A solid acid catalyst, its preparation method and application

Abstract

This invention discloses a solid acid catalyst, its preparation method, and its application. The solid acid catalyst, based on its weight and by mass fraction, comprises: a) 54%–98% alumina support; b) 1%–30% at least one metal selected from Group IVB and / or Group IV; c) 0.001%–1% Pt metal; d) 0.1%–5% at least one metal selected from Group IIA; e) 0.1%–10% sulfate ions; the sum of the strong acid content and the medium-strong acid content of the catalyst accounts for ≥80% of the total acid content of the catalyst; the proportion of the strong acid content to the total acid content of the catalyst is ≤50%. This catalyst is used in the toluene disproportionation and alkyl transfer reaction, and features low reaction temperature, low hydrogen consumption, and good stability.

Description

Technical Field

[0001] This invention belongs to the field of solid catalysts, specifically relating to a solid acid catalyst, its preparation method, and its application. Background Technology

[0002] Toluene disproportionation and alkyl transfer reactions are among the core reactions in aromatic hydrocarbon complexes, and the product xylene is an important organic feedstock. Improving the catalytic performance of catalysts to reduce energy and material consumption in the disproportionation and alkyl transfer processes is a crucial way to reduce costs and increase efficiency in this process. Alkyl transfer reactions are acid-catalyzed reactions, and controlling the acid properties of solid acids to match this reaction is a key research focus in catalyst design. Solid acid catalysts are widely used in various industrial production processes. Among them, solid superacids obtained after sulfation are an important type of solid acid. Metal oxides generally achieve a significant increase in acid strength after sulfation. By adding promoters to control the distribution of acid strength, the acid properties of the catalyst can be matched with the reaction.

[0003] CN113492016A discloses a two-component catalyst for toluene disproportionation and alkyl transfer, and its preparation method. The catalyst comprises a modified needle-shaped MOR molecular sieve and a modified nano-ZSM-5 molecular sieve. The modified needle-shaped MOR molecular sieve is prepared by impregnation and modification of needle-shaped hydrogen-form MOR molecular sieves with an aspect ratio of 3–10:1 using inorganic oxides. The modified nano-ZSM-5 molecular sieve is prepared by impregnation and modification of hydrogen-form nano-ZSM-5 molecular sieves with a particle size of 50–300 nm using inorganic oxides. The inorganic oxides are one or more oxides of Co, Mo, Ru, Cu, Be, and W. When using this catalyst, the reaction temperature is required to be 300–500℃, and the hydrogen-to-hydrogen ratio is required to be 10:1–1:1.

[0004] CN102909066A discloses a toluene disproportionation and alkyl transfer catalyst. This catalyst is composed of a hydrogen-form EU-1 / Beta composite molecular sieve, an inorganic refractory oxide, and a second metal component. CN102909068A discloses a toluene disproportionation and alkyl transfer catalyst. This catalyst is composed of a hydrogen-form EU-1 / ZSM-5 composite molecular sieve, an inorganic refractory oxide, and a second metal component.

[0005] In summary, current research on toluene disproportionation and alkyl transfer catalysts mainly focuses on molecular sieve systems, and the reaction temperatures and hydrogen consumption are generally high. There are few literature reports on the use of sulfated metal oxide systems for low-temperature reactions. Summary of the Invention

[0006] To address the issues of high reaction temperature and hydrogen consumption in the toluene disproportionation and alkyl transfer reaction of existing technologies, this invention provides a novel solid acid catalyst, its preparation method, and its application. This catalyst, used in the toluene disproportionation and alkyl transfer reaction, features low reaction temperature, low hydrogen consumption, and good stability.

[0007] The first aspect of this invention provides a solid acid catalyst, which, based on the weight of the catalyst and expressed as a mass fraction, comprises:

[0008] a) 54%–98% alumina carrier;

[0009] b) 1% to 30% of at least one metal selected from Group IVB and / or Group IV, as the corresponding metal oxide;

[0010] c) 0.001% to 1% Pt metal;

[0011] d) 0.1% to 5% of at least one metal selected from Group IIA;

[0012] e) 0.1%–10% sulfate ions;

[0013] The sum of the strong acid content and the medium strong acid content of the catalyst accounts for ≥80% of the total acid content of the catalyst, preferably 80% to 99%; the proportion of the strong acid content to the total acid content of the catalyst is ≤50%, preferably 5% to 50%.

[0014] According to the present invention, the sum of the strong acid content and the medium strong acid content of the catalyst is preferably 80% to 95% of the total acid content of the catalyst, for example, 82%, 83%, 84%, 85%, 89%, 90%, 92%, 93%, 95%, etc., and any value within the range formed by any two of these values.

[0015] According to the present invention, the proportion of the strong acid content of the catalyst to the total acid content of the catalyst is more preferably 20% to 50%, for example, 20%, 25%, 28%, 30%, 35%, 40%, 45%, 46%, 48%, 50%, etc., and any value within the range formed by any two of these values.

[0016] According to the present invention, preferably, the catalyst comprises:

[0017] a) 68%–88% alumina carrier;

[0018] b) 10% to 25% of at least one metal selected from Group IVB and / or Group IV, as the corresponding metal oxide;

[0019] c) 0.01% to 0.5% Pt metal;

[0020] d) 0.5% to 2% of at least one metal selected from Group IIA;

[0021] e) 1% to 5% sulfate ions.

[0022] According to the present invention, the alumina in component a) is mesoporous alumina; the pore size distribution of the alumina is 2–50 nm. The specific surface area of ​​the alumina is ≥350 m². 2 / g, preferably 350-500m 2 / g.

[0023] According to the present invention, component b) is at least one selected from Zr, Ti, and Sn, preferably Zr.

[0024] According to the present invention, component d) is at least one selected from Ca, Ba, and Mg, preferably Mg.

[0025] A second aspect of the present invention provides a method for preparing the above-mentioned solid acid catalyst, comprising:

[0026] (1) Mix alumina, component b) source and precipitant, and then add component d) source to obtain a mixture;

[0027] (2) The mixture obtained in step (1) is subjected to a first hydrothermal reaction, a second hydrothermal reaction, and a third hydrothermal reaction, and then separated to obtain a solid.

[0028] (3) The solid-loaded Pt obtained in step (2) is first calcined;

[0029] (4) The first calcination product obtained in step (3) is treated with a sulfation reagent and then calcined a second time to obtain the catalyst.

[0030] According to the present invention, the reaction temperature of the second hydrothermal reaction is higher than that of the first hydrothermal reaction; the temperature of the third hydrothermal reaction is higher than that of the second hydrothermal reaction. Preferably, the reaction temperature of the second hydrothermal reaction is 10–50°C higher than that of the first hydrothermal reaction. The reaction temperature of the third hydrothermal reaction is 10–50°C higher than that of the second hydrothermal reaction.

[0031] According to the present invention, in step (1), the source of component b) is a metal salt containing component b), preferably a soluble metal salt. Further, the source of component b) includes at least one of a nitrate, acetate, or chloride of the metal of component b), preferably an acetate. The alumina is mesoporous alumina. The pore size distribution of the alumina is 2–50 nm. The specific surface area of ​​the alumina is ≥350 m² / m³. 2 / g, preferably 350-500m 2 / g. The precipitant is at least one of urea, KOH, and NaOH. The molar ratio of component b) metal to precipitant is 1:1 to 1:30, preferably 1:5 to 15.

[0032] According to the present invention, a suitable amount of water may be added to the alumina, component b) source, and precipitant system. The mass ratio of alumina added to water is in the range of 1:0.5 to 1:50.

[0033] According to the present invention, in step (1), the alumina, component b) source and precipitant are thoroughly stirred after mixing. The stirring temperature is 15-40°C, and the stirring time is 3-12 hours.

[0034] According to the present invention, further, in step (1), after adding component d), ultrasonic treatment is performed. The ultrasonic operation is carried out in a water bath of an ultrasonic instrument. The ultrasonic frequency is 20–150 kHz, the ultrasonic temperature is 15–40 °C, and the ultrasonic time is 1–5 h.

[0035] According to the present invention, in step (2), the apparatus for the hydrothermal reaction is a hydrothermal reactor. The temperature of the first hydrothermal reaction is 120–150°C, and the time is 2–20 h; the temperature of the second hydrothermal reaction is 150–170°C, and the time is 2–20 h; the temperature of the third hydrothermal reaction is 170–200°C, and the time is 2–20 h. The reaction times of the first, second, and third hydrothermal reactions can be the same or different.

[0036] According to the present invention, in step (2), the solid obtained after separation can be washed and / or dried. Washing can be performed using at least one of ethanol and deionized water. The drying temperature is 60–120°C, and the time is 2–20 h.

[0037] According to the present invention, the loading of Pt in step (3) can be carried out by impregnation. That is, the solid obtained in step (2) is impregnated in a Pt source solution. The Pt source is at least one of chloroplatinic acid and platinum chloride. The impregnation temperature is 15-40°C and the time is 2-20 h. After impregnation, drying can be performed. The drying temperature is 60-120°C and the time is 2-20 h. The atmosphere for the first calcination is an oxygen atmosphere, preferably air. The temperature for the first calcination is 300-500°C and the time is 2-20 h.

[0038] According to the present invention, in step (4), the sulfation reagent is at least one of sulfuric acid, ammonium sulfate, and ammonium bisulfate. The sulfation reagent exists in solution form. The concentration of the sulfation reagent solution is 0.1–3 mol / L, preferably 0.5–1.5 mol / L. The mass of the first calcined product and the volume of the sulfation reagent satisfy the following relationship: 1 g / 10 mL to 1 g / 200 mL. The sulfation reagent treatment is carried out by immersion, preferably by stirring. The sulfation treatment temperature is 15–40°C, and the time is 2–20 h. After sulfation treatment, drying can be performed. The drying temperature is 60–120°C, and the drying time is 2–20 h.

[0039] According to the present invention, in step (4), the atmosphere for the second roasting is an oxygen-containing atmosphere, preferably air. The temperature for the second roasting is 300–650°C, and the time is 2–20 h.

[0040] The third aspect of the present invention provides the application of the above-described solid acid catalyst or the solid acid catalyst prepared by the above method in the toluene disproportionation and alkyl transfer reaction.

[0041] According to the present invention, the reaction conditions for the application are as follows: reaction temperature of 100–500°C, preferably 100–300°C, more preferably below 300°C; reaction pressure of 1.0–8.0 MPa; hydrogen-to-hydrocarbon molar ratio of 0.1–10, preferably 0.1–5; and liquid feedstock weight hourly space velocity of 0.5–10 h⁻¹. -1 .

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] 1. The solid acid catalyst of the present invention comprises: a) 54%–98% alumina support; b) 1%–30% at least one metal selected from Group IVB and / or Group IV; c) 0.001%–1% Pt metal; d) 0.1%–5% at least one metal selected from Group IIA; e) 0.1%–10% sulfate ions; wherein the sum of the strong acid content and the medium-strong acid content of the catalyst accounts for ≥80% of the total acid content of the catalyst; and the strong acid content accounts for ≤50% of the total acid content of the catalyst. The inventors of the present invention have discovered that in the toluene disproportionation and alkyl transfer reaction, strong Brønsted acid sites are beneficial for the transfer of active protons on the catalyst surface, but are more prone to deactivation, while medium-strong acid sites can simultaneously ensure the conversion rate and stability of the reaction. Therefore, by controlling the ratio of these two acid sites in the catalyst, the stability of the catalyst can be effectively improved. The sulfate ions and group IVB and / or group IV metal oxides dispersed in the pore structure of the mesoporous material of the present invention have high acid strength and acid density, enabling alkyl transfer reactions at lower temperatures.

[0044] 2. In the preparation method provided by this invention, mesoporous alumina is used as a support, and group IVB and / or group IV metals and group IIA metals are introduced by precipitation. The mixture undergoes three hydrothermal reactions, followed by loading Pt metal and treatment with a sulfation reagent to prepare the catalyst. The preparation method of this invention is simple to operate, economical, and easy to industrialize. This method, through three hydrothermal reactions, further preferably incorporates Lewis basic metal oxides as promoters into the raw materials. The resulting catalyst has an appropriate acid content distribution, and by controlling the ratio of strong acid to medium-strong acid in the catalyst, the catalyst stability can be effectively improved.

[0045] 3. In existing technologies, the reaction temperature for toluene disproportionation and alkyl transfer reactions is generally required to be relatively high, typically between 300 and 500°C. The solid acid catalyst provided by this invention, used for toluene disproportionation and alkyl transfer reactions, features low reaction temperature, low hydrogen consumption, and good stability. More preferably, the solid acid catalyst provided by this invention is suitable for toluene disproportionation and alkyl transfer reactions at temperatures below 300°C. Detailed Implementation

[0046] The technical solution of the present invention will be further illustrated below with reference to the embodiments, but it is not limited to the following embodiments.

[0047] In this invention, the N2 isothermal adsorption-desorption characterization was performed using a 3Flex-Physisorption fully automated specific surface area and pore size distribution analyzer manufactured by Micromeritics, Inc., USA. The adsorbate was high-purity N2, and the adsorption temperature was -196℃. Before testing, the sample was pretreated under vacuum at 350℃ for 3 hours to remove adsorbed impurities. The specific surface area was calculated using the BET method, and the pore structure characteristics were analyzed using the BJH method.

[0048] In this invention, the acidity and acid content of the sample are determined using a Nexsus™ Py-IR spectrometer from Nicolet, USA. During the test, the sample is pressed into a pellet and evacuated to 10°C. -4 Pa, heat treatment at 400℃ for 2 hours, then static adsorption of pyridine for 1 minute after the temperature drops to 200℃, followed by equilibration for 5 minutes, low vacuum for 10 minutes, high vacuum for 30 minutes, and then gradually heating the sample cell. Py-IR images of the sample were collected at 200℃, 300℃, and 400℃ respectively. The amount of strong acid was calculated as the amount of acid desorbed at 400℃, the amount of medium-strong acid was calculated as the amount of acid desorbed at 300℃ minus the amount of acid desorbed at 400℃, and the amount of weak acid was calculated as the amount of acid desorbed at 200℃ minus the amount of acid desorbed at 300℃. The total amount of acid was the sum of the amounts of weak acid, medium-strong acid, and strong acid.

[0049] In this invention, unless otherwise specified, % refers to mass percentage.

[0050]

Example 1

[0051] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 71.2% of the total catalyst weight, Zr (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0052] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0053] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140℃, 160℃ and 190℃ for 15h respectively. After washing with deionized water, it was dried at 90℃ for 12h to obtain solid powder A3.

[0054] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0055] (4) The solid powder A4 was sulfated according to the ratio of 1 g / 50 mL of solid powder A4 to sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The solid powder was stirred together at 30 °C for 10 h, dried at 90 °C for 10 h, and calcined at 600 °C for 5 h to obtain catalyst C1.

[0056] The composition and acid properties of the catalyst are shown in Table 1.

[0057] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4MPa. The temperature was then lowered to 290℃, the hydrogen-hydrogen molar ratio was adjusted to 0.5, and after the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0058]

Example 2

[0059] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 84.2% of the total catalyst weight, Zr (as ZrO2) comprised 12% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0060] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0061] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0062] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0063] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0064] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0065]

Example 3

[0066] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), mixed with tetrabutyl titanate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 71.4% of the total catalyst weight, Ti (as TiO2) comprised 25% of the total catalyst weight, the molar ratio of Ti to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0067] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0068] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0069] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0070] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0071] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0072]

Example 4

[0073] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 71.2% of the total catalyst weight, Zr (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0074] A calcium acetate solution was added to mixture A1, wherein the weight percentage of Ca was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0075] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0076] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0077] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0078] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0079]

Example 5

[0080] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 72.2% of the total catalyst weight, Zr (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0081] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 0.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0082] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0083] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0084] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0085] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0086]

Example 6

[0087] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 71.2% of the total catalyst weight, Zr (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0088] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0089] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 8 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0090] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0091] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0092] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0093]

Example 7

[0094] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. Mesoporous alumina comprised 71.2% of the total catalyst weight, Zr (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0095] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0096] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 130, 150 and 170 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0097] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0098] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0099] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0100]

Example 8

[0101] (1) Mesoporous alumina (specific surface area of ​​390 m²) 2 / g), was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30℃ for 10h. The mesoporous alumina comprised 71.5% of the total catalyst weight, the Zr weight percentage (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0102] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0103] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0104] (3) Using chloroplatinic acid as a precursor, Pt (0.05% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0105] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0106] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0107] Comparative Example 1

[0108] (1) Alumina (specific surface area of ​​120 m²) 2 The alumina ( / g) was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at 30°C for 10 hours. The alumina comprised 72.7% of the total catalyst weight, the Zr weight percentage (as ZrO2) comprised 25% of the total catalyst weight, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, yielding mixture A1.

[0109] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0110] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0111] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0112] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0113] The catalyst composition is shown in Table 1.

[0114] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0115] Comparative Example 2

[0116] (1) Mesoporous alumina (same as in Example 1) was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at a temperature of 30°C for 10 hours. The mesoporous alumina accounted for 71.2% of the total weight of the catalyst, the weight percentage of Zr (calculated as ZrO2) was 25% of the total weight of the catalyst, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, resulting in mixture A1.

[0117] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0118] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 150°C for 48 hours. After washing with deionized water, it was dried at 90°C for 12 hours to obtain solid powder A3.

[0119] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst) was impregnated onto solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain solid powder A4.

[0120] (4) Solid powder A4 was sulfated at a ratio of 1 g / 50 mL with sulfation reagent. 1 mol / L dilute sulfuric acid was used as the sulfation reagent. The mixture was stirred together with the solid powder at 30 °C for 10 h, dried at 90 °C for 10 h, and then calcined at 600 °C for 5 h to obtain catalyst C1.

[0121] The catalyst composition is shown in Table 1.

[0122] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0123] Comparative Example 3

[0124] (1) Mesoporous alumina (same as in Example 1) was mixed with zirconium oxynitrate and urea in deionized water and stirred thoroughly at a temperature of 30°C for 10 hours. The mesoporous alumina accounted for 73.2% of the total weight of the catalyst, the weight percentage of Zr (calculated as ZrO2) was 25% of the total weight of the catalyst, the molar ratio of Zr to urea was 1:10, and the mass ratio of alumina to deionized water was 1:10, resulting in mixture A1.

[0125] A magnesium acetate solution was added to mixture A1, wherein the weight percentage of Mg was 1.5% of the total weight of the catalyst. The mixture was ultrasonicated at 50 kHz and 30 °C for 3 h to obtain mixture A2.

[0126] (2) The mixture A2 was transferred into a hydrothermal reactor and hydrothermally reacted at 140, 160 and 190 °C for 15 h respectively. After washing with deionized water, it was dried at 90 °C for 12 h to obtain solid powder A3.

[0127] (3) Using chloroplatinic acid as a precursor, Pt (0.3% by weight of the total catalyst weight) was impregnated on solid powder A3, dried at 90°C for 12 h, and then calcined at 450°C for 10 h to obtain the catalyst.

[0128] The catalyst composition is shown in Table 1.

[0129] The catalyst evaluation conditions were as follows: 5g of catalyst C1 was weighed and loaded into a fixed-bed reactor, hydrogen gas was introduced at a rate of 70mL / min, and the reactor was kept at 450℃ for 2 hours under a pressure of 4Ma. The temperature was then lowered to 290℃, and the hydrogen-hydrogen molar ratio was adjusted to 0.5. After the temperature stabilized, toluene and 1,2,4-trimethylbenzene (mass ratio of 1:1) were introduced and reacted for 20 hours. The reaction results are shown in Table 1.

[0130] Table 1. Preparation and composition of catalysts in each example.

[0131]

[0132]

[0133] Note: *The content of component b) is based on the metal oxide corresponding to the metal, such as Zr corresponding to ZrO2 and Ti corresponding to TiO2.

[0134] **Multiple hydrothermal conditions for the same catalyst are performed in the order from top to bottom.

[0135] Table 2. Acid properties and evaluation results of each catalyst example.

[0136]

[0137]

[0138] Note: ***The ratio of the sum of strong acid and medium strong acid content of the catalyst to the total acid content of the catalyst.

[0139] The specific 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 combining the 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 solid acid catalyst, based on the weight of the catalyst and expressed as a mass fraction, the solid acid catalyst comprises: a) 54%~98% alumina carrier; b) 1% to 30% selected from at least one of Zr and Ti, based on the corresponding metal oxide; c) 0.001%~1% Pt metal; d) 0.1% to 5% of at least one selected from Ca and Mg; e) 0.1%~10% sulfate ions; The sum of the strong acid content and the medium strong acid content of the catalyst accounts for ≥80% of the total acid content of the catalyst; the proportion of the strong acid content in the total acid content of the catalyst is 5%~50%. The acid content was determined by Py-IR. The strong acid content was calculated as the acid content after desorption at 400℃, the medium strong acid content was calculated as the acid content after desorption at 300℃ minus the acid content after desorption at 400℃, and the weak acid content was calculated as the acid content after desorption at 200℃ minus the acid content after desorption at 300℃. The total acid content was the sum of the weak acid, medium strong acid, and strong acid contents. The specific surface area of ​​the alumina carrier is ≥350m². 2 / g.

2. The catalyst according to claim 1, characterized in that, The sum of the strong acid content and the medium strong acid content of the catalyst accounts for 80% to 99% of the total acid content of the catalyst; the strong acid content accounts for 5% to 50% of the total acid content of the catalyst.

3. The catalyst according to claim 1, characterized in that, The alumina in component a) is mesoporous alumina.

4. The catalyst according to claim 3, characterized in that, The pore size distribution of the alumina in component a) is 2~50 nm.

5. A method for preparing the catalyst according to any one of claims 1 to 4, comprising: (1) Mix alumina, component b) source and precipitant, and then add component d) source to obtain a mixture; (2) The mixture obtained in step (1) is subjected to a first hydrothermal reaction, a second hydrothermal reaction, and a third hydrothermal reaction, and then separated to obtain a solid; (3) The solid-loaded Pt obtained in step (2) is first calcined; (4) Treat the first calcination product obtained in step (3) with a sulfation reagent, and then calcine it a second time to obtain the catalyst; In step (2), the reaction temperature of the second hydrothermal reaction is higher than that of the first hydrothermal reaction; the temperature of the third hydrothermal reaction is higher than that of the second hydrothermal reaction.

6. The preparation method according to claim 5, characterized in that, In step (2), the reaction temperature of the second hydrothermal reaction is 10~50℃ higher than that of the first hydrothermal reaction; the reaction temperature of the third hydrothermal reaction is 10~50℃ higher than that of the second hydrothermal reaction.

7. The preparation method according to claim 5, characterized in that, In step (2), the temperature of the first hydrothermal reaction is 120~150℃ and the time is 2~20h; and / or, the temperature of the second hydrothermal reaction is 150~170℃ and the time is 2~20h; and / or, the temperature of the third hydrothermal reaction is 170~200℃ and the time is 2~20h.

8. The preparation method according to claim 5, characterized in that, In step (1), the source of component b) is a metal salt containing component b); And / or, the alumina is mesoporous alumina; the pore size distribution of the alumina is 2~50 nm; the specific surface area of ​​the alumina is ≥350 m² / g. 2 / g; And / or, the precipitant is at least one of urea, KOH, and NaOH; And / or, the molar ratio of component b) metal to precipitant is 1:1 to 1:

30.

9. The preparation method according to claim 8, characterized in that, In step (1), the source of component b) is a soluble metal salt; And / or, the specific surface area of ​​the alumina is 350~500 m². 2 / g.

10. The preparation method according to claim 9, characterized in that, In step (1), the source of component b) includes at least one of the nitrate, acetate, and chloride of the metal of component b).

11. The preparation method according to claim 10, characterized in that, In step (1), the source of component b) is the acetate of the metal of component b).

12. The preparation method according to claim 5, characterized in that, In step (3), the atmosphere of the first roasting is an oxygen atmosphere; the temperature of the first roasting is 300~500℃, and the time is 2~20h.

13. The preparation method according to claim 12, characterized in that, In step (3), the atmosphere for the first roasting is air.

14. The preparation method according to claim 5, characterized in that, In step (4), the sulfation reagent is at least one of sulfuric acid, ammonium sulfate, and ammonium bisulfate; the sulfation reagent exists in solution form; and the concentration of the sulfation reagent solution is 0.1~3 mol / L.

15. The preparation method according to claim 5, characterized in that, In step (4), the atmosphere of the second roasting is an oxygen atmosphere; the temperature of the second roasting is 300~650℃ and the time is 2~20h.

16. The preparation method according to claim 15, characterized in that, In step (4), the atmosphere for the second roasting is air.

17. The application of a catalyst according to any one of claims 1 to 4 or a solid acid catalyst prepared by any one of claims 5 to 16 in the toluene disproportionation and alkyl transfer reaction.

18. The application according to claim 17, characterized in that, The reaction conditions for this application are as follows: reaction temperature 100~500℃, reaction pressure 1.0~8.0 MPa, hydrogen-to-hydrocarbon molar ratio 0.1~10, and liquid feed weight hourly space velocity 0.5~10 h⁻¹. -1 .

19. The application according to claim 18, characterized in that, The reaction conditions for the application are: the reaction temperature is below 300℃.

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