A kind of synthetic method of antioxidant 44PD

Abstract

The invention discloses a synthesis method of an antioxidant 44PD, and belongs to the technical field of chemical synthesis. The method comprises the following steps: placing p-nitroaniline, butanone and a catalyst in a dry reaction kettle, sealing the reaction kettle, replacing the reaction kettle with nitrogen and hydrogen in turn, introducing hydrogen to pressurize the reaction kettle, and heating the reaction kettle to obtain the antioxidant 44PD. The catalyst uses activated carbon as a carrier to load three metal active components, namely platinum, nickel and copper. The catalyst is used in combination to optimize the catalytic performance. The platinum, nickel and copper form a solid solution, which can limit the shedding of copper and avoid the occurrence of "copper damage" that has an adverse effect on the antioxidant performance and gasoline rubber. The synergistic effect between nickel and platinum atoms can change the electronic environment and the d-band center position of the platinum atoms, thereby increasing the oxidation potential of the platinum and restricting the agglomeration and shedding of the platinum, which is beneficial to the catalysis, repeated use and recovery of the platinum.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for synthesizing an antioxidant 44PD. Background Art

[0002] Antioxidants are mainly divided into solid antioxidants and liquid antioxidants, both of which can increase the stability of petroleum products. However, due to the difficulty in mixing solid antioxidants with oil products and poor antioxidant properties, solid antioxidants are less used, which has led to the widespread development and application of liquid antioxidants. Antioxidant 44PD is a widely used and high-performance liquid amine antioxidant. Its full name is N,N'-di-sec-butyl-p-phenylenediamine. It is an amine antioxidant with excellent performance and is particularly suitable for use as a cracking or thermal cracking gasoline additive. Adding a very small amount to gasoline can very effectively prevent olefin oxidation and inhibit the formation of colloids.

[0003] At present, the method for mass production of antioxidant 44PD is mainly the reductive alkylation reaction of p-phenylenediamine and 2-butanone, usually using copper-based metals for hydrogenation catalysis, which has the defects of low catalytic efficiency and low selectivity, restricting the mass production of 44PD. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a method for synthesizing an antioxidant 44PD.

[0005] In the present invention, activated carbon is used as a catalyst carrier, which has stable acid and alkali resistance, a developed pore structure, a huge specific surface area and excellent adsorption performance. In addition, the precious metals platinum and nickel loaded on the activated carbon are relatively easy to be recovered through the combustion of the carbon carrier. The metal loading rate can be increased through oxidation pretreatment, and the reaction rate and selectivity can be increased. The catalyst is loaded with three metal active components of platinum, nickel and copper. Platinum has the advantages of high catalytic activity, strong selectivity, small usage amount and the like. When used in combination with nickel and copper, the catalytic performance can be optimized. Moreover, platinum, nickel and copper form a solid solution, which can limit the shedding of the copper catalyst and cause "copper damage". The synergistic effect between nickel and platinum atoms can increase the oxidation potential of platinum, restrict platinum agglomeration and shedding, and is beneficial to the catalysis and recovery and reuse of platinum.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for synthesizing an antioxidant 44PD comprises the following steps:

[0008] Put p-nitroaniline, butanone and a catalyst into a dry reactor, seal the reactor, introduce nitrogen to replace it continuously for 3 times, then replace it with hydrogen for 2 times, then introduce hydrogen into the reactor until the pressure in the reactor is 5MPa, heat it to 170°C and keep stirring at 500r / min, react for 10h under this condition, cool it to room temperature after the reaction, filter out the catalyst, remove excess butanone and generated sec-butanol by atmospheric distillation, and obtain antioxidant 44PD; the mass ratio of p-nitroaniline, butanone and catalyst is 1:4:0.5;

[0009] The specific reaction process is as follows:

[0010]

[0011] Furthermore, the catalyst is a Pt-Ni-Cu catalyst, which is prepared by the following steps:

[0012] S1. Put the activated carbon into a stoppered conical flask, add 5% hydrogen peroxide, put the conical flask into a 50°C constant temperature water bath oscillator and shake for 3 hours, then take it out, filter it, rinse it with deionized water, put it into a 100°C drying oven and dry it for 4 hours to obtain an activated carbon carrier; the ratio of activated carbon to 5% hydrogen peroxide is 1g:10mL;

[0013] S2. Add the activated carbon carrier and 3% chloroplatinic acid solution into a conical flask, dilute with water, continue stirring for 3 hours, filter the impregnated solution, put the solid into a 70°C drying oven for 3 hours, and then put it into a high-temperature tube furnace, pass a mixed gas of H2:N2 with a volume ratio of 1:10, control the flow rate at 0.5L / min, heat to 280°C, heat for 2 hours, cool to room temperature after completion, take out and wash with deionized water, put it into a 70°C drying oven for 3 hours to obtain a Pt catalyst; the ratio of the activated carbon carrier, 3% chloroplatinic acid solution, and water is 1g:1g:30mL;

[0014] S3. Place Pt catalyst, nickel nitrate hexahydrate and copper nitrate trihydrate in deionized water, stir for 30 minutes to obtain a uniformly dispersed solution, let stand for 3 hours, filter, wash with deionized water until neutral, transfer the washed sample to a 70°C drying oven for drying, grind the dried solid into powder and calcine at 600°C for 4 hours to obtain Pt-Ni-Cu catalyst; the ratio of Pt catalyst, nickel nitrate hexahydrate and copper nitrate trihydrate is 10g:2.4g:2g.

[0015] As a catalyst, activated carbon has stable acid and alkali resistance, a developed pore structure, a huge specific surface area and excellent adsorption performance. In addition, the precious metals Pt and Ni loaded on the activated carbon are easier to recover through the combustion of the carbon carrier. The S1 oxidation pretreatment can increase the number of oxygen-containing groups on the inner surface of the carbon material pores. The oxygen-containing groups can make the adsorption of metal particles more stable and increase the metal loading rate. They can play a catalytic role in the reaction and increase the reaction rate and selectivity.

[0016] The catalyst is loaded with three metallic active ingredients: platinum, nickel and copper. Platinum has the advantages of high catalytic activity, strong selectivity and low usage. When used in combination with nickel and copper, the catalytic performance can be optimized. Moreover, platinum, nickel and copper form a solid solution, which can limit the shedding of copper catalyst and avoid "copper damage", which has adverse effects on antioxidant performance and gasoline rubber. The synergistic effect between nickel and platinum atoms can change the electronic environment and d-band center position of platinum atoms, increase the oxidation potential of platinum, restrict platinum agglomeration and shedding, and is beneficial to the catalysis, repeated use and recycling of platinum.

[0017] Beneficial effects of the present invention:

[0018] In the present invention, activated carbon is used as a catalyst carrier, which has stable acid and alkali resistance, a developed pore structure, a huge specific surface area and excellent adsorption performance. In addition, the precious metals platinum and nickel loaded on the activated carbon are relatively easy to be recovered through the combustion of the carbon carrier. The metal loading rate can be increased through oxidation pretreatment, and the reaction rate and selectivity can be increased. The catalyst is loaded with three metal active components of platinum, nickel and copper. Platinum has the advantages of high catalytic activity, strong selectivity, small usage amount and the like. When used in combination with nickel and copper, the catalytic performance can be optimized. Moreover, platinum, nickel and copper form a solid solution, which can limit the shedding of the copper catalyst and cause "copper damage". The synergistic effect between nickel and platinum atoms can increase the oxidation potential of platinum, restrict platinum agglomeration and shedding, and is beneficial to the catalysis and recovery and reuse of platinum. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] Preparation of catalyst

[0022] S1. Put 10g of activated carbon into a stoppered ground-mouth conical flask, add 100mL of 5% hydrogen peroxide, put the conical flask into a 50°C constant temperature water bath oscillator and shake for 3h, then take it out, filter it, rinse it with deionized water, and put it into a 100°C drying oven for 4h to obtain an activated carbon carrier;

[0023] S2, add 10g activated carbon carrier and 10g 3% chloroplatinic acid solution into a conical flask, dilute with 200mL water, continue stirring for 3h, filter the impregnated solution, put the solid into a 70℃ drying oven for 3h, then put it into a high-temperature tube furnace, pass H2:N2 mixed gas with a volume ratio of 1:10, control the flow rate at 0.5L / min, heat to 280℃, heat for 2h, cool to room temperature after completion, take out and wash with deionized water, put it into a 70℃ drying oven for 3h, and obtain Pt catalyst;

[0024] S3. Place 10 g of Pt catalyst, 2.4 g of nickel nitrate hexahydrate and 2 g of copper nitrate trihydrate in deionized water, stir for 30 min to obtain a uniformly dispersed solution, let stand for 3 h, filter, wash with deionized water until neutral, transfer the washed sample to a 70°C drying oven for drying, grind the dried solid into powder and calcine at 600°C for 4 h to obtain a Pt-Ni-Cu catalyst.

[0025] Example 2

[0026] Preparation of catalyst

[0027] S1. Put 20g of activated carbon into a stoppered ground-mouth conical flask, add 200mL of 5% hydrogen peroxide, put the conical flask into a 50°C constant temperature water bath oscillator and shake for 3h, then take it out, filter it, rinse it with deionized water, and put it into a 100°C drying oven for 4h to obtain an activated carbon carrier;

[0028] S2, add 20g activated carbon carrier and 20g 3% chloroplatinic acid solution into a conical flask, dilute with 400mL water, continue stirring for 3h, filter the impregnated solution, put the solid into a 70℃ drying oven for 3h, then put it into a high-temperature tube furnace, pass H2:N2 mixed gas with a volume ratio of 1:10, control the flow rate at 0.5L / min, heat to 280℃, heat for 2h, cool to room temperature after completion, take out and wash with deionized water, put it into a 70℃ drying oven for 3h to obtain a Pt catalyst;

[0029] S3. Place 20 g of Pt catalyst, 4.8 g of nickel nitrate hexahydrate and 4 g of copper nitrate trihydrate in deionized water, stir for 30 min to obtain a uniformly dispersed solution, let stand for 3 h, filter, wash with deionized water until neutral, transfer the washed sample to a 70°C drying oven for drying, grind the dried solid into powder and calcine at 600°C for 4 h to obtain a Pt-Ni-Cu catalyst.

[0030] Example 3

[0031] 10 g of p-nitroaniline, 40 g of butanone and 5 g of the catalyst prepared in Example 1 were placed in a dry reactor, the reactor was sealed, nitrogen was introduced for continuous replacement 3 times, and then hydrogen was introduced for replacement 2 times, and then hydrogen was introduced into the reactor until the pressure in the reactor was 5 MPa, the temperature was raised to 170°C and stirred at a constant speed of 500 r / min, and the reaction was carried out under this condition for 10 h. After the reaction was completed, the reactor was cooled to room temperature, the catalyst was filtered out, and the excess butanone and the generated sec-butanol were removed by atmospheric distillation to obtain antioxidant 44PD.

[0032] Example 4

[0033] 20 g of p-nitroaniline, 80 g of butanone and 10 g of the catalyst prepared in Example 2 were placed in a dry reactor, the reactor was sealed, nitrogen was introduced for continuous replacement 3 times, and then hydrogen was introduced for replacement 2 times, and then hydrogen was introduced into the reactor until the pressure in the reactor was 5 MPa, the temperature was raised to 170°C and stirred at a constant speed of 500 r / min, and the reaction was carried out under this condition for 10 h. After the reaction was completed, the reactor was cooled to room temperature, the catalyst was filtered out, and the excess butanone and the generated sec-butanol were removed by atmospheric distillation to obtain antioxidant 44PD.

[0034] Example 5

[0035] 5 g of the catalyst prepared in Example 1 was reacted ten times according to the raw materials and preparation process of Example 3 to obtain the antioxidant 44PD.

[0036] The products obtained in Examples 3-5 were quantitatively analyzed by gas chromatography and the conversion rate of p-nitroaniline and the selectivity of antioxidant 44PD were calculated. The results are shown in the following table:

[0037] p-phenylenediamine conversion rate (%) Antioxidant 44PD selectivity (%) Example 3 100 97.2 Example 4 100 97.3 Example 5 100 96.8

[0038] It can be seen from the data in the above table that the synthesis process of the present invention has extremely high reaction conversion rate and selectivity, the catalyst can be reused, and has good application prospects.

[0039] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0040] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for synthesizing an antioxidant 44PD, which is synthesized by catalysis of p-nitroaniline and butanone with a catalyst; It is characterized in that The catalyst is a Pt-Ni-Cu catalyst, which is prepared by the following steps: S1. Put the activated carbon into a stoppered ground-mouth conical flask, add 5% hydrogen peroxide, put the conical flask into a 50°C constant temperature water bath oscillator and shake for 3 hours, then take it out, filter it, rinse it with deionized water, and put it into a 100°C drying oven to dry for 4 hours to obtain an activated carbon carrier; S2. Add the activated carbon carrier and 3% chloroplatinic acid solution into a conical flask, dilute with water, continue stirring for 3 hours, filter the impregnated solution, put the solid into a 70°C drying oven for 3 hours, and then put it into a high-temperature tube furnace, pass a mixed gas of H2:N2 with a volume ratio of 1:10, control the flow rate at 0.5L / min, heat to 280°C, heat for 2 hours, cool to room temperature after completion, take out and wash with deionized water, put it into a 70°C drying oven for 3 hours to obtain a Pt catalyst; S3. Place Pt catalyst, nickel nitrate hexahydrate and copper nitrate trihydrate in deionized water, stir for 30 minutes to obtain a uniformly dispersed solution, let stand for 3 hours, filter, wash with deionized water until neutral, transfer the washed sample to a 70°C drying oven for drying, grind the dried solid into powder and calcine at 600°C for 4 hours to obtain Pt-Ni-Cu catalyst.

2. The method for synthesizing the antioxidant 44PD according to claim 1, characterized in that: The steps include: Place p-nitroaniline, butanone and a catalyst into a dry reactor, seal the reactor, introduce nitrogen for three times, then replace with hydrogen for two times, then introduce hydrogen into the reactor until the pressure inside the reactor is 5 MPa, heat to 170°C and maintain stirring at 500 r / min, react under this condition for 10 hours, after the reaction is completed, cool to room temperature, filter out the catalyst, and remove excess butanone and generated sec-butanol by atmospheric distillation to obtain antioxidant 44PD.

3. The method for synthesizing the antioxidant 44PD according to claim 1, characterized in that: The mass ratio of p-nitroaniline, butanone and catalyst is 1:4:0.

5.

4. The method for synthesizing the antioxidant 44PD according to claim 1, characterized in that: In step S1, the ratio of activated carbon to 5% hydrogen peroxide is 1 g:10 mL.

5. The method for synthesizing the antioxidant 44PD according to claim 1, characterized in that: In step S2, the ratio of the activated carbon carrier, 3% chloroplatinic acid solution and water is 1 g: 1 g: 30 mL.

6. The method for synthesizing the antioxidant 44PD according to claim 1, characterized in that: In step S3, the ratio of the amount of Pt catalyst, nickel nitrate hexahydrate, and copper nitrate trihydrate used is 10g:2.4g:2g.

Images