A catalyst for synthesizing benzophenone from benzoic acid, its preparation method and application

Abstract

The present invention discloses a catalyst for synthesizing benzophenone from benzoic acid, a preparation method thereof, and an application thereof. The catalyst is a cerium-zirconium-manganese composite metal oxide, denoted as Ce a Zr b Mn c O x , wherein a:b:c is (1-4):(5-8):1, and a + b + c = 10, x = 19. The catalyst provided by the present invention, when used for synthesizing benzophenone from benzoic acid, does not require pressurization, the reaction conditions are mild, the reaction yield is high, and no oxidant is used. The reaction can remove the oxygen in the organic matter without hydrogen, while converting the highly active carboxyl group and increasing the length of the carbon chain of the organic matter, generating a more stable compound, the reaction is safer, and the by-product is water, which conforms to the development concept of green environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of benzophenone preparation, and particularly relates to a catalyst for synthesizing benzophenone from benzoic acid, a preparation method thereof, and an application thereof. Background Art

[0002] Benzophenone is a very important fine chemical. It is a colorless crystal under normal temperature and pressure, and is mainly used in the synthesis of drugs, the manufacture of fragrances, and can also be used in the film manufacturing industry. Benzophenone has a wide range of applications in pharmaceutical synthesis, the fragrance industry, and polymer materials, and can also be used as a photoinitiator in the photocuring industry, etc.

[0003] Currently, the industrial synthesis routes of benzophenone mainly include carbonylation method, acylation method, nitric acid oxidation method, etc. The carbonylation method generally reacts under high temperature and high pressure; a large amount of waste acid is generated during the acylation method, which corrodes equipment and it is relatively difficult to reuse the catalyst; the nitric acid oxidation method has problems such as long reaction time, serious equipment corrosion, and environmental pollution. In recent years, many new synthesis methods have been disclosed, and among them, more are to explore new catalytic materials to catalyze the oxidation of diphenylmethane to prepare benzophenone. CN101462936A uses oxygen as an oxidant and uses Ni, Fe, Zn salts or oxides as catalysts to catalyze the oxidation of diphenylmethane to prepare benzophenone, with a yield of 89% - 99%. CN201810676935 uses diphenylmethane as a raw material, and under the action of a catalyst, adds an oxidant H2O2 for oxidation to prepare benzophenone, and the yield can reach more than 80%. Although the yield of this route is high, the preparation process is complex and cumbersome, the economy is poor, it requires a strong oxidant, by-products are generated, and in addition, problems such as low stability of the catalyst also limit its further application. Summary of the Invention

[0004] Aiming at the defects of the prior art, the present invention provides a catalyst for synthesizing benzophenone from benzoic acid, a preparation method thereof, and an application thereof. When preparing benzophenone, it does not require pressurization and does not use an oxidant, and the reaction conditions are mild.

[0005] A catalyst for synthesizing benzophenone from benzoic acid, the catalyst is a cerium-zirconium-manganese composite metal oxide, expressed as Ce a Zr b Mn c O x , wherein, a:b:c is (1 - 4):(5 - 8):1, and a + b + c = 10, x is the number of oxygen atoms required to satisfy the oxidation states of each metal element, x = 19.

[0006] The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with a parallel flow, includes the following steps:

[0007] (1) Dissolve the water-soluble metal salts of cerium, zirconium, and manganese in water to obtain an active component solution;

[0008] (2) At 50 - 80 °C, simultaneously and separately drip the active component solution and the precipitant into deionized water. During the dripping process, control the pH of the system to be 8 - 10. After the dripping is completed, maintain the temperature and continue aging for 8 - 24 h;

[0009] (3) Perform centrifugation, wash the centrifuged solid to neutral, dry, calcine, and grind to obtain the catalyst.

[0010] Preferably, in the active component solution, the total molar concentration of cerium, zirconium, and manganese is 0.5 - 3.0 mol / L.

[0011] Preferably, the water-soluble metal salts of cerium, zirconium, and manganese are their corresponding nitrates, carbonates, sulfates, or chlorides.

[0012] Preferably, the precipitant is 20 - 30 wt% ammonia water, 20 - 30 wt% sodium carbonate, 20 - 30 wt% sodium bicarbonate, or 20 - 30 wt% urea.

[0013] Preferably, the drying conditions are drying at 100 - 120 °C for 6 - 8 h; the calcination conditions are heating to 500 - 600 °C at a heating rate of 2 - 3 °C / min and then maintaining for 7 - 9 h.

[0014] A method for synthesizing benzophenone from benzoic acid includes the following steps:

[0015] Step 1: Using nitrogen as the carrier gas, introduce benzoic acid into a gasifier for gasification;

[0016] Step 2: Load the catalyst into a fixed-bed reactor, then introduce the gasified benzoic acid, and react at 220 - 350 °C and 0 MPa. Condense and collect the reaction products; the catalyst is the catalyst for synthesizing benzophenone from benzoic acid of the present invention.

[0017] Preferably, in Step 1, the flow rate of nitrogen is 30 - 80 mL / min; benzoic acid is injected by a peristaltic pump with a flow rate of 0.01 - 3 mL / min; the temperature of the gasifier is 270 - 300 °C.

[0018] Preferably, in Step 2, the liquid hourly space velocity of benzoic acid is 0.2 - 60.

[0019] Advantages of the present invention:

[0020] (1)The catalyst provided by the present invention, when used for synthesizing benzophenone from benzoic acid, does not require pressurization, has mild reaction conditions, high reaction yields, does not use oxidants, and can remove oxygen in organic substances without hydrogen. While converting highly active carboxyl groups, it also increases the length of the carbon chain of organic substances, generates more stable compounds, makes the reaction safer, and the by-product is water, which conforms to the development concept of green environmental protection;

[0021] (2)The composite metal oxide provided by the present invention belongs to a bifunctional catalyst. It has basic sites that can activate hydrogen and acidic sites that can adsorb carboxylates, with high catalytic activity. At the same time, the catalyst preparation method is simple, the process route is mature, the raw materials are widely sourced and inexpensive, making it suitable for large-scale production;

[0022] (3)The process route for synthesizing benzophenone is simple in process flow and easy to operate, greatly saving the equipment cost. At the same time, it has a high atom utilization rate and belongs to an atom-economic reaction. Specific Embodiments

[0023] The reaction principle involved in the present invention is as follows:

[0024] 。

[0025] Example 1

[0026] 1. A catalyst for synthesizing benzophenone from benzoic acid, the catalyst being a cerium-zirconium-manganese composite metal oxide, represented as Ce3Zr6Mn1O 19 ;

[0027] 2. The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with a parallel flow, and includes the following steps:

[0028] (1)Dissolve cerium nitrate, zirconium nitrate, and manganese nitrate in water to obtain a component solution with a total metal concentration of 0.5 mol / L, and prepare a 25wt% ammonia water solution as a precipitant;

[0029] (2)At 80 °C, simultaneously drop the active component solution and the precipitant into deionized water respectively. During the dropping process, control the pH of the system to be 9 - 10. After the dropping is completed, keep the temperature and continue aging for 24 h;

[0030] (3)Perform centrifugation, wash the centrifuged solid with deionized water until it is neutral, dry it at 120 °C for 6 h, heat it to 550 °C at a heating rate of 2 °C / min and calcine it for 8 h, grind it, and sieve it to 40 - 60 mesh to obtain the catalyst;

[0031] 3. The method for synthesizing benzophenone from benzoic acid includes the following steps:

[0032] Step 1: Using nitrogen at a flow rate of 30 mL / min as the carrier gas, benzoic acid is injected through a peristaltic pump into a vaporizer for vaporization. The temperature of the vaporizer is 270 °C, and the injection flow rate of benzoic acid is 0.01 mL / min.

[0033] Step 2: The catalyst obtained in this example is loaded into a fixed-bed reactor, and then the vaporized benzoic acid is introduced. The liquid hourly space velocity of benzoic acid is 0.2, and the reaction is carried out at 220 °C and 0 MPa. The reaction products are condensed and collected at a condensation temperature of 0 °C, and quantitative calculation is performed by gas chromatography analysis.

[0034] Example 2

[0035] 1. A catalyst for synthesizing benzophenone from benzoic acid, wherein the catalyst is a cerium-zirconium-manganese composite metal oxide, represented as Ce3Zr6Mn1O 19 。

[0036] 2. The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with parallel flow, and includes the following steps:

[0037] (1) Dissolve cerium nitrate, zirconium nitrate, and manganese nitrate in water to obtain a component solution with a total metal concentration of 3 mol / L, and prepare a 25 wt% ammonia water solution as the precipitant;

[0038] (2) At 80 °C, the active component solution and the precipitant are simultaneously dropped into deionized water respectively. During the dropping process, control the pH of the system to be 9 - 10. After the dropping is completed, keep the temperature and continue aging for 24 h;

[0039] (3) Perform centrifugation, wash the centrifuged solid with deionized water until it is neutral, dry it at 120 °C for 6 h, heat it to 550 °C at a heating rate of 2 °C / min for calcination for 8 h, grind it, and sieve it to 40 - 60 mesh to obtain the catalyst.

[0040] 3. The method for synthesizing benzophenone from benzoic acid is the same as that in Example 1.

[0041] Example 3

[0042] 1. A catalyst for synthesizing benzophenone from benzoic acid, wherein the catalyst is a cerium-zirconium-manganese composite metal oxide, represented as Ce4Zr5Mn1O 19 。

[0043] 2. The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with parallel flow, and includes the following steps:

[0044] (1) Dissolve cerium nitrate, zirconium nitrate, and manganese nitrate in water to obtain a component solution with a total metal concentration of 2 mol / L, and prepare a 25 wt% ammonia water solution as the precipitant;

[0045] (2) At 80 °C, the active component solution and the precipitant are simultaneously dropped into deionized water respectively. During the dropping process, the pH of the system is controlled to be 9 - 10. After the dropping is completed, the temperature is maintained and aging continues for 24 h;

[0046] (3) Centrifugation is carried out. The solid obtained by centrifugation is washed with deionized water until neutral, dried at 120 °C for 6 h, calcined at a heating rate of 2 °C / min to 550 °C for 8 h, ground, and sieved to 40 - 60 mesh to obtain the catalyst.

[0047] 3. The method for synthesizing benzophenone from benzoic acid is the same as that in Example 1.

[0048] Example 4

[0049] 1. A catalyst for synthesizing benzophenone from benzoic acid, the catalyst is a cerium-zirconium-manganese composite metal oxide, represented as Ce2Zr7Mn1O 19 ;

[0050] 2. The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with parallel flow, includes the following steps:

[0051] (1) Cerium nitrate, zirconium nitrate, and manganese nitrate are dissolved in water to obtain a component solution with a total metal concentration of 2 mol / L, and a 25 wt% sodium carbonate solution is prepared as the precipitant;

[0052] (2) At 80 °C, the active component solution and the precipitant are simultaneously dropped into deionized water respectively. During the dropping process, the pH of the system is controlled to be 9 - 10. After the dropping is completed, the temperature is maintained and aging continues for 24 h;

[0053] (3) Centrifugation is carried out. The solid obtained by centrifugation is washed with deionized water until neutral, dried at 120 °C for 6 h, calcined at a heating rate of 2 °C / min to 550 °C for 8 h, ground, and sieved to 40 - 60 mesh to obtain the catalyst;

[0054] 3. The method for synthesizing benzophenone from benzoic acid is the same as that in Example 1.

[0055] Example 5

[0056] 1. A catalyst for synthesizing benzophenone from benzoic acid, the catalyst is a cerium-zirconium-manganese composite metal oxide, represented as Ce1Zr8Mn1O 19 ;

[0057] 2. The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with parallel flow, includes the following steps:

[0058] (1) Dissolve cerium nitrate, zirconium nitrate, and manganese nitrate in water to obtain a component solution with a total metal concentration of 2 mol / L, and prepare a 20 wt% urea solution as a precipitant;

[0059] (2) At 80 °C, simultaneously drop the active component solution and the precipitant into deionized water respectively. During the dropping process, control the pH of the system to be 9 - 10. After the dropping is completed, keep the temperature and continue aging for 24 h;

[0060] (3) Perform centrifugation. Wash the centrifuged solid with deionized water until it is neutral, dry it at 120 °C for 6 h, calcine it at a heating rate of 2 °C / min to 550 °C for 8 h, grind it, and sieve it to 40 - 60 mesh to obtain the catalyst;

[0061] 3. The method for synthesizing benzophenone from benzoic acid is the same as that in Example 1.

[0062] Example 6

[0063] 1. A catalyst for synthesizing benzophenone from benzoic acid, the catalyst being a cerium-zirconium-manganese composite metal oxide, represented as Ce3Zr6Mn1O 19 ;

[0064] 2. The preparation method of the catalyst for synthesizing benzophenone from benzoic acid, which is prepared by co-precipitation with parallel flow, and includes the following steps:

[0065] (1) Dissolve cerium nitrate, zirconium nitrate, and manganese nitrate in water to obtain a component solution with a total metal concentration of 0.5 mol / L, and prepare a 30 wt% ammonia water solution as a precipitant;

[0066] (2) At 50 °C, simultaneously drop the active component solution and the precipitant into deionized water respectively. During the dropping process, control the pH of the system to be 8 - 9. After the dropping is completed, keep the temperature and continue aging for 8 h;

[0067] (3) Perform centrifugation. Wash the centrifuged solid with deionized water until it is neutral, dry it at 100 °C for 8 h, calcine it at a heating rate of 3 °C / min to 600 °C for 7 h, grind it, and sieve it to 40 - 60 mesh to obtain the catalyst;

[0068] 3. The method for synthesizing benzophenone from benzoic acid is the same as that in Example 1.

[0069] Example 7

[0070] The catalyst used is the catalyst of Example 1. The method for synthesizing benzophenone from benzoic acid is as follows:

[0071] Step 1: Using nitrogen gas at a flow rate of 80 mL / min as the carrier gas, benzoic acid is injected into the vaporizer through a peristaltic pump for vaporization. The temperature of the vaporizer is 300 °C, and the injection flow rate of benzoic acid is 3 mL / min;

[0072] Step 2: The catalyst obtained in this example is loaded into a fixed-bed reactor, and then the vaporized benzoic acid is introduced. The liquid hourly space velocity of benzoic acid is 60, and the reaction is carried out at 220 °C and 0 MPa. The reaction products are condensed and collected at a condensation temperature of 0 °C, and quantitative calculation is performed by gas chromatography analysis.

[0073] Example 8

[0074] The catalyst used is the catalyst of Example 1. The method for synthesizing benzophenone using benzoic acid is as follows:

[0075] Step 1: Using nitrogen gas at a flow rate of 30 mL / min as the carrier gas, benzoic acid is injected into the vaporizer through a peristaltic pump for vaporization. The temperature of the vaporizer is 270 °C, and the injection flow rate of benzoic acid is 0.01 mL / min;

[0076] Step 2: The catalyst obtained in this example is loaded into a fixed-bed reactor, and then the vaporized benzoic acid is introduced. The liquid hourly space velocity of benzoic acid is 0.2, and the reaction is carried out at 350 °C and 0 MPa. The reaction products are condensed and collected at a condensation temperature of 0 °C, and quantitative calculation is performed by gas chromatography analysis.

[0077] The reaction results of each example are shown in Table 1;

[0078] 。

Claims

1. A method for synthesizing benzophenone using benzoic acid, characterized in that: It includes the following steps: Step 1: Using nitrogen as the carrier gas, introduce benzoic acid into the gasifier for gasification; Step 2: Load the catalyst into the fixed-bed reactor, then introduce the gasified benzoic acid, react at 220 - 350 °C and 0 MPa, and condense and collect the reaction products; The catalyst is a cerium-zirconium-manganese composite metal oxide, represented as Ce a Zr b Mn c O x , where a:b:c is (1-4):(5-8):1, and a + b + c = 10, x = 19; The catalyst is prepared by co-current coprecipitation.

2. The method for synthesizing benzophenone using benzoic acid according to claim 1, characterized in that: The preparation method of the catalyst includes the following steps: (1) Dissolve the water-soluble metal salts of cerium, zirconium, and manganese in water to obtain an active component solution; (2) At 50 - 80 °C, simultaneously dropwise add the active component solution and the precipitant into deionized water respectively. During the dropping process, control the pH of the system to be 8 - 10. After the dropping is completed, keep the temperature and continue aging for 8 - 24 h; (3) Perform centrifugation, wash the centrifuged solid to neutral, dry, calcine, and grind to obtain the catalyst.

3. The method for synthesizing benzophenone using benzoic acid according to claim 2, characterized in that: In the active component solution, the total molar concentration of cerium, zirconium, and manganese is 0.5 - 3.0 mol / L.

4. The method for synthesizing benzophenone using benzoic acid according to claim 2, characterized in that: The precipitant is 20 - 30 wt% ammonia water, 20 - 30 wt% sodium carbonate solution, 20 - 30 wt% sodium bicarbonate solution, or 20 - 30 wt% urea solution.

5. The method for synthesizing benzophenone using benzoic acid according to claim 2, characterized in that: The drying conditions are drying at 100 - 120 °C for 6 - 8 h; the calcination conditions are heating to 500 - 600 °C at a heating rate of 2 - 3 °C / min and then maintaining for 7 - 9 h.

6. The method for synthesizing benzophenone using benzoic acid according to claim 1, characterized in that: In Step 1, the flow rate of nitrogen is 30 - 80 mL / min; benzoic acid is injected by a peristaltic pump with a flow rate of 0.01 - 3 mL / min; the temperature of the gasifier is 270 - 300 °C.

7. The method for synthesizing benzophenone using benzoic acid according to claim 1, characterized in that: In Step 2, the liquid hourly space velocity of benzoic acid is 0.2 - 60.