A ternary H x V2O5 / LaVO4 / WO3 catalyst and its preparation method and application

Abstract

The present invention discloses a ternary H x The invention discloses a V2O5 / LaVO4 / WO3 catalyst and its preparation method and application, which belongs to the technical field of photothermal catalytic oxidation catalyst. x A ternary V2O5 / LaVO4 / WO3 composite material employs a gel method, using citric acid as a template to uniformly disperse the trimetallic salts and maintain the system's amorphous structure. The exposed crystal faces of the catalyst are then effectively regulated by controlling the calcination temperature. The reaction exhibits good catalytic activity and selectivity for adipic acid in the absence of solvent. The invention is simple to operate, utilizes readily available and inexpensive raw materials and catalysts, requires minimal catalyst dosage, allows for easy separation of the product and catalyst, exhibits stable recyclability, and can be reused multiple times, making it suitable for large-scale production.

Description

Technical Field

[0001] The present invention belongs to the technical field of photothermal catalytic oxidation catalysts, and specifically relates to a ternary H x V2O5 / LaVO4 / WO3 catalyst, preparation method and application thereof. Background Art

[0002] Adipic acid and its derivatives are extremely important commercial aliphatic dibasic organic acids capable of polycondensation to form polymers, primarily used in the preparation of polyamides, polyesters, polyurethane resins, and nylon-66 fibers. Furthermore, adipic acid can be used as an additive in the production of lubricants, cosmetics, fertilizers, gelatin, paper, wax, and other products, finding widespread application in the pharmaceutical, chemical, and food industries. Furthermore, adipic acid serves as a building block for the synthesis of hexamethylenediamine, adipic acid esters, and adiponitrile in organic synthesis, thus demonstrating its importance in the fine chemical industry. Currently, the most common method for industrially synthesizing adipic acid is to oxidize cyclohexane with molecular oxygen to produce K / A oil (cyclohexanone and cyclohexanol), which is then oxidized with 50% to 60% concentrated nitric acid to yield the desired product. Producing 1 ton of adipic acid requires 1.3 tons of nitric acid at a concentration of 68%, generating 0.25 tons of N₂O, nitric acid vapor, and waste acid, resulting in significant environmental pollution and high denitrification energy consumption, hindering the development of adipic acid production technology. Developing a chemical process that directly produces adipic acid from cyclohexane via a single-step oxidation with molecular oxygen or hydrogen peroxide is economical, green, and sustainable. However, this process involves multiple cascade reactions involving selective activation and inhibition of different C—H bonds. Therefore, selectively oxidizing the relatively inert C—H bonds of cyclohexane and inhibiting the more active adipic acid to CO₂ and H₂O is one of the most challenging and challenging research topics in heterogeneous catalysis.

[0003] Photocatalytic cyclohexane oxidation is a green and sustainable method for producing KA oil by catalyzing cyclohexane using the energy of ultraviolet-visible light (D. Peng, Applied Catalysis A: General 653(33)(2023)119067.). Researchers have prepared a series of related photocatalysts using corresponding materials and successfully produced KA oil by oxidizing cyclohexane under pure light conditions. Some researchers have even achieved the one-step photocatalytic production of AA (R. Goyal, B. Sarkar, S. Sameer, A. Bag, A. Bordoloi, ACS Applied Nano Materials 2(9)(2019)5989-5999.). However, despite the high selectivity of photocatalytic oxidation of cyclohexane, its conversion rate is usually very low (≤1%) and its quantum efficiency is also poor, which hinders its application (Y. Ide, S. Tominaka, Y. Yoneno, K. Komaguchi, T. Takei, H. Nishida, N. Tsunoji, A. Machida, T. Sano, Chemical Science 10(27)(2019)6604-6611.). In industry, the oxidation of cyclohexane is carried out by thermal catalytic oxidation, which is not only high in temperature and pressure, but also has a large number of byproducts and cannot be reasonably regulated (G. Xu, Y. Zhang, D. Peng, D. Sheng, Y. Zhang, Y. Tian, ​​D. Materials Research Bulletin 146(57)(2022)111602.). Combining photocatalysis with thermal catalysis to fully utilize the synergistic effect of photogenerated carriers and thermal energy to achieve efficient conversion of cyclohexane has become a hot topic (ZjWang, H.Song, H.Liu, J.Ye.AngewandteChemie International Edition 59(21)(2020)8016-8035.). Photothermal synergistic catalytic oxidation of cyclohexane solves the problems of low photocatalytic efficiency and high energy consumption in thermal catalysis (J.Zhang, J.Liu, X.Wang, J.Mai, W.Zhao, Z.Ding, Y.Fang, Applied Catalysis B:Environmental 259(28)(2019)118063.).Therefore, photothermal synergistic catalysis is considered to be an effective way to achieve highly selective and active oxidation of cyclohexane. The rational development of new photothermal synergistic catalysts is of great significance to further improve the efficiency of photothermal catalysis (X.Chen, A.Yang, G.Wang, M.Wei, N.Liu, B.Li, L.Chemical Engineering Journal 446(27)(2022)137134.).

[0004] The current problem with the solvent-free photothermal oxidation of cyclohexane is that the conversion rate is low and the main product is KA oil. There are few photothermal catalytic synergistic catalysts that can produce adipic acid in one step. For example, under the conditions of 120°C, 5h, and xenon lamp (220W, λ≥300nm), the cyclohexane conversion rate is 9.0% and the KA oil selectivity is 99.0%, but no adipic acid is produced. Summary of the Invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the present invention aims to provide a ternary H x V2O5 / LaVO4 / WO3 catalyst, its preparation method and application are used to solve the technical problem that cyclohexane cannot be oxidized to adipic acid in one step and high selectivity of adipic acid is guaranteed in the current solvent-free photothermal synergistic system.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention discloses a ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0008] S1: Mixing VOCl2 solution and tungsten salt to obtain a mixed solution; adding lanthanum nitrate solution and anhydrous citric acid to the mixed solution, and stirring to obtain a gel;

[0009] S2: drying the gel to obtain precursor powder;

[0010] S3: After calcining the precursor powder, the ternary H x V2O5 / LaVO4 / WO3 catalyst.

[0011] Furthermore, in S1, the VOCl2 solution is obtained by mixing and stirring a vanadium salt and concentrated hydrochloric acid; the stirring time is 2 to 5 hours.

[0012] Furthermore, in S1, the vanadium salt is vanadium pentoxide; and the concentration of the concentrated hydrochloric acid is 13-14 mol / L.

[0013] Furthermore, in S1, the solvent is C6H8O7; the tungsten salt is WCl6; the lanthanum acid solution is La(NO3)3·6H20 solution; and the molar ratio of La:V:W:C6H8O7 elements in the obtained gel is 3:10:1:(30-39).

[0014] Furthermore, in S1, before the VOCl2 solution and the tungsten salt are mixed, the pH value of the VOCl2 solution is adjusted to 6-7; when the lanthanum acid solution and the solvent are added to the mixed solution, the temperature of the mixed solution is 70-100°C.

[0015] Furthermore, in S2, the drying process is performed at a temperature of 60 to 180°C and for a time of 24 to 48 hours.

[0016] Furthermore, in S3, the process parameters of the calcination treatment are calcination at 350-650° C. for 4 hours.

[0017] The present invention also discloses a ternary H x V2O5 / LaVO4 / WO3 catalyst.

[0018] The present invention also discloses the above-mentioned ternary H x Application of V2O5 / LaVO4 / WO3 catalyst, the ternary H x V2O5 / LaVO4 / WO3 catalyst was used as a catalytic material for the one-step preparation of adipic acid from cyclohexane under solvent-free conditions by photothermal synergistic catalysis. The reaction conditions for the preparation were as follows: the ternary H x V2O5 / LaVO4 / WO3 catalyst reacts with cyclohexane under light conditions to prepare adipic acid.

[0019] Furthermore, the illumination is performed using a xenon lamp; the ternary H x The usage ratio of V2O5 / LaVO4 / WO3 catalyst and cyclohexane is (40-70) mg:(7.6) g; during the reaction, O2 is introduced, and the pressure of O2 is 1-2 MPa.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention discloses a ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst is to uniformly disperse lanthanum source, vanadium source and tungsten source in an amorphous precursor by a gel method, and the introduction of concentrated hydrochloric acid can ensure that there is a certain amount of proton acid (h +) exists. Ensure that the three are evenly dispersed during the calcination process while ensuring H x The stable existence of V2O5. Existing literature shows that The combined action of acid and oxygen vacancies plays a crucial role in the one-step oxidation of cyclohexane to adipic acid. This enables the one-step production of adipic acid from cyclohexane under solvent-free, photothermal, and thermal conditions. This catalyst offers advantages such as simple and safe process steps, low product cost, and a short production cycle.

[0022] The present invention also discloses a ternary H x Compared with the existing catalyst, the V2O5 / LaVO4 / WO3 catalyst prepared by the present invention has a x V2O5 / LaVO4 / WO3 powder has high purity and is suitable for large-scale production.

[0023] The present invention also discloses the above-mentioned ternary H x Application of V2O5 / LaVO4 / WO3 catalyst as a catalytic material for the one-step preparation of adipic acid from cyclohexane under solvent-free conditions by photothermal synergistic catalysis. The ternary metal mixed catalyst of acid and oxygen vacancy ensures the successful one-step oxidation of cyclohexane to adipic acid under photothermal and solvent-free conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The ternary H prepared at different calcination temperatures in Examples 1 to 4 x XRD pattern of V2O5 / LaVO4 / WO3 catalyst;

[0025] Figure 2 The ternary H x Diagram of five-cycle use of V2O5 / LaVO4 / WO3 catalyst. DETAILED DESCRIPTION

[0026] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0028] Herein, all features such as values, amounts, amounts, and concentrations defined in numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0029] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0030] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0031] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0032] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0033] Example 1

[0034] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0035] S1: In this embodiment, the amount of raw materials is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:39; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 with 2-5mol / L hydrochloric acid; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of 2.598g of lanthanum nitrate hexahydrate solution is added, and the mixture is vigorously stirred at 60-90°C until the solvent is completely evaporated to obtain a green gel;

[0036] S2: The obtained gel was placed in an oven at 120°C for 24 h to obtain a precursor powder;

[0037] S3: The precursor powder was placed in a muffle furnace, calcined at 350 ° C for 4 h, and naturally cooled to room temperature to obtain H x V2O5 / LaVO4 / WO3-350 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0038] Example 2

[0039] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0040] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:39; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of lanthanum nitrate hexahydrate solution is added, and the mixture is vigorously stirred at 90°C until the solvent is completely evaporated to obtain a gel;

[0041] S2: The obtained gel was placed in an oven at 60°C for 24 h to obtain a precursor powder;

[0042] S3: Place the precursor powder in a muffle furnace, calcine at 450 ° C for 3 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-450 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0043] Example 3

[0044] A ternary H xThe preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0045] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:39; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of lanthanum nitrate hexahydrate solution is added, and the mixture is vigorously stirred at 90°C until the solvent is completely evaporated to obtain a gel;

[0046] S2: The obtained gel was placed in an oven at 180°C for 48 hours to obtain a precursor powder;

[0047] S3: Place the precursor powder in a muffle furnace, calcine at 550 ° C for 3 to 5 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-550 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0048] Example 4

[0049] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0050] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:39; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 4-6 for later use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of a solution containing 2.598g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 60°C until the solvent is completely evaporated to obtain a gel;

[0051] S2: placing the obtained gel in an oven at 180°C for 24-48 hours to obtain a precursor powder;

[0052] S3: Place the precursor powder in a muffle furnace, calcine at 650℃ for 3-5h, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0053] Example 5

[0054] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0055] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 of 3:10:1:30; 2 g of vanadium pentoxide is weighed and dissolved in 15 mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2 hours to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for later use; 0.666 g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20 mL of a solution containing 2.598 g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 80°C until the solvent is completely evaporated to obtain a gel;

[0056] S2: The obtained gel was placed in an oven at 150°C for 40 h to obtain a precursor powder;

[0057] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 5 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0058] Example 6

[0059] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0060] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:31; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirring is performed at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of a solution containing 2.598g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 70°C until the solvent is completely evaporated to obtain a gel;

[0061] S2: The obtained gel was placed in an oven at 110°C for 35 h to obtain a precursor powder;

[0062] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 4 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0063] Example 7

[0064] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0065] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 of 3:10:1:32; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of lanthanum nitrate hexahydrate solution is added, and the mixture is vigorously stirred at 85°C until the solvent is completely evaporated to obtain a gel;

[0066] S2: The obtained gel was placed in an oven at 75°C for 40 h to obtain a precursor powder;

[0067] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 5 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0068] Example 8

[0069] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0070] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:33; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of a solution containing 2.598g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 80°C until the solvent is completely evaporated to obtain a gel;

[0071] S2: The obtained gel was placed in an oven at 180°C for 48 hours to obtain a precursor powder;

[0072] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 4 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary Hx V2O5 / LaVO4 / WO3 catalyst).

[0073] Example 9

[0074] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0075] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 of 3:10:1:34; 2 g of vanadium pentoxide is weighed and dissolved in 15 mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2 hours to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666 g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20 mL of a solution containing 2.598 g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 80°C until the solvent is completely evaporated to obtain a gel;

[0076] S2: The obtained gel was placed in an oven at 120°C for 48 hours to obtain a precursor powder;

[0077] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 4 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0078] Example 10

[0079] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0080] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:35; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of a solution containing 2.598g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 60-90°C until the solvent is completely evaporated to obtain a gel;

[0081] S2: placing the obtained gel in an oven at 60-180°C for 30 hours to obtain a precursor powder;

[0082] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 4 hours, and cool naturally to room temperature to obtain Hx V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0083] Example 11

[0084] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0085] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:36; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of a solution containing 2.598g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 90°C until the solvent is completely evaporated to obtain a gel;

[0086] S2: The obtained gel was placed in an oven at 60°C for 48 hours to obtain a precursor powder;

[0087] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 5 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0088] Example 12

[0089] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0090] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 of 3:10:1:37; 2 g of vanadium pentoxide is weighed and dissolved in 15 mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2 hours to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for later use; 0.666 g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20 mL of a solution containing 2.598 g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 65°C until the solvent is completely evaporated to obtain a gel;

[0091] S2: The obtained gel was placed in an oven at 80°C for 25 h to obtain a precursor powder;

[0092] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 5 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0093] Example 13

[0094] A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst comprises the following steps:

[0095] S1: In this embodiment, the raw material dosage is selected according to the molar ratio of La:V:W:C6H8O7 elements of 3:10:1:38; 2g of vanadium pentoxide is weighed and dissolved in 15mL of concentrated hydrochloric acid to mix uniformly, and then rotary stirred at 95°C for 2h to obtain a VOCl2 solution, and the pH value of the VOCl2 solution is adjusted to 6-7 for standby use; 0.666g of tungsten hexachloride is added to the VOCl2 solution, and after it is completely dissolved, 20mL of a solution containing 2.598g of lanthanum nitrate hexahydrate is added, and the mixture is vigorously stirred at 85°C until the solvent is completely evaporated to obtain a gel;

[0096] S2: The obtained gel was placed in an oven at 80°C for 35 h to obtain a precursor powder;

[0097] S3: Place the precursor powder in a muffle furnace, calcine at 650 ° C for 5 hours, and cool naturally to room temperature to obtain H x V2O5 / LaVO4 / WO3-650 powder (ternary H x V2O5 / LaVO4 / WO3 catalyst).

[0098] Application Example 1

[0099] 7.6 g of cyclohexane and H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-350 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0100] Application Example 2

[0101] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-450 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0102] Application Example 3

[0103] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-550 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0104] Application Example 4

[0105] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0106] Application Example 5

[0107] 7.6 g of cyclohexane and 40 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0108] Application Example 6

[0109] 7.6 g of cyclohexane and 60 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0110] Application Example 7

[0111] 7.6 g of cyclohexane and 70 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0112] Application Example 8

[0113] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. xV2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 0.6 MPa. The reaction results are shown in Table 1.

[0114] Application Example 9

[0115] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 0.8 MPa. The reaction results are shown in Table 1.

[0116] Application Example 10

[0117] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1.2 MPa. The reaction results are shown in Table 1.

[0118] Application Example 11

[0119] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1.4 MPa. The reaction results are shown in Table 1.

[0120] Application Example 12

[0121] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 4 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0122] Application Example 13

[0123] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 5 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0124] Application Example 14

[0125] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 7 h under the irradiation of a xenon lamp (λ≥400nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0126] Application Example 15

[0127] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 8 h under the irradiation of a xenon lamp (λ≥400 nm) and an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0128] Application Example 16

[0129] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted at 120°C for 6 h in an O2 atmosphere of 1 MPa. The reaction results are shown in Table 1.

[0130] Application Example 17

[0131] 7.6 g of cyclohexane and 50 mg of H were added to a 100 mL polytetrafluoroethylene-lined photothermal reactor. x V2O5 / LaVO4 / WO3-650 was reacted under xenon lamp (λ≥400nm) and 1MPa O2 atmosphere for 6h. The reaction results are shown in Table 1.

[0132] For H x XRD analysis of the V2O5 / LaVO4 / WO3-650 catalyst revealed that the material exhibited an amorphous structure during calcination. This structure was extremely unstable, easily soluble in water, and capable of undergoing redox reactions with water. After calcination at 350 and 450 °C, it was found that, except for WO3, H x In addition to the V2O5 and LaVO4 crystal phases, there are also V2WO6 and V2O5 crystal phases, which indicates that the catalysts calcined at these two temperatures are composed of multiple materials. When the calcination temperature is greater than 450℃, the V2WO6 and V2O5 crystal phases disappear and are replaced by WO3, H x The main crystal images are V2O5 and LaVO4, indicating that the catalyst H x V2O5 / LaVO4 / WO3 was successfully prepared.

[0133] Table 1 Catalyst activity table

[0134]

[0135] The reaction conditions are: 50 mg of catalyst, xenon lamp (λ≥400 nm), where TC represents pure thermal reaction and PTC represents photothermal reaction. The temperature, pressure and time may vary in different embodiments.

[0136] Figure 1 The ternary H prepared at different calcination temperatures in Examples 1 to 13 x The XRD patterns of V2O5 / LaVO4 / WO3 catalysts were analyzed to determine the crystalline phase and structural changes of the monomer and ternary complex. Figure 1 As shown in Figure 2, the XRD patterns of all samples are within the range of 10-80°. After calcination at 350 and 450 °C, not only H x The crystal planes of V2O5, LaVO4, and WO3 can also be found. The crystal phases of V2WO6 (PDF#23-1475), (002), (200) and V2O5 (PDF#53-0538) (101) and (100), (010) can also be found. This indicates that the material is a mixture of several metal oxides, which is not what we want. However, when the calcination temperature of the material is increased to above 550℃, the crystal planes of V2WO6 and V2O5 disappear, and only H x The crystal surface of V2O5, LaVO4, and WO3, the increase in temperature leads to H x The crystal plane strength of V2O5, LaVO4 and WO3 increases, which indicates that the purity of the material is greatly improved. Figure 1 As shown, the crystal plane of the catalyst prepared by calcination at 650℃ is x V2O5, WO3 and LaVO4 are completely consistent. This proves that H x V2O5 / LaVO4 / WO3 ternary composite material has been successfully prepared.

[0137] Figure 2 Shown is H x The catalytic performance results of the V2O5 / LaVO4 / WO3-650 catalyst after 5 cycles are shown in the figure. The cyclohexane conversion rate in this first cycle was 11.01%, and the AA selectivity was 58.51%. In the fifth cycle, the cyclohexane conversion rate was 7.87%, and the AA selectivity was 53.37%. It can be clearly seen that after 5 cycles, the catalyst conversion rate and AA selectivity gradually decreased, and the by-products gradually increased. This is because H x The acidic species on the surface of V2O5 are gradually consumed during the reaction, resulting in The disappearance of acidic sites changes the catalyst structure, resulting in an enhanced ability of cyclohexane to adsorb on the catalyst, which leads to an increase in by-products and a decrease in conversion rate.

[0138] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A ternary H x The preparation method of V2O5 / LaVO4 / WO3 catalyst is characterized in that: The following steps are involved: S1: Mixing VOCl2 solution and tungsten salt to obtain a mixed solution; Adding lanthanum nitrate solution and anhydrous citric acid to the mixed solution and stirring to obtain a gel; the VOCl2 solution is obtained by mixing vanadium pentoxide and concentrated hydrochloric acid and stirring for 2 to 5 hours; S2: drying the gel to obtain precursor powder; S3: After calcining the precursor powder, the ternary H x V2O5 / LaVO4 / WO3 catalyst.

2. A ternary H according to claim 1 x The preparation method of V2O5 / LaVO4 / WO3 catalyst is characterized in that: In S1, the concentration of the concentrated hydrochloric acid is 13-14 mol / L.

3. A ternary H according to claim 2 x The preparation method of V2O5 / LaVO4 / WO3 catalyst is characterized in that: In S1, the tungsten salt is WCl6; the lanthanum acid solution is La(NO3)3·6H20 solution; and the molar ratio of La:V:W:C6H8O7 in the obtained gel is 3:10:1:(30~39).

4. A ternary H according to claim 1 x The preparation method of V2O5 / LaVO4 / WO3 catalyst is characterized in that: In S1, before the VOCl2 solution and the tungsten salt are mixed, the pH value of the VOCl2 solution is adjusted to 6-7.

5. A ternary H according to claim 1 x The preparation method of V2O5 / LaVO4 / WO3 catalyst is characterized in that: In S2, the drying process is performed at a temperature of 60-180° C. and for a time of 24-48 h.

6. A ternary H according to claim 1 x The preparation method of V2O5 / LaVO4 / WO3 catalyst is characterized in that: In S3, the process parameters of the calcination treatment are calcination at 350-650° C. for 4 h.

7. A ternary H x V2O5 / LaVO4 / WO3 catalyst, characterized in that The ternary H x The V2O5 / LaVO4 / WO3 catalyst is prepared by a preparation method.

8. The ternary H according to claim 7 x The application of V2O5 / LaVO4 / WO3 catalyst is characterized in that The ternary H x V2O5 / LaVO4 / WO3 catalyst was used as a catalytic material for the one-step preparation of adipic acid from cyclohexane under solvent-free conditions by photothermal synergistic catalysis. The reaction conditions for the preparation were as follows: the ternary H x V2O5 / LaVO4 / WO3 catalyst reacts with cyclohexane under light conditions to prepare adipic acid.

9. The ternary H according to claim 8 x The application of V2O5 / LaVO4 / WO3 catalyst is characterized in that The illumination is carried out by using a xenon lamp; the ternary H x The usage ratio of V2O5 / LaVO4 / WO3 catalyst and cyclohexane is (40~70) mg:(7.6) g; during the reaction, O2 is introduced, and the pressure of O2 is 1~2 MPa.

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