliary metal component supported on the support; wherein the support comprises at least one support matrix selected from alkali metal carbonates and alkali metal bicarbonates and a binder, the active metal component is at least one selected from alkali metal elements, and the auxiliary metal component is at least one selected from sixth-period transition metal elements. Based on the mass of the support and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

2. The catalyst of claim 1, wherein, At least one of the following conditions must be met: The carrier matrix is ​​selected from at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. The binder is selected from at least one of graphite and modified graphite, preferably from at least one of graphite and fluorinated graphite.

3. The catalyst of claim 1 or 2, wherein, At least one of the following conditions must be met: The active metal component is selected from at least one of lithium, sodium, potassium, rubidium, and cesium, preferably sodium and potassium, and more preferably, the mass ratio of sodium to potassium is 1:5-5:1 based on elements. The auxiliary metal component is at least one selected from iridium, platinum and gold, preferably at least one of platinum and gold; The mass ratio of the active metal component to the auxiliary metal component, based on metal elements, is 1:(0.0001-2), preferably 1:(0.001-1).

4. The catalyst of any one of claims 1-3, wherein, In the carrier, the content of the binder relative to the mass of the carrier matrix is ​​0.02-10 wt%, preferably 0.1-5 wt%, and more preferably 0.2-3 wt%.

5. The catalyst of any one of claims 1-4, wherein, At least one of the following conditions must be met: The specific surface area of the carrier is 0.15-20 m 2 / g, preferably 0.2-5 m 2 / g; The pore volume of the carrier is 0.0002-0.05 mL / g, preferably 0.0003-0.02 mL / g; The average pore size of the carrier is 4.5-60 nm, preferably 5-18 nm; The particle size of the carrier is 0.2-5.0 mm, preferably 0.3-3.0 mm.

6. A process for the preparation of a catalyst, characterized in that The preparation method includes the following steps: (1) Mix at least one carrier matrix, binder and pore expander selected from alkali metal carbonates and alkali metal bicarbonates, optionally add solvent and then mold to obtain a mixture molded body; (2) After the mixture is optionally crushed and / or sieved, the resulting carrier precursor is calcined to obtain the carrier; (3) Loading the auxiliary metal component and the active metal component onto the carrier; The active metal component is selected from at least one alkali metal element, and the auxiliary metal component is selected from at least one transition metal element of the sixth period. Based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

7. The preparation method according to claim 6, wherein it satisfies at least one of the following characteristics: The carrier matrix is ​​selected from at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. The binder is selected from at least one of graphite and modified graphite, preferably from at least one of graphite and fluorinated graphite; The pore-expanding agent is at least one selected from polyethylene glycol, guar gum powder, and cellulose derivatives, preferably at least one selected from guar gum powder, methylcellulose, and carboxymethylcellulose; The content of the binder relative to the mass of the carrier matrix is ​​0.02-10 wt%, preferably 0.1-5 wt%, and more preferably 0.2-3 wt%. The content of the pore-expanding agent relative to the mass of the carrier matrix is ​​0.1-20 wt%, preferably 1.0-10 wt%, and more preferably 2.0-5 wt%. In step (1), no solvent is used. After mixing, the mixture is compressed into tablets to obtain a molded mixture. The preferred conditions for tablet compression are: pressure 10-30 MPa, holding pressure for 1-10 min.

8. The preparation method according to claim 6 or 7, wherein it satisfies at least one of the following characteristics: In step (2), after the mixture is crushed and / or sieved, the resulting carrier precursor is calcined to obtain a carrier. Preferably, the particle size of the crushed and / or sieved carrier precursor is 0.2-5.0 mm, and more preferably 0.3-3.0 mm. In step (2), the calcination conditions are as follows: the calcination temperature is 300-800℃, preferably 400-600℃, the calcination time is 1-10h, preferably 2-8h, and the calcination atmosphere is an inert gas atmosphere or an oxygen-containing atmosphere.

9. The preparation method according to any one of claims 6-8, wherein it satisfies at least one of the following characteristics: In step (3), the carrier and the auxiliary metal component are first mixed in an inert gas atmosphere to load the auxiliary metal component. Preferably, the first mixing conditions are: mixing temperature of 100-500℃, preferably 200-400℃; mixing time of 1-8h, preferably 2-4h; and the inert gas is at least one selected from nitrogen, argon, neon and helium. In step (3), the carrier and the active metal component are mixed for the second time under an inert gas atmosphere to load the active metal component. Preferably, the second mixing conditions are: mixing temperature of 100-600℃, preferably 200-400℃; mixing time of 0.5-8h, preferably 1-6h; and the inert gas is at least one selected from nitrogen, argon, neon and helium. In step (3), the auxiliary metal component is loaded first, and then the active metal component is loaded; or, the active metal component is loaded first, and then the auxiliary metal component is loaded; or the active metal component and the active metal component are loaded together. The auxiliary metal component is at least one selected from iridium, platinum and gold, preferably at least one of platinum and gold; The active metal component is selected from at least one of lithium, sodium, potassium, rubidium, and cesium, preferably sodium and potassium, and more preferably, the mass ratio of sodium to potassium is 1:5-5:1 based on elements. The mass ratio of the active metal component to the auxiliary metal component, based on metal elements, is 1:(0.0001-2), preferably 1:(0.001-1).

10. A process for the preparation of a catalyst, characterized in that, The preparation method includes the following steps: (1') At least one carrier matrix, binder, pore expander and auxiliary metal component selected from alkali metal carbonate and alkali metal bicarbonate are mixed and then molded to obtain a mixture molded body; (2') The mixture is optionally crushed and / or sieved, and then calcined to obtain a carrier loaded with metal components. (3') Load the active metal component onto the carrier obtained in step (2'); The active metal component is selected from at least one alkali metal element, and the auxiliary metal component is selected from at least one transition metal element of the sixth period. Based on the mass of the carrier and calculated by metal element, the content of the active metal component is 1-20 wt%, preferably 2-10 wt%, and the content of the auxiliary metal component is 0.001-10 wt%, preferably 0.002-5 wt%.

11. A process for the preparation of 4-methyl-1-pentene by dimerization of propylene, which process comprises the steps of: In an inert gas atmosphere, propylene is contacted with a catalyst to carry out selective polymerization of propylene; The catalyst is characterized in that it is the catalyst according to any one of claims 1-5, or the catalyst prepared by the preparation method according to any one of claims 6-10.

12. The method of claim 11, wherein, The conditions of the contact include: reaction pressure 4-16 MPa, preferably 6-12 MPa; reaction temperature 110-180℃, preferably 120-160℃; liquid hourly space velocity 0.2-6h -1 , preferably 0.6-3h -1 .

13. Use of the catalyst according to any one of claims 1-5, or the catalyst prepared by the preparation method according to any one of claims 6-10, in a method for preparing 4-methyl-1-pentene from propylene dimerization.

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