Alkyl-substituted 1, 4-bis (2-pyridylmethyl)-1, 4-diazane coordination metal peroxide catalyst, composite catalyst, preparation method and application

Abstract

The invention discloses an alkyl substituted 1, 4-bis (2-pyridylmethyl)-1, 4-diazane coordination metal peroxide catalyst, a compound catalyst, a preparation method and application, and the general formula of the alkyl substituted 1, 4-bis (2-pyridylmethyl)-1, 4-diazane coordination metal peroxide catalyst is shown in the specification. The composite catalyst comprises an alkyl substituted 1, 4-bis (2-pyridyl methyl)-1, 4-diazane coordination metal peroxide catalyst, a cocatalyst, a regulator, a protective agent and a solvent. The alkyl-substituted 1, 4-bis (2-pyridylmethyl)-1, 4-diazane coordinated metal peroxide catalyst and the compound catalyst can improve the selectivity of the reaction for preparing fatty acid by oxidizing fatty aldehyde, increase the reaction activity, can be repeatedly used, are low in cost, have a relatively high utilization rate, and are particularly suitable for the oxidation reaction of C4-C18 fatty aldehyde.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic catalysis, and particularly relates to an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst, a composite catalyst, a preparation method and application. BACKGROUND

[0002] Fatty acids are basic raw materials for oil and fat chemical industry, and are widely used in various industries such as textiles, food, medicine, daily chemical industry, petroleum chemical industry, rubber and plastic, mining, transportation, casting, metal processing, ink, paint and the like. Among them, C8-C 14 Fatty acids are mainly used for producing surfactants, C 16 -C 18 Fatty acids are mainly used for producing stearic acid, esters, fatty acid salts, cationic surfactants and synthetic resins.

[0003] Fatty acids are currently mainly obtained by condensation and oxidation process using C2-C4 fatty aldehyde as raw material, and direct oxidation using corresponding fatty alcohol / fatty aldehyde as raw material. The fatty alcohol oxidation process has the characteristics of fast reaction speed, large heat release, flammable and explosive reaction materials, explosive by-products and the like, and has been a process with frequent accidents. At the same time, a large amount of three wastes are generated in this process, causing serious environmental problems. Oxygen is a cheap, clean and pollution-free and atom-economical oxidant. The method for preparing fatty acids by directly oxidizing fatty aldehyde with oxygen has significant advantages over other methods.

[0004] As a typical inert fatty straight-chain primary alcohol, the catalytic oxidation of n-octanol has always been the focus of attention. Using molecular oxygen as an oxidant, n-octanol can only be catalytically oxidized to octanal, and usually complex additives are needed. Ji Hongbing, Qian Yu, He Dugui, et al. One-step catalytic oxidation of n-octanol to n-octanoic acid [J]. Chemical Industry, 2005, (09): 1673-1678, reported a solid RuCo(OH)2CeO2 catalyst which can use molecular oxygen as the only oxidant and efficiently oxidize n-octanol to octanoic acid in one step. The scheme can obtain a yield of 97% at 60℃ for 4 hours. However, the catalyst is expensive and difficult to prepare, and needs to be used with 20 times of trifluorotoluene, which makes it not competitive in the market.

[0005] Research on synthesis of iso-octanoic acid by catalytic oxidation of iso-octanol with oxygen; Shenyang University of Technology, 2017, reported that by adjusting the solution environment to pH>7 with sodium hydroxide, then adding iso-octanol, followed by multiple times of potassium permanganate, under vigorous stirring, the reaction was carried out for about 10h, to generate potassium iso-octanoate and potassium hydroxide, then sulfuric acid was added to the solution after the reaction to adjust the pH to about 2, using the principle of strong acid to produce weak acid, to oxidize to generate iso-octanoic acid and potassium sulfate, and finally iso-octanoic acid was obtained by distillation separation. The yield of this process is about 65%, but the amount of potassium permanganate used is large, the production cost is high, and environmental pollution problems will also be caused.

[0006] Shi Guo-zhu, Wang Hui-lin, Li En-fu, et al. Preparation of iso-octanoic acid [J]. Coatings Industry, 1980, 05: 13-15, reported that the nitric acid oxidation process needs to use ammonium metavanadate as a catalyst, with iso-octanol as a substrate, under the reaction conditions of 70-80℃, the oxidation is continuously carried out for about 5h, and the yield of iso-octanoic acid can reach 60%-65%. However, this process route has several problems: the strong corrosive nature of nitric acid increases the manufacturing and selection cost of equipment. At the same time, under the action of nitric acid, esters are easily produced as by-products during the reaction process, increasing the separation difficulty and being not conducive to the production of high-quality iso-octanoic acid.

[0007] The above reported synthesis methods used in the experiment of oxidation of fatty alcohols / aldehydes to fatty acids all have the disadvantages of long reaction steps, complex operation, high raw material cost or post-treatment cost, etc., and cannot be applied to the industrial scale production of fatty acids. SUMMARY

[0008] The purpose of the present application is to provide an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst, a composite catalyst, a preparation method and an application. The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst or the composite catalyst can be used for the oxidation of fatty aldehydes to prepare fatty acids, has high activity and high selectivity, can be repeatedly used, has low cost, and is suitable for the industrial production of fatty acids.

[0009] In order to achieve the above purpose, the technical solutions of a specific embodiment provided by the present application are as follows: An alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst, the general formula of which is shown in formula (I): ; B is selected from any one of copper ion, sodium ion, iron ion, potassium ion, zinc ion, ammonium ion, dodecyl dimethyl benzyl ammonium ion, dodecyl trimethyl ammonium ion, octadecyl trimethyl ammonium ion, octadecyl dimethyl benzyl ammonium ion, aliphatic tributyl phosphonium ion, tetrabutyl phosphonium ion, hexyl tributyl phosphonium ion, tributyl ethyl phosphonium ion, tetramethyl ammonium ion, tetraethyl ammonium ion, tetrabutyl ammonium ion, benzyl trimethyl ammonium ion, benzyl triphenyl phosphonium ion, benzyl triethyl ammonium ion; M is selected from any one of nickel, chromium, cobalt, manganese, copper, calcium, sodium, molybdenum, lanthanum, cerium, tungsten, scandium, titanium, zirconium, vanadium; R1 is selected from C1-C 10 alkyl; R2 is selected from C1-C 10 alkyl; x is selected from any integer between 1-20; y is selected from any integer between 1-20.

[0010] The technical scheme provided by another specific embodiment of the present application is as follows: A preparation method of an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane coordination metal peroxide catalyst, comprising the following steps: The metal compound is dissolved in deionized water, the pH of the solution is adjusted to make the solution acidic, and then the peroxide is added to obtain a metal peroxide solution; The metal peroxide solution, the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane and the salt are mixed, filtered and dried to obtain the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane coordination metal peroxide catalyst.

[0011] In one or more embodiments of the present application, the metal compound is selected from any one of sodium molybdate, sodium tungstate, molybdenum acetylacetone, tungsten hexacarbonyl, cobalt sulfate, nickel nitrate, nickel acetate, manganese chloride, manganese sulfate, copper sulfate, copper nitrate, calcium chloride, calcium carbonate, chromium chloride, chromium sulfate, lanthanum nitrate, lanthanum chloride, cerium nitrate, cerium sulfate, scandium chloride, scandium nitrate, titanium tetrachloride, titanyl sulfate, zirconium chloride, zirconium nitrate and sodium metavanadate; and / or, The peroxide is selected from any one of hydrogen peroxide and sodium percarbonate; and / or, The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane is selected from any one of N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-ethyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-isopropyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-n-butyl-2-pyridylmethyl)-1,4-diazabicycloheptane; and / or, The salt is selected from any one of octadecyl trimethyl ammonium chloride, octadecyl trimethyl ammonium bromide, lithium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, ammonium bromide, manganese bromide, iron bromide, copper bromide, dodecyl trimethyl ammonium chloride, hexyl tributyl phosphonium bromide, ethyl tributyl phosphonium bromide, aliphatic tributyl phosphonium bromide, tetrabutyl phosphonium bromide, tetramethyl ammonium chloride, tetraethyl ammonium chloride, tetrabutyl ammonium chloride, benzyl trimethyl ammonium chloride, benzyl triethyl ammonium chloride.

[0012] In one or more embodiments of the present application, the pH of the solution of the metal compound dissolved in deionized water is adjusted to 3-4.

[0013] Another specific embodiment of the present application provides a technical solution as follows: A composite catalyst, comprising the above-mentioned alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia coordination metal peroxide catalyst.

[0014] In one or more embodiments of the present application, a co-catalyst is further included, and the weight ratio of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia coordination metal peroxide catalyst to the co-catalyst is 100:(1-200); The co-catalyst is selected from one or more of potassium salt, sodium salt, iron salt, magnesium salt, zinc salt, nickel salt, chromium salt, cobalt salt, manganese salt, copper salt, calcium salt, sodium salt, molybdenum salt, lanthanum salt, cerium salt, tungsten salt, scandium salt, titanium salt, zirconium salt, vanadium salt, oxide of potassium, oxide of sodium, oxide of iron, oxide of magnesium, oxide of zinc, oxide of nickel, oxide of chromium, oxide of cobalt, oxide of manganese, oxide of copper, oxide of calcium, oxide of sodium, oxide of molybdenum, oxide of lanthanum, oxide of cerium, oxide of tungsten, oxide of scandium, oxide of titanium, oxide of zirconium, oxide of vanadium.

[0015] In one or more embodiments of the present application, a regulator is further included, and the weight ratio of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia coordination metal peroxide catalyst to the regulator is 100:(1-200); The regulator is selected from one or more of phosphomolybdic acid, phosphotungstic acid, tetrabutyl ammonium bromide, boric acid, silicotungstic acid, and phosphomolybdovanadic acid.

[0016] In one or more embodiments of the present application, a protective agent is further included, and the weight ratio of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia coordination metal peroxide catalyst to the protective agent is 100:(10-200); The protective agent is selected from one or more of sodium acetate, ammonium bromide, cetyl trimethyl ammonium bromide, phenyl trimethyl ammonium bromide, sodium molybdate, and N-hydroxy phthalimide.

[0017] In one or more embodiments of the present application, a solvent is also included, and the weight ratio of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabutane ligand metal peroxide catalyst to the solvent is 100:(10-1000); The solvent is selected from one or more of dichloromethane, dichloroethane, tetrahydrofuran, diethyl ether, chloroform, toluene, carbon tetrachloride, 1,4-dioxane, dibutyl ether, methyl tert-butyl ether, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, ethyl acetate, and propyl acetate.

[0018] Another specific embodiment of the present application provides a technical solution as follows: A preparation method of a composite catalyst, wherein a solvent and alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabutane are mixed, and stirring is performed at 20-100°C for 40-120 min.

[0019] In one or more embodiments of the present application, the following steps are also included: The protective agent and the solvent are mixed to obtain a solution; the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabutane is added to the solution, stirring is performed at 20-100°C for 40-120 min; the auxiliary catalyst is added, and ultrasonic treatment is performed at 35-80°C for 40-60 min; the adjusting agent is added, and stirring is performed at 35-80°C for 40-60 min to obtain the composite catalyst.

[0020] Another specific embodiment of the present application provides a technical solution as follows: Application of an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabutane ligand metal peroxide catalyst or a composite catalyst in a reaction for preparing a fatty acid by oxidizing a fatty aldehyde as a raw material.

[0021] In one or more embodiments of the present application, the fatty aldehyde has a general structure as shown in formula (II): ; wherein m is any integer between 1 and 20; R3 is selected from hydrogen, an alkyl group, an alkoxy group, an ester group, a hydroxyl group, an amine group, a halogen, or an aromatic group, the alkyl group is a straight-chain or branched-chain aliphatic hydrocarbon group having C n H 2n+1 a straight-chain or branched-chain aliphatic hydrocarbon group having C n H 2n+1 a straight-chain or branched-chain aliphatic hydrocarbon group having C

[0022] Compared with the prior art, the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst and the composite catalyst can increase the selectivity and reactivity of the reaction of preparing fatty acid by oxidizing fatty aldehyde, can be repeatedly used, has low cost, has high utilization rate, and is particularly suitable for C4-C 18 The oxidation reaction of the fatty aldehyde. DETAILED DESCRIPTION

[0023] In order for those skilled in the art to better understand the technical solutions in the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in combination with the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work should belong to the protection scope of the present disclosure.

[0024] A specific embodiment of the present disclosure provides an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst, the general formula of which is shown in formula (I): , wherein B is selected from any one of copper ion, sodium ion, iron ion, potassium ion, zinc ion, ammonium ion, dodecyl dimethyl benzyl ammonium ion, dodecyl trimethyl ammonium ion, octadecyl trimethyl ammonium ion, octadecyl dimethyl benzyl ammonium ion, aliphatic tributyl phosphonium ion, tetrabutyl phosphonium ion, hexyl tributyl phosphonium ion, tributyl ethyl phosphonium ion, tetramethyl ammonium ion, tetraethyl ammonium ion, tetrabutyl ammonium ion, benzyl trimethyl ammonium ion, benzyl triphenyl phosphonium ion, and benzyl triethyl ammonium ion; M is selected from any one of nickel, chromium, cobalt, manganese, copper, calcium, sodium, molybdenum, lanthanum, cerium, tungsten, scandium, titanium, zirconium, and vanadium; R1 is selected from C1-C5 alkyl; R2 is selected from C1-C5 alkyl; x is selected from any integer between 1 and 20; and y is selected from any integer between 1 and 20. 10 alkyl; R2 is selected from C1-C 10 alkyl; x is selected from any integer between 1 and 20; and y is selected from any integer between 1 and 20.

[0025] Preferably, B is selected from tetrabutyl ammonium ion, benzyl trimethyl ammonium ion, iron ion, potassium ion, zinc ion, ammonium ion, or manganese ion; R1 is selected from C1-C5 alkyl; R2 is selected from C1-C5 alkyl; x is selected from an integer between 1 and 5; and y is selected from an integer between 1 and 5.

[0026] Preferably, B is selected from butyl ethyl phosphonium ion, sodium ion, magnesium ion, potassium ion, and zinc ion; M is selected from molybdenum, chromium, cobalt, nickel, or vanadium; R1 is selected from methyl, ethyl, or isopropyl; R2 is selected from methyl, ethyl, or isopropyl; x is 1; and y is 1 or 2.

[0027] Another embodiment of the present application provides a preparation method of an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane complex metal peroxide catalyst, comprising steps 1-2.

[0028] Step 1, the metal compound is dissolved in deionized water, the pH of the solution is adjusted to make the solution acidic, and then the peroxide is added to obtain a metal peroxide solution.

[0029] Specifically, the temperature for adding the metal compound into the deionized water is room temperature, and the pH of the solution is adjusted to 3-4 by using hydrochloric acid or sulfuric acid. The metal compound is selected from any one of sodium molybdate, sodium tungstate, molybdenum acetylacetone, tungsten hexacarbonyl, cobalt sulfate, nickel nitrate, nickel acetate, manganese chloride, manganese sulfate, copper sulfate, copper nitrate, calcium chloride, calcium carbonate, chromium chloride, chromium sulfate, lanthanum nitrate, lanthanum chloride, cerium nitrate, cerium sulfate, scandium chloride, scandium nitrate, titanium tetrachloride, titanyl sulfate, zirconium chloride, zirconium nitrate, and sodium metavanadate. The peroxide is selected from any one of hydrogen peroxide and sodium percarbonate.

[0030] Step 2, the metal peroxide solution, the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane, and the salt are mixed, filtered, and dried to obtain the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane complex metal peroxide catalyst.

[0031] Specifically, the metal peroxide solution is heated to 50-90°C, and then mixed and reacted with the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane and the salt. The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane is selected from any one of N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-ethyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-isopropyl-2-pyridylmethyl)-1,4-diazabicycloheptane, and N,N'-bis(6-n-butyl-2-pyridylmethyl)-1,4-diazabicycloheptane. The salt is selected from any one of octadecyl trimethyl ammonium chloride, octadecyl trimethyl ammonium bromide, lithium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, ammonium bromide, manganese bromide, iron bromide, copper bromide, dodecyl trimethyl ammonium chloride, hexyl tributyl phosphonium bromide, tributyl ethyl phosphonium bromide, aliphatic tributyl phosphonium bromide, tetrabutyl phosphonium bromide, tetramethyl ammonium chloride, tetraethyl ammonium chloride, tetrabutyl ammonium chloride, benzyl trimethyl ammonium chloride, and benzyl triethyl ammonium chloride.

[0032] The metal salt in the present application provides M n+ After dissolution, hydrochloric acid or sulfuric acid is added to adjust the pH to 3-4, so as to destroy the weak coordination of the metal salt ligand and make M n+Partially dissociated and in a reactive state; after adding a peroxide such as H2O2, H2O2 acts as an oxidant, causing M to... n+ Oxidation to higher valence M n+ (May be M) 3+ At the same time, H2O2 itself is partially converted into peroxyligands (O2). 2- This provides reactive oxygen species for the subsequent formation of the metal peroxide core structure.

[0033] The ligand used in this invention is a typical polydentate nitrogen-containing chelate ligand, containing four potential coordination sites: two nitrogen atoms on the pyridine ring (strongly basic, readily donating lone pairs of electrons); and two nitrogen atoms on the 1,4-diazacyclic heptane ring (aliphatic amine nitrogen, also possessing coordination ability). When the ligand interacts with [M... n+ -(O2 2- When the intermediate comes into contact, the four nitrogen atoms pass through the "lone pair electrons → M" pathway. n+ The coordinate key of "+empty track", and [M] n+ -(O2 2- [Forms an octahedral coordination configuration (coordination number 6: 4 N atoms + 2 from peroxy ligands (O2)] 2- The O atom of the polydentate ligand (the chelation effect) greatly enhances the stability of the complex through the "chelation effect" (the polydentate ligand forms a ring structure with the metal). Heating to 50℃-90℃ provides energy to overcome the activation energy of the coordination reaction, accelerating the reaction between the ligand and [M]. n+ -(O2 2- The coordination rate of )】】.

[0034] The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordination metal peroxide catalyst obtained through the above reaction utilizes the electronic and steric properties of the ligands, leveraging the pyridine ring and diazane structure, to "capture" aliphatic aldehydes through hydrogen bonding and dipole interactions, increasing their collision with the active center. The metal M coordinates and activates the peroxide group, while the R and B groups balance the spatial positions, weakening the O / O bond. Feedback electrons activate the C=O bond and α-H of the aliphatic aldehyde, lowering the reaction energy barrier. This results in the specific catalysis of aliphatic aldehyde oxidation to fatty acids, exhibiting high activity and selectivity, and can be reused multiple times, demonstrating high utilization, especially suitable for C4-C... 18 Oxidation of fatty aldehydes.

[0035] Another specific embodiment of the present invention provides a composite catalyst comprising an alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane coordinated metal peroxide catalyst, a co-catalyst, a regulator, a protectant, and a solvent in a weight ratio of 100:(1-200):(1-200):(10-200):(10-1000).

[0036] Specifically, the co-catalyst is selected from one or more of potassium salts, sodium salts, iron salts, magnesium salts, zinc salts, nickel salts, chromium salts, cobalt salts, manganese salts, copper salts, calcium salts, sodium salts, molybdenum salts, lanthanum salts, cerium salts, tungsten salts, scandium salts, titanium salts, zirconium salts, vanadium salts, potassium oxides, sodium oxides, iron oxides, magnesium oxides, zinc oxides, nickel oxides, chromium oxides, cobalt oxides, manganese oxides, copper oxides, calcium oxides, sodium oxides, molybdenum oxides, lanthanum oxides, cerium oxides, tungsten oxides, scandium oxides, titanium oxides, zirconium oxides, vanadium oxides.

[0037] Exemplarily, the co-catalyst is selected from one or more of phosphomolybdic acid, manganese bromide, sodium bromide, chromium trioxide, chromium chloride, potassium dichromate, calcium chloride, calcium hypochlorite, tungsten oxide, sodium tungstate, scandium oxide, scandium nitrate, scandium chloride, zirconium dioxide, zirconium oxychloride, vanadium oxide, sodium vanadate, cerium nitrate, ceric sulfate, cerium oxide, cerium chloride, cerium hydroxide, lanthanum cerium chloride, lanthanum cerium carbonate, lanthanum oxide, lanthanum chloride, lanthanum hydroxide, lanthanum nitrate, lanthanum carbonate, lanthanum fluoride, lanthanum hexaboride, sodium hypochlorite, sodium perchlorate, cerium nitrate, cerium sulfate, cerium acetate, manganese acetate, manganese nitrate, manganese sulfate, vanadium oxide, cobalt oxide, silver nitrate, zirconium oxide, zirconium acetate, iron nitrate, iron sulfate, iron chloride, copper sulfate, copper acetate, copper nitrate, magnesium sulfate, magnesium acetate, zinc acetate, zinc sulfate, sodium molybdate, potassium acetate, potassium sulfate.

[0038] The adjusting agent is selected from one or more of phosphomolybdic acid, phosphotungstic acid, tetrabutylammonium bromide, boric acid, silicotungstic acid and phosphomolybdovanadic acid, the protective agent is selected from one or more of sodium acetate, ammonium bromide, cetyltrimethylammonium bromide, phenyltrimethylammonium bromide, sodium molybdate and N-hydroxy phthalimide, and the solvent is selected from one or more of dichloromethane, dichloroethane, tetrahydrofuran, diethyl ether, chloroform, toluene, carbon tetrachloride, 1,4-dioxane, dibutyl ether, methyl tert-butyl ether, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, ethyl acetate and propyl acetate.

[0039] By selecting the above kinds of co-catalyst, adjusting agent, protective agent and solvent, the prepared co-catalyst can improve the selectivity and reactivity of the oxidation reaction of fatty aldehyde, and can be used multiple times with high utilization rate.

[0040] Preferably, the protective agent is one or more of ammonium bromide, cetyltrimethylammonium bromide, phenyltrimethylammonium bromide and N-hydroxyphthalimide; the solvent is one or more of formic acid, acetic acid and propionic acid; the compound as shown in formula (I) is one or more of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia-coordinated metal peroxide with Cr (chromium), Mo (molybdenum), V (vanadium), Co (cobalt) or Ni (nickel) as the central metal; the co-catalyst is one or more of manganese sulfate, cerium sulfate, cerium nitrate, copper nitrate, manganese acetate, silver nitrate, zirconium dioxide, zirconium oxychloride, vanadium oxide, sodium vanadate, cerium nitrate, ceric sulfate, cerium oxide, cerium chloride, cerium hydroxide, iron nitrate, zirconium acetate and magnesium sulfate; and the regulator is one or more of phosphomolybdic acid, phosphotungstic acid and silicotungstic acid.

[0041] Preferably, the weight ratio of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia-coordinated metal peroxide catalyst, the co-catalyst, the regulator, the protective agent and the solvent is 100:(1-50):(1-50):(10-100):(120-500); the compound as shown in formula (I) is selected from one of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia-coordinated metal peroxide with Cr (chromium), Mo (molybdenum), V (vanadium), Co (cobalt) or Zr (zirconium) as the central metal; the co-catalyst is selected from one or more of manganese acetate, zirconium acetate, magnesium acetate and cerium acetate; the regulator is selected from one or more of phosphomolybdic acid, phosphotungstic acid and silicotungstic acid; the protective agent is selected from one or more of ammonium bromide, cetyltrimethylammonium bromide, phenyltrimethylammonium bromide and N-hydroxyphthalimide; and the solvent is selected from one or more of dichloromethane, tetrahydrofuran, diethyl ether, dichloromethane, chloroform, acetonitrile, toluene, methanol, ethanol, carbon tetrachloride, formic acid, acetic acid, propionic acid and ethyl acetate.

[0042] Another specific embodiment of the present application provides a preparation method of the composite catalyst, comprising the following steps: mixing the protective agent and the solvent to obtain a solution; adding the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane to the solution, stirring at 20-100°C for 40-120 min; then adding the co-catalyst, ultrasonicating at 35-80°C for 40-60 min; and then adding the regulator, stirring at 35-80°C for 40-60 min to obtain the composite catalyst.

[0043] Another specific embodiment of the present application provides an application of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia-coordinated metal peroxide catalyst or the composite catalyst as described above in the reaction of oxidizing fatty aldehyde to prepare fatty acid.

[0044] Specifically, the fatty aldehyde is of the general formula (II): wherein m is selected from any integer between 1 and 20; R3 is selected from hydrogen, alkyl, alkoxy, ester, hydroxyl, amine, halogen or aromatic group, and the alkyl is a straight chain or branched hydrocarbon group having C n H 2n+1 wherein n is selected from any integer between 1 and 8; R4 is selected from hydrogen, alkyl, alkoxy, ester, hydroxyl, amine, halogen or aromatic group, and the alkyl is a straight chain or branched hydrocarbon group having C n H 2n+1 wherein n is selected from any integer between 1 and 8.

[0045] For example, the alkyl is selected from a straight chain or branched hydrocarbon group of methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-butyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, pentyl, hexyl, heptyl, octyl.

[0046] Further, the fatty aldehyde is added into a reaction solvent, and then a complex catalyst is added at an amount of 0.2% to 5% by weight of the fatty aldehyde, and air is introduced at a speed of 150 ml / s to 600 ml / s, and the reaction is stirred at 90°C to 120°C for 2h to 6h, preferably for 3h to 6h. The reaction solvent is acetic acid.

[0047] The application will be further described in detail below with reference to specific examples.

[0048] Example 1 The preparation method of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabutane coordination metal peroxide catalyst in this example is as follows: Step 1: 450 mL of deionized water is added to cobalt acetylacetonate (25.91 g, 0.1 mol) solid at room temperature, and a solution a is obtained after the solid is completely dissolved. Diluted sulfuric acid is added dropwise to the solution a until the pH of the solution is 3, and a solution b is obtained. After continuing to stir for about 60 min, 300 mL of 30% hydrogen peroxide solution is slowly added to the solution b to obtain a solution c. Deionized water is added to the solution c until the total volume of the liquid is 1100 mL, and a solution d is obtained.

[0049] Step 2: Solution d was heated to 80°C, N,N'-bis(6-methyl-2-pyridinylmethyl)- 1,4-diazepane (31.02 g, 0.10 mol) and tetrabutylammonium bromide (70.92 g, 0.22 mol) were added to solution d, and stirred for about 1.5 h while heating, then centrifuged for 15 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 61.32 g of a light yellow solid was obtained, which was N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-006, and the catalyst yield reached 93.15%.

[0050] N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane nuclear magnetic resonance characterization data are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.42 (t, J = 7.7 Hz, 1H), 7.19 (dd, J = 7.7, 1.1 Hz, 1H), 7.05 - 6.99 (m, 1H), 3.58 (s, 2H), 2.65 - 2.54 (m, 4H), 2.48 (d, J = 0.7 Hz, 3H), 1.79 - 1.68 (m, 1H).

[0051] Example 2 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4- diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: 450 mL of deionized water was added to a solid of cobalt sulfate (15.50 g, 0.1 mol) at room temperature, and solution a was obtained after the solid was completely dissolved. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 4, and solution b was obtained. After stirring for about 60 min, 300 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c until the total volume of the liquid was 1100 mL, and solution d was obtained.

[0052] Step 2: Solution d was heated to 50 °C, N,N'-bis(6-methyl-2-pyridinylmethyl)- 1,4-diazepane (31.02 g, 0.10 mol) and phenyltrimethylammonium bromide (47.54 g, 0.22 mol) were added to solution d, after stirring for about 1.5 h with heating, centrifugation was performed for 15 min. Filtration was performed, and the solid obtained after filtration was placed in a vacuum drying oven to dry, obtaining 47.17 g of a light yellow solid, which was N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-007, and the catalyst yield reached 89.62%.

[0053] N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane nuclear magnetic resonance characterization data are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.42 (t, J = 7.7 Hz, 1H), 7.19 (dd, J = 7.7, 1.1 Hz, 1H), 7.05 - 6.99 (m, 1H), 3.58 (s, 2H), 2.65 - 2.54 (m, 4H), 2.48 (d, J = 0.7 Hz, 3H), 1.79 - 1.68 (m, 1H).

[0054] Example 3 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4- diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: 800 mL of deionized water was added to a solid of cobalt sulfate (31.00 g, 0.2 mol) at room temperature, and after the solid was completely dissolved, solution a was obtained. Dilute hydrochloric acid was added dropwise to solution a until the pH of the solution was 3, obtaining solution b. After continuing to stir for about 3, 600 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c until the total volume of the liquid was 2200 mL, obtaining solution d.

[0055] Step 2: Solution d was heated to 50 °C, N,N'-bis(6-methyl-2-pyridinylmethyl)- 1,4-diazepane (68.24 g, 0.22 mol) and magnesium acetate (15.66 g, 0.22 mol) were added to solution d, after stirring for about 2 h with heating, centrifugation was performed for 20 min. Filtration was performed, and the solid obtained after filtration was placed in a vacuum drying oven to dry, obtaining 98.6 g of a yellow solid, which was N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-008, and the catalyst yield reached 93.61%.

[0056] N,N'-Bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane NMR characterization data are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.42 (t, J = 7.7 Hz, 1H), 7.19 (dd, J = 7.7, 1.1 Hz, 1H), 7.05 - 6.99 (m, 1H), 3.58 (s, 2H), 2.65 - 2.54 (m, 4H), 2.48 (d, J = 0.7 Hz, 3H), 1.79 - 1.68 (m, 1H).

[0057] Example 4 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4-diazepane coordination metal peroxide catalyst in this example is as follows: Step 1: Add 400 mL of deionized water to a solid of cobalt sulfate (15.50 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, a solution a is obtained. Add dilute phosphoric acid dropwise to solution a until the solution pH is 3 to obtain solution b. Continue stirring for about 1.5, then slowly add 300 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c to a total liquid volume of 1100 mL to obtain solution d.

[0058] Step 2: Heat solution d to 80°C, and add N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane (34.10 g, 0.11 mol) and ammonium acetate (8.41 g, 0.12 mol) to solution d while stirring and heating for about 2 h, then centrifuge for 20 min using a centrifuge. Filter, and place the solid obtained after filtration in a vacuum drying oven to obtain 46.21 g of a yellow solid, which is the N,N'-bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane-coordinated metal peroxide catalyst YG-77-1-009, with a catalyst yield of 86.77%.

[0059] N,N'-Bis(6-methyl-2-pyridinylmethyl)-1,4-diazepane NMR characterization data are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.42 (t, J = 7.7 Hz, 1H), 7.19 (dd, J = 7.7, 1.1 Hz, 1H), 7.05 - 6.99 (m, 1H), 3.58 (s, 2H), 2.65 - 2.54 (m, 4H), 2.48 (d, J = 0.7 Hz, 3H), 1.79 - 1.68 (m, 1H).

[0060] Example 5 The preparation method of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane ligated metal peroxide catalyst in this example is as follows: Step 1: Add 400 mL of deionized water to cobalt acetylacetonate (25.91 g, 0.1 mol) solid at room temperature, and after the solid is completely dissolved, a solution a is obtained. Add dilute hydrochloric acid dropwise to solution a until the pH of the solution is 3 to obtain solution b. Continue stirring for about 50 min, then slowly add 300 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c to a total liquid volume of 1100 mL to obtain solution d.

[0061] Step 2: Heat solution d to 80°C, and add N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane (37.20 g, 0.12 mol) and benzyltriphenylphosphonium bromide (53.20 g, 0.12 mol) to solution d while stirring and heating for about 2 h, then centrifuge for 20 min using a centrifuge. Filter, and place the solid obtained after filtration in a vacuum drying oven to obtain 56.13 g of yellow solid. The yellow solid is N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane ligated metal peroxide catalyst YG-77-1-010, and the catalyst yield is 87.52%.

[0062] The NMR characterization data of N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.42 (t, J = 7.7 Hz, 1H), 7.19 (dd, J = 7.7, 1.1 Hz, 1H), 7.05 - 6.99 (m, 1H), 3.58 (s, 2H), 2.65 - 2.54 (m, 4H), 2.48 (d, J = 0.7 Hz, 3H), 1.79 - 1.68 (m, 1H).

[0063] Example 6 The preparation method of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4- diazabicycloheptane complex metal peroxide catalyst in this example is as follows: Step 1: Add 400 mL of deionized water to cobalt acetylacetonate (25.91 g, 0.1 mol) solid at room temperature, and after the solid is completely dissolved, a solution a is obtained. Add dilute sulfuric acid dropwise to solution a until the solution pH is 3 to obtain solution b. After continuing to stir for about 30 min, slowly add 200 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 1100 mL to obtain solution d.

[0064] Step 2: Heat solution d to 60°C, and add N,N'-bis(6-methyl-2-pyridylmethyl)-1,4- diazabicycloheptane (37.20 g, 0.12 mol) and octadecyltrimethylammonium chloride (76.57 g, 0.22 mol) to solution d. Stir while heating for about 2 h, and then centrifuge for 20 min using a centrifuge. Filter, and place the solid obtained after filtration in a vacuum drying oven to obtain 49.23 g of yellow solid. The yellow solid is N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane complex metal peroxide catalyst YG-77-1-011, and the catalyst yield is 89.69%.

[0065] The NMR characterization data of N,N'-bis(6-methyl-2-pyridylmethyl)-1,4- diazabicycloheptane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.42 (t, J = 7.7 Hz, 1H), 7.19 (dd, J = 7.7, 1.1 Hz, 1H), 7.05 - 6.99 (m, 1H), 3.58 (s, 2H), 2.65 - 2.54 (m, 4H), 2.48 (d, J = 0.7 Hz, 3H), 1.79 - 1.68 (m, 1H).

[0066] Example 7 The preparation method of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4- diazabicycloheptane complex metal peroxide catalyst in this example is as follows: Step 1: To a solid of cobalt sulfate (15.50 g, 0.1 mol) add 300 mL of deionized water at room temperature, and after the solid is completely dissolved, obtain solution a. To solution a, add dilute sulfuric acid dropwise until the solution pH is 3 to obtain solution b. After continuing to stir for about 30 min, slowly add 300 mL of 30% urea hydrogen peroxide solution to solution b to obtain solution c. To solution c, add deionized water to a total liquid volume of 1000 mL to obtain solution d.

[0067] Step 2: Heat solution d to 50°C, and to solution d, add N,N'-bis(6-ethyl-2-pyridylmethyl)-1,4-diazepane (37.20 g, 0.11 mol) and tetrabutylammonium bromide (70.92 g, 0.22 mol). After stirring while heating for about 1 h, centrifuge for 20 min using a centrifuge. Filter, and after drying the solid obtained after filtering in a vacuum drying oven, obtain 58.68 g of a yellow solid, which is the N,N'-bis(6-ethyl-2-pyridylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-012, with a catalyst yield of 89.56%.

[0068] N,N'-bis(6-ethyl-2-pyridylmethyl)-1,4-diazepane nuclear magnetic resonance characterization data are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0069] Example 8 The preparation method of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: To a solid of cobalt sulfate (15.50 g, 0.1 mol) add 300 mL of deionized water at room temperature, and after the solid is completely dissolved, obtain solution a. To solution a, add dilute sulfuric acid dropwise until the solution pH is 3 to obtain solution b. After continuing to stir for about 30 min, slowly add 300 mL of 30% urea hydrogen peroxide solution to solution b to obtain solution c. To solution c, add deionized water to a total liquid volume of 1000 mL to obtain solution d.

[0070] Step 2: Solution d was heated to 90°C, N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4- diazepane (37.20 g, 0.11 mol) and octadecyltrimethylammonium chloride (76.57 g, 0.22 mol) were added to solution d, and stirred for about 2 h while heating, then centrifuged for 20 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 56.12 g of purple red solid was obtained, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-013, and the catalyst yield reached 87.62%.

[0071] The NMR characterization data of N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0072] Example 9 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: Chromium nitrate nonahydrate (40.01 g, 0.1 mol) was added to 300 mL of deionized water at room temperature, and solution a was obtained after the solid was completely dissolved. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 3-4, and solution b was obtained. After stirring for about 60 min, 200 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c to a total liquid volume of 1000 mL to obtain solution d.

[0073] Step 2: Solution d was heated to 60°C, N,N'-bis(6-ethyl-2-pyridinylmethyl)- 1,4-diazepane (37.20 g, 0.11 mol) and octadecyltrimethylammonium chloride (76.57 g, 0.22 mol) were added to solution d, and stirred for about 1 h while heating, then centrifuged for 20 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 59.12 g of purple red solid was obtained, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-014, and the catalyst yield reached 97.82%.

[0074] The NMR characterization data of N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4- diazepane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0075] Example 10 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4- diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: At room temperature, 300 mL of deionized water was added to a solid nickel sulfate (15.48 g, 0.1 mol), and after the solid was completely dissolved, solution a was obtained. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 3, and solution b was obtained. After continuing to stir for about 60 min, 300 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c to a total liquid volume of 1000 mL to obtain solution d.

[0076] Step 2: Solution d was heated to 60°C, N,N'-bis(6-ethyl-2-pyridinylmethyl)- 1,4-diazepane (37.20 g, 0.11 mol) and octadecyltrimethylammonium chloride (76.57 g, 0.22 mol) were added to solution d, and stirred for about 1 h while heating, then centrifuged for 20 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 36.62 g of purple red solid was obtained, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-015, and the catalyst yield reached 89.51%.

[0077] The NMR characterization data of N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4- diazepane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0078] Example 11 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4- diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: At room temperature, 300 mL of deionized water was added to a solid nickel sulfate (15.48 g, 0.1 mol), and after the solid was completely dissolved, solution a was obtained. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 3, and solution b was obtained. After continuing to stir for about 30 min, 200 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c to a total liquid volume of 1000 mL to obtain solution d.

[0079] Step 2: Solution d was heated to 60°C, N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4- diazepane (37.20 g, 0.11 mol) and tetrabutylammonium bromide (70.92 g, 0.22 mol) were added to solution d, and stirred for about 2 h while heating, then centrifuged for 20 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 46.51 g of blue solid was obtained, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-016, and the catalyst yield reached 93.21%.

[0080] The NMR characterization data of N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0081] Example 12 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: 300 mL of deionized water was added to sodium metavanadate (12.19 g, 0.1 mol) solid at room temperature, and solution a was obtained after the solid was completely dissolved. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 3, and solution b was obtained. After continuing to stir for about 50 min, 200 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c to a total liquid volume of 1000 mL to obtain solution d.

[0082] Step 2: Solution d was heated to 60°C, N,N'-bis(6-ethyl-2-pyridinylmethyl)- 1,4-diazepane (37.20 g, 0.11 mol) and octadecyltrimethylammonium chloride (76.57 g, 0.22 mol) were added to solution d, and stirred for about 1 h while heating, then centrifuged for 20 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 31.12 g of white solid was obtained, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-017, and the catalyst yield reached 89.55%.

[0083] The NMR characterization data of N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4- diazepane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0084] Example 13 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4- diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: 300 mL of deionized water was added to sodium metavanadate (12.19 g, 0.1 mol) solid at room temperature, and solution a was obtained after the solid was completely dissolved. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 3, and solution b was obtained. After continuing to stir for about 60 min, 200 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c to a total liquid volume of 1000 mL to obtain solution d.

[0085] Step 2: Solution d was heated to 50°C, N,N'-bis(6-ethyl-2-pyridinylmethyl)- 1,4-diazepane (37.20 g, 0.11 mol) and tetrabutylammonium bromide (70.92 g, 0.22 mol) (76.57 g, 0.22 mol) were added to solution d, and stirred for about 2 h while heating, then centrifuged for 20 min. The solid obtained after filtration was placed in a vacuum drying oven to dry, and 34.24 g of yellow solid was obtained, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-018, and the catalyst yield reached 87.28%.

[0086] The NMR characterization data of N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4- diazepane are as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0087] Example 14 The preparation method of the alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4- diazepane coordinated metal peroxide catalyst in this example is as follows: Step 1: At room temperature, 300 mL of deionized water was added to a solid nickel sulfate (15.48 g, 0.1 mol), and after the solid was completely dissolved, solution a was obtained. Dilute sulfuric acid was added dropwise to solution a until the pH of the solution was 3, and solution b was obtained. After continuing to stir for about 30 min, 200 mL of 30% hydrogen peroxide solution was slowly added to solution b to obtain solution c. Deionized water was added to solution c until the total volume of the liquid was 1000 mL, and solution d was obtained.

[0088] Step 2: Solution d was heated to 55°C, and N,N'-bis(6-ethyl-2-pyridinylmethyl)- 1,4-diazepane (37.20 g, 0.11 mol) and ammonium acetate (8.41 g, 0.12 mol) were added to solution d. After stirring for about 2 h while heating, the solution was centrifuged for 20 min. The solid obtained after filtration was dried in a vacuum oven to obtain 58.10 g of yellow solid, which was N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-019. The catalyst yield was 91.34%.

[0089] N,N'-bis(6-ethyl-2-pyridinylmethyl)-1,4-diazepane was characterized by nuclear magnetic resonance as follows: 1H NMR (500 MHz, Chloroform-d) δ 7.74 (t, J = 7.9 Hz, 1H), 7.21 (dd, J = 8.1, 1.1 Hz, 1H), 7.00 (dd, J = 7.7, 1.1 Hz, 1H), 3.61 (s, 2H), 2.75 (q, J = 7.2 Hz, 2H), 2.65 - 2.58 (m, 2H), 2.56 (s, 2H), 1.79 - 1.68 (m, 1H), 1.31 - 1.24 (m, 3H).

[0090] Example 15 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added to 20.0 g of ethanol, and the mixture was stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridinylmethyl)-1,4-diazepane coordinated metal peroxide catalyst YG-77-1-006 was added to the mixture of step (1), and mixture B was obtained after stirring and heating at 80°C for 30 min; Step (3): 0.5 g of cerium cobalt acetate was added to the mixture B formed in step (2) to obtain mixture C; Step (4): 0.1 g of phosphotungstic acid was added to the mixture C formed in step (3), and the composite catalyst 1 was obtained after stirring at 80°C for 60 min, with a total of 39.7 g.

[0091] Example 16 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added into 20.0 g of acetonitrile, and stirred at room temperature until the solid was completely dissolved to obtain a mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia metal peroxide catalyst YG-77-1-019 was added into the mixture of step (1), and stirred at 60°C for 45 min to obtain a mixture B; Step (3): 0.5 g of cerium acetate was added into the mixture B formed in step (2) to obtain a mixture C; Step (4): 0.1 g of phosphomolybdic acid was added into the mixture C formed in step (3), and stirred at 70°C for 60 min to obtain a composite catalyst 1, with a total of 39.6 g.

[0092] Example 17 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added into 20.0 g of methanol, and stirred at room temperature until the solid was completely dissolved to obtain a mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia metal peroxide catalyst YG-77-1-007 was added into the mixture of step (1), and stirred at 60°C for 30 min to obtain a mixture B; Step (3): 0.5 g of zinc acetate was added into the mixture B formed in step (2) to obtain a mixture C; Step (4): 0.1 g of phosphomolybdic acid was added into the mixture C formed in step (3), and stirred at 90°C for 60 min to obtain a composite catalyst 1, with a total of 40.1 g.

[0093] Example 18 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added into 20.0 g of ethanol, and stirred at room temperature until the solid was completely dissolved to obtain a mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonia metal peroxide catalyst YG-77-1-008 was added into the mixture of step (1), and stirred at 70°C for 30 min to obtain a mixture B; Step (3): 0.5 g of zinc acetate was added into the mixture B formed in step (2) to obtain a mixture C; Step (4): 0.1 g of phosphomolybdic acid was added into the mixture C formed in step (3), and stirred at 90°C for 60 min to obtain a composite catalyst 1, with a total of 40.2 g.

[0094] Example 19 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of phenyltrimethylammonium bromide was added with 20.0 g of methanol, and the mixture was stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonane-coordinated metal peroxide catalyst YG-77-1-009 was added to the mixture of step (1), and the mixture was heated and stirred at 70°C for 30 min to obtain mixture B; Step (3): 0.5 g of cerium acetate was added to the mixture B formed in step (2) to obtain mixture C; Step (4): 0.1 g of phosphotungstic acid was added to the mixture C formed in step (3), and the mixture was stirred at 90°C for 60 min to obtain a total of 38.9 g of composite catalyst 1.

[0095] Example 20 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of phenyltrimethylammonium bromide was added with 20.0 g of methanol, and the mixture was stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonane-coordinated metal peroxide catalyst YG-77-1-010 was added to the mixture of step (1), and the mixture was heated and stirred at 60°C for 30 min to obtain mixture B; Step (3): 0.5 g of manganese acetate was added to the mixture B formed in step (2) to obtain mixture C; Step (4): 0.1 g of phosphotungstic acid was added to the mixture C formed in step (3), and the mixture was stirred at 60°C for 60 min to obtain a total of 39.2 g of composite catalyst 1.

[0096] Example 21 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of phenyltrimethylammonium bromide was added with 20.0 g of methanol, and the mixture was stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonane-coordinated metal peroxide catalyst YG-77-1-011 was added to the mixture of step (1), and the mixture was heated and stirred at 100°C for 20 min to obtain mixture B; Step (3): 0.5 g of magnesium acetate was added to the mixture B formed in step (2) to obtain mixture C; Step (4): To the mixture C formed from step (3), 0.1 g of tungstophosphoric acid was added, stirred at 90 °C for 60 min to obtain the composite catalyst 1, total 39.8 g.

[0097] Example 22 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added to 20.0 g of dibutyl ether, stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane-coordinated metal peroxide catalyst YG-77-1-012 was added to the mixture of step (1), heated and stirred at 100 °C for 20 min to obtain mixture B; Step (3): 0.5 g of manganese acetate was added to the mixture B formed from step (2) to obtain mixture C; Step (4): To the mixture C formed from step (3), 0.1 g of tungstophosphoric acid was added, stirred at 90 °C for 60 min to obtain the composite catalyst 1, total 39.8 g.

[0098] Example 23 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added to 20.0 g of dibutyl ether, stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane-coordinated metal peroxide catalyst YG-77-1-013 was added to the mixture of step (1), heated and stirred at 60 °C for 30 min to obtain mixture B; Step (3): 0.5 g of sodium acetate was added to the mixture B formed from step (2) to obtain mixture C; Step (4): To the mixture C formed from step (3), 0.1 g of tungstophosphoric acid was added, stirred at 90 °C for 60 min to obtain the composite catalyst 1, total 39.8 g.

[0099] Example 24 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of N-hydroxyphthalimide was added to 20.0 g of dibutyl ether, stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): To the mixture of step (1), 10.0 g of alkyl substituted 1,4-bis(2- pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane complexed metal peroxide catalyst YG-77-1-014 was added, and after stirring and heating at 100°C for 30 min, mixture B was obtained; Step (3): To the mixture B obtained in step (2), 0.5 g of cerium acetate was added to obtain mixture C; Step (4): To the mixture C obtained in step (3), 0.1 g of phosphomolybdic acid was added, and after stirring at 90°C for 60 min, 39.6 g of the composite catalyst 1 was obtained.

[0100] Example 25 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of N-hydroxyphthalimide was added to 20.0 g of methanol, and after stirring at room temperature until the solid was completely dissolved, mixture A was obtained; Step (2): To the mixture of step (1), 10.0 g of alkyl substituted 1,4-bis(2- pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane complexed metal peroxide catalyst YG-77-1-015 was added, and after stirring and heating at 60°C for 30 min, mixture B was obtained; Step (3): To the mixture B obtained in step (2), 0.5 g of sodium acetate was added to obtain mixture C; Step (4): To the mixture C obtained in step (3), 0.1 g of phosphomolybdic acid was added, and after stirring at 90°C for 60 min, 39.0 g of the composite catalyst 1 was obtained.

[0101] Example 26 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of N-hydroxyphthalimide was added to 20.0 g of ethanol, and after stirring at room temperature until the solid was completely dissolved, mixture A was obtained; Step (2): To the mixture of step (1), 10.0 g of alkyl substituted 1,4-bis(2- pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane complexed metal peroxide catalyst YG-771-016 was added, and after stirring and heating at 60°C for 30 min, mixture B was obtained; Step (3): To the mixture B obtained in step (2), 0.5 g of zirconium acetate was added to obtain mixture C; Step (4): To the mixture C obtained in step (3), 0.1 g of phosphotungstic acid was added, and after stirring at 90°C for 60 min, 40.1 g of the composite catalyst 1 was obtained.

[0102] Example 27 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of N-hydroxyphthalimide was added with 20.0 g of methanol, and the mixture was stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonane-coordinated metal peroxide catalyst YG-77-1-017 was added to the mixture of step (1), and the mixture was heated and stirred at 60°C for 30 min to obtain mixture B; Step (3): 0.5 g of cerium acetate was added to the mixture B formed in step (2) to obtain mixture C; Step (4): 0.1 g of silicotungstic acid was added to the mixture C formed in step (3), and the mixture was stirred at 90°C for 60 min to obtain a total of 38.9 g of composite catalyst 1.

[0103] Example 28 The preparation method of the composite catalyst in this example is as follows: Step (1): 10.0 g of ammonium bromide was added with 20.0 g of dibutyl ether, and the mixture was stirred at room temperature until the solid was completely dissolved to obtain mixture A; Step (2): 10.0 g of alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazonane-coordinated metal peroxide catalyst YG-77-1-018 was added to the mixture of step (1), and the mixture was heated and stirred at 100°C for 30 min to obtain mixture B; Step (3): 0.5 g of manganese acetate was added to the mixture B formed in step (2) to obtain mixture C; Step (4): 0.1 g of silicotungstic acid was added to the mixture C formed in step (3), and the mixture was stirred at 90°C for 60 min to obtain a total of 38.8 g of composite catalyst 1.

[0104] Example 29 In this example, a mixed acid of n-hexanoic acid, n-octanoic acid and n-nonanoic acid was prepared by oxidizing a mixed aldehyde of n-hexanal, n-octanal and n-nonanal (mass ratio 2:2:6), as follows: Into a 250 mL titanium high-pressure reactor, manganese bromide (0.1 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane-coordinated metal peroxide catalyst YG-771-006 (0.25 g), sodium acetate (0.1 g), phosphotungstic acid (0.05 g), acetic acid (20 g), and aliphatic aldehyde (20 g) were sequentially added. After the high-pressure reactor was installed, nitrogen was filled into the reactor to a pressure of 1.5 MPa for 15 minutes. The reactor was considered to have good airtightness if the pressure decreased by no more than 5%. After the nitrogen was discharged, the temperature was raised to 40°C, and air was introduced into the reactor to a pressure of 1.0 MPa. The air flow was continuously controlled at 150 mL / min, and the reaction was completed after five hours. The reaction solution was orange red, and the total weight of the reaction solution was 42.1 g.

[0105] 0.2 g of the reaction solution was taken, toluene was used as an internal standard, 0.05 g of toluene was taken, and 2 g of ethyl acetate was added for dilution. The sample was then tested. The test data was substituted into the internal standard curve to calculate that the aliphatic aldehyde remained 0.93 g, the aliphatic acid was 20.28 g, the conversion rate of the aliphatic aldehyde was 95.38%, and the selectivity of the aliphatic acid reached 95.21%.

[0106] Example 30 In this example, a mixed acid of n-hexanoic acid, n-octanoic acid, and n-nonanoic acid was prepared by oxidizing a mixed aldehyde of n-hexyl aldehyde, n-octyl aldehyde, and n-nonyl aldehyde (mass ratio 2:2:6), as follows: Into a 250 mL titanium high-pressure reactor, sodium bromide (0.25 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane-coordinated metal peroxide catalyst YG-771-006 (0.25 g), zinc acetate (0.25 g), phosphomolybdic acid (0.05 g), acetonitrile (1.0 g), acetic acid (100 g), and aliphatic aldehyde (50 g) were sequentially added. After the high-pressure reactor was installed, nitrogen was filled into the reactor to a pressure of 1.5 MPa for 15 minutes. The reactor was considered to have good airtightness if the pressure decreased by no more than 5%. After the nitrogen was discharged, the temperature was raised to 30°C, and air was introduced into the reactor to a pressure of 1.0 MPa. The air flow was continuously controlled at 200 mL / min, and the reaction was completed after five hours. The reaction solution was orange red, and the total weight of the reaction solution was 155.4 g.

[0107] 0.2 g of the reaction solution was taken, toluene was used as an internal standard, 0.1 g of toluene was taken, and 2 g of acetonitrile was added for dilution. The sample was then tested. The test data was substituted into the internal standard curve to calculate that the aliphatic aldehyde remained 0.95 g, the aliphatic acid was 54.10 g, the conversion rate of the aliphatic aldehyde was 98.10%, and the selectivity of the aliphatic acid reached 95.17%.

[0108] Example 31 This example is prepared by oxidation of a mixture of n-hexanal, n-octanal, n-nonyl aldehyde (mass ratio 3:3:4) to prepare a mixture of n-hexanoic acid, n-octanoic acid, n-nonyl acid, and the specific process is as follows: Into a 250 mL titanium high-pressure reactor, hexadecyl trimethyl ammonium bromide (0.5 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane-coordinated metal peroxide catalyst YG-77-1-008 (0.5 g), zirconium acetate (0.25 g), phosphotungstic acid (0.05 g), methanol (1.0 g), acetic acid (25 g), and fatty aldehyde (50 g) were sequentially added. After the high-pressure reactor was installed, nitrogen was filled into the reactor to a pressure of 1.5 MPa for 15 minutes. If the pressure decreased by no more than 5%, it was considered that the reactor had good airtightness. After the nitrogen was discharged, the temperature was raised to 30°C, and air was passed into the reactor to a pressure of 1.0 MPa. Continuous air flow was controlled at 300 mL / min, and the reaction was completed after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 74.2 g.

[0109] 0.1 g of the reaction liquid was taken, toluene was used as an internal standard, 0.1 g of toluene was taken, and after dilution with 2 g of acetonitrile, the sample was tested. The test data was substituted into the internal standard curve to calculate that the residual fatty aldehyde was 1.22 g, the fatty acid was 53.3 g, the conversion rate of fatty aldehyde was 97.56%, and the selectivity of fatty acid reached 93.38%.

[0110] Example 32 This example is prepared by oxidation of a mixture of n-hexanal, 2-methyl pentanal, n-heptanal, 2-methyl hexanal, n-octanal, 2-methyl heptanal (mass ratio 1:1:1:5:1.5:0.5) to prepare a mixture of n-hexanoic acid, 2-methyl pentanoic acid, n-heptanoic acid, 2-methyl hexanoic acid, n-octanoic acid, and 2-methyl heptanoic acid, and the specific process is as follows: Into a 250 mL titanium high-pressure reactor, sodium bromide (0.5 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane-coordinated metal peroxide catalyst YG-77-1-009 (0.5 g), manganese acetate 0.25 g), molybdophosphoric acid (0.05 g), acetonitrile (1.0 g), acetic acid (25 g), and fatty aldehyde (50 g) were sequentially added. After the high-pressure reactor was installed, nitrogen was filled into the reactor to a pressure of 1.5 MPa for 15 minutes. If the pressure decreased by no more than 5%, it was considered that the reactor had good airtightness. After the nitrogen was discharged, the temperature was raised to 30°C, and air was passed into the reactor to a pressure of 1.0 MPa. Continuous air flow was controlled at 200 mL / min, and the reaction was completed after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 154.6 g.

[0111] Take 0.1 g of the reaction solution, toluene as internal standard, take 0.1 g of toluene, dilute with 2 g of acetonitrile, and then test by injection. The test data are substituted into the internal standard curve to calculate that the mixed aldehyde is left over 1.61 g, the mixed acid is 56.1 g, the conversion rate of the mixed aldehyde is 96.78%, and the selectivity of the mixed acid reaches 96.2%.

[0112] Example 33 In this example, a mixed acid of n-octanoic acid, n-undecanoic acid and n-dodecanoic acid is prepared by oxidizing a mixed aldehyde of n-octyl aldehyde, n-undecyl aldehyde and n-dodecyl aldehyde (mass ratio 3:5:2), as follows: Into a 250 mL titanium high-pressure reaction kettle, phenyltrimethylammonium bromide (0.5 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane complex metal peroxide catalyst YG-77-1-010 (0.5 g), cerium acetate (0.25 g), phosphomolybdic acid (0.05 g), methanol (1.0 g), dichloroethane (25 g) and fatty aldehyde (50 g) are sequentially added. After the high-pressure reaction kettle is installed, nitrogen is filled to a pressure of 1.5 MPa in the kettle for 15 minutes. If the pressure decreases by no more than 5%, it is considered that the reaction kettle has good airtightness. After the nitrogen is discharged, the temperature is raised to 60°C, and air is passed into the reaction kettle to a pressure of 1.0 MPa. The air is continuously passed at a flow rate of 200 mL / min, and the reaction is stopped after three hours. The reaction solution is orange yellow, and the total weight of the reaction solution is 79.10 g.

[0113] Take 0.1 g of the reaction solution, toluene as internal standard, take 0.1 g of toluene, dilute with 2 g of acetonitrile, and then test by injection. The test data are substituted into the internal standard curve to calculate that the mixed aldehyde is left over 1.61 g, the mixed acid is 56.1 g, the conversion rate of the mixed aldehyde is 96.78%, and the selectivity of the mixed acid reaches 96.2%.

[0114] Example 34 In this example, a mixed acid of n-octanoic acid, n-undecanoic acid and n-dodecanoic acid is prepared by oxidizing a mixed aldehyde of n-octyl aldehyde, n-undecyl aldehyde and n-dodecyl aldehyde (mass ratio 4:4:2), as follows: Into a 250 mL titanium high-pressure reaction kettle, phenyl trimethyl ammonium bromide (0.5 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane complex metal peroxide catalyst YG-77-1-011 (0.5 g), manganese acetate (0.25 g), phosphomolybdic acid (0.05 g), methanol (1.0 g), dichloroethane (100 g), and fatty aldehyde (50 g) were sequentially added. After the high-pressure reaction kettle was installed, nitrogen was filled into the kettle until the pressure in the kettle was 1.5 MPa, and the pressure was maintained for 15 minutes. If the pressure decreased by no more than 5%, the reaction kettle was considered to have good airtightness. After the nitrogen was discharged, the temperature was increased to 60°C, air was introduced into the kettle until the pressure in the kettle was 1.0 MPa, and the air was continuously introduced at a flow rate of 200 mL / min. The reaction was completed after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 156.3 g.

[0115] 0.1 g of the reaction liquid was taken, toluene was used as an internal standard, 0.1 g of toluene was taken, and after dilution with 2 g of acetonitrile, the sample was tested. The test data was substituted into the internal standard curve to calculate that the fatty aldehyde remained 1.21 g, the fatty acid was 55.10 g, the conversion rate of the fatty aldehyde was 97.58%, and the selectivity of the fatty acid reached 98.21%.

[0116] Example 35 In this example, a mixed acid of n-octanoic acid, n-undecanoic acid, and n-dodecanoic acid was prepared by oxidizing a mixed aldehyde of n-octyl aldehyde, n-undecyl aldehyde, and n-dodecyl aldehyde (mass ratio 2:4:4), as follows. Into a 250 mL titanium high-pressure reaction kettle, phenyl trimethyl ammonium bromide (0.5 g), alkyl-substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane complex metal peroxide catalyst YG-77-1-012 (0.5 g), magnesium acetate (0.25 g), phosphotungstic acid (0.05 g), methanol (1.0 g), dichloroethane (100 g), and fatty aldehyde (50 g) were sequentially added. After the high-pressure reaction kettle was installed, nitrogen was filled into the kettle until the pressure in the kettle was 1.5 MPa, and the pressure was maintained for 15 minutes. If the pressure decreased by no more than 5%, the reaction kettle was considered to have good airtightness. After the nitrogen was discharged, the temperature was increased to 70°C, air was introduced into the kettle until the pressure in the kettle was 1.0 MPa, and the air was continuously introduced at a flow rate of 200 mL / min. The reaction was completed after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 157.1 g.

[0117] 0.1 g of the reaction liquid was taken, toluene was used as an internal standard, 0.1 g of toluene was taken, and after dilution with 2 g of acetonitrile, the sample was tested. The test data was substituted into the internal standard curve to calculate that the fatty aldehyde remained 1.21 g, the fatty acid was 55.10 g, the conversion rate of the fatty aldehyde was 97.58%, and the selectivity of the fatty acid reached 98.21%.

[0118] Example 36 This example is to n-hexyl aldehyde, n-heptyl aldehyde (mass ratio of 7:3) mixed aldehyde oxidation preparation n-hexanoic acid, n-heptanoic acid mixed acid, as follows: Into 250 mL titanium high pressure reactor, in turn, add ammonium bromide (0.5 g), alkyl substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane coordination of metal peroxide catalyst YG-77-1-013 (0.5 g), manganese acetate (0.25 g), phosphotungstic acid (0.05 g), ethanol (1.0 g), dichloroethane (100 g), aliphatic aldehyde (50 g). After the high pressure reactor is installed, fill nitrogen to the pressure in the kettle is 1.5 MPa for 15 minutes, the pressure is reduced by not more than 5% is considered to be good gas tightness of the reactor. After the nitrogen is discharged, the temperature is raised to 40 DEG C, the air is passed to the pressure in the reactor is 1.0 MPa, continuous air, control flow is 200 mL / min, after three hours of reaction, end. The reaction liquid is orange, the total weight of the reaction liquid is 156.0 g.

[0119] Take 0.1 g of the reaction liquid, toluene as internal standard, take 0.1 g of toluene, add 2 g of acetonitrile dilution, then sample test. The test data is substituted into the internal standard curve to calculate the remaining 1.55 g of aliphatic aldehyde, 54.1 g of fatty acid, the conversion rate of aliphatic aldehyde is 96.90%, and the selectivity of fatty acid is 97.69%.

[0120] Example 37 This example is to n-hexyl aldehyde, n-heptyl aldehyde (mass ratio of 5:5) mixed aldehyde oxidation preparation n-hexanoic acid, n-heptanoic acid mixed acid, as follows: Into 250 mL titanium high pressure reactor, in turn, add ammonium bromide (0.5 g), alkyl substituted 1,4-bis (2-pyridylmethyl) -1,4-diazane coordination of metal peroxide catalyst YG-77-1-013 (0.5 g), manganese acetate (0.25 g), phosphotungstic acid (0.05 g), ethanol (1.0 g), dichloroethane (100 g), aliphatic aldehyde (50 g). After the high pressure reactor is installed, fill nitrogen to the pressure in the kettle is 1.5 MPa for 15 minutes, the pressure is reduced by not more than 5% is considered to be good gas tightness of the reactor. After the nitrogen is discharged, the temperature is raised to 40 DEG C, the air is passed to the pressure in the reactor is 1.0 MPa, continuous air, control flow is 200 mL / min, after three hours of reaction, end. The reaction liquid is orange, the total weight of the reaction liquid is 156.0 g.

[0121] Take 0.1 g of the reaction liquid, toluene as internal standard, take 0.1 g of toluene, add 2 g of acetonitrile dilution, then sample test. The test data is substituted into the internal standard curve to calculate the remaining 1.55 g of aliphatic aldehyde, 54.1 g of fatty acid, the conversion rate of aliphatic aldehyde is 96.90%, and the selectivity of fatty acid is 97.69%.

[0122] Example 38 This example is prepared by oxidation of a mixture of n-hexanal and n-heptanal (mass ratio 5:5) to prepare a mixture of n-hexanoic acid and n-heptanoic acid, as follows: Into a 250 mL titanium high-pressure reaction kettle, N-hydroxyphthalimide (0.5 g), metal peroxide catalyst YG-77-1-015 coordinated by alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane (0.5 g), cerium acetate (0.25 g), phosphomolybdic acid (0.05 g), acetonitrile (1.0 g), dichloroethane (100 g), and aliphatic aldehyde (50 g) were sequentially added. After the high-pressure reaction kettle was installed, nitrogen was charged to a pressure of 1.5 MPa in the kettle for 15 minutes. If the pressure decreased by no more than 5%, the reaction kettle was considered to have good airtightness. After the nitrogen was discharged, the temperature was raised to 40°C, and air was passed into the reaction kettle to a pressure of 1.0 MPa. The air flow was continuously controlled at 200 mL / min, and the reaction was ended after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 155.6 g.

[0123] A sample of 0.1 g of the reaction liquid was taken, toluene was used as an internal standard, and a sample of 0.1 g of toluene was taken. After dilution with 2 g of acetonitrile, the sample was tested. The test data were substituted into the internal standard curve to calculate that the aliphatic aldehyde remained 1.4 g, the aliphatic acid was 53.72 g, the conversion rate of the aliphatic aldehyde was 97.20%, and the selectivity of the aliphatic acid was 95.16%.

[0124] Example 39 This example is prepared by oxidation of a mixture of n-hexanal and n-heptanal (mass ratio 2:8) to prepare a mixture of n-hexanoic acid and n-heptanoic acid, as follows: Into a 250 mL titanium high-pressure reaction kettle, N-hydroxyphthalimide (0.5 g), metal peroxide catalyst YG-77-1-016 coordinated by alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane (0.5 g), manganese acetate (0.25 g), phosphomolybdic acid (0.05 g), methanol (1.0 g), dichloroethane (100 g), and aliphatic aldehyde (50 g) were sequentially added. After the high-pressure reaction kettle was installed, nitrogen was charged to a pressure of 1.5 MPa in the kettle for 15 minutes. If the pressure decreased by no more than 5%, the reaction kettle was considered to have good airtightness. After the nitrogen was discharged, the temperature was raised to 100°C, and air was passed into the reaction kettle to a pressure of 1.0 MPa. The air flow was continuously controlled at 200 mL / min, and the reaction was ended after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 154.3 g.

[0125] A sample of 0.1 g of the reaction liquid was taken, toluene was used as an internal standard, and a sample of 0.1 g of toluene was taken. After dilution with 2 g of acetonitrile, the sample was tested. The test data were substituted into the internal standard curve to calculate that the aliphatic aldehyde remained 1.4 g, the aliphatic acid was 53.72 g, the conversion rate of the aliphatic aldehyde was 97.20%, and the selectivity of the aliphatic acid was 95.16%.

[0126] Example 40 In this example, a mixed acid of n-hexanoic acid and n-heptanoic acid was prepared by oxidizing a mixed aldehyde of n-hexanal and n-heptanal (mass ratio 8:2), specifically as follows: Into a 250 mL titanium high-pressure reaction kettle, N-hydroxyphthalimide (0.5 g), metal peroxide catalyst YG-77-1-017 coordinated by alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane (0.5 g), zirconium acetate (0.25 g), silicotungstic acid (0.05 g), ethanol (1.0 g), dichloroethane (100 g), and aliphatic aldehyde (50 g) were sequentially added. After the high-pressure reaction kettle was installed, nitrogen was filled into the kettle to a pressure of 1.5 MPa and maintained for 15 minutes. The reaction kettle was considered to have good airtightness if the pressure decreased by no more than 5%. After the nitrogen was discharged, the temperature was raised to 40°C, air was introduced into the kettle to a pressure of 1.0 MPa, and the air flow was continuously controlled at 200 mL / min. The reaction was stopped after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 158.36 g.

[0127] 0.1 g of the reaction liquid was taken, toluene was used as an internal standard, 0.1 g of toluene was taken, and after dilution with 2 g of acetonitrile, the sample was tested. The test data were substituted into the internal standard curve to calculate that the aliphatic aldehyde remained 0.41 g, the aliphatic acid was 57.89 g, the conversion rate of the aliphatic aldehyde was 99.91%, and the selectivity of the aliphatic acid reached 98.99%.

[0128] Example 41 In this example, a mixed acid of n-hexanoic acid and n-heptanoic acid was prepared by oxidizing a mixed aldehyde of n-hexanal and n-heptanal (mass ratio 5:5), specifically as follows: Into a 250 mL titanium high-pressure reaction kettle, N-hydroxyphthalimide (0.5 g), metal peroxide catalyst YG-77-1-018 coordinated by alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane (0.5 g), cerium acetate (0.25 g), silicotungstic acid (0.05 g), methanol (1.0 g), acetic acid (100 g), and aliphatic aldehyde (50 g) were sequentially added. After the high-pressure reaction kettle was installed, nitrogen was filled into the kettle to a pressure of 1.5 MPa and maintained for 15 minutes. The reaction kettle was considered to have good airtightness if the pressure decreased by no more than 5%. After the nitrogen was discharged, the temperature was raised to 50°C, air was introduced into the kettle to a pressure of 1.0 MPa, and the air flow was continuously controlled at 200 mL / min. The reaction was stopped after three hours. The reaction liquid was orange yellow, and the total weight of the reaction liquid was 156.8 g.

[0129] Take 0.1 g of the reaction solution, toluene as internal standard, take 0.1 g of toluene, dilute with 2 g of acetonitrile, and then test by injection. The test data are substituted into the internal standard curve to calculate that the residual fatty aldehyde is 2.86 g, the fatty acid is 53.65 g, the conversion rate of fatty aldehyde is 94.28%, and the selectivity of fatty acid reaches 94.95%.

[0130] Example 42 In this example, a mixed acid of n-hexanoic acid, 2-ethylbutyric acid, n-heptanoic acid and 2-methylhexanoic acid is prepared by oxidizing a mixed aldehyde of n-hexyl aldehyde, 2-ethylbutyl aldehyde, n-heptyl aldehyde and 2-methylhexyl aldehyde (mass ratio 3:3:2:2), as follows: Into a 250 mL titanium high-pressure reaction kettle, ammonium bromide (0.5 g), alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane-coordinated metal peroxide catalyst YG-77-1-019 (0.5 g), manganese acetate (0.25 g), silicotungstic acid (0.05 g), methanol (1.0 g), acetic acid (100 g) and fatty aldehyde (50 g) are sequentially added. After the high-pressure reaction kettle is installed, nitrogen is filled into the kettle to a pressure of 1.5 MPa and maintained for 15 minutes. If the pressure decreases by no more than 5%, it is considered that the reaction kettle has good airtightness. After the nitrogen is discharged, the temperature is raised to 70°C, air is introduced into the reaction kettle to a pressure of 1.0 MPa, and the air is continuously introduced at a flow rate of 200 mL / min. The reaction is completed after three hours. The reaction solution is orange yellow, and the total weight of the reaction solution is 154.2 g.

[0131] Take 0.1 g of the reaction solution, toluene as internal standard, take 0.1 g of toluene, dilute with 2 g of acetonitrile, and then test by injection. The test data are substituted into the internal standard curve to calculate that the residual fatty aldehyde is 2.86 g, the fatty acid is 53.65 g, the conversion rate of fatty aldehyde is 94.28%, and the selectivity of fatty acid reaches 94.95%.

[0132] Comparative Example The experimental operation method of the comparative example is consistent with that of Example 35, except that the amount of the materials added is different. The amount of the materials added and the experimental results are shown in Table 1.

[0133] Table 1 Amount of materials added and experimental results of comparative examples

[0134] As shown in Table 1, in Comparative Example 8, no alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane-coordinated metal peroxide catalyst YG-77-1-012 is added, and both the conversion rate of fatty aldehyde and the conversion rate of fatty acid are extremely low. In Example 35, the conversion rate and the selectivity are the best, which indicates that the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazane-coordinated metal peroxide catalyst prepared in the present application can effectively catalyze the oxidation of fatty aldehyde to prepare fatty acid, and has high activity and high selectivity.

[0135] In combination with Comparative Examples 1-7, adjusting one component or the proportion of one component in the metal peroxide catalyst coordinated with the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicyclo[2.2.2]octane as the main catalyst, the cocatalyst, the regulator, the protective agent, and the solvent has a great influence on the effect of the catalytic reaction, indicating that the above components can effectively improve the effect of the catalytic reaction when used in a suitable proportion, and also indicating that the above components have a synergistic effect on the catalytic reaction.

[0136] It is apparent to those skilled in the art that the present disclosure is not limited to the details of the foregoing exemplary embodiments, and that the present disclosure can be implemented in other specific forms without departing from the spirit or essential characteristics of the present disclosure. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the present disclosure is defined by the appended claims rather than the foregoing description, and it is intended to include all changes falling within the meaning and range of equivalents of the elements of the claims. Any mark in the claims should not be considered as limiting the claims involved.

[0137] Furthermore, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this manner only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. An alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane complex metal peroxide catalyst characterized by, The general formula is shown as formula (I): （Ⅰ） B is selected from any one of copper ion, sodium ion, iron ion, potassium ion, zinc ion, ammonium ion, dodecyl dimethyl benzyl ammonium ion, dodecyl trimethyl ammonium ion, octadecyl trimethyl ammonium ion, octadecyl dimethyl benzyl ammonium ion, aliphatic tributyl phosphonium ion, tetrabutyl phosphonium ion, hexyl tributyl phosphonium ion, tributyl ethyl phosphonium ion, tetramethyl ammonium ion, tetraethyl ammonium ion, tetrabutyl ammonium ion, benzyl trimethyl ammonium ion, benzyl triphenyl phosphonium ion, benzyl triethyl ammonium ion; M is selected from any one of nickel, chromium, cobalt, manganese, copper, calcium, sodium, molybdenum, lanthanum, cerium, tungsten, scandium, titanium, zirconium, vanadium; R1is selected from C1-C 10 alkyl; R2is selected from C1-C 10 alkyl; x is selected from any integer between 1 and 20; y is selected from any integer between 1 and 20.

2. A process for the preparation of an alkyl-substituted 1,4-bis(2-pyridylmethyl)- 1,4-diazoniabicyclo[2.2.2]octane complex metal peroxide catalyst characterized by, The method comprises the following steps: dissolving the metal compound in deionized water, adjusting the pH of the solution to make the solution acidic, and then adding a peroxide to obtain a metal peroxide solution; mixing the metal peroxide solution, the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane and a salt, filtering and drying to obtain the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane coordination metal peroxide catalyst.

3. The process for preparing an alkyl-substituted 1,4-bis(2-pyridylmethyl)- 1,4-diazoniabicyclo[2.2.2]octane complex metal peroxide catalyst according to claim 2, characterized in that, The metal compound is selected from any one of sodium molybdate, sodium tungstate, molybdenum acetylacetone, tungsten hexacarbonyl, cobalt sulfate, nickel nitrate, nickel acetate, manganese chloride, manganese sulfate, copper sulfate, copper nitrate, calcium chloride, calcium carbonate, chromium chloride, chromium sulfate, lanthanum nitrate, lanthanum chloride, cerium nitrate, cerium sulfate, scandium chloride, scandium nitrate, titanium tetrachloride, titanyl sulfate, zirconium chloride, zirconium nitrate and sodium metavanadate; and / or, The peroxide is selected from any one of hydrogen peroxide and sodium percarbonate; and / or, The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane is selected from any one of N,N'-bis(6-methyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-ethyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-isopropyl-2-pyridylmethyl)-1,4-diazabicycloheptane, N,N'-bis(6-n-butyl-2-pyridylmethyl)-1,4-diazabicycloheptane; and / or, The salt is selected from any one of octadecyl trimethyl ammonium chloride, octadecyl trimethyl ammonium bromide, lithium chloride, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, ammonium bromide, manganese bromide, iron bromide, copper bromide, dodecyl trimethyl ammonium chloride, hexyl tributyl phosphonium bromide, tributyl ethyl phosphonium bromide, aliphatic tributyl phosphonium bromide, tetrabutyl phosphonium bromide, tetramethyl ammonium chloride, tetraethyl ammonium chloride, tetrabutyl ammonium chloride, benzyl trimethyl ammonium chloride, benzyl triethyl ammonium chloride.

4. The process for preparing the alkyl-substituted 1,4-bis(2-pyridylmethyl)- 1,4-diazoniabicyclo[2.2.2]octane complex metal peroxide catalyst according to claim 2, characterized by, The pH of the solution of the metal compound dissolved in deionized water is adjusted to 3-4.

5. A composite catalyst characterized by comprising The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane coordination metal peroxide catalyst of claim 1. The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazabicycloheptane coordination metal peroxide catalyst of claim 1.

6. The composite catalyst according to claim 5, characterized in that, The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst and the auxiliary catalyst are in a weight ratio of 100:(1-200); The auxiliary catalyst is selected from one or more of potassium salt, sodium salt, iron salt, magnesium salt, zinc salt, nickel salt, chromium salt, cobalt salt, manganese salt, copper salt, calcium salt, sodium salt, molybdenum salt, lanthanum salt, cerium salt, tungsten salt, scandium salt, titanium salt, zirconium salt, vanadium salt, potassium oxide, sodium oxide, iron oxide, magnesium oxide, zinc oxide, nickel oxide, chromium oxide, cobalt oxide, manganese oxide, copper oxide, calcium oxide, sodium oxide, molybdenum oxide, lanthanum oxide, cerium oxide, tungsten oxide, scandium oxide, titanium oxide, zirconium oxide, vanadium oxide.

7. The composite catalyst according to claim 5, wherein The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst and the regulator are in a weight ratio of 100:(1-200); The regulator is selected from one or more of phosphomolybdic acid, phosphotungstic acid, tetrabutylammonium bromide, boric acid, silicotungstic acid and phosphomolybdovanadic acid.

8. The composite catalyst according to claim 5, wherein The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst and the protective agent are in a weight ratio of 100:(10-200); The protective agent is selected from one or more of sodium acetate, ammonium bromide, cetyltrimethylammonium bromide, phenyltrimethylammonium bromide, sodium molybdate and N-hydroxyphthalimide.

9. The composite catalyst according to claim 5, wherein The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst and the solvent are in a weight ratio of 100:(10-1000); The solvent is selected from one or more of dichloromethane, dichloroethane, tetrahydrofuran, diethyl ether, chloroform, toluene, carbon tetrachloride, 1,4-dioxane, dibutyl ether, methyl tert-butyl ether, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, ethyl acetate and propyl acetate.

10. A method for producing a composite catalyst, characterized by, The solvent and the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst of claim 1 are mixed, stirred at 20-100℃ for 40-120min.

11. The method of claim 10, wherein the composite catalyst is prepared by the steps of: Further comprising the following steps: The protective agent and the solvent are mixed to obtain a solution; The alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst is added to the solution, stirred at 20-100℃ for 40-120min; The auxiliary catalyst is added, ultrasonically treated at 35-80℃ for 40-60min; The regulator is added, stirred at 35-80℃ for 40-60min to obtain the composite catalyst.

12. Use of the alkyl-substituted 1,4-bis(2-pyridylmethyl)-1,4-diazoniabicyclo[2.2.2]octane coordination metal peroxide catalyst of claim 1 or the composite catalyst of any one of claims 5-9 in the reaction of preparing fatty acid from fatty aldehyde as raw material.

13. Use according to claim 12, characterized in that, The fatty aldehyde has a general formula as shown in formula (II): （Ⅱ） wherein m is selected from any integer between 1 and 20; R3is selected from hydrogen, alkyl, alkoxy, ester, hydroxyl, amine, halogen or aromatic group, the alkyl is a straight or branched aliphatic group having C n H 2n+1 straight or branched aliphatic group having Cn is any integer between 1 and 8; R4is selected from hydrogen, alkyl, alkoxy, ester, hydroxyl, amine, halogen or aromatic group, the alkyl is a straight or branched aliphatic group having C n H 2n+1 straight or branched aliphatic group having Cn is any integer between 1 and 8.

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