Catalyst for alcohol dehydration to produce alpha-olefins, preparation method thereof, and method for alcohol dehydration to produce alpha-olefins

Abstract

The present invention relates to the technical field of alcohol dehydration, and specifically to a catalyst for producing alpha-olefins by dehydrating alcohol, a preparation method thereof, and a method for producing alpha-olefins by dehydrating alcohol. The catalyst comprises: 84-99.88 wt% of a main component, 0.04-6 wt% of a Group IIA oxide, 0.05-8 wt% of a Group IIIB oxide, and 0.03-10 wt% of a transition metal oxide; wherein the main component is selected from at least one of Group IVB oxides; and the transition metal oxide is selected from at least one of Group VIB oxides, Group VIII oxides, Group IB oxides, and Group IIB oxides. The present invention rationally modifies the catalyst by introducing Group IIA metal elements, Group IIIB metal elements, and Group VIB, VIII, IB, and IIB metal elements into the main component, thereby suppressing carbon deposition of the catalyst in the alcohol dehydration reaction, improving the catalytic performance of the catalyst, and promoting the efficient conduct of the alcohol dehydration reaction to produce alpha-olefins.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing alpha-olefins by dehydrating alcohols, and in particular to a catalyst for preparing alpha-olefins by dehydrating alcohols, a preparation method thereof, and a method for preparing alpha-olefins by dehydrating alcohols. Background Art

[0002] α-olefins are terminal olefins with the general molecular formula CH2=CH-R (R is an alkyl group). They have rapidly grown as petrochemical raw materials in recent years and are widely used in various fields such as oil additives, surfactants, plasticizers, fungicides, and emulsifiers. Methods for preparing α-olefins include alcohol dehydration, paraffin cracking, solvent extraction, Fischer-Tropsch synthesis, and ethylene oligomerization. Among them, alcohol dehydration offers a simple process, mild reaction conditions, high product purity and ease of separation, a relatively clean production process, and low energy consumption during distillation, meeting contemporary requirements for green chemical synthesis. This route has subsequently been developed into industrial-scale production. The development of new catalysts is key to resolving the technical challenges of catalytic alcohol dehydration to produce α-olefins.

[0003] CN 101940938A discloses a heteropoly acid modified alumina ethanol dehydration catalyst and a preparation method thereof; the catalyst comprises the following components by weight: a) 0.5-30 parts of heteropoly acid, b) 70-99.5 parts of alumina, wherein the heteropoly acid is selected from H X AB 12 O 40 nH2O or (NH4) m HpAB 12 O 40 nH2O has at least one heteropolyacid having a keggin structure. This invention primarily addresses the high cost and low ethylene yield issues of existing ethanol dehydration catalysts. However, the heteropolyacid catalysts of this invention are difficult to separate from the product, making catalyst recovery difficult.

[0004] CN 112275315A discloses a sulfur-modified metal-supported molecular sieve catalyst, its preparation method, and its application in the preparation of isosorbide. The sulfur-modified metal-supported molecular sieve catalyst is obtained by sequentially modifying an H-type molecular sieve with a metal salt and a sulfur-containing compound; the amount of strong acid is 0.45-0.55 mmol g -1 , the amount of weak acid is 0.18-0.31mmol g -1 , the ratio of B acid to L acid is 3-4. The catalyst realizes the formation of metal acid active center sites inside the molecular sieve, and at the same time adjusts the surface acidity and diffusion performance of the molecular sieve, so that it has a suitable ratio of B acid to L acid and good anti-coking function, which promotes the efficient dehydration reaction of sorbitol. However, the catalyst modified with sulfate ion has poor thermal stability, short service life, easy carbon deposition and deactivation, and SO4 2-It is easy to lose in liquid phase reactions, resulting in a decrease in catalytic activity, thus limiting its application in industrial production.

[0005] EP 3233765B1 discloses a heteropolyacid catalyst supported on a mixed oxide and its use in the dehydration of ethanol to produce ethylene. The supported heteropolyacid catalyst comprises the following components: i) a mixed oxide of silica and a transition metal oxide as a support, wherein silica accounts for at least 50 wt% of the weight of the mixed oxide support; or ii) a mixed oxide of zirconium oxide and different transition metal oxides as a support, wherein zirconium oxide accounts for at least 50 wt% of the weight of the mixed oxide support. The transition metal oxide is selected from oxides of Group IIIB-VIB metals, preferably oxides of Sc, Y, La, Ti, Zr, Hf, Nb, Ta, or W. Compared to conventional supported heteropolyacid catalysts, this catalyst exhibits a longer catalyst life in alcohol dehydration reactions. However, the heteropolyacid catalyst has a relatively small specific surface area, which limits its catalytic activity.

[0006] CN 108745422A discloses a 1,4-butanediol dehydration catalyst with controllable surface acidity and alkalinity, as well as a preparation method and application. In this method, a zirconia support is selected as a carrier, and the active component is loaded onto the zirconia support to obtain a supported catalyst. The catalyst prepared in this manner is used in the dehydration of 1,4-butanediol to produce 3-butene-1-ol. However, the catalyst preparation process and composition are complex, resulting in relatively low 1,4-butanediol conversion and 3-butene-1-ol selectivity.

[0007] In summary, it is difficult for existing catalysts used in the alcohol dehydration reaction to produce α-olefins to simultaneously take into account catalytic activity, product selectivity, service life and stability. Summary of the Invention

[0008] The present invention aims to overcome the problem that existing catalysts for the reaction of dehydrating alcohols to produce α-olefins are difficult to achieve simultaneously balanced catalytic activity, product selectivity, service life and stability, and to provide a catalyst for dehydrating alcohols to produce α-olefins, a preparation method thereof, and a method for dehydrating alcohols to produce α-olefins.

[0009] To achieve the above objectives, the present invention provides, in a first aspect, a catalyst for the dehydration of alcohols to produce α-olefins. The catalyst comprises, based on the total amount of the catalyst, 84-99.88 wt% of a main component, 0.04-6 wt% of a Group IIA oxide, 0.05-8 wt% of a Group IIIB oxide, and 0.03-10 wt% of a transition metal oxide; wherein the main component is selected from at least one of Group IVB oxides; and the transition metal oxide is selected from at least one of Group VIB oxides, Group VIII oxides, Group IB oxides, and Group IIB oxides.

[0010] A second aspect of the present invention provides a method for preparing a catalyst for dehydration of alcohols to produce α-olefins, wherein the method comprises: mixing a main component source, a Group IIA salt, a Group IIIB salt, and a transition metal salt in a solvent at a molar ratio of 1:0.0001-0.1:0.0001-0.1:0.0001-0.1 to obtain a mixed solution; then contacting the mixed solution with a precipitant to perform a coprecipitation reaction, and then aging the obtained reaction product; and then calcining the aged product;

[0011] Wherein, the main component is selected from at least one of Group IVB metal sources; and the transition metal salt is selected from one of Group VIB salts, Group VIII salts, Group IB salts and Group IIB salts.

[0012] The third aspect of the present invention provides a catalyst for dehydration of alcohols to produce α-olefins, prepared according to the method described in the second aspect.

[0013] A fourth aspect of the present invention provides a method for producing α-olefins by dehydrating alcohols, comprising: contacting alcohol with the catalyst for producing α-olefins by dehydrating alcohols as described in the first or third aspect in the presence or absence of a carrier gas to carry out a dehydration reaction.

[0014] Through the above technical solution, the present invention introduces Group IIA metal elements, Group IIIB metal elements and Group VIB, VIII, IB, and IIB metal elements into the main component to rationally modify the catalyst, thereby suppressing carbon deposition on the catalyst during the alcohol dehydration reaction, extending the service life of the catalyst, and efficiently carrying out the alcohol dehydration reaction to prepare α-olefins. DETAILED DESCRIPTION

[0015] The endpoints of the ranges and any values ​​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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0016] As described above, the first aspect of the present invention provides a catalyst for dehydration of alcohols to produce α-olefins, wherein, based on the total amount of the catalyst, the catalyst comprises: 84-99.88 wt% of a main component, 0.04-6 wt% of a Group IIA oxide, 0.05-8 wt% of a Group IIIB oxide, and 0.03-10 wt% of a transition metal oxide; wherein the main component is selected from at least one of Group IVB oxides; and the transition metal oxide is selected from at least one of Group VIB oxides, Group VIII oxides, Group IB oxides, and Group IIB oxides.

[0017] In the present invention, by introducing Group IIA metal elements, Group IIIB metal elements and transition metal elements into the main component to rationally modify the catalyst, the acidity and basicity of the catalyst can be controlled within a certain range, carbon deposition of the catalyst during the alcohol dehydration reaction can be suppressed, the service life of the catalyst can be significantly extended, and the efficient production of α-olefins by dehydration of alcohol can be promoted.

[0018] According to the present invention, in order to further reduce the occurrence of side reactions, under preferred conditions, based on the total amount of the catalyst, the catalyst includes: 89-99.68wt% of the main component, 0.1-4wt% of the Group IIA oxide, 0.12-3.5wt% of the Group IIIB oxide and 0.1-3.5wt% of the transition metal oxide.

[0019] In some preferred embodiments of the present invention, based on the total weight of the catalyst, the content of the Group VIB oxide is 85 parts by weight or more, preferably 89-99.68 parts by weight, per 100 parts by weight of the catalyst. For example, it can be 89 parts by weight, 89.5 parts by weight, 90 parts by weight, 90.5 parts by weight, 91 parts by weight, 91.5 parts by weight, 92 parts by weight, 92.5 parts by weight, 93 parts by weight, 93.5 parts by weight, 94 parts by weight, 94.5 parts by weight, 95 parts by weight, 95.5 parts by weight, 96 parts by weight, 96.5 parts by weight, 97 parts by weight, 97.5 parts by weight, 98 parts by weight, 98.5 parts by weight, 99 parts by weight, 99.68 parts by weight, or any value in a range consisting of any two of the above values.

[0020] In some preferred embodiments of the present invention, based on the total weight of the catalyst, the content of the Group IIA oxide is 0.04-6 parts by weight, preferably 0.1-4 parts by weight, for every 100 parts by weight of the catalyst. For example, it can be 0.1 part by weight, 0.5 part by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, or any value in the range consisting of any two of the above values.

[0021] In some preferred embodiments of the present invention, based on the total amount of the catalyst, the content of the Group IIIB oxide can be 0.05-8 parts by weight, preferably 0.12-3.5 parts by weight, per 100 parts by weight of the catalyst. For example, it can be 0.12 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, or any value in the range consisting of any two of the above values.

[0022] In some preferred embodiments of the present invention, based on the total amount of the catalyst, the content of the transition metal oxide can be 0.03-10 parts by weight, preferably 0.1-3.5 parts by weight, relative to every 100 parts by weight of the catalyst. For example, it can be 0.1 part by weight, 0.15 part by weight, 0.2 part by weight, 0.4 part by weight, 0.8 part by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, or any value in the range consisting of any two of the above values.

[0023] According to the present invention, further preferably, the weight ratio of the Group IIA oxide, the Group IIIB oxide and the transition metal oxide is 0.2-20:0.4-10:1; preferably 0.3-6:0.5-5:1; more preferably 1-5:0.5-2.5:1; under the above preferred conditions, the carbon deposition phenomenon of the catalyst in the alcohol dehydration reaction can be better suppressed, and the service life of the catalyst can be further extended.

[0024] In the present invention, in order to improve the compatibility of the main component with Group IIA oxides, Group IIIB oxides and transition metal oxides and optimize the pore diffusivity and pore structure stability of the catalyst, under preferred conditions, the main component is zirconium dioxide.

[0025] In the present invention, the Group IIA oxide is preferably at least one selected from magnesium oxide, calcium oxide, strontium oxide and barium oxide; more preferably magnesium oxide and / or calcium oxide.

[0026] In the present invention, the Group IIIB metal is preferably at least one selected from lanthanum oxide, cerium oxide, ytterbium oxide, neodymium oxide and praseodymium oxide; more preferably lanthanum oxide and / or cerium oxide.

[0027] In the present invention, the transition metal oxide is preferably selected from at least one of chromium oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide and silver oxide; more preferably nickel oxide and / or copper oxide.

[0028] In some preferred embodiments of the present invention, in the catalyst, the pore volume with a pore diameter in the range of 1.7-2.6 nm accounts for more than 65% of the total pore volume of the catalyst, preferably 70-90%; the pore volume with a pore diameter less than 1.7 nm accounts for 0-8% of the total pore volume of the catalyst; under the above preferred embodiments, the selectivity of α-olefins can be improved while reducing the carbon deposition phenomenon of the catalyst; further preferably, the pore volume of the catalyst is 0.08-0.2 mL·g -1 The specific surface area of ​​the catalyst is 40-120m 2 ·g -1 .

[0029] According to the present invention, in order to further improve the selectivity of α-olefins and reduce the carbon deposition of the catalyst, the CO2 adsorption capacity of the catalyst is 0.15-0.33 mmol·g -1 , preferably 0.27-0.33 mmol g -1 .

[0030] According to the present invention, under preferred conditions, the amount of the medium-strong acid centers of the catalyst is less than 45%, preferably less than 25%, based on the total amount of the weak acid centers and the medium-strong acid centers of the catalyst. Under the above preferred conditions, the selectivity of α-olefins can be further improved and the carbon deposition of the catalyst can be reduced.

[0031] The amount of medium-strong acid centers of the catalyst refers to the amount of NH3 desorbed by the catalyst at 250-450° C. using the NH3-TPD test method.

[0032] In the present invention, the specific surface area, pore volume and the ratio of pore volumes of different pore diameters of the catalyst are measured by nitrogen adsorption-desorption method, for details refer to GB / T6609.35-2009.

[0033] The present invention does not particularly limit the composition of the main component and the Group IIA oxide, Group IIIB oxide, and transition metal oxide. The Group IIA oxide, Group IIIB oxide, and transition metal oxide may be supported on the main component or dispersed within the main component; in the present invention, dispersion within the main component is preferred. In the present invention, the dispersion or support of the Group IIA oxide, Group IIIB oxide, and transition metal oxide has little effect on the microstructure of the catalyst. Therefore, the resulting catalyst has a pore structure similar to that of the main component.

[0034] In the present invention, the catalyst can be prepared by an existing method.

[0035] A second aspect of the present invention provides a method for preparing a catalyst for dehydration of alcohols to produce α-olefins, wherein the method comprises: mixing a main component source, a Group IIA salt, a Group IIIB salt, and a transition metal salt in a solvent at a molar ratio of 1:0.0001-0.1:0.0001-0.1:0.0001-0.1 to obtain a mixed solution; then contacting the mixed solution with a precipitant to perform a coprecipitation reaction, and aging the obtained reaction product; and then calcining the aged product; wherein the main component is selected from at least one of the Group IVB metal sources; and the transition metal salt is selected from one of the Group VIB salt, the Group VIII salt, the Group IB salt, and the Group IIB salt.

[0036] In the above catalyst preparation method, those skilled in the art will understand that: if the main component source already contains the required amount of Group IIA salt, Group IIIB salt and transition metal salt, then only this raw material (main component source) needs to be used for molding; if the raw material providing the main component source does not contain Group IIA salt, Group IIIB salt and transition metal salt or the content of the elements is low (insufficient), then the required elements can be additionally introduced.

[0037] In the present invention, since the Group IIA salt, Group IIIB salt and transition metal salt are introduced during the preparation of the main component, the Group IIA salt, Group IIIB salt and transition metal salt are mainly present in the bulk phase of the main component, that is, dispersed in the main component.

[0038] According to the present invention, under preferred conditions, the main component source is selected from at least one of zirconium oxychloride, zirconium nitrate, zirconyl nitrate and zirconyl sulfate.

[0039] Further preferably, the precipitant is selected from at least one of ammonia water, urea, sodium hydroxide and sodium carbonate.

[0040] In the present invention, the Group IIA salt is present in the form of a Group IIA salt solution (referred to as solution A), and the Group IIA salt is selected from at least one of Group IIA nitrates, Group IIA formates, Group IIA oxalates, and Group IIA lactates; preferably, it is a Group IIA nitrate; further preferably, the Group IIA nitrate is selected from at least one of magnesium nitrate, calcium nitrate, strontium nitrate, and barium nitrate, preferably magnesium nitrate and / or calcium nitrate; the solvent in the solution is selected from water and / or ethanol, preferably water.

[0041] In the present invention, the Group IIIB salt is present in the form of a Group IIIB salt solution (referred to as solution B), and the Group IIIB salt is selected from at least one of Group IIIB nitrates, Group IIIB formates, Group IIIB oxalates, and Group IIIB lactates; preferably, it is a Group IIIB nitrate; further preferably, the Group IIIB nitrate is selected from at least one of lanthanum nitrate, cerium nitrate, neodymium nitrate, and praseodymium nitrate, preferably, lanthanum nitrate and / or cerium nitrate; the solvent in the solution is selected from water and / or ethanol, preferably, water.

[0042] In the present invention, the transition metal salt is present in the form of a solution of a transition metal salt (referred to as solution C), and the transition metal salt is selected from at least one of transition metal nitrates, transition metal formates, transition metal oxalates and transition metal lactates; preferably, a transition metal nitrate; further preferably, the transition metal nitrate is selected from at least one of chromium nitrate, iron nitrate, cobalt nitrate, nickel nitrate, copper nitrate, zinc nitrate and silver nitrate, preferably nickel nitrate and / or copper nitrate; the solvent in the solution is selected from water and / or ethanol, preferably water.

[0043] In the present invention, solution A, solution B, and solution C can be mixed and then added to the system containing the main component source, or they can be added separately to the system containing the main component source; when they are added separately to the system containing the main component source, there is no special limitation on the order of adding solution A, solution B, and solution C.

[0044] According to the present invention, under preferred conditions, the aging conditions include: a temperature of 50-90°C, for example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, or any value in the range consisting of any two of the above values; preferably, the aging time is 1-9h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, or any value in the range consisting of any two of the above values.

[0045] According to the present invention, under preferred conditions, the method further comprises: centrifuging, washing and drying the product obtained by aging; wherein, the drying time can be reasonably selected according to the drying temperature, the amount of material and the type of drying equipment, so that the moisture content of the dried material does not affect the subsequent roasting. Under preferred conditions, the drying temperature is 80-150°C, for example, it can be 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C or any value in the range formed by any two of the above values; the drying time is 5-20h; for example, it can be 5h, 5.5h, 6h, 6. 5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h, 15h, 15.5h, 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h, or any value in the range of any two of the above values.

[0046] According to the present invention, roasting can remove the crystal water in the salt and decompose the salt to generate oxides. Under preferred conditions, the roasting conditions include: a temperature of 500-1100°C and a time of 2-20h; illustratively, the roasting temperature can be 500°C, 525°C, 550°C, 600°C, 625°C, 650°C, 675°C, 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C or any value in the range of any two of the above values; the roasting The time can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h, 15h, 15.5h, 16h, 16.5h, 17h, 17.5h, 18h, 18.5h, 19h, 19.5h, 20h or any value in the range composed of any two of the above values.

[0047] The third aspect of the present invention provides a catalyst for dehydration of alcohols to produce α-olefins, prepared according to the method described in the second aspect.

[0048] Preferably, based on the total amount of the catalyst, the catalyst comprises: 84-99.88 wt% of a main component, 0.04-6 wt% of a Group IIA oxide, 0.05-8 wt% of a Group IIIB oxide, and 0.03-10 wt% of a transition metal oxide; wherein the main component is selected from at least one of Group IVB oxides; and the transition metal oxide is selected from at least one of Group VIB oxides, Group VIII oxides, Group IB oxides, and Group IIB oxides;

[0049] Preferably, the weight ratio of the Group IIA oxide, the Group IIIB oxide and the transition metal oxide is 0.2-20:0.4-10:1; preferably 0.3-6:0.5-5:1; more preferably 1-5:0.5-2.5:1.

[0050] Preferably, in the catalyst, the pore volume with a pore diameter in the range of 1.7-2.6 nm accounts for more than 65% of the total pore volume of the catalyst, preferably 70-90%; the pore volume with a pore diameter less than 1.7 nm accounts for 0-8% of the total pore volume of the catalyst; the pore volume of the catalyst is 0.08-0.2 mL·g -1 .

[0051] Preferably, the specific surface area of ​​the catalyst is 40-120m 2 ·g -1 .

[0052] Preferably, the CO2 adsorption capacity of the catalyst is 0.15-0.33 mmol·g -1 , preferably 0.27-0.33mmolg -1 .

[0053] Preferably, the amount of the medium-strong acid centers of the catalyst is less than 45%, preferably less than 25%, based on the total amount of the weak acid centers and the medium-strong acid centers of the catalyst.

[0054] A fourth aspect of the present invention provides a method for producing α-olefins by dehydrating alcohols, wherein the method comprises: in the presence or absence of a carrier gas, contacting alcohol with the catalyst for producing α-olefins by dehydrating alcohols according to the first aspect or the third aspect to carry out a dehydration reaction.

[0055] Preferably, the dehydration reaction conditions include: temperature of 240-370°C, preferably 250-350°C; pressure of 0.085-0.25 MPa; liquid phase volume space velocity of 0.1-0.8h -1 , preferably 0.15-0.6h -1 ;

[0056] Preferably, when carrier gas is present, the flow rate of the carrier gas is 15-45 mL min -1 , preferably 18-38 mL min -1 .

[0057] According to the present invention, under preferred conditions, the alcohol is selected from C2-C 18 further preferably, the alcohol is selected from at least one of 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-undecanol, 2-dodecanol, 2-tridecanol, 2-tetradecanol, 2-hexadecanol, 2-heptadecanol and 2-octadecanol.

[0058] In the following examples, the elemental composition of the catalysts was analyzed by ICP-MS; the testing instrument was VISTA Pro CCD spectrometer (Varian);

[0059] The specific surface area, pore volume, and the proportion of pore volume of different pore sizes of the catalyst were measured using the BET (Bettmann-Emmett-Teller) method. For details, refer to GB / T 6609.35-2009. Instrument name: Automatic Micropore & Chemisorption Analyzer (ASAP2420, Micromeritics, USA).

[0060] The CO2 desorption capacity of the catalyst was tested by CO2-TPD, the desorption temperature was 100-600℃, and the test conditions were: accurately weigh about 0.1g of sample into the sample tube, and under the condition of He gas purge, the sample was desorbed at 10℃ min -1 Raise to 600℃, stay for 1h, then reduce to 120℃, change the gas to 10% CO2-He mixture, adsorb for 60min, then change to He gas purge for 1h, start counting after the baseline is stable, and use 10℃ min -1 The temperature was raised to 600°C and maintained for 30 minutes. The recording was stopped, and the experiment was completed. The peak area was integrated to calculate the CO2 desorption amount (the basicity of the catalyst). The instrument used was an Automated Catalyst Characterization System (Autochem 2920, manufactured by MICROMERITICS, USA).

[0061] The amount of medium-strong acidic centers in the catalyst was tested by NH3-TPD with a desorption temperature of 250-450°C. The test conditions were: accurately weigh about 0.1g of sample into a sample tube and desorb at 10°C / min under He purge conditions. -1 Raise to 600℃, stay for 1h, then reduce to 120℃, change the gas to 10% NH3-He mixed gas, adsorb for 60min, then change to He gas purge for 1h, start counting after the baseline is stable, and calculate at 10℃·min -1 Raise the temperature to 600°C and hold for 30 minutes. Stop recording and the experiment is complete. Integrate the peak area to calculate the NH3 desorption amount. Test instrument: Automated Catalyst Characterization System (Autochem 2920, manufactured by MICROMERITICS, USA).

[0062] The amount of weak acid centers of the catalyst is tested using NH3-TPD with a desorption temperature of 100-250°C. The specific test method is the same as the acid site test method.

[0063] The carbon deposits on the catalyst were measured using an O2-TPO test. The test conditions were as follows: 0.2 g of sample was accurately weighed, and argon was used as the carrier gas at a flow rate of 40 mL / min. The sample was pretreated at 150°C for 60 minutes, then cooled to 100°C. A mixture of oxygen and argon (20% oxygen by volume) was used as the analytical gas at a flow rate of 40 mL / min. The sample was then subjected to a temperature-programmed oxidation process at a rate of 10°C / min to 900°C. The CO2 and CO gas signals were detected during the temperature-programmed oxidation process. The test instrument was a fully automatic temperature-programmed chemical adsorption instrument (AutoChem II 2920, manufactured by Micromeritics, USA).

[0064] Example 1

[0065] Dissolve 1.62 mol zirconium oxynitrate, 0.053 mol calcium nitrate tetrahydrate, 0.034 mol lanthanum nitrate, and 0.002 mol chromium nitrate nonahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 , Ca 2+ The concentration is 0.018 mol L -1 、La 3+ The concentration is 0.011 mol L -1 Cr 3+ The concentration is 0.0007 mol L -1 A mixed solution of 25 wt% ammonia solution was prepared; in a 75°C water bath with vigorous stirring, an aqueous ammonia solution (25 wt%) was added dropwise to adjust the pH to 10.2 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.4 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 80°C for 2 h and then at 120°C for 2 h; finally, the dried product was calcined in a muffle furnace at 500°C for 2 h to obtain a sample ZrO2 / CaO / La2O3 / Cr2O3, which was designated as catalyst C-1. The test results are shown in Tables 1 and 2.

[0066] Example 2

[0067] Dissolve 1.61 mol zirconium oxynitrate, 0.141 mol calcium nitrate tetrahydrate, 0.0014 mol praseodymium nitrate tetrahydrate, and 0.086 mol ferric nitrate nonahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 , Ca 2+ The concentration is 0.047 mol L -1 、Pr 3+ The concentration is 0.0005 mol L -1 、Fe 3+ The concentration is 0.029 mol L -1a mixed solution; in an 80°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 9.9 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.5 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 85°C for 2 h and then at 130°C for 2 h; finally, the dried product was calcined in a muffle furnace at 650°C for 2 h to obtain a sample ZrO2 / CaO / Pr2O3 / Fe2O3, recorded as catalyst C-2, and the test results are shown in Tables 1 and 2.

[0068] Example 3

[0069] Dissolve 1.60 mol zirconium oxynitrate, 0.0035 mol calcium nitrate tetrahydrate, 0.041 mol neodymium nitrate, and 0.017 mol cobalt nitrate hexahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.53 mol L -1 , Ca 2+ The concentration is 0.0012 mol L -1 、Nd 3+ The concentration is 0.014 mol L -1 、Co 3+ The concentration is 0.006 mol L -1 A mixed solution of 25 wt% ammonia was added dropwise in a 90°C water bath with vigorous stirring to adjust the pH to 10 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.65 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 90°C for 2 h and then at 125°C for 2 h; finally, the dried product was calcined in a muffle furnace at 900°C for 2 h to obtain a sample ZrO2 / CaO / Nd2O3 / CoO, recorded as catalyst C-3. The test results are shown in Tables 1 and 2.

[0070] Example 4

[0071] Dissolve 1.59 mol zirconium oxynitrate, 0.04 mol calcium nitrate tetrahydrate, 0.0038 mol cerium nitrate, and 0.0034 mol nickel nitrate hexahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.53 mol L -1 , Ca 2+ The concentration is 0.013 mol L -1 、Ce 3+ The concentration is 0.0013 mol L -1 、Ni 2+ The concentration is 0.0011 mol L -1a mixed solution; in a 70°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10.1 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.4 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 95°C for 2 h and then at 140°C for 2 h; finally, the dried product was calcined in a muffle furnace at 700°C for 2 h to obtain a sample ZrO2 / CaO / CeO2 / NiO, recorded as catalyst C-4, and the test results are shown in Tables 1 and 2.

[0072] Example 5

[0073] Dissolve 1.58 mol zirconium oxynitrate, 0.049 mol calcium nitrate tetrahydrate, 0.0079 mol lanthanum nitrate, and 0.008 mol copper nitrate trihydrate in 3 L of deionized water to prepare a zirconium concentration of 0.53 mol L -1 , Ca 2+ The concentration is 0.0163 mol L -1 、La 3+ The concentration is 0.0026 mol L -1 、Cu 2+ The concentration is 0.0027 mol L -1 A mixed solution of 25 wt% ammonia solution was prepared; in a 65°C water bath with vigorous stirring, an aqueous ammonia solution (25 wt%) was added dropwise to adjust the pH to 10.2 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.7 h; it was then centrifuged and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 80°C for 2 h and then at 130°C for 2 h; finally, the dried product was calcined in a muffle furnace at 600°C for 2 h to obtain a sample ZrO2 / CaO / La2O3 / CuO, which was designated as catalyst C-5. The test results are shown in Tables 1 and 2.

[0074] Example 6

[0075] Dissolve 1.62 mol zirconium oxynitrate, 0.088 mol calcium nitrate tetrahydrate, 0.002 mol ytterbium nitrate, and 0.003 mol zinc nitrate hexahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 , Ca 2+ The concentration is 0.029 mol L -1 、Yb 3+ The concentration is 0.0007 mol L -1 、Zn 2+ The concentration is 0.001 mol L -1a mixed solution; in a 60°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 9.9 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.3 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 85°C for 2 h and then at 135°C for 2 h; finally, the dried product was calcined in a muffle furnace at 550°C for 2 h to obtain a sample ZrO2 / CaO / Yb2O3 / ZnO, recorded as catalyst C-6. The test results are shown in Table 1.

[0076] Example 7

[0077] Dissolve 1.63 mol zirconium oxynitrate, 0.064 mol magnesium nitrate, 0.010 mol cerium nitrate, and 0.032 mol nickel nitrate hexahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 Mg 2+ The concentration is 0.021 mol L -1 、Ce 3+ The concentration is 0.003 mol L -1 、Ni 2+ The concentration is 0.011 mol L -1 a mixed solution; in a 75°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.8 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 90°C for 2 h and then at 140°C for 2 h; finally, the dried product was calcined in a muffle furnace at 750°C for 2 h to obtain a sample ZrO2 / MgO / CeO2 / NiO, recorded as catalyst C-7, and the test results are shown in Tables 1 and 2.

[0078] Example 8

[0079] Dissolve 1.6 mol zirconium oxynitrate, 0.077 mol barium nitrate, 0.0006 mol lanthanum nitrate, and 0.124 mol copper nitrate trihydrate in 3 L of deionized water to prepare a zirconium concentration of 0.53 mol L -1 、Ba 2+ The concentration is 0.026 mol L -1 、La 3+ The concentration is 0.0002 mol L -1 、Cu 2+ The concentration is 0.041 mol L -1a mixed solution; in an 80°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10.1 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.9 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 90°C for 2 h and then at 115°C for 2 h; finally, the dried product was calcined in a muffle furnace at 600°C for 2 h to obtain a sample ZrO2 / BaO / La2O3 / CuO, denoted as catalyst C-8. The test results are shown in Tables 1 and 2.

[0080] Example 9

[0081] Dissolve 1.59 mol zirconium oxynitrate, 0.0008 mol strontium nitrate, 0.09 mol cerium nitrate, and 0.0012 mol copper nitrate trihydrate in 3 L of deionized water to prepare a zirconium concentration of 0.53 mol L -1 、Sr 2+ The concentration is 0.0003 mol L -1 、Ce 3+ The concentration is 0.03 mol L -1 、Cu 2+ The concentration is 0.0004 mol L -1 a mixed solution; in an 85°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10.2 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.2 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 90°C for 2 h and then at 125°C for 2 h; finally, the dried product was calcined in a muffle furnace at 800°C for 2 h to obtain a sample ZrO2 / BaO / La2O3 / CuO, recorded as catalyst C-9. The test results are shown in Tables 1 and 2.

[0082] Comparative Example 1

[0083] The catalyst was prepared according to the method of Example 4, except that pseudo-boehmite powder (specific surface area 398m 2 g -1 , pore volume 0.99 mL g -1 , the sulfur content is 0.85g per 100g of Al2O3 powder) as the main component source, and the sample Al2O3 / CaO / CeO2 / NiO was obtained, which was recorded as catalyst D-1. The test results are shown in Tables 1 and 2.

[0084] Comparative Example 2

[0085] The catalyst was prepared according to the method of Example 4, except that zirconium oxide powder was used as the main component source to obtain a sample of ZrO2 (powder) / CaO / CeO2 / NiO, which was recorded as catalyst D-2. The test results are shown in Tables 1 and 2.

[0086] Comparative Example 3

[0087] Dissolve 1.62 mol zirconium oxynitrate, 0.053 mol calcium nitrate tetrahydrate, and 0.034 mol lanthanum nitrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 , Ca 2+ The concentration is 0.018 mol L -1 、La 3+ The concentration is 0.011 mol L -1 a mixed solution; in a 75°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10.2 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.4 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 80°C for 2 h and then at 120°C for 2 h; finally, the dried product was calcined in a muffle furnace at 500°C for 2 h to obtain a sample ZrO2 / CaO / La2O3, recorded as catalyst D-3, and the test results are shown in Tables 1 and 2.

[0088] Comparative Example 4

[0089] The catalyst was prepared according to the method of Example 1, except that 0.3 mol of chromium nitrate nonahydrate was weighed and dissolved in 3 L of deionized water to obtain a sample ZrO2 / CaO / La2O3 / Cr2O3, which was recorded as catalyst D-4. The test results are shown in Tables 1 and 2.

[0090] Comparative Example 5

[0091] Dissolve 1.62 mol zirconium oxynitrate, 0.053 mol calcium nitrate tetrahydrate, and 0.002 mol chromium nitrate nonahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 , Ca 2+ The concentration is 0.018 mol L -1 Cr 3+ The concentration is 0.0007 mol L -1a mixed solution; in a 75°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10.2 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.4 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 80°C for 2 h and then at 120°C for 2 h; finally, the dried product was calcined in a muffle furnace at 500°C for 2 h to obtain a sample ZrO2 / CaO / Cr2O3, recorded as catalyst D-5, and the test results are shown in Tables 1 and 2.

[0092] Comparative Example 6

[0093] The catalyst was prepared according to the method of Example 1, except that 0.12 mol of lanthanum nitrate was weighed and dissolved in 3 L of deionized water to obtain a sample ZrO2 / CaO / La2O3 / Cr2O3, which was recorded as catalyst D-6. The test results are shown in Tables 1 and 2.

[0094] Comparative Example 7

[0095] Dissolve 1.62 mol zirconium oxynitrate, 0.034 mol lanthanum nitrate, and 0.002 mol chromium nitrate nonahydrate in 3 L of deionized water to prepare a zirconium concentration of 0.54 mol L -1 、La 3+ The concentration is 0.011 mol L -1 Cr 3+ The concentration is 0.0007 mol L -1 a mixed solution; in a 75°C water bath with vigorous stirring, adding an aqueous ammonia solution (25 wt%) dropwise to adjust the pH to 10.2 to obtain a precipitate system; the precipitate system was allowed to stand in a beaker for 2.4 h; then centrifuged, and the obtained precipitate was washed with deionized water to a pH of 6.5, followed by drying at 80°C for 2 h and then at 120°C for 2 h; finally, the dried product was calcined in a muffle furnace at 500°C for 2 h to obtain a sample ZrO2 / La2O3 / Cr2O3, recorded as catalyst D-7. The test results are shown in Tables 1 and 2.

[0096] Comparative Example 8

[0097] The catalyst was prepared according to the method of Example 1, except that 0.28 mol of calcium nitrate tetrahydrate was weighed and dissolved in 3 L of deionized water to obtain a sample ZrO2 / La2O3 / Cr2O3, which was recorded as catalyst D-8. The test results are shown in Tables 1 and 2.

[0098] Comparative Example 9

[0099] The catalyst was prepared according to the method of Example 1, except that the calcination temperature during the preparation of the catalyst was 250°C. The sample ZrO2 / CaO / La2O3 / Cr2O3 (250°C) was obtained and was recorded as catalyst D-9. The test results are shown in Tables 1 and 2.

[0100] Comparative Example 10

[0101] The catalyst was prepared according to the method of Example 1, except that the calcination temperature during the preparation of the catalyst was 1200°C. The sample ZrO2 / CaO / La2O3 / Cr2O3 (1000°C) was obtained and was recorded as catalyst D-10. The test results are shown in Tables 1 and 2.

[0102] Table 1

[0103]

[0104]

[0105] Note: * The content refers to the weight of Group IIA oxide relative to 100 g of catalyst;

[0106] ** The content refers to the weight of Group IIIB oxide relative to 100 g of catalyst;

[0107] *** The content refers to the weight of the transition metal oxide relative to 100 g of the catalyst.

[0108] Table 2

[0109]

[0110] Note: * Medium-strong acid refers to the percentage of the medium-strong acid center of the catalyst based on the total amount of the weak acid center and the medium-strong acid center of the catalyst;

[0111] ** 1.7-2.6 nm refers to the percentage of pore volume with pore diameters within the range of 1.7-2.6 nm to the total pore volume of the composite catalyst.

[0112] Test Example 1

[0113] This test example is used to illustrate the method for preparing 4-methyl-1-pentene by dehydrating methyl isobutyl carbinol (MIBC).

[0114] Weigh 50 mL of catalyst and load it into a fixed bed reactor. Use nitrogen to preheat at 300 ° C for 1 hour. Use a metering pump to feed methyl isobutyl carbinol into the reaction system. The liquid phase volume space velocity of methyl isobutyl carbinol is 0.3 h -1The dehydration reaction was carried out in the reactor at a temperature of 310°C and a pressure of 0.1 MPa. After the reaction stabilized (i.e., after 500 hours of reaction), the reaction liquid was sampled and analyzed. The analysis results are listed in Table 3.

[0115] The sampling and analysis method is gas chromatography, which is calibrated by preparing correction factors of standard samples;

[0116] The conversion rate and selectivity were calculated based on the molar content of each component in the reaction solution (methyl isobutyl carbinol is abbreviated as MIBC, 4-methyl-1-pentene is 4MP1, 4-methyl-2-pentene is 4MP2, and methyl isobutyl ketone is MIBK).

[0117] MIBC conversion rate = 100% - n1 / [(n1+n2+n3+n4)+2×n5]×100%

[0118] 4MP1 selectivity = n2 / [(n2+n3+n4)+2×n5]×100%

[0119] 4MP2 selectivity = n3 / [(n2+n3+n4)+2×n5]×100%

[0120] Wherein, n1 is the molar content of MIBC in the reaction solution; n2 is the molar content of 4MP1 in the reaction solution; n3 is the molar content of 4MP2 in the reaction solution; n4 is the molar content of MIBK in the reaction solution; and n5 is the molar content of oligomers in the reaction solution.

[0121] 4MP1 ratio = 4MP1 / (4MP2+4MP1)×100%

[0122] The 4MP1 ratio is the ratio of 4MP1 selectivity to the sum of 4MP1 and 4MP2 selectivities, that is, the ratio of α-olefin to the sum of α-olefin and β-olefin, indicating that the product generated by the reaction contains more α-olefin, that is, the selectivity of α-olefin is high.

[0123] Table 3

[0124]

[0125]

[0126] It can be seen from the data in Table 3 that the conversion rates of the catalysts C-1 to C-9 of the present invention are higher than those of the comparative catalysts D-1 to D-10.

[0127] The above catalysts were unloaded and characterized after continuous reaction for 1800 hours. The results showed that the carbon deposits of catalysts C-1 to C-9 prepared in the examples of the present invention were all less than 2 wt%; while the carbon deposits of catalysts D-1 to D-10 prepared in the comparative example were 3.8-10 wt%, indicating that catalysts C-1 to C-9 prepared in the examples of the present invention had better stability and less carbon deposits.

[0128] After 1800 h of catalytic reaction, the conversion rate and selectivity of catalysts C-1 to C-9 did not change significantly compared with those at 500 h; the conversion rate of MIBC decreased by no more than 1.5%, and the reduction in the proportion of 4MP1 was no more than 1%; while the conversion rate and the proportion of 4MP1 of D-1 to D-10 were significantly reduced after 1800 h of catalytic reaction compared with those at 500 h, with the reduction in conversion rate being 14-36% and the reduction in 4MP1 proportion being 20%-50%; this indicates that the catalysts prepared in accordance with the embodiments of the present invention have a longer service life.

[0129] Test Example 2

[0130] This test example is used to illustrate the method for preparing 1-pentene by dehydrating 2-pentanol.

[0131] 50 mL of the catalyst of Example 4 was weighed and loaded into a fixed-bed reactor. The reactor was preheated at 300°C for 1 h using nitrogen. 2-pentanol was fed into the reaction system using a metering pump. The liquid phase volumetric space velocity of 2-pentanol was 0.4 h -1 The dehydration reaction was carried out in the reactor at a temperature of 310°C and a pressure of 0.1 MPa. After the reaction stabilized (i.e., after 500 hours of reaction), the reaction liquid was sampled and analyzed. The analysis results are listed in Table 4.

[0132] The sampling and analysis method is gas chromatography analysis, which is calibrated by preparing correction factors of standard samples; the conversion rate and selectivity are calculated based on the molar content of each component in the reaction solution.

[0133] 2-pentanol conversion rate = 100% - w1 / [(w1+w2+w3)+2×w4]×100%

[0134] 1-Pentene selectivity = w2 / [(w2+w3)+2×w4]×100%

[0135] 2-pentene selectivity = w3 / [(w2+w3)+2×w4]×100%

[0136] w1 is the molar content of 2-pentanol in the reaction solution; w2 is the molar content of 1-pentene in the reaction solution; w3 is the molar content of 2-pentene in the reaction solution; and w4 is the molar content of oligomers in the reaction solution.

[0137] 1-pentene ratio = 1-pentene / (2-pentene + 1-pentene) × 100%

[0138] The 1-pentene ratio is the ratio of 1-pentene selectivity to the sum of 1-pentene and 2-pentene selectivities, that is, the ratio of α-olefins to the sum of α-olefins and β-olefins, indicating that the products generated by the reaction have more α-olefins, that is, the selectivity of α-olefins is high.

[0139] Table 4

[0140] Reaction time 2-pentanol conversion, % 1-pentene proportion, % 500h 92.52 90.3 1800h 92.47 89.9

[0141] As can be seen from Table 4, in the reaction of catalyzing the dehydration of 2-pentanol to produce 2-pentene by catalyst A-4, the conversion rate of 2-pentanol is as high as 92.52%, and the selectivity of 1-pentene is as high as 90.3%. After 1800 hours of catalytic reaction, the conversion rate of 2-pentanol and the selectivity of 1-pentene do not change significantly compared with those after 500 hours, indicating that the catalyst obtained in this embodiment of the present invention has a long service life.

[0142] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A catalyst for dehydration of alcohols to α-olefins, characterized in that: Based on the total amount of the catalyst, the catalyst comprises: 84-99.88 wt% of a main component, 0.04-6 wt% of a Group IIA oxide, 0.05-8 wt% of a Group IIIB oxide, and 0.03-3.5 wt% of a transition metal oxide; Wherein, the main component is selected from zirconium oxide in Group IVB oxides; The Group IIA oxide is at least one selected from magnesium oxide, calcium oxide, strontium oxide and barium oxide; The Group IIIB oxide is at least one selected from lanthanum oxide, cerium oxide, ytterbium oxide, neodymium oxide and praseodymium oxide; The transition metal oxide is selected from at least one of Group VIB oxides, Group VIII oxides, Group IB oxides and Group IIB oxides; The pore volume of the catalyst is 0.08-0.2 mL·g -1 ; The amount of medium-strong acid centers of the catalyst is less than 45% based on the total amount of weak acid centers and medium-strong acid centers of the catalyst; the amount of medium-strong acid centers of the catalyst refers to the amount of NH3 desorbed by the catalyst at 250-450°C using the NH3-TPD test method; the amount of weak acid centers of the catalyst refers to the amount of NH3 desorbed by the catalyst at 100-250°C using the NH3-TPD test method.

2. The catalyst according to claim 1, wherein Based on the total amount of the catalyst, the catalyst comprises: 89-99.68 wt% of a main component, 0.1-4 wt% of a Group IIA oxide, 0.12-3.5 wt% of a Group IIIB oxide, and 0.1-3.5 wt% of a transition metal oxide.

3. The catalyst according to claim 1 or 2, wherein The weight ratio of the Group IIA oxide, the Group IIIB oxide and the transition metal oxide is 0.2-20:0.4-10:

1.

4. The catalyst according to claim 3, wherein The weight ratio of the Group IIA oxide, the Group IIIB oxide and the transition metal oxide is 0.3-6:0.5-5:

1.

5. The catalyst according to claim 1 or 2, wherein The transition metal oxide is selected from at least one of chromium oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide and silver oxide.

6. The catalyst according to claim 1 or 2, wherein In the catalyst, the pore volume with a pore diameter in the range of 1.7-2.6 nm accounts for more than 65% of the total pore volume of the catalyst.

7. The catalyst according to claim 6, wherein In the catalyst, the pore volume with a pore diameter in the range of 1.7-2.6 nm accounts for 70-90% of the total pore volume of the catalyst.

8. The catalyst according to claim 1 or 2, wherein The specific surface area of ​​the catalyst is 40-120m 2 ·g -1 .

9. The catalyst according to any one of claims 1 or 2, wherein The CO2 adsorption capacity of the catalyst is 0.15-0.33 mmol·g -1 .

10. The catalyst according to claim 1 or 2, wherein The amount of the medium-strong acidic centers of the catalyst is less than 25% based on the total amount of the weak acidic centers and the medium-strong acidic centers of the catalyst.

11. A method for preparing the catalyst for dehydration of alcohols to α-olefins according to any one of claims 1 to 10, characterized in that: The method comprises: mixing a main component source, a Group IIA salt, a Group IIIB salt, and a transition metal salt in a solvent at a molar ratio of 1:0.0001-0.1:0.0001-0.1:0.0001-0.1 to obtain a mixed solution; then contacting the mixed solution with a precipitant to perform a coprecipitation reaction, and then aging the obtained reaction product; and then calcining the aged product. wherein the main component is selected from at least one of the Group IVB metal sources; The transition metal salt is selected from one of Group VIB salts, Group VIII salts, Group IB salts and Group IIB salts.

12. The method according to claim 11, wherein The main component source is selected from at least one of zirconium oxychloride, zirconium nitrate, zirconyl nitrate and zirconyl sulfate.

13. The method according to claim 11 or 12, wherein: The precipitant is selected from at least one of ammonia water, urea, sodium hydroxide and sodium carbonate.

14. The method according to claim 11 or 12, wherein: The aging conditions include: temperature of 50-90° C. and time of 1-9 hours.

15. The method according to claim 11 or 12, wherein: The calcination conditions include: a temperature of 500-1100° C. and a time of 2-20 hours.

16. A catalyst for dehydration of alcohols to produce α-olefins prepared by the method according to any one of claims 11 to 15.

17. A method for preparing α-olefins by dehydrating alcohols, characterized in that: The method comprises: in the presence or absence of a carrier gas, contacting alcohol with the catalyst for alcohol dehydration to α-olefins according to any one of claims 1 to 10 and 16 to carry out a dehydration reaction.

18. The method according to claim 17, wherein: The dehydration reaction conditions include: temperature of 240-370°C; pressure of 0.085-0.25 MPa; liquid phase volume space velocity of 0.1-0.8 h -1 .

19. The method according to claim 18, wherein The dehydration reaction conditions include: temperature of 250-350°C; liquid phase volume space velocity of 0.15-0.6 h -1 .

20. The method according to any one of claims 17 to 19, wherein: When carrier gas is present, the flow rate of the carrier gas is 15-45 mL·min -1 .

21. The method according to claim 20, wherein When carrier gas is present, the flow rate of the carrier gas is 18-38 mL·min -1 .

22. The method according to any one of claims 17 to 19, wherein: The alcohol is selected from C2-C 18 of alcohol.

23. The method according to claim 22, wherein The alcohol is selected from at least one of 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-undecanol, 2-dodecanol, 2-tridecanol, 2-tetradecanol, 2-hexadecanol, 2-heptadecanol, and 2-octadecanol.

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