Pyridinedicarboxylic acid coordinated catalyst, composite catalyst, preparation method and application

Abstract

The invention discloses a pyridinedicarboxylic acid coordinated catalyst, a composite catalyst, a preparation method and application. The general formula of the catalyst is # imgabs0 # B; the catalyst is calcium ions, sodium ions, magnesium ions, lithium ions, potassium ions, ammonium ions, octadecyl dimethyl benzyl ammonium ions, octadecyl trimethyl ammonium ions, dodecyl dimethyl benzyl ammonium ions, dodecyl trimethyl ammonium ions, octyl tributyl phosphonium ions, tetrabutyl phosphonium ions, hexyl tributyl phosphonium ions and tributyl ethyl phosphonium ions; the ionic liquid is a tetrabutyl phosphonium ion, a tributyl hexyl phosphonium ion, a tetramethyl ammonium ion, a tetraethylammonium ion, a tetrabutyl ammonium ion, a benzyl trimethyl ammonium ion, a benzyl triphenyl phosphonium ion or a benzyl triethylammonium ion; m is Cr, Mo, V, W, Cu, Fe, Co, Ni or Zr; r is a C1-C10 alkyl group; x is an integer between 1 and 20; and y is an integer between 1 and 40, so that the p-nitrotoluene oxidation reaction selectivity and the p-nitrotoluene conversion rate can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemistry, and in particular relates to a pyridinedicarboxylic acid coordinated catalyst, a composite catalyst, a preparation method and an application. Background Art

[0002] p-Nitrotoluene is an organic compound with the chemical formula C7H7NO2. It is a light yellow crystalline powder, insoluble in water, but easily soluble in ethanol, ether and benzene. It is mainly used to manufacture p-toluidine, toluene diisocyanate, etc. It is also used as an intermediate for pesticides, dyes, medicines, plastics and synthetic fiber additives. p-Nitrobenzoic acid is a widely used intermediate for medicines, pesticides and dyes. It is mainly used in pesticides to synthesize insecticides and mildewproofing agents. It is mainly used in medicines for anesthetics such as procaine, p-aminomethylbenzoic acid, procainamide, etc. It can also be used as raw materials for organic synthesis, dyes and color films, and has broad market prospects.

[0003] At present, there are two main processes for synthesizing p-nitrobenzoic acid in industry: liquid phase catalytic oxygen oxidation and nitric acid oxidation. The former uses glacial acetic acid as solvent, which causes serious equipment corrosion, large solvent consumption, and is difficult to recycle and reuse. In addition, heavy metal catalysts are required, which causes great environmental pollution and high production costs. The latter has low production costs and simple product post-processing, but the reaction requires high pressure, produces large amounts of waste gas and waste acid, and is subject to many restrictions of environmental protection laws and regulations, making it difficult to meet the needs of the existing market.

[0004] Patent CN1524842A discloses a method for preparing p-nitrobenzoic acid in a mixed solvent of acetic acid and dichlorotoluene using p-nitrotoluene as a reaction raw material, cobalt acetate as a catalyst, azobisisobutyronitrile as an initiator, and oxygen as an oxidant. The method utilizes dichlorotoluene to slow down the corrosion of acetic acid on equipment, but the reaction time is long and the yield is low, which is not conducive to industrial production.

[0005] Patent US20080139841A1 improves the cobalt acetate-oxygen oxidation system of p-nitrotoluene. Although the yield is improved, the method uses acetic acid as a solvent, which is extremely corrosive to equipment. In addition, acetic acid has a high boiling point and is difficult to recover. The initiator N-hydroxyphthalimide used is expensive. Overall, the production cost of this method is high and its market competitive advantage is not obvious.

[0006] Patent CN108658777A discloses a method for synthesizing p-nitrobenzoic acid, which uses 2-p-nitrobenzoyl-2-acetylamino-1,3-propanediol and nitric acid as raw materials and water as solvent, and can produce p-nitrobenzoic acid by reaction at normal pressure and 100°C. However, the preparation cost of the raw material 2-p-nitrobenzoyl-2-acetylamino-1,3-propanediol is high, and the formaldehyde used in the preparation process is a highly toxic substance, which is not conducive to industrial production.

[0007] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] The purpose of the present invention is to provide a pyridinedicarboxylic acid coordinated catalyst, a composite catalyst, a preparation method and an application. The pyridinedicarboxylic acid coordinated catalyst and the composite catalyst can effectively improve the selectivity of the p-nitrotoluene oxidation reaction and the p-nitrotoluene conversion rate.

[0009] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0010] A pyridinedicarboxylic acid coordinated catalyst, the catalyst general formula is as shown in formula (I):

[0011]

[0012] Wherein, B is selected from calcium ion, sodium ion, magnesium ion, lithium ion, potassium ion, ammonium ion, octadecyldimethylbenzylammonium ion, octadecyltrimethylammonium ion, dodecyldimethylbenzylammonium ion, dodecyltrimethylammonium ion, octyltributylphosphonium ion, tetrabutylphosphonium ion, hexyltributylphosphonium ion, tributylethylphosphonium ion, tetrabutylphosphonium ion, tributylhexylphosphonium ion, tetramethylammonium ion, tetraethylammonium ion, tetrabutylammonium ion, benzyltrimethylammonium ion, benzyltriphenylphosphonium ion or benzyltriethylammonium ion;

[0013] M is selected from Cr, Mo, V, W, Cu, Fe, Co, Ni and Zr;

[0014] R is selected from C1~C 10 alkyl;

[0015] x is selected from an integer between 1 and 20;

[0016] y is an integer selected from 1 to 40.

[0017] Another specific embodiment of the present invention provides a technical solution as follows:

[0018] A method for preparing a pyridinedicarboxylic acid coordinated catalyst comprises the following steps:

[0019] Dissolve the metal compound in deionized water, adjust the solution pH to 1-4, then add peroxide and deionized water to obtain a metal peroxide solution;

[0020] Alkyl-substituted pyridinedicarboxylic acid and salt are added to a metal peroxide solution, stirred, centrifuged, filtered and dried to obtain a pyridinedicarboxylic acid coordinated catalyst.

[0021] In one or more embodiments of the present invention, the pyridinedicarboxylic acid is selected from pyridine-2,6-dicarboxylic acid, 4-hydroxypyridine-2,6-dicarboxylic acid and 4-methoxypyridine-2,6-dicarboxylic acid.

[0022] In one or more embodiments of the present invention, the metal compound is selected from ammonium molybdate, sodium molybdate, chromium nitrate, cobalt sulfate, cobalt nitrate, nickel nitrate, nickel sulfate, nickel acetate tetrahydrate, sodium tungstate, copper nitrate, iron nitrate, zirconium acetate, ammonium metavanadate and sodium metavanadate.

[0023] In one or more embodiments of the present invention, the peroxide is selected from hydrogen peroxide, m-chloroperbenzoic acid, tert-butyl hydroperoxide and urea peroxide.

[0024] In one or more embodiments of the present invention, the salt is selected from octadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, sodium chloride, lithium chloride, potassium chloride, ammonium bromide, magnesium chloride, calcium chloride, magnesium acetate, ammonium acetate, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyldimethylbenzylammonium bromide, octyltributylphosphonium bromide, hexyltributylphosphonium bromide, octadecyldimethylbenzylammonium bromide, tetrabutylphosphonium bromide, tributylethylphosphonium bromide, tributylhexylphosphonium bromide, tetrabutylammonium chloride, tetramethylammonium chloride, benzyltrimethylammonium chloride, tetraethylammonium chloride, benzyltriethylammonium chloride and benzyltriphenylphosphonium bromide.

[0025] Another specific embodiment of the present invention provides a technical solution as follows:

[0026] A composite catalyst comprises the above-mentioned pyridinedicarboxylic acid coordinated catalyst.

[0027] In one or more embodiments of the present invention, a cocatalyst is further included, and the weight ratio of the pyridinedicarboxylic acid coordinated catalyst to the cocatalyst is 100:(1-500);

[0028] The auxiliary catalyst is selected from cerium nitrate, cerium sulfate, cerium acetate, manganese acetate, manganese nitrate, manganese sulfate, vanadium oxide, cobalt oxide, silver nitrate, zirconium oxide, zirconium acetate, ferric nitrate, ferric sulfate, ferric chloride, copper sulfate, copper acetate, copper nitrate, magnesium sulfate, magnesium acetate, zinc acetate, zinc sulfate, sodium molybdate, potassium acetate and potassium sulfate.

[0029] In one or more embodiments of the present invention, a regulator is further included, and the weight ratio of the pyridinedicarboxylic acid coordinated catalyst to the regulator is 100:(1-500);

[0030] The regulator is selected from phosphomolybdic acid, phosphotungstic acid, tetrabutylammonium bromide, boric acid, silicotungstic acid and phosphomolybdic vanadic acid.

[0031] In one or more embodiments of the present invention, a protective agent is also included, and the weight ratio of the pyridinedicarboxylic acid coordinated catalyst to the protective agent is 100: (1-500);

[0032] The protective agent is selected from sodium acetate, ammonium bromide, azobisisobutyronitrile, hexadecyltrimethylammonium bromide, phenyltrimethylammonium bromide, sodium molybdate and N-hydroxyphthalimide.

[0033] In one or more embodiments of the present invention, a solvent is further included, and the weight ratio of the pyridinedicarboxylic acid coordinated catalyst to the solvent is 100:(50-10000);

[0034] The solvent is selected from the group consisting of dichloromethane, 1,4-dioxane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid and ethyl acetate.

[0035] Another specific embodiment of the present invention provides a technical solution as follows:

[0036] A method for preparing a composite catalyst comprises the following steps:

[0037] Mix the protective agent and the solvent to obtain a solution;

[0038] Add the catalyst coordinated with pyridine dicarboxylic acid to the solution and stir at 20°C to 100°C for 10 to 60 minutes;

[0039] Add the auxiliary catalyst and stir at 20℃~100℃ for 30~60min;

[0040] Then add a regulator, stir at 20°C to 100°C for 10 to 60 minutes to obtain a composite catalyst.

[0041] Another specific embodiment of the present invention provides a technical solution as follows:

[0042] A use of the pyridinedicarboxylic acid coordinated catalyst, the pyridinedicarboxylic acid coordinated catalyst prepared by the preparation method of the pyridinedicarboxylic acid coordinated catalyst, or the composite catalyst in catalytic oxidation of p-nitrotoluene to prepare p-nitrobenzoic acid.

[0043] Compared with the prior art, the pyridinedicarboxylic acid coordinated catalyst and composite catalyst of the present invention can improve the selectivity of the p-nitrotoluene oxidation reaction, increase the reaction activity, and can be applied multiple times with a high utilization rate. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0045] A specific embodiment of the present invention provides a pyridinedicarboxylic acid coordinated catalyst, the catalyst having a general formula as shown in formula (I):

[0046]

[0048] Wherein, B is selected from calcium ion, sodium ion, magnesium ion, lithium ion, potassium ion, ammonium ion, octadecyldimethylbenzylammonium ion, octadecyltrimethylammonium ion, dodecyldimethylbenzylammonium ion, dodecyltrimethylammonium ion, octyltributylphosphonium ion, tetrabutylphosphonium ion, hexyltributylphosphonium ion, tributylethylphosphonium ion, tetrabutylphosphonium ion, tributylhexylphosphonium ion, tetramethylammonium ion, tetraethylammonium ion, tetrabutylammonium ion, benzyltrimethylammonium ion, benzyltriphenylphosphonium ion or benzyltriethylammonium ion; M is selected from Cr, Mo, V, W, Cu, Fe, Co, Ni and Zr; R is selected from Cl~C 10 alkyl; x is selected from an integer between 1 and 20; y is selected from an integer between 1 and 40.

[0049] Preferably, B is selected from dodecyltrimethylammonium ion, octadecyltrimethylammonium ion, lithium ion, sodium ion, potassium ion, magnesium ion, calcium ion, ammonium ion or benzyltriphenylphosphonium ion; M is Mo, Cr, Co, Ni, V, Cu and Fe; R is selected from C1 to C5 alkyl; x is selected from an integer between 1 and 5; y is selected from an integer between 1 and 5.

[0050] More preferably, B is selected from octadecyltrimethylammonium ion, sodium ion, magnesium ion, ammonium ion or benzyltriphenylphosphonium ion; M is selected from Mo, Cr, Co, Ni and V; R is selected from methyl, ethyl, isopropyl; x is 1; y is 1 or 2.

[0051] Exemplary, the pyridine dicarboxylic acid coordinated catalyst is:

[0052]

[0053]

[0054] Another specific embodiment of the present invention provides a method for preparing a pyridinedicarboxylic acid coordinated catalyst, comprising the following steps 1-2.

[0055] Step 1, dissolving a metal compound in deionized water, adjusting the solution pH to 1-4, and then adding peroxide and deionized water to obtain a metal peroxide solution.

[0056] Specifically, the metal compound is added to deionized water at room temperature, and the pH value of the solution is adjusted with an inorganic acid reagent, wherein the inorganic acid reagent is selected from sulfuric acid, phosphoric acid, hydrochloric acid and nitric acid. The metal compound is selected from ammonium molybdate, sodium molybdate, chromium nitrate, cobalt sulfate, cobalt nitrate, nickel nitrate, nickel sulfate, nickel acetate tetrahydrate, sodium tungstate, copper nitrate, iron nitrate, zirconium acetate, ammonium metavanadate and sodium metavanadate, and the peroxide is selected from hydrogen peroxide, m-chloroperbenzoic acid, tert-butyl hydroperoxide and urea peroxide.

[0057] Step 2, adding alkyl-substituted pyridinedicarboxylic acid and salt to the metal peroxide solution, stirring, centrifuging, filtering, and drying to obtain a pyridinedicarboxylic acid coordinated catalyst.

[0058] Specifically, the metal peroxide solution is heated to 30° C. to 90° C., and then pyridine dicarboxylic acid and salt are added, the stirring time is 1 to 10 hours, the centrifugation time is 20 to 200 minutes, the drying temperature is 60° C. to 120° C., and the drying time is 2 to 24 hours.

[0059] The pyridinedicarboxylic acid is selected from pyridine-2,6-dicarboxylic acid, 4-hydroxypyridine-2,6-dicarboxylic acid and 4-methoxypyridine-2,6-dicarboxylic acid, and the salt is selected from octadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, sodium chloride, lithium chloride, potassium chloride, ammonium bromide, magnesium chloride, calcium chloride, magnesium acetate, ammonium acetate, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyldimethylbenzylammonium bromide, octyltributylphosphonium bromide, hexyltributylphosphonium bromide, octadecyldimethylbenzylammonium bromide, tetrabutylphosphonium bromide, tributylethylphosphonium bromide, tributylhexylphosphonium bromide, tetrabutylammonium chloride, tetramethylammonium chloride, benzyltrimethylammonium chloride, tetraethylammonium chloride, benzyltriethylammonium chloride and benzyltriphenylphosphonium bromide.

[0060] Another specific embodiment of the present invention provides a composite catalyst, including a catalyst coordinated by pyridinedicarboxylic acid, a cocatalyst, a regulator, and a protective agent. The composite catalyst is dissolved in a solvent before use. The weight ratio of the catalyst coordinated by pyridinedicarboxylic acid, the cocatalyst, the regulator, the protective agent and the solvent is 100:(1~500):(1~500):(1~500):(50~10000).

[0061] Specifically, the auxiliary catalyst is selected from cerium nitrate, cerium sulfate, cerium acetate, manganese acetate, manganese nitrate, manganese sulfate, vanadium oxide, cobalt oxide, silver nitrate, zirconium oxide, zirconium acetate, ferric nitrate, ferric sulfate, ferric chloride, copper sulfate, copper acetate, copper nitrate, magnesium sulfate, magnesium acetate, zinc acetate, zinc sulfate, sodium molybdate, potassium acetate and potassium sulfate, the regulator is selected from phosphomolybdic acid, phosphotungstic acid, tetrabutylammonium bromide, boric acid, silicotungstic acid and phosphomolybdicvanadic acid, the protective agent is selected from sodium acetate, ammonium bromide, azobisisobutyronitrile, hexadecyltrimethylammonium bromide, phenyltrimethylammonium bromide, sodium molybdate and N-hydroxyphthalimide, and the solvent is selected from dichloromethane, 1,4-dioxane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid and ethyl acetate.

[0062] Preferably, the weight ratio of the pyridinedicarboxylic acid coordinated catalyst, the cocatalyst, the regulator, the protective agent and the solvent is 100:(1-50):(10-100):(10-50):(100-1000), the pyridinedicarboxylic acid coordinated catalyst is selected from pyridinedicarboxylic acid coordinated catalysts with Cr, Mo, V, Co or Ni as the central metal, the cocatalyst is selected from manganese acetate, zirconium acetate, magnesium acetate and cerium acetate, the regulator is selected from phosphomolybdic acid, phosphotungstic acid and silicotungstic acid, the protective agent is selected from azobisisobutyronitrile, hexadecyltrimethylammonium bromide, phenyltrimethylammonium bromide and N-hydroxyphthalimide, and the solvent is selected from methanol, ethanol and acetonitrile.

[0063] Selecting the above types of cocatalysts can help improve the reaction rate and catalytic efficiency, can help inhibit the occurrence of side reactions, and improve the selectivity of the target product. Selecting the above types of regulators is conducive to promoting catalyst activation, improving reaction efficiency, and can also enhance catalyst stability so that the reaction proceeds normally. Selecting the above types of protective agents can prevent catalyst deactivation to a certain extent, ensure the activity of the catalyst, and improve the stability of the catalyst.

[0064] Another specific embodiment of the present invention provides a method for preparing a composite catalyst, comprising the following steps: mixing a protective agent and a solvent to obtain a solution; adding a catalyst coordinated by pyridinedicarboxylic acid to the solution, and stirring at 20°C to 100°C for 10 to 60 minutes; then adding a co-catalyst, and stirring at 20°C to 100°C for 30 to 60 minutes; then adding a regulator, and stirring at 20°C to 100°C for 10 to 60 minutes to obtain a composite catalyst.

[0065] Another specific embodiment of the present invention provides the use of the above-mentioned pyridinedicarboxylic acid coordinated catalyst, the pyridinedicarboxylic acid coordinated catalyst prepared by the preparation method of the pyridinedicarboxylic acid coordinated catalyst, or the above-mentioned composite catalyst in catalytic oxidation of p-nitrotoluene to prepare p-nitrobenzoic acid.

[0066] Specifically, p-nitrotoluene is dissolved in a solvent, a catalyst coordinated with pyridine dicarboxylic acid or a composite catalyst is added thereto, air is introduced at a rate of 1 to 20 mL / s, and the reaction is stirred at 50° C. to 160° C. for 1 to 20 hours. Taking the composite catalyst as an example, the amount of the composite catalyst added is 0.01 to 5% of the weight of p-nitrotoluene. The solvent is acetic acid.

[0067] Preferably, the reaction temperature is 100° C. to 150° C., the reaction time is 4 to 8 h, the air introduction rate is 5 to 10 mL / s, and the amount of the composite catalyst added is 0.1 to 1% of the weight of p-nitrotoluene.

[0068] More preferably, the reaction temperature is 60-90° C., the reaction time is 2-5 h, and the air introduction rate is 2-5 mL / s.

[0069] The present invention is further described in detail below in conjunction with specific embodiments.

[0070] Pyridinedicarboxylic acid coordinated catalyst example

[0071] Example 1

[0072] Add 500 mL of deionized water to solid sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 60 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0073] Heat solution d to 25°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 10 minutes. Filter, and dry the solid obtained after filtration in a vacuum drying oven to obtain 54.39 g of yellow solid, which is the catalyst YG-S45-001 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 92.17%. NMR characterization data are as follows:

[0074] 1H NMR(400MHz,DMSO-d6)δ8.89(s,1H),8.24(d,1H),7.50(s,1H),3.60(t,2H),3 .47(s,9H),2.76(s,3H),1.76-1.72(m,2H),1.54-1.07(m,30H),0.89(t,3H).

[0075] Example 2

[0076] Add 500 mL of deionized water to solid sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 60 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0077] Heat solution d to 25°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and sodium chloride (6.43 g, 0.11 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 10 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 33.49 g of yellow solid, which is the catalyst YG-S45-002 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 93.01%. NMR characterization data are as follows:

[0078] 1H NMR (400MHz, DMSO-d6) δ8.86 (s, 1H), 8.62 (d, 1H), 2.72 (s, 3H).

[0079] Example 3

[0080] Add 500 mL of deionized water to solid sodium molybdate (41.20 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute hydrochloric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 100 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0081] Heat solution d to 50°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and magnesium acetate (15.66 g, 0.11 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 30 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 59.34 g of yellow solid, which is the catalyst YG-S45-003 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 89.85%. NMR characterization data are as follows:

[0082] 1H NMR (400MHz, DMSO-d6) δ9.02 (s, 1H), 8.65 (d, 1H), 7.26 (s, 1H), 2.51 (s, 3H).

[0083] Example 4

[0084] Add 500 mL of deionized water to solid sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute phosphoric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 5 minutes, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0085] Heat solution d to 100°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and ammonium acetate (8.41 g, 0.11 mol) to solution d, stir while heating for about 2 hours, and centrifuge for 5 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 33.01 g of yellow solid, which is the catalyst YG-S45-004 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 92.14%. NMR characterization data are as follows:

[0086] 1H NMR (400MHz, DMSO-d6) δ8.60(d,1H),8.23(d,1H),7.51(s,1H),7.23(t,4H),2.71(s,3H).

[0087] Example 5

[0088] Add 500 mL of deionized water to a solid of sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute nitric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 30 minutes, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0089] Heat solution d to 80°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and benzyltriphenylphosphonium bromide (53.20 g, 0.12 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 20 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 58.18 g of yellow solid, which is the catalyst YG-S45-005 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 90.08%. NMR characterization data are as follows:

[0090] 1H NMR(400MHz,DMSO-d6)δ8.92(s,1H),8.66(d,1H),8.31(d,1H),8.25(d,1H),7.97-7.85(m,3H),7.81-7 .63(m,12H),7.54(s,1H),7.35-7.25(m,1H),7.26-7.18(m,2H),6.99(d,2H),5.25(d,2H),2.74(s,3H).

[0091] Example 6

[0092] Add 500 mL of deionized water to a solid of sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 10 min, then slowly add 200 mL of 30% m-chloroperbenzoic acid solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0093] Heat solution d to 60°C, add 4-hydroxypyridine-2,6-dicarboxylic acid (20.14 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 6 hours, and centrifuge for 15 minutes. Filter, and dry the solid obtained after filtration in a vacuum drying oven to obtain 60.58 g of yellow solid, which is the catalyst YG-S45-006 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 90.06%. NMR characterization data are as follows:

[0094] 1H NMR(400MHz,DMSO-d6)δ8.61(d,1H),8.24(d,1H),7.50(s,1H),3.60(t,2H),3 .48(s,9H),3.41(q,2H),1.76-1.72(m,2H),1.55-1.06(m,33H),0.89(t,3H).

[0095] Example 7

[0096] Add 500 mL of deionized water to solid sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 30 minutes, then slowly add 200 mL of 30% urea peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0097] Heat solution d to 50°C, add 4-methoxypyridine-2,6-dicarboxylic acid (20.69 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 10 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 54.58 g of yellow solid, which is the catalyst YG-S45-007 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 91.64%. The NMR characterization data are as follows:

[0098] 1H NMR(400MHz,DMSO-d6)δ8.87(s,1H),8.27(d,1H),7.50(s,1H),3.60(t,2H),3.4 8(s,9H),3.44-3.40(m,1H),1.76-1.72(m,2H),1.53-1.04(m,36H),0.89(t,3H).

[0099] Example 8

[0100] Add 500 mL of deionized water to solid chromium nitrate nonahydrate (40.01 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 30 minutes, then slowly add 200 mL of 30% tert-butyl hydroperoxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0101] Heat solution d to 25°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and octadecyltrimethylammonium chloride (76.57 g, 0.22 mol) to solution d, stir while heating for about 5 hours, and centrifuge for 20 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 55.98 g of purple-red solid, which is the catalyst YG-S45-008 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 88.75%. The NMR characterization data are as follows:

[0102] 1H NMR(400MHz,DMSO-d6)δ8.94(s,1H),8.31(d,1H),8.26(d,1H),7.51(s,1H),3.60(t ,2H),3.47(s,9H),2.77(s,3H),1.77-1.72(m,2H),1.54-1.08(m,30H),0.90(t,3H).

[0103] Example 9

[0104] Add 500 mL of deionized water to solid chromium nitrate nonahydrate (40.01 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 120 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0105] Heat solution d to 100°C, add 4-hydroxypyridine-2,6-dicarboxylic acid (20.14 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 30 minutes. Filter, and dry the solid obtained after filtration in a vacuum drying oven to obtain 50.15 g of purple-red solid, which is the catalyst YG-S45-009 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 91.64%. NMR characterization data are as follows:

[0106] 1H NMR(400MHz,DMSO-d6)δ8.92(s,1H),8.29(d,1H),8.26(d,1H),7.51(s,1H),3.60 (t,2H),3.48(s,9H),3.41(q,2H),1.76(m,2H),1.56-1.03(m,33H),0.89(t,3H).

[0107] Example 10

[0108] Add 500 mL of deionized water to solid chromium nitrate nonahydrate (40.01 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 100 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0109] Heat solution d to 60°C, add 4-methoxypyridine-2,6-dicarboxylic acid (20.69 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 8 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 50.21 g of purple-red solid, which is the catalyst YG-S45-010 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 93.31%. NMR characterization data are as follows:

[0110] 1H NMR(400MHz,DMSO-d6)δ8.90(s,1H),8.29(d,1H),8.25(d,1H),7.51(s,1H),3.60(t,2H ),3.49(s,9H),3.42-3.39(m,1H),1.76-1.72(m,2H),1.53-1.02(m,36H),0.89(t,3H).

[0111] Embodiment 11

[0112] Add 500 mL of deionized water to solid cobalt nitrate hexahydrate (29.10 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 30 minutes, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0113] Heat solution d to 45°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 10 hours, and centrifuge for 5 to 10 minutes. Filter, and dry the solid obtained after filtration in a vacuum drying oven to obtain 52.91 g of blue solid, which is the catalyst YG-S45-011 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 92.09%. NMR characterization data are as follows:

[0114] 1H NMR(400MHz,DMSO-d6)δ8.94(s,1H),8.68(d,1H),8.27(d,1H),7.53(s,1H),3.62(t ,2H),3.48(s,9H),2.78(s,3H),1.78-1.73(m,2H),1.57-1.07(m,30H),0.92(t,3H).

[0115] Example 12

[0116] Add 500 mL of deionized water to nickel acetate tetrahydrate (24.88 g, 0.1 mol) solid at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 80 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0117] Heat solution d to 45°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 3 hours, and centrifuge for 20 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 48.28 g of white solid, which is the catalyst YG-S45-012 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 88.14%. The NMR characterization data are as follows:

[0118] 1H NMR(400MHz,DMSO-d6)δ8.93(s,1H),8.32(d,1H),8.27(d,1H),7.52(s,1H),3.61(t ,2H),3.48(s,9H),2.77(s,3H),1.76-1.72(m,2H),1.55-1.04(m,33H),0.91(t,3H).

[0119] Embodiment 13

[0120] Add 500 mL of deionized water to solid sodium metavanadate (12.19 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 120 min, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0121] Heat solution d to 30°C, add pyridine-2,6-dicarboxylic acid (18.38 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 2 hours, and centrifuge for 30 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 49.21 g of yellow solid, which is the catalyst YG-S45-013 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 90.28%. NMR characterization data are as follows:

[0122] 1H NMR(400MHz,DMSO-d6)δ8.90(s,1H),8.63(d,1H),8.25(d,1H),7.51(s,1H),3.61(t ,2H),3.48(s,9H),2.75(s,3H),1.77-1.72(m,2H),1.55-1.06(m,30H),0.90(t,3H).

[0123] Embodiment 14

[0124] Add 500 mL of deionized water to solid sodium molybdate (20.60 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 30 minutes, then slowly add 200 mL of 30% H2O2 solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0125] Heat solution d to 55°C, add 4-hydroxypyridine-2,6-dicarboxylic acid (20.14 g, 0.11 mol) and octadecyltrimethylammonium chloride (38.29 g, 0.11 mol) to solution d, stir while heating for about 10 hours, and centrifuge for 10 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 53.27 g of yellow solid, which is the catalyst YG-S45-014 coordinated with pyridinedicarboxylic acid, and the catalyst yield reaches 92.81%. The NMR characterization data are as follows:

[0126] 1H NMR(400MHz,DMSO-d6)δ8.90(s,1H),8.63(d,1H),8.25(d,1H),7.51(s,1H),3.60(t,2H ),3.49(s,9H),3.42-3.39(m,1H),1.75-1.71(m,2H),1.53-1.02(m,36H),0.89(t,3H).

[0127] Composite Catalyst Example

[0128] Embodiment 15

[0129] Step (a): adding 20.0 g of methanol to 10.0 g of N-hydroxyphthalimide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0130] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-001 to the mixed solution of step (a), and heat at 80° C. with stirring for 30 min to obtain a mixture B;

[0131] Step (c): adding 0.1 g of manganese acetate to the mixture B formed in step (b) to obtain a mixture C;

[0132] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 60 minutes to obtain a total of 31.2 g of composite catalyst 1.

[0133] Embodiment 16:

[0134] Step (a): adding 20.0 g of methanol to 10.0 g of ammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0135] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-002 to the mixed solution of step (a), and heat at 80° C. with stirring for 30 min to obtain a mixture B;

[0136] Step (c): adding 0.1 g of manganese acetate to the mixture B formed in step (b) to obtain a mixture C;

[0137] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 120° C. for 60 minutes to obtain a total of 31.2 g of composite catalyst 2.

[0138] Embodiment 17:

[0139] Step (a): adding 20.0 g of methanol to 10.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0140] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-003 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0141] Step (c): adding 0.1 g of manganese acetate to the mixture B formed in step (b) to obtain a mixture C;

[0142] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 120° C. for 60 minutes to obtain a total of 31.2 g of composite catalyst 3.

[0143] Embodiment 18:

[0144] Step (a): adding 20.0 g of methanol to 10.0 g of phenyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0145] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-004 to the mixed solution of step (a), and heat at 70° C. with stirring for 60 min to obtain a mixture B;

[0146] Step (c): adding 0.1 g of manganese acetate to the mixture B formed in step (b) to obtain a mixture C;

[0147] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 80° C. for 60 minutes to obtain a total of 31.2 g of composite catalyst 4.

[0148] Embodiment 19:

[0149] Step (a): adding 30.0 g of ethanol to a solid mixture of 5.0 g of ammonium bromide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0150] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-005 to the mixed solution of step (a), and heat at 100° C. with stirring for 30 min to obtain a mixture B;

[0151] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0152] Step (d): Add 0.1 g of phosphotungstic acid to the mixture C formed in step (c), stir at 110° C. for 120 minutes, and obtain a total of 41.2 g of composite catalyst 5.

[0153] Embodiment 20:

[0154] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0155] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-006 to the mixed solution of step (a), and heat with stirring at 50° C. for 240 min to obtain a mixture B;

[0156] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0157] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 120° C. for 40 minutes to obtain a total of 41.2 g of composite catalyst 6.

[0158] Embodiment 21:

[0159] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0160] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-007 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0161] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0162] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 60 minutes to obtain a total of 41.2 g of composite catalyst 7.

[0163] Embodiment 22:

[0164] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0165] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-008 to the mixed solution of step (a), and heat with stirring at 60° C. for 100 min to obtain a mixture B;

[0166] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0167] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 120 minutes to obtain a total of 41.2 g of composite catalyst 8.

[0168] Embodiment 23:

[0169] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0170] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-009 to the mixed solution of step (a), and heat at 60° C. with stirring for 60 min to obtain a mixture B;

[0171] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0172] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 120° C. for 60 minutes to obtain a total of 41.2 g of composite catalyst 9.

[0173] Embodiment 24:

[0174] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0175] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-010 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0176] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0177] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 60 minutes to obtain a composite catalyst 10 in a total amount of 41.2 g.

[0178] Embodiment 25:

[0179] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0180] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-011 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0181] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0182] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 60 minutes to obtain a total of 41.2 g of composite catalyst 11.

[0183] Embodiment 26:

[0184] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0185] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-012 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0186] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0187] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), stir at 100° C. for 60 minutes, and obtain a total of 41.2 g of composite catalyst 12.

[0188] Embodiment 27:

[0189] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0190] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-013 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0191] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0192] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 60 minutes to obtain a total of 41.2 g of composite catalyst 13.

[0193] Embodiment 28:

[0194] Step (a): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of hexadecyltrimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0195] Step (b): add 1.0 g of pyridinedicarboxylic acid coordinated catalyst YG-S45-014 to the mixed solution of step (a), and heat at 80° C. with stirring for 60 min to obtain a mixture B;

[0196] Step (c): adding 0.1 g of cerium acetate to the mixture B formed in step (b) to obtain a mixture C;

[0197] Step (d): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (c), and stir at 100° C. for 60 minutes to obtain a total of 41.2 g of the composite catalyst 14.

[0198] Application Examples

[0199] Embodiment 29

[0200] Add azobisisobutyronitrile (0.05g), pyridine dicarboxylic acid coordinated catalyst YG-S45-001 (0.1g), manganese acetate (0.01g), phosphomolybdic acid (0.01g), methanol (2.0g), acetic acid (50g), and p-nitrotoluene (100g) in sequence to a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure in the autoclave is 0.5MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, it is considered that the air tightness of the autoclave is good. After the nitrogen is discharged, heat it to 80°C, ventilate the air until the pressure in the autoclave is 0.4MPa, vent the air continuously, control the flow rate to 400-500mL / min, and end the reaction after three hours. The reaction solution is dark green, and the total weight of the reaction solution is 163.75g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the raw material has been completely converted, the conversion rate of p-nitrotoluene is 100%, and the selectivity of the product p-nitrobenzoic acid reaches 95.8%.

[0201] Embodiment 30

[0202] Add ammonium bromide (0.1g), pyridine dicarboxylic acid coordinated catalyst YG-S45-002 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (2.0g), acetic acid (50g), and p-nitrotoluene (100g) in sequence to a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure inside the autoclave is 0.5MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, it is considered that the air tightness of the autoclave is good. After the nitrogen is discharged, the temperature is raised to 60°C, and air is passed until the pressure inside the autoclave is 0.4MPa. The air is passed continuously, and the flow rate is controlled to be 400-500mL / min. The reaction ends after three hours. The reaction liquid is dark green, and the total weight of the reaction liquid is weighed to be 162.06g. Take 0.1g of the reaction liquid, toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the raw material has been completely converted, the conversion rate of p-nitrotoluene is 100%, and the selectivity of the product p-nitrobenzoic acid reaches 91.6%.

[0203] Embodiment 31

[0204] Add hexadecyltrimethylammonium bromide (0.1g), pyridine dicarboxylic acid coordinated catalyst YG-S45-003 (0.1g), manganese acetate (0.01g), phosphomolybdic acid (0.01g), methanol (2.0g), acetic acid (50g), and p-nitrotoluene (100g) to a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure inside the autoclave is 0.5MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, the air tightness of the autoclave is considered good. After the nitrogen is discharged, heat it to 80℃, ventilate it until the pressure inside the autoclave is 0.4MPa, vent it continuously, control the flow rate to 400-500mL / min, and end the reaction after three hours. The reaction liquid is dark green, and the total weight of the reaction liquid is 164.94g. Take 0.1g of the reaction liquid, use toluene as the internal standard, take 0.1g of toluene, dilute it with 30g of acetonitrile, and then inject it for testing. The analysis results showed that the raw material had been completely converted, the conversion rate of p-nitrotoluene was 100%, and the selectivity of the product p-nitrobenzoic acid reached 93.0%.

[0205] Embodiment 32

[0206] Add phenyltrimethylammonium bromide (0.1g), pyridine dicarboxylic acid coordinated catalyst YG-S45-004 (0.1g), manganese acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), and p-nitrotoluene (100g) in sequence to a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure in the autoclave is 0.5MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, it is considered that the air tightness of the autoclave is good. After the nitrogen is discharged, heat it to 80°C, ventilate the air until the pressure in the autoclave is 0.4MPa, vent the air continuously, control the flow rate to 400-500mL / min, and end the reaction after three hours. The reaction solution is dark green, and the total weight of the reaction solution is 161.34g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the raw material has been completely converted, the conversion rate of p-nitrotoluene is 100%, and the selectivity of the product p-nitrobenzoic acid reaches 94.2%.

[0207] Embodiment 33

[0208] Add azobisisobutyronitrile (0.05g), hexadecyltrimethylammonium bromide (0.05g), pyridinedicarboxylic acid coordinated catalyst YG-S45-005 (0.1g), cerium acetate (0.01g), phosphotungstic acid (0.01g), methanol (3.0g), acetic acid (50g), and p-nitrotoluene (100g) in sequence to a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure inside the autoclave is 0.5MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, it is considered that the air tightness of the autoclave is good. After the nitrogen is discharged, heat it to 80°C, ventilate it with air until the pressure inside the autoclave is 0.4MPa, vent it continuously, control the flow rate to 400-500mL / min, and end the reaction after three hours. The reaction solution is dark green, and the total weight of the reaction solution is 165.28g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 96.7%, and the selectivity of the product p-nitrobenzoic acid reaches 94.5%.

[0209] Embodiment 34

[0210] N-hydroxyphthalimide (0.05g), hexadecyltrimethylammonium bromide (0.05g), pyridine dicarboxylic acid coordinated catalyst YG-S45-006 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 161.87g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 98.2%, and the selectivity of the product p-nitrobenzoic acid reaches 93.3%.

[0211] Embodiment 35

[0212] N-hydroxyphthalimide (0.05g), hexadecyltrimethylammonium bromide (0.05g), pyridine dicarboxylic acid coordinated catalyst YG-S45-007 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 165.21g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the raw material has been completely converted, the conversion rate of p-nitrotoluene is 100%, and the selectivity of the product p-nitrobenzoic acid reaches 96.0%.

[0213] Embodiment 36

[0214] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-008 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 164.11g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 91.5%, and the selectivity of the product p-nitrobenzoic acid reaches 90.8%.

[0215] Embodiment 37

[0216] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-009 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 165.53g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the raw material has been completely converted, the conversion rate of p-nitrotoluene is 100%, and the selectivity of the product p-nitrobenzoic acid reaches 98.1%.

[0217] Embodiment 38

[0218] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-010 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 165.53g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 94.7%, and the selectivity of the product p-nitrobenzoic acid reaches 93.9%.

[0219] Embodiment 39

[0220] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-011 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 166.08g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 95.0%, and the selectivity of the product p-nitrobenzoic acid reaches 97.8%.

[0221] Embodiment 40

[0222] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-012 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 166.02g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 98.1%, and the selectivity of the product p-nitrobenzoic acid reaches 95.3%.

[0223] Embodiment 41

[0224] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-013 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 162.99g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 95.7%, and the selectivity of the product p-nitrobenzoic acid reaches 93.8%.

[0225] Embodiment 42

[0226] N-hydroxyphthalimide (0.5g), hexadecyltrimethylammonium bromide (0.5g), pyridine dicarboxylic acid coordinated catalyst YG-S45-014 (0.1g), cerium acetate (0.01g), phosphomolybdic acid (0.01g), methanol (3.0g), acetic acid (50g), p-nitrotoluene (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure in the autoclave was 0.5MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 80°C, and air was passed through until the pressure in the autoclave was 0.4MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after three hours. The reaction solution was dark green, and the total weight of the reaction solution was weighed to be 163.39g. Take 0.1g of the reaction solution, use toluene as the internal standard, take 0.1g of toluene, add 30g of acetonitrile to dilute, and then inject the sample for testing. The analysis results show that the conversion rate of p-nitrotoluene is 99.0%, and the selectivity of the product p-nitrobenzoic acid reaches 96.6%.

[0227] Comparative Example

[0228] The specific operation method of the comparative example is consistent with that of Example 29, and the material addition amounts and experimental results are shown in Table 1.

[0229] Table 1 Material addition amount and experimental results in comparative examples

[0230]

[0231]

[0232] In summary, compared with the catalyst in Comparative Example 8 without the addition of pyridinedicarboxylic acid coordination, the selectivity of p-nitrotoluene and p-nitrobenzoic acid in Example 29 is excellent, indicating that the catalyst coordinated with pyridinedicarboxylic acid can improve the selectivity of the p-nitrotoluene oxidation reaction and increase the reaction activity.

[0233] Compared with Comparative Examples 1-7, the result of the p-nitrotoluene oxidation reaction in Example 29 is better, indicating that the use of a cocatalyst, a regulator, a protective agent and a catalyst coordinated by pyridine dicarboxylic acid can better catalyze the oxidation of p-nitrotoluene to p-nitrobenzoic acid. In addition, it can be seen from Examples 30-42 that the selectivity of p-nitrobenzoic acid in the examples is more than 90%, and the conversion rate of p-nitrotoluene is as high as 100%, which also verifies that the use of a cocatalyst, a regulator, a protective agent and a catalyst coordinated by pyridine dicarboxylic acid can effectively improve the selectivity of the p-nitrotoluene oxidation reaction and the conversion rate of p-nitrobenzoic acid.

[0234] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0235] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A pyridinedicarboxylic acid coordinated catalyst, characterized in that: The catalyst general formula is shown in formula (I): Wherein, B is selected from calcium ion, sodium ion, magnesium ion, lithium ion, potassium ion, ammonium ion, octadecyldimethylbenzylammonium ion, octadecyltrimethylammonium ion, dodecyldimethylbenzylammonium ion, dodecyltrimethylammonium ion, octyltributylphosphonium ion, tetrabutylphosphonium ion, hexyltributylphosphonium ion, tributylethylphosphonium ion, tetrabutylphosphonium ion, tributylhexylphosphonium ion, tetramethylammonium ion, tetraethylammonium ion, tetrabutylammonium ion, benzyltrimethylammonium ion, benzyltriphenylphosphonium ion or benzyltriethylammonium ion; M is selected from Cr, Mo, V, W, Cu, Fe, Co, Ni and Zr; R is selected from C1~C 10 alkyl; x is selected from an integer between 1 and 20; y is an integer selected from 1 to 40.

2. A method for preparing a pyridinedicarboxylic acid coordinated catalyst according to claim 1, characterized in that: The following steps are involved: Dissolve the metal compound in deionized water, adjust the solution pH to 1-4, then add peroxide and deionized water to obtain a metal peroxide solution; Alkyl-substituted pyridinedicarboxylic acid and salt are added to a metal peroxide solution, stirred, centrifuged, filtered and dried to obtain a pyridinedicarboxylic acid coordinated catalyst.

3. The method for preparing a pyridinedicarboxylic acid coordinated catalyst according to claim 2, characterized in that: The pyridinedicarboxylic acid is selected from pyridine-2,6-dicarboxylic acid, 4-hydroxypyridine-2,6-dicarboxylic acid and 4-methoxypyridine-2,6-dicarboxylic acid.

4. The method for preparing a pyridinedicarboxylic acid coordinated catalyst according to claim 2, characterized in that: The metal compound is selected from ammonium molybdate, sodium molybdate, chromium nitrate, cobalt sulfate, cobalt nitrate, nickel nitrate, nickel sulfate, nickel acetate tetrahydrate, sodium tungstate, copper nitrate, iron nitrate, zirconium acetate, ammonium metavanadate and sodium metavanadate.

5. The method for preparing a pyridinedicarboxylic acid coordinated catalyst according to claim 2, characterized in that: The peroxide is selected from hydrogen peroxide, meta-chloroperbenzoic acid, tert-butyl hydroperoxide and urea peroxide.

6. The method for preparing a pyridinedicarboxylic acid coordinated catalyst according to claim 2, characterized in that: The salt is selected from octadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, sodium chloride, lithium chloride, potassium chloride, ammonium bromide, magnesium chloride, calcium chloride, magnesium acetate, ammonium acetate, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyldimethylbenzylammonium bromide, octyltributylphosphonium bromide, hexyltributylphosphonium bromide, octadecyldimethylbenzylammonium bromide, tetrabutylphosphonium bromide, tributylethylphosphonium bromide, tributylhexylphosphonium bromide, tetrabutylammonium chloride, tetramethylammonium chloride, benzyltrimethylammonium chloride, tetraethylammonium chloride, benzyltriethylammonium chloride and benzyltriphenylphosphonium bromide.

7. A composite catalyst, characterized in that The catalyst comprises the pyridinedicarboxylic acid coordinated catalyst according to claim 1.

8. The composite catalyst according to claim 7, characterized in that It also includes a cocatalyst, wherein the weight ratio of the pyridinedicarboxylic acid coordinated catalyst to the cocatalyst is 100:(1-500); The auxiliary catalyst is selected from cerium nitrate, cerium sulfate, cerium acetate, manganese acetate, manganese nitrate, manganese sulfate, vanadium oxide, cobalt oxide, silver nitrate, zirconium oxide, zirconium acetate, ferric nitrate, ferric sulfate, ferric chloride, copper sulfate, copper acetate, copper nitrate, magnesium sulfate, magnesium acetate, zinc acetate, zinc sulfate, sodium molybdate, potassium acetate and potassium sulfate.

9. The composite catalyst according to claim 7, characterized in that It also includes a regulator, and the weight ratio of the pyridine dicarboxylic acid coordinated catalyst to the regulator is 100: (1-500); The regulator is selected from phosphomolybdic acid, phosphotungstic acid, tetrabutylammonium bromide, boric acid, silicotungstic acid and phosphomolybdic vanadic acid.

10. The composite catalyst according to claim 7, characterized in that It also includes a protective agent, and the weight ratio of the pyridine dicarboxylic acid coordinated catalyst to the protective agent is 100: (1-500); The protective agent is selected from sodium acetate, ammonium bromide, azobisisobutyronitrile, hexadecyltrimethylammonium bromide, phenyltrimethylammonium bromide, sodium molybdate and N-hydroxyphthalimide.

11. The composite catalyst according to claim 7, characterized in that It also includes a solvent, and the weight ratio of the pyridinedicarboxylic acid coordinated catalyst to the solvent is 100:(50-10000); The solvent is selected from the group consisting of dichloromethane, 1,4-dioxane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid and ethyl acetate.

12. A method for preparing the composite catalyst according to any one of claims 7 to 11, characterized in that: The following steps are involved: Mix the protective agent and the solvent to obtain a solution; Add the catalyst coordinated with pyridine dicarboxylic acid to the solution and stir at 20°C to 100°C for 10 to 60 minutes; Add the auxiliary catalyst and stir at 20℃~100℃ for 30~60min; Then add a regulator, stir at 20°C to 100°C for 10 to 60 minutes to obtain a composite catalyst.

13. Use of a pyridinedicarboxylic acid coordinated catalyst according to claim 1, a pyridinedicarboxylic acid coordinated catalyst prepared by the preparation method of a pyridinedicarboxylic acid coordinated catalyst according to any one of claims 2 to 6, or a composite catalyst according to any one of claims 7 to 11 in catalytic oxidation of p-nitrotoluene to prepare p-nitrobenzoic acid.

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