A method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene

Abstract

The present invention provides a method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene. The method aims to provide a method for continuously preparing benzyl alcohol, benzaldehyde and benzoic acid with high efficiency, good safety, and environmental protection. The method comprises the following steps: dispersing a metal naphthenate composite salt catalyst and a non-metallic aerobic oxidation co-catalyst into toluene; continuously introducing air at a flow rate of 100-1500 mL / min into a closed system; and reacting at a set temperature of 40-140°C, an infusion pump flow rate of 5-40 mL / min, and a back pressure of 0-5 MPa to obtain the products of benzyl alcohol, benzaldehyde and benzoic acid. The catalyst used in the technical solution provided by the present invention has the advantages of high product selectivity, low cost, few by-products, low reaction temperature, and high production capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical industry, and in particular to a method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene. Background Art

[0002] Benzyl alcohol, also known as benzyl alcohol, is found in nature primarily as an ester in essential oils. It is widely used in solvents, plasticizers, preservatives, fragrances, soaps, pharmaceuticals, and dyes. Currently, methods for preparing benzyl alcohol primarily include hydrolysis of benzyl chloride, oxidation of toluene, synthesis of benzyl alcohol from benzene and formaldehyde, and hydrolysis of benzyl esters. The hydrolysis of benzyl chloride is the predominant industrialized method both domestically and internationally. However, because the reaction involves azeotropic hydrolysis in an aqueous solution containing an alkali, benzyl alcohol is also produced as a benzyl ether. Therefore, increasing pressure, temperature, or alkali concentration hinders the production of benzyl alcohol.

[0003] Benzaldehyde, also known as benzoinaldehyde, is widely used in the production of m-oxybenzaldehyde, lauric acid, lauryl aldehyde, malachite green, benzyl benzoate, benzylaniline, and benzyl acetone. It is also used in the blending of soap flavors and food flavors. It is also used in organic synthesis, as a solvent, for the determination of ozone and methylene groups adjacent to carbonyl groups, for the analysis of phenols and alkaloids, and in the preparation of fragrances. Currently, the main industrialized production methods include toluene chlorination and hydrolysis, direct oxidation of toluene, oxidation of benzyl alcohol, indirect electrochemical oxidation of toluene, hydrogenation reduction of benzoic acid or methyl esters, cinnamaldehyde, and air oxidation of dibenzyl ether. Currently, most benzaldehyde products in China are derived from benzyl chloride, a byproduct of benzyl chloride production. Due to the low content of benzyl chloride and the large fluctuation in purity after separation, the process conditions for its production are difficult to control, limiting yield and output.

[0004] Benzoic acid, also known as benzoic acid, is a chemically stable, flaky or needle-shaped crystal that is resistant to oxidation. It is an important organic chemical raw material and chemical reaction intermediate. Its wide range of applications includes food preservatives, antibacterial agents for latex, toothpaste, jam, and other foods, alkyd resin modifiers, dye intermediates, dye mordants, pharmaceuticals, plasticizers, fragrance raw materials, and fiber intermediates. It is also a key raw material for the production of caprolactam and benzoic acid. Benzoic acid production methods include benzyl trichloride hydrolysis, phthalic anhydride decarboxylation, toluene liquid-phase air oxidation, toluene potassium permanganate oxidation, benzamide atmospheric pressure microwave heating, and H2O2 catalytic oxidation. Among the above-mentioned synthesis methods, the main method is toluene liquid phase air oxidation; the benzyl trichloride hydrolysis method contains chlorine and is not suitable for use in the food industry; the product of the phthalic anhydride decarboxylation method is difficult to purify and is costly, so it is only used in the manufacture of small-volume pharmaceutical products; the toluene potassium permanganate oxidation method is commonly used in the laboratory synthesis of benzoic acid, but it is costly and not suitable for industrial production; the benzamide atmospheric pressure microwave heating method has not yet been reported in more depth; the H2O2 catalytic oxidation method has gradually attracted people's attention due to its green process, but the H2O2 has limited oxidation capacity and is easily decomposed by heat, often requiring the addition of excessive H2O2 to achieve more benzaldehyde conversion, resulting in waste of resources and potential safety hazards. At present, the use of O2 / air as an oxygen source has the advantages of being cheap, green and pollution-free, mild conditions during the reaction process, and high reaction efficiency, making this method feasible.

[0005] Reactors can be categorized as batch reactors or continuous reactors. However, batch reactors have limited air / O₂ injection capacity, resulting in low selectivity and conversion rates for toluene oxidation using batch reactors. Continuous processes offer advantages over traditional processes, such as higher product yields, faster reaction rates, and improved process safety. Given the strengths and weaknesses of current production methods for these two substances, there is an urgent need for an environmentally friendly method for catalyzing the oxidation of toluene to produce benzyl alcohol, benzaldehyde, and benzoic acid, with mild reaction conditions, high selectivity for benzyl alcohol, benzaldehyde, and benzoic acid, and minimal byproducts. Summary of the Invention

[0006] In response to the shortcomings of the above-mentioned methods for producing benzyl alcohol, benzaldehyde, and benzoic acid, the present invention primarily addresses the technical problem of providing a method and application for the biomimetic catalytic air oxidation of toluene to produce benzyl alcohol / aldehyde / acid. The method uses air as the oxidant, a metal naphthenate as the catalyst, and a non-metallic aerobic oxidation catalyst as a co-catalyst, utilizing its unique structure and ability to activate molecular oxygen. The reaction system is characterized by ease of operation, mild reaction conditions, and high catalytic efficiency. Furthermore, the system produces high selectivity for benzyl alcohol, benzaldehyde, and benzoic acid, produces few byproducts, and can be carried out at relatively low reaction temperatures.

[0007] The object of the present invention is achieved through the following scheme:

[0008] A method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene comprises dispersing a metal naphthenate composite salt catalyst and a non-metallic aerobic oxidation co-catalyst in toluene, continuously introducing air at a flow rate of 100-1500 mL / min into a closed system, and reacting at a set temperature of 40-140°C, an infusion pump flow rate of 5-40 mL / min, and a back pressure of 0-5 MPa to obtain the products of benzyl alcohol, benzaldehyde, and benzoic acid.

[0009] Wherein: the mass of metal naphthenate complex salt is 500-3500ppm;

[0010] The mass of the non-metallic aerobic oxidation catalyst is 200-1800ppm.

[0011] Furthermore, in the above-mentioned method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, the metal naphthenate composite salt is composed of at least one of the compounds described in formula (1) and at least one of the compounds shown in formula (2);

[0012]

[0013] In formula (1);

[0014] M1 is one of zinc, copper, and cobalt;

[0015]

[0016] In formula (2), M2 is one of manganese, nickel, barium, calcium, and magnesium.

[0017] Furthermore, in the above-mentioned method of biomimetic catalytic air oxidation of toluene to produce benzyl alcohol / aldehyde / acid, the non-metallic aerobic oxidation co-catalyst is one of phthalimide, N,N′-dihydroxypyromellitic acid imide, N-hydroxyphthalimide, and N-acetylphthalimide.

[0018] Furthermore, in the above-mentioned method of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, the reaction temperature is 50-140°C.

[0019] Furthermore, in the above-mentioned method of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, the addition amount of the catalyst metal naphthenate is 654-3270 ppm.

[0020] Furthermore, in the above-mentioned method of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, the mass of the non-metallic aerobic oxidation catalyst is 305.2-1526 ppm.

[0021] Furthermore, in the above-mentioned method of biomimetic catalytic air oxidation of toluene to produce benzyl alcohol / aldehyde / acid, the gas flow rate is 200-1400 mL / min.

[0022] Furthermore, in the above-mentioned method of biomimetic catalytic air oxidation of toluene to produce benzyl alcohol / aldehyde / acid, the flow rate of the infusion pump is 10-30 mL / min.

[0023] Furthermore, in the above-mentioned method of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, the back pressure is 0-2.5 MPa.

[0024] Furthermore, in the above-mentioned method of biomimetic catalytic air oxidation of toluene to produce benzyl alcohol / aldehyde / acid, the added amount of the catalyst metal naphthenate is 1308 ppm, and the mass of the non-metallic aerobic oxidation catalyst is 1220.8 ppm.

[0025] The present invention provides a method for analyzing the reaction results as follows: after the reaction is completed, an appropriate amount of the reaction solution is collected for analysis. Gas chromatography is performed using naphthalene as an internal standard to calculate the conversion rate of toluene and the selectivity of benzyl alcohol, benzaldehyde, and benzoic acid.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The technical solution provided by the present invention uses metal naphthenate as a catalyst, and cooperates with a non-metallic aerobic oxidation co-catalyst to catalytically oxidize and prepare benzyl alcohol, benzaldehyde and benzoic acid. The metal naphthenate catalyst has good activity and selectivity. The toluene conversion rate can reach up to 10-40%, the selectivity of benzyl alcohol and benzaldehyde can reach up to 50-85%, and the selectivity of benzoic acid can reach up to 20-50%.

[0028] 2. The technical solution provided by the present invention uses toluene as both a reaction substrate and a reaction solvent, and uses oxygen as an oxidant to directly oxidize toluene. The process is simple and the reaction conditions are mild.

[0029] 3. The metal naphthenate used in the present invention has high catalytic activity and excellent adaptability to the reaction. The catalyst dosage is small, and only the ppm level is required to significantly improve the reaction efficiency. The process is simple, green and safe, and has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the chromatogram of the product analyzed by gas chromatography using online sampling in Example 5. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0032] Example 1

[0033] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0034] A mixed catalyst of 1308ppm of cobalt naphthenate, barium naphthenate, and magnesium naphthenate, with a mass ratio of 7.125:1.875:1, and 1220.8ppm of phthalimide were added to a 500mL screw-capped bottle. 4.34mol of toluene were added, resulting in a total volume of 458.7mL. Air was used as the oxygen source at a gas flow rate of 200mL / min, and the reaction solution was pumped in at an infusion pump flow rate of 10mL / min with a back pressure of 0 MPa. After continuous reaction at 50°C for 10min, the reaction solution was placed in a low-temperature reactor to reduce the temperature of the reaction solution. The low-temperature reactor temperature was -5°C for 5min, and the low-boiling-point and vaporized organic matter was liquefied into a liquid phase. After the reaction, naphthalene was used as the internal standard, and the product was analyzed by gas chromatography using online sampling, and the internal standard method was used to quantify the product.

[0035] The results showed that the toluene conversion rate was 11%, the selectivity of the products benzyl alcohol and benzaldehyde was 83%, and the selectivity of the product benzoic acid was 17%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0036] The structural formula of cobalt naphthenate is as follows:

[0037]

[0038] The structural formula of the barium naphthenate is as follows:

[0039]

[0040] The structural formula of the magnesium naphthenate is as follows:

[0041]

[0042] Example 2

[0043] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0044] A mixed catalyst of 1308 ppm of copper naphthenate, barium naphthenate, and calcium naphthenate in a mass ratio of 7.125:1.875:1 and 1220.8 ppm of N,N'-dihydroxypyromellitic acid imide were added to a 500 mL screw-capped bottle. 4.34 mol of toluene was added to a total volume of 458.7 mL. Air was used as an oxygen source at a gas flow rate of 400 mL / min, and the reaction solution was pumped in at an infusion pump flow rate of 15 mL / min under a back pressure of 0.5 MPa. After continuous reaction at 65°C for 10 minutes, the reaction solution was placed in a low-temperature reactor to reduce the temperature of the reaction solution to -5°C for 5 minutes to liquefy the vaporized organic matter with a low boiling point into a liquid phase. After the reaction, naphthalene was used as an internal standard, and the product was analyzed by gas chromatography using online sampling and internal standard method for quantitative product analysis.

[0045] The results showed that the toluene conversion rate was 18%, the selectivity of the products benzyl alcohol and benzaldehyde was 78%, and the selectivity of the product benzoic acid was 22%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0046] The copper naphthenate structural formula is as follows:

[0047]

[0048] The structural formula of calcium naphthenate is as follows:

[0049]

[0050] The structural formula of the barium naphthenate is as follows:

[0051]

[0052] Example 3

[0053] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0054] By the mixed catalyst of zinc naphthenate, magnesium naphthenate and nickel naphthenate of 1308ppm, the mass ratio of described zinc naphthenate, magnesium naphthenate and nickel naphthenate is 7.125: 1.875: 1, and the N-hydroxyphthalimide of 1220.8ppm is joined in 500mL screw bottle, the toluene of 4.34mol is added, cumulative volume is 458.7mL, and the air with gas flow rate is 600mL / min is oxygen source, and with infusion pump flow rate, is that 20mL / min pumps into reaction solution, back pressure 1.0MPa.After serialization reaction 10min under 80 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the organic matter with low boiling point and vaporized is liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0055] The results showed that the toluene conversion rate was 26%, the selectivity of the products benzyl alcohol and benzaldehyde was 74%, and the selectivity of the product benzoic acid was 26%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0056] The structural formula of zinc naphthenate is as follows:

[0057]

[0058] The structural formula of the magnesium naphthenate is as follows:

[0059]

[0060] The structural formula of nickel naphthenate is as follows:

[0061]

[0062] Example 4

[0063] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0064] By the mixed catalyst of zinc naphthenate, barium naphthenate and nickel naphthenate of 1308ppm, the mass ratio of described zinc naphthenate, barium naphthenate and nickel naphthenate is 7.125: 1.875: 1, and the N-acetyl phthalimide of 1220.8ppm is joined in 500mL screw bottle, add the toluene of 4.34mol, cumulative volume is 458.7mL, take the air that gas flow rate is 800mL / min as oxygen source, take infusion pump flow rate as 25mL / min pumps into reaction solution, back pressure 1.5MPa.After serialization reaction 10min under 95 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the low boiling point and organic matter that has vaporized are liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0065] The results showed that the toluene conversion rate was 35%, the selectivity of the products benzyl alcohol and benzaldehyde was 69%, and the selectivity of the product benzoic acid was 31%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0066] The structural formula of zinc naphthenate is as follows:

[0067]

[0068] The structural formula of the barium naphthenate is as follows:

[0069]

[0070] The structural formula of nickel naphthenate is as follows:

[0071]

[0072] Example 5

[0073] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0074] A mixed catalyst of 1308 ppm of cobalt naphthenate, manganese naphthenate, and nickel naphthenate, with a mass ratio of 7.125:1.875:1, and 1220.8 ppm of N-hydroxyphthalimide were added to a 500 mL screw-cap bottle. 4.34 mol of toluene were added, resulting in a total volume of 458.7 mL. Air was used as the oxygen source at a gas flow rate of 1000 mL / min, and the reaction solution was pumped into the reaction solution at an infusion pump flow rate of 20 mL / min, with a back pressure of 1.0 MPa. After continuous reaction at 110°C for 10 minutes, the reaction solution was placed in a low-temperature reactor to reduce the temperature of the reaction solution. The low-temperature reactor temperature was -5°C for 5 minutes to liquefy the low-boiling-point and vaporized organic matter into a liquid phase. After the reaction, the product was analyzed by gas chromatography using naphthalene as the internal standard. The internal standard method was used to quantify the product. The spectrum is shown in Figure 1. Figure 1 .

[0075] The results showed that the toluene conversion rate was 12%, the selectivity of the products benzyl alcohol and benzaldehyde was 80%, and the selectivity of the product benzoic acid was 20%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0076] The structural formula of cobalt naphthenate is as follows:

[0077]

[0078] The result formula of the manganese naphthenate is as follows:

[0079]

[0080] The structural formula of nickel naphthenate is as follows:

[0081]

[0082] Example 6

[0083] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0084] By the mixed catalyst of the cobalt naphthenate of 1308ppm, zinc naphthenate and nickel naphthenate, the mass ratio of described cobalt naphthenate, zinc naphthenate and nickel naphthenate is 7.125: 1.875: 1, and the phthalimide of 1220.8ppm is joined in 500mL screw bottle, the toluene of 4.34mol is added, cumulative volume is 458.7mL, and the air with gas flow rate is 1000mL / min is oxygen source, and with infusion pump flow rate, is that 15mL / min pumps into reaction solution, back pressure 1.5MPa.After serialization reaction 10min under 110 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the organic matter with low boiling point and vaporized is liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0085] The results showed that the toluene conversion rate was 37%, the selectivity of the products benzyl alcohol and benzaldehyde was 66%, and the selectivity of the product benzoic acid was 34%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0086] The structural formula of cobalt naphthenate is as follows:

[0087]

[0088] The structural formula of zinc naphthenate is as follows:

[0089]

[0090] The structural formula of nickel naphthenate is as follows:

[0091]

[0092] Example 7

[0093] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0094] By the mixed catalyst of the cobalt naphthenate of 1308ppm, copper naphthenate and manganese naphthenate, the mass ratio of described cobalt naphthenate, copper naphthenate and manganese naphthenate is 7.125: 1.875: 1, and the N-acetyl phthalimide of 1220.8ppm is joined in 500mL screw bottle, add the toluene of 4.34mol, cumulative volume is 458.7mL, take the air that gas flow rate is 1200mL / min as oxygen source, take infusion pump flow rate as 20mL / min pumps into reaction solution, back pressure 2.0MPa.After serialization reaction 10min under 125 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the organic matter that boiling point is low and has vaporized is liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0095] The results showed that the toluene conversion rate was 27%, the selectivity of the products benzyl alcohol and benzaldehyde was 58%, and the selectivity of the product benzoic acid was 42%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0096] The structural formula of cobalt naphthenate is as follows:

[0097]

[0098] The copper naphthenate structural formula is as follows:

[0099]

[0100] The result formula of the manganese naphthenate is as follows:

[0101]

[0102] Example 8

[0103] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0104] By the mixed catalyst of copper naphthenate, manganese naphthenate and magnesium naphthenate of 1308ppm, described cobalt naphthenate, copper naphthenate and manganese naphthenate mass ratio are 7.125: 1.875: 1, and the N of 1220.8ppm, N'-dihydroxypyromellitic acid imide joins in 500mL screw bottle, add the toluene of 4.34mol, cumulative volume is 458.7mL, take the air that gas flow rate is 1200mL / min as oxygen source, take infusion pump flow rate as 15mL / min pumps into reaction solution, back pressure 2.5MPa.After serialization reaction 10min under 140 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the organic matter that boiling point is low and has vaporized is liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0105] The results showed that the toluene conversion rate was 39%, the selectivity of the products benzyl alcohol and benzaldehyde was 54%, and the selectivity of the product benzoic acid was 46%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0106] The copper naphthenate structural formula is as follows:

[0107]

[0108] The result formula of the manganese naphthenate is as follows:

[0109]

[0110] The structural formula of the magnesium naphthenate is as follows:

[0111]

[0112] Example 9

[0113] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0114] By the mixed catalyst of zinc naphthenate, manganese naphthenate and calcium naphthenate of 1308ppm, the mass ratio of described zinc naphthenate, manganese naphthenate and calcium naphthenate is 7.125: 1.875: 1, and the phthalimide of 1220.8ppm is joined in 500mL screw bottle, the toluene of 4.34mol is added, cumulative volume is 458.7mL, and the air that takes gas flow rate as 1400mL / min is oxygen source, and takes infusion pump flow rate as 20mL / min and pumps into reaction solution, back pressure 2.5MPa.After serialization reaction 10min under 140 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the organic matter that boiling point is low and has vaporized is liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0115] The results showed that the toluene conversion rate was 29%, the selectivity of the products benzyl alcohol and benzaldehyde was 55%, and the selectivity of the product benzoic acid was 45%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0116] The structural formula of the zinc epoxyate is as follows:

[0117]

[0118] The result formula of the manganese naphthenate is as follows:

[0119]

[0120] The structural formula of calcium naphthenate is as follows:

[0121]

[0122] Example 10

[0123] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0124] By the mixed catalyst of the cobalt naphthenate of 1308ppm, manganese naphthenate and calcium naphthenate, the mass ratio of described cobalt naphthenate, manganese naphthenate and calcium naphthenate is 7.125: 1.875: 1, and the N-acetyl phthalimide of 1220.8ppm is joined in 500mL screw bottle, add the toluene of 4.34mol, cumulative volume is 458.7mL, take the air that gas flow rate is 1400mL / min as oxygen source, take the infusion pump flow rate as 30mL / min and pump into reaction solution, back pressure 1.0MPa.After serialization reaction 10min under 110 ℃ of conditions, be placed in low-temperature reactor to reduce reacting liquid temperature, low-temperature reactor temperature is-5 ℃, and the time is 5min, and the organic matter that boiling point is low and has vaporized is liquefied into liquid phase.After the reaction, adopt using naphthalene as internal standard, online sampling utilizes gas chromatographic analysis product, takes internal standard method quantitative product.

[0125] The results showed that the toluene conversion rate was 35%, the selectivity of the products benzyl alcohol and benzaldehyde was 51%, and the selectivity of the product benzoic acid was 49%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0126] The structural formula of cobalt naphthenate is as follows:

[0127]

[0128] The result formula of the manganese naphthenate is as follows:

[0129]

[0130] The structural formula of calcium naphthenate is as follows:

[0131]

[0132] Comparative Example 1

[0133] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0134] 1308ppm of zinc naphthenate catalyst and 1220.8ppm of phthalimide were added to a 500mL screw-capped bottle, followed by 4.34mol of toluene. The total volume was 458.7mL. Air with a gas flow rate of 200mL / min was used as an oxygen source, and the reaction solution was pumped in at a flow rate of 10mL / min using an infusion pump at a back pressure of 0MPa. After continuous reaction at 50°C for 10min, the reaction solution was placed in a low-temperature reactor to reduce the reaction solution temperature. The low-temperature reactor temperature was -5°C for 5min, and the organic matter with a low boiling point and having been vaporized was liquefied into a liquid phase. After the reaction, naphthalene was used as an internal standard, and online sampling was performed to analyze the product using gas chromatography, and the internal standard method was used to quantify the product.

[0135] The results showed that the toluene conversion rate was 7%, the selectivity of the products benzyl alcohol and benzaldehyde was 73%, and the selectivity of the product benzoic acid was 27%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0136] The structural formula of the zinc epoxyate is as follows:

[0137]

[0138] Comparative Example 2

[0139] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0140] 1308ppm of manganese naphthenate and barium naphthenate mixed catalyst and 1220.8ppm of phthalimide were added to a 500mL screw-capped bottle, 4.34mol of toluene was added, and the cumulative volume was 458.7mL. Air with a gas flow rate of 200mL / min was used as the oxygen source, and the reaction solution was pumped in at an infusion pump flow rate of 10mL / min, with a back pressure of 0MPa. After continuous reaction at 50°C for 10min, the reaction was placed in a low-temperature reactor to reduce the reaction solution temperature. The low-temperature reactor temperature was -5°C for 5min, and the organic matter with a low boiling point and that had been vaporized was liquefied into a liquid phase. After the reaction, naphthalene was used as an internal standard, and online sampling was performed to analyze the product using gas chromatography, and the internal standard method was used to quantify the product.

[0141] The results showed that the toluene conversion rate was 8%, the selectivity of the products benzyl alcohol and benzaldehyde was 78%, and the selectivity of the product benzoic acid was 22%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0142] The result formula of the manganese naphthenate is as follows:

[0143]

[0144] The structural formula of the barium naphthenate is as follows:

[0145]

[0146] Comparative Example 3

[0147] A method and application of preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, comprising the following steps:

[0148] 1220.8 ppm of phthalimide was added to a 500 mL screw-cap bottle, along with 4.34 mol of toluene, for a total volume of 458.7 mL. Air was used as the oxygen source at a flow rate of 200 mL / min, and the reaction solution was pumped in at a flow rate of 10 mL / min using an infusion pump, with a back pressure of 0 MPa. After a continuous reaction at 50°C for 10 minutes, the reaction solution was placed in a low-temperature reactor to lower the temperature to -5°C for 5 minutes, allowing the low-boiling, vaporized organic matter to liquefy into a liquid phase. After the reaction, the product was analyzed by gas chromatography using naphthalene as an internal standard, and the internal standard method was used to quantify the product.

[0149] The results showed that the toluene conversion rate was 8%, the selectivity of the products benzyl alcohol and benzaldehyde was 67%, and the selectivity of the product benzoic acid was 33%, indicating that the oxidation catalytic method used in the present invention can be used to efficiently prepare benzyl alcohol, benzaldehyde and benzoic acid from toluene.

[0150] By comparing Examples 1-10 with Comparative Examples 1-3, it can be seen that the catalytic oxidation of toluene with the addition of only the metal naphthenate of formula (1), only the metal naphthenate of formula (2), or only the non-metallic aerobic oxidation co-catalyst is lower in terms of both toluene conversion and benzyl alcohol and benzaldehyde selectivity than the addition of at least one metal naphthenate of formula (1) and at least one metal naphthenate of formula (2) and the addition of a non-metallic aerobic oxidation co-catalyst.

Claims

1. A method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene, characterized in that: A metal naphthenate complex salt catalyst and a non-metallic aerobic oxidation co-catalyst are dispersed in toluene, and air is continuously introduced into the closed system at a flow rate of 100-1500 mL / min. The reaction is carried out at a set temperature of 40-140°C, an infusion pump flow rate of 5-40 mL / min, and a back pressure of 0-5 MPa to obtain the products benzyl alcohol, benzaldehyde, and benzoic acid. Wherein: the mass of metal naphthenate complex salt is 500-3500ppm; The mass of non-metallic aerobic oxidation catalyst is 200-1800ppm; The metal cycloalkane salt composite salt is composed of at least one of the compounds described in formula (1) and at least one of the compounds shown in formula (2); ； In formula (1); M1 is one of zinc, copper, and cobalt; ； In formula (2), M2 is one of manganese, nickel, barium, calcium, and magnesium; The non-metallic aerobic oxidation co-catalyst is one of phthalimide, N,N'-dihydroxypyromellitic imide, N-hydroxyphthalimide and N-acetylphthalimide.

2. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, characterized in that: The set temperature is 50-140°C.

3. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, characterized in that: The addition amount of the catalyst metal naphthenate was 654-3270 ppm.

4. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, characterized in that: The mass of the non-metallic aerobic oxidation catalyst is 305.2-1526 ppm.

5. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, characterized in that: Air was introduced continuously at a flow rate of 200-1400 mL / min.

6. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, characterized in that: The infusion pump flow rate is 10-30 mL / min.

7. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, characterized in that: The back pressure is 0-2.5 MPa.

8. The method for preparing benzyl alcohol / aldehyde / acid by biomimetic catalytic air oxidation of toluene according to claim 1, 3 or 4, characterized in that: The added amount of the catalyst metal naphthenate is 1308 ppm, and the mass of the non-metallic aerobic oxidation catalyst is 1220.8 ppm.

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