CN117772187A

CN117772187A - Noble metal catalyst and preparation method and application thereof

Info

Publication number: CN117772187A
Application number: CN202211167637.0A
Authority: CN
Inventors: 吴其建; 魏鹏辉; 韦志强; 洪庆军; 储政; 管庆宝; 陈永平
Original assignee: China Petroleum and Chemical Corp; Sinopec Nanjing Chemical Industry Corp; Research Institute of Sinopec Nanjing Chemical Industry Co Ltd
Current assignee: China Petroleum and Chemical Corp; Sinopec Nanjing Chemical Industry Corp; Research Institute of Sinopec Nanjing Chemical Industry Co Ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2024-03-29

Abstract

The invention discloses a noble metal catalyst and a preparation method and application thereof, belonging to the technical field of catalysts and preparation of anti-aging agent 6 PPD; the catalyst comprises a carrier and active components, wherein the mass percentages of the carrier and the active components are as follows: 99.90 to 99.96 percent and 0.04 to 0.10 percent; the active component is platinum and/or palladium; the carrier is activated carbon;the specific surface area of the activated carbon is 1161m ² /g～1238m ² Per g, total pore volume of 0.86m ³ /g～0.92m ³ Per g, mesoporous volume of 0.77m ³ /g～0.82m ³ /g; the invention can overcome the defects of high reaction temperature and high reaction hydrogen pressure of the existing copper catalyst, and simultaneously avoid the influence of copper ions lost to products on downstream products; the problem of high production cost caused by easy loss of the existing powder Pt/C catalyst can be avoided; when the catalyst is applied to the preparation of the antioxidant 6PPD, the conversion rate of the 4-aminodiphenylamine is 100%, the selectivity of the antioxidant 6PPD is more than or equal to 99.4%, and the mass ratio of the 4-methyl-2-pentanone to the 4-methyl-2-pentanol is more than or equal to 99.0/1.0.

Description

Noble metal catalyst and preparation method and application thereof

Technical Field

The invention belongs to the technical field of catalysts and preparation of an anti-aging agent 6PPD, and particularly relates to a noble metal catalyst and a preparation method and application thereof.

Background

A large number of walnut shells are produced after the walnut is processed. At present, a large amount of walnut shells are directly discarded or burned to cause great waste of resources, and the walnut shells are used as raw materials for preparing the activated carbon, so that the activated carbon has wide sources and low price, and the resource is optimally utilized.

The active carbon has a crystal structure and a pore structure, and the surface of the active carbon has a certain chemical structure. The adsorption performance of activated carbon depends not only on the physical structure of the activated carbon, but also on the chemical structure of the activated carbon surface. In the process of preparing activated carbon, the edge chemical bonds of the aromatic sheet formed in the carbonization stage are broken to form edge carbon atoms having unpaired electrons, and the edge carbon atoms have unsaturated chemical bonds, exhibiting a function similar to crystallization defects, because the presence of crystallization defects is widely used as a catalyst carrier. However, the mesoporous size of the traditional carbon carrier is smaller, and the diffusion of reactants, intermediate transition states and product molecules is hindered, so that the reactants are difficult to reach active centers, and part of pore structures cannot play a role of a reaction channel in catalytic reaction, so that the activated carbon needs to be subjected to modified reaming.

The antioxidant 6PPD is a main stream variety of the common p-phenylenediamine antioxidants for processing the rubber at home and abroad at present, belongs to aromatic amine antioxidants, and is widely applied to industrial rubber products such as tires, cables and the like. The main production process of the antioxidant 6PPD is a reductive amination method, which takes 4-aminodiphenylamine and 4-methyl-2-pentanone as raw materials and carries out reductive amination by hydrogen under certain temperature, pressure and the existence of a catalyst to obtain the antioxidant 6PPD.

Chinese patent CN114054057A discloses a preparation method and an evaluation method for synthesizing an anti-aging agent 6PPD vulcanized noble metal catalyst, wherein the prepared 0.3-10% Pt/C (wt) sulfur-containing catalyst is used for synthesizing the anti-aging agent 6PPD through catalytic hydrogenation, the reaction conversion rate is more than or equal to 98.7%, and the selectivity of the anti-aging agent 6PPD is more than or equal to 97.9%.

Chinese patent CN102146042A synthesizes the anti-aging agent 6PPD by adopting a two-step method of condensing and hydrogenating 2% -5% of Pt/C (wt), the input mass of the catalyst is 2% -4% of the mass of methyl isobutyl ketone, the reaction selectivity is more than or equal to 98.1%, the product purity is more than or equal to 98.2%, the anti-aging agent 6PPD is synthesized by adopting a two-step method of condensing and hydrogenating 0.8% -5.0% of Pd/C (wt), the input mass of the catalyst is 3% -6% of the mass of the methyl isobutyl ketone, the selectivity of the anti-aging agent 6PPD is more than or equal to 98.6%, and the product purity is more than or equal to 98.3%.

Japanese patent JP55100344 selects 4% Pt/C catalyst to catalyze and hydrogenate and synthesize the anti-aging agent 6PPD, and the yield of the anti-aging agent 6PPD reaches 98%.

Chinese patent CN102260176A describes a process for continuously producing an anti-aging agent 6PPD by using a nickel catalyst, wherein a gas-liquid-solid fixed bed hydrogenation reactor is adopted, the reaction temperature is 165-230 ℃, the pressure is 5.5-6.0 MPa, the ketoamine ratio is 2-4:1, the hydrogen-oil ratio is 2000-5000:1, and the reaction conversion rate is more than or equal to 95.1%.

The copper catalyst fixed bed is used for continuously polycondensing and hydrogenating 4-aminodiphenylamine and 4-methyl-2-pentanone to produce an anti-aging agent 6PPD, the reaction temperature is 130-220 ℃, the reaction hydrogen pressure is 3.0-6.0 MPa, 5-8 kg of high-carbon ketone is produced in ton products, 50kg of tetramethyl dipentaerythritol is produced in ton products, the purity of the anti-aging agent 6PPD is 98.0%, the reaction temperature is high, the reaction hydrogen pressure is high, the catalyst selectivity is poor, the side reaction ketone is serious in alcohol conversion, and the purity of finished products is low. 0.3-10% Pt/C catalyst is used for replacing copper catalyst to produce antioxidant 6PPD, the reaction temperature is 80-150 ℃, the reaction hydrogen pressure is 1.0-3.0 MPa, 4.0-4.5 kg of tetramethyl dipentaerythritol is produced in ton product, the purity of antioxidant 6PPD is 98.5%, the reaction temperature is low, the reaction hydrogen pressure is low, the catalyst selectivity is high, the side reaction ketone is less in alcohol conversion, and the purity of the finished product is high. However, the fixed bed is used for producing 1 ten thousand tons of anti-aging agent 6PPD, 5.5 tons of noble metal catalyst are needed to be prepared, the preparation cost of the noble metal catalyst is about 680 ten thousand yuan, and the one-time input cost is too high, calculated by the Pt content in the noble metal catalyst being 0.3 percent.

At present, the Pt/C catalyst is mainly in powder type, particle type, spherical type, cylindrical type and the like, the powder type and the particle type Pt/C catalyst are generally used for a kettle type reactor and a fluidized bed reactor, the spherical type Pt/C catalyst is generally used for a moving bed reactor, and the cylindrical type Pt/C catalyst is generally used for a fixed bed reactor. Although Pt/C catalysts have various forms, the problems of agglomeration and deactivation of the Pt grains of the active component exist. In addition, the Pt/C noble metal catalyst used in the fixed bed is in a columnar structure, and the catalytic process generally occurs on the surface of the catalyst, so that the platinum atoms on the surface layer participate in the reaction, and the platinum atoms on the inner layer do not basically participate in the reaction, so that most of the platinum atoms are in a 'no-service' state.

In order to prevent Pt grain growth in Pt/C catalysts, different treatments have been investigated: introducing rhenium inhibits sintering of the platinum, anchors the platinum to the support surface, and prevents migration of the platinum and loss of metal surface area; rhenium and sulfur are introduced, and the synergistic effect of the rhenium and the sulfur dilutes and splits Pt into smaller atomic groups; tin is introduced to alloy with platinum, thereby reducing the number of adjacent platinum atoms. However, in the existing Pt/C catalyst, the content of Pt is relatively high, the mass content of Pt in Chinese patent CN114054057A is 0.3-10%, the mass content of Pt in Chinese patent CN102146042A is 2-5%, and the mass content of Pt/C catalyst Pt in Japanese patent JP55100344 is 4%.

Therefore, in order to prevent the active component Pt from growing and agglomerating, and simultaneously not introducing other elements, and simultaneously mobilizing more platinum atoms to participate in the reaction, the invention provides a noble metal catalyst for preparing the anti-aging agent 6PPD.

Disclosure of Invention

Aiming at the situation, the invention provides a noble metal catalyst and a preparation method and application thereof, and the spherical noble metal catalyst with a plurality of spines on the outer surface is prepared by using an active carbon carrier with larger specific surface area, total pore volume and mesoporous volume to load active component platinum, wherein the noble metal catalyst has low Pt content, the mass percent content is only 0.04-0.10%, the noble metal dosage is less, the one-time preparation cost of the noble metal catalyst used for producing the anti-aging agent 6PPD by a fixed bed is greatly reduced, and the problems of high Pt content, high cost and easy growth, agglomeration and inactivation of active component Pt grains in the existing Pt/C catalyst can be solved; when the spherical noble metal catalyst with a plurality of spines on the surface is applied to the preparation of the antioxidant 6PPD, the problems that the existing copper-based catalyst has high reaction temperature and high reaction hydrogen pressure, copper ions are lost to products to cause adverse effects on downstream products, the existing powder Pt/C catalyst is easy to lose, the one-time investment cost is too high and the like can be solved.

In order to solve the technical problems, the first aspect of the invention provides a catalyst, which comprises a carrier and an active component, wherein the mass percentages of the carrier and the active component are as follows: 99.90 to 99.96 percent and 0.04 to 0.10 percent; the active component is platinum and/or palladium, wherein the platinum and the palladium exist in a simple substance form; the carrier is activated carbon; the specific surface area of the activated carbon is 928.8m ² /g～1486m ² Per g, total pore volume of 0.69m ³ /g～1.10m ³ Per g, mesoporous volume of 0.62m ³ /g～0.98m ³ /g; the living beingThe sexual carbon is spherical with a plurality of spines on the outer surface; the ratio of the platinum and/or palladium grains with the grain diameter of 2 nm-20 nm in the total number of the platinum and/or palladium grains in the catalyst is more than or equal to 88%, wherein the ratio of the platinum and/or palladium grains with the grain diameter of 2 nm-20 nm in the total number of the platinum and/or palladium grains is estimated according to a scanning electron microscope. The spherical active carbon with a plurality of spines on the surface can maximally lead the active components to be positioned on the spines, and is not easy to agglomerate.

According to some embodiments of the invention, the activated carbon has a specific surface area of 1161m ² /g～1238m ² Per g, total pore volume of 0.86m ³ /g～0.92m ³ Per g, mesoporous volume of 0.77m ³ /g～0.82m ³ /g；

And/or the compressive strength of the activated carbon is 3.368kg/cm ³ ～5.11kg/cm ³ Ash content is 0.46% -0.96%; preferably, the activated carbon has a compressive strength of 4.21kg/cm ³ ～4.26kg/cm ³ Ash content is 0.58-0.80%;

and/or the ratio of the platinum and/or palladium grains with the grain diameter of 2 nm-20 nm in the catalyst to the total number of the platinum and/or palladium grains is more than or equal to 90.5 percent.

According to some embodiments of the invention, the activated carbon is subjected to an oxidative modification treatment.

According to some embodiments of the invention, before the activated carbon is oxidatively modified, the method further comprises the step of carbonizing and activating the walnut shell under the condition of air isolation;

and/or, before the carbonization, the method further comprises the steps of drying, crushing and screening the walnut shells;

and/or, the carbonization results in a char, the carbonization temperature being 350 ℃ to 650 ℃, such as 380 ℃, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃; the carbonization time is 0.5 h-5.5 h, such as 2h, 2.5h, 3.0h, 3.5h, 4.0h, 5.0h;

and/or, the activation is carried out to obtain the preparation activated carbon, in the activation process, steam is introduced into the carbide, and the mass ratio of the carbide to the steam is (0.10-0.35): 1, for example 0.15: 1. 0.18: 1. 0.20: 1. 0.25: 1. 0.30: 1. 0.35:1, a step of; the temperature of the water vapor is 150 ℃ to 280 ℃, such as 150 ℃, 180 ℃, 200 ℃, 250 ℃, 280 ℃; preferably, the temperature of the activation is 700 ℃ to 1000 ℃, such as 700 ℃, 750 ℃, 800 ℃, 850 ℃, 880 ℃, 900 ℃, 1000 ℃; the activation time is 6 h-10 h, such as 6h, 7h, 8h, 9h, 10h; introducing water vapor into the carbide, wherein the water vapor is used as an activating agent to play a role in pore-forming and opening;

and/or the oxidation is selected from any one of air oxidation, oxygen oxidation, hydrogen peroxide oxidation and sulfuric acid oxidation; preferably, when air oxidation or oxygen oxidation is selected, the temperature of the oxidation is 300-550 ℃, such as 450 ℃, 480 ℃, 500 ℃; the time is 2 to 3 hours, such as 2 hours, 2.5 hours and 3.0 hours; when hydrogen peroxide or sulfuric acid is selected for oxidization, the temperature of oxidization is 10-60 ℃, such as 20 ℃, 25 ℃, 30 ℃ and 35 ℃; for 1h to 4h, such as 2h, 4h; further preferably, when hydrogen peroxide is selected for oxidization, the mass ratio of the activated carbon to the hydrogen peroxide is 1: (2.0 to 4.0); the mass concentration of the hydrogen peroxide is 10% -33%; when sulfuric acid is selected for oxidation, the mass ratio of the active carbon to the sulfuric acid is 1: (1.8-3.5); the mass concentration of the sulfuric acid is 70% -98%; the oxidation is that the micropore structure is destroyed, and the pores among the micropore structures are opened to form mesopores; secondly, the acidic oxygen-containing functional groups on the surface of the activated carbon are increased, and the affinity of a large amount of acidic groups to metal is enhanced, so that the dispersity of metal components is good, the combination of the active components and the acidic groups is firmer, and the stability is better;

and/or, after the oxidation, a step of compression molding is further included; preferably, the binder is added during the compression molding process, and the addition amount of the binder is 1.5% -4.5% of the mass of the activated carbon, for example, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%; the adhesive is selected from one of silica sol, alumina sol, polyvinyl alcohol, polyacrylate, polystyrene, furfural resin, coal tar and asphalt; further preferably, the pressure of the press forming is 20 to 35MPa, for example 22, 25, 30, 32, 35MPa; the temperature is 150 ℃ to 250 ℃, such as 160 ℃, 185 ℃, 190 ℃, 220 ℃, 230 ℃, 240 ℃. The spherical active carbon with a plurality of spines on the surface can be obtained by compression molding.

In a second aspect, the present invention provides a method for preparing the above catalyst, comprising the steps of mixing a precursor solution containing an active ingredient with a carrier, and reducing under a hydrogen atmosphere.

According to some embodiments of the invention, the ratio of the active ingredient-containing precursor solution to the carrier is (5 to 50): 1, for example 20: 1. 25: 1. 30: 1. 35: 1. 40: 1. 45: 1. 50:1, a step of; preferably, the active ingredient-containing precursor solution is a platinum salt solution or a palladium salt solution; further preferably, the platinum salt solution is one or more of platinum chloride solution, platinum acetate solution, platinum nitrate solution and chloroplatinic acid solution; the palladium salt solution is one or more of palladium chloride solution, palladium acetate solution and palladium nitrate solution; still further preferably, the active ingredient-containing precursor solution has a mass concentration of 0.01% to 0.15%, for example 0.10%;

and/or, the mixing is specifically impregnating the support with an active ingredient-containing precursor solution; preferably, the temperature of the impregnation is 15 ℃ to 45 ℃, e.g. 25 ℃, 30 ℃, 40 ℃, 45 ℃; the time is 2 h-8 h, such as 2.0h, 2.5h, 3.0h, 3.5h, 4.0h, 4.5h, 5.0h;

and/or the temperature of the reduction is 80 ℃ to 250 ℃, such as 100 ℃, 150 ℃, 180 ℃, 200 ℃, 220 ℃; the time is 0.5 h-8 h, such as 1h, 1.5h, 2h, 3h and 6h; the pressure is 0.5MPa to 5.0MPa, for example 0.5MPa, 1.5MPa, 2.5MPa, 4.0MPa, 4.5MPa, 5.0MPa;

and/or, the reduction further comprises a washing and drying step; specifically, distilled water is used for washing to be neutral, the drying temperature is 100-150 ℃, and the drying time is 1-5 h.

The third aspect of the invention provides a preparation method of an anti-aging agent 6PPD, which comprises the step of reacting 4-aminodiphenylamine, 4-methyl-2-pentanone and hydrogen in the presence of the catalyst to obtain the anti-aging agent 6PPD.

According to some embodiments of the invention, the molar ratio of 4-aminodiphenylamine, 4-methyl-2-pentanone is 1: (2.7 to 3.5), for example, 1:2.7, 1:2.8, 1:2.9, 1:3.0, 1:3.2, 1:3.5; the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is (1300 to 2000): 1, e.g. 1300:1. 1350:1. 1400:1. 1500:1. 1800:1. 2000:1, a step of;

and/or the reaction temperature is 78-105 ℃, e.g., 78 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃, 100 ℃, 105 ℃; the hydrogen pressure is 0.9MPa to 1.2MPa, for example 0.9MPa, 1.0MPa, 1.1MPa and 1.2MPa;

according to some embodiments of the invention, the reaction is followed by a step of distilling the reaction solution, removing water and 4-methyl-2-pentanone and 4-methyl-2-pentanol.

The beneficial effects are that:

the raw materials of the active carbon carrier adopted in the noble metal catalyst are from walnut shells, so that the source is wide, the price is low, the active carbon prepared from the walnut shells is resource-optimized, and the prepared active carbon has high mechanical strength and low ash content;

the activated carbon carrier used in the invention is oxidized and modified, so that the number of micropores is reduced, the mesoporous size is enlarged, the diffusion of reactants, intermediate transition states and product molecules is facilitated, the acidic oxygen-containing functional groups such as phenolic hydroxyl groups, lactone groups, carboxyl groups and carbonyl groups of the oxidized activated carbon are obviously increased, the pH value is changed from neutral to acidic, and the hydrophilicity, the ion exchange capacity and the affinity to metal of the oxidized and modified activated carbon are enhanced;

the noble metal catalyst prepared by the invention can overcome the defects of high reaction temperature and high reaction hydrogen pressure of the existing copper catalyst, and simultaneously avoid the influence of copper ions lost to products on downstream products; the problem of high production cost caused by easy loss of the existing powder Pt/C catalyst can be avoided; the problems of high one-time investment cost and the like of the existing precious metal catalyst fixed bed for preparing the antioxidant 6PPD can be solved; when the catalyst is applied to the preparation of the antioxidant 6PPD, the conversion rate of the 4-aminodiphenylamine is 100%, the selectivity of the antioxidant 6PPD is more than or equal to 99.4%, and the mass ratio of the 4-methyl-2-pentanone to the 4-methyl-2-pentanol is more than or equal to 99.0/1.0.

Detailed Description

The invention will be further illustrated with reference to the following examples. The present invention is not limited by these examples.

The gas chromatograph used in the gas chromatograph test is an Agilent 7890 gas chromatograph;

the fixed bed reactor is purchased from Tianjin Qingpeng volitation technology Co., ltd, and the product name is fixed bed evaluation device-A, the delivery number is 11700007-15-MY2199-0003-A;

the fluidized bed furnace is not particularly limited, and commercial products can be used for preparing the noble metal catalyst of the invention.

Example 1

The embodiment provides a noble metal catalyst, and the preparation method comprises the following steps:

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 3.5 hours under the conditions of air isolation and 500 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.20:1, inputting the activated carbon into a fluidized bed furnace, activating the activated carbon for 8 hours at the temperature of 850 ℃ to prepare the prepared activated carbon, and carrying out air oxidation modification on the prepared activated carbon at the temperature of 450 ℃ for 3 hours to obtain the activated carbon; wherein the temperature of the water vapor is 200 ℃;

adding an adhesive with the mass of 2.0% into the active carbon, stirring uniformly, pressing and forming to obtain a spherical active carbon carrier with a plurality of spines on the outer surface, impregnating the spherical active carbon carrier with the plurality of spines on the outer surface by using a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 2 hours under the condition of the temperature of 180 ℃ and the pressure of 2.5MPa in a hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.05%, and the proportion of platinum grains with the particle size of 2-20 nm in the noble metal catalyst in the total number of grains is 93.5%.

Wherein the adhesive is polyvinyl alcohol (brand numbers 17-78); the pressure of the compression molding is 30MPa, and the temperature is 230 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 20:1, the impregnation time was 5.0h and the impregnation temperature was 30 ℃.

Example 2

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 3.0h under the conditions of air isolation and 550 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.18:1, inputting the mixture into a fluidized bed furnace, activating the mixture for 9 hours at the temperature of 800 ℃ to prepare prepared activated carbon, and oxidizing and modifying the prepared activated carbon by oxygen for 2 hours at the temperature of 500 ℃ to obtain activated carbon; wherein the temperature of the water vapor is 250 ℃;

adding binder with the mass of 2.5% into the active carbon, stirring uniformly, pressing and forming to obtain a spherical active carbon carrier with a plurality of spines on the outer surface, impregnating the spherical active carbon carrier with a plurality of spines on the outer surface by using a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 3 hours under the condition of the temperature of 150 ℃ and the pressure of 1.5MPa in the hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.05%, and the proportion of platinum grains with the particle size of 2-20 nm in the noble metal catalyst in the total number of grains is 92.0%.

Wherein the adhesive is polyacrylate; the pressure of the compression molding is 35MPa, and the temperature is 240 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 25:1, the impregnation time was 4.5h and the impregnation temperature was 40 ℃.

Example 3

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 2.5 hours under the conditions of air isolation and 600 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.15:1, inputting the activated carbon into a fluidized bed furnace, activating the activated carbon for 9 hours at the temperature of 750 ℃ to prepare the prepared activated carbon, and oxidizing and modifying the prepared activated carbon by hydrogen peroxide for 2 hours at the temperature of 25 ℃ to obtain the activated carbon; wherein the temperature of the water vapor is 280 ℃; the mass ratio of the prepared active carbon to the hydrogen peroxide is 1:2.0, the mass concentration of the hydrogen peroxide is 30%;

adding 3.0% of binder into the active carbon, stirring uniformly, pressing and forming by a custom mold to obtain a spherical active carbon carrier with a plurality of spines on the surface, impregnating the spherical active carbon carrier with a plurality of spines on the surface by using a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 1h under the condition of the temperature of 200 ℃ and the pressure of 4.5MPa in the hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.05%, and the proportion of platinum grains with the particle size of 2-20 nm in the noble metal catalyst in the total number of grains is 91.5%.

Wherein the adhesive is polystyrene; the pressure of the compression molding is 32MPa, and the temperature is 220 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 30:1, the impregnation time was 4.0h and the impregnation temperature was 30 ℃.

Example 4

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 2.0h under the conditions of air isolation and 650 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.25:1, inputting the mixture into a fluidized bed furnace, activating the mixture for 10 hours at the temperature of 700 ℃ to prepare prepared activated carbon, and oxidizing and modifying the prepared activated carbon with sulfuric acid for 2 hours at the temperature of 35 ℃ to obtain activated carbon; wherein the temperature of the water vapor is 150 ℃; the mass ratio of the active carbon to the sulfuric acid is 1:2.5, the mass concentration of sulfuric acid is 75%;

adding 3.5% of binder into the active carbon, stirring uniformly, pressing to obtain a spherical active carbon carrier with a plurality of spines on the outer surface, impregnating the spherical active carbon carrier with a plurality of spines on the outer surface with a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 1h under the condition of 220 ℃ and 5.0MPa of pressure in hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.05%, and the proportion of platinum grains with the grain diameter of 2-20 nm in the noble metal catalyst in the total number of grains is 93.0%.

Wherein the binder is coal tar; the pressure of the compression molding is 25MPa, and the temperature is 185 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 35:1, the impregnation time was 3.5h and the impregnation temperature was 40 ℃.

Example 5

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 3.5 hours under the conditions of air isolation and 500 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.30:1, inputting the mixture into a fluidized bed furnace, activating the mixture for 8 hours at the temperature of 880 ℃ to prepare prepared activated carbon, and carrying out air oxidation modification on the prepared activated carbon at the temperature of 480 ℃ for 2.5 hours to obtain activated carbon; wherein the temperature of the water vapor is 180 ℃;

adding 1.5% of binder into the active carbon, stirring uniformly, pressing to obtain a spherical active carbon carrier with a plurality of spines on the outer surface, impregnating the spherical active carbon carrier with a plurality of spines on the outer surface with a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 1h under the condition of the temperature of 200 ℃ and the pressure of 4.5MPa in the hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.05%, and the proportion of platinum grains with the grain diameter of 2-20 nm in the noble metal catalyst in the total number of grains is 91.0%.

Wherein the binder is asphalt; the pressure of the compression molding is 22MPa, and the temperature is 190 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 40:1, the impregnation time was 3.0h and the impregnation temperature was 45 ℃.

Example 6

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 4.0 hours under the conditions of air isolation and 450 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.15:1, inputting the activated carbon into a fluidized bed furnace, activating the activated carbon for 7 hours at 900 ℃ to prepare the prepared activated carbon, and oxidizing and modifying the prepared activated carbon by hydrogen peroxide for 2 hours at 30 ℃ to obtain the activated carbon; wherein the temperature of the water vapor is 200 ℃; the mass ratio of the activated carbon to the hydrogen peroxide is 1:4.0, the mass concentration of the hydrogen peroxide is 15%;

adding an adhesive with the mass of 2.0% into the active carbon, stirring uniformly, pressing and forming to obtain a spherical active carbon carrier with a plurality of spines on the outer surface, impregnating the spherical active carbon carrier with the plurality of spines on the outer surface by using a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 1.5 hours under the condition of the temperature of 180 ℃ and the pressure of 4.0MPa in the hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.04%, and the proportion of platinum grains with the particle size of 2-20 nm in the noble metal catalyst in the total number of grains is 95.5%.

Wherein the adhesive is nano aluminum sol, and the solid content is 20%; the pressure of the compression molding is 30MPa, and the temperature is 185 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 45:1, the impregnation time was 2.5h and the impregnation temperature was 25 ℃.

Example 7

drying and crushing walnut shells, screening, carbonizing a screened walnut shell sample for 5.0h under the conditions of air isolation and 380 ℃, and then mixing the carbonized material and water vapor according to the mass ratio of 0.35:1, inputting the activated carbon into a fluidized bed furnace, activating the activated carbon for 6 hours at the temperature of 1000 ℃ to prepare the prepared activated carbon, and oxidizing and modifying the prepared activated carbon by hydrogen peroxide for 4 hours at the temperature of 20 ℃ to obtain the activated carbon; wherein the temperature of the water vapor is 180 ℃; the mass ratio of the activated carbon to the hydrogen peroxide is 1:3.0, the mass concentration of the hydrogen peroxide is 20%;

adding 1.5% of binder into the active carbon, stirring uniformly, pressing to obtain a spherical active carbon carrier with a plurality of spines on the outer surface, impregnating the spherical active carbon carrier with a plurality of spines on the outer surface with a chloroplatinic acid solution with the mass concentration of 0.10%, reducing for 6 hours under the condition of the temperature of 100 ℃ and the pressure of 0.5MPa in the hydrogen atmosphere, washing and drying to obtain the noble metal catalyst, namely the supported platinum carbon catalyst, wherein the mass percentage of platinum in the noble metal catalyst is 0.10%, and the proportion of platinum grains with the grain diameter of 2-20 nm in the noble metal catalyst in the total number of grains is 90.5%.

Wherein the adhesive is silica sol (model neutral, specification NS15-30/1, purchased from Zhejiang De Lixin micro-nano technology Co., ltd.); the pressure of the compression molding is 25MPa, and the temperature is 160 ℃; the addition ratio of the chloroplatinic acid solution with the mass concentration of 0.10 percent to the active carbon carrier is 50:1, the impregnation time was 2.0h and the impregnation temperature was 25 ℃.

Comparative example 1

This comparative example further provides a noble metal catalyst

The procedure of example 7 was used, except that the activated carbon was not oxidatively modified; the mass percentage of platinum in the prepared noble metal catalyst is 0.10 percent.

Comparative example 2

This comparative example further provides a noble metal catalyst

The method of example 7 was used, except that commercial walnut shell activated carbon (from Kunshan Guanghua activated carbon Co., ltd., particle size 10-28 mesh 95% or more, pH 6-8, and burned residue 0.3% or less) was purchased; the mass percentage of platinum in the prepared noble metal catalyst is 0.10 percent.

Preparation example 1

The preparation example further provides a preparation method of the anti-aging agent 6PPD, which comprises the following preparation steps:

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 1 into a fixed bed reactor, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 100 ℃ and the system hydrogen pressure is 1.0MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in Table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:3.5, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is 2000:1.

preparation example 2

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 2 into a fixed bed reaction device, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 95 ℃ and the system hydrogen pressure is 1.0MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in the table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:3.2, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is 1800:1.

preparation example 3

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 3 into a fixed bed reaction device, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 90 ℃ and the system hydrogen pressure is 1.1MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in Table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:3.0, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is 1500:1.

preparation example 4

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 4 into a fixed bed reaction device, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 85 ℃ and the system hydrogen pressure is 1.1MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in Table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:2.9, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone was 1400:1.

preparation example 5

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 5 into a fixed bed reaction device, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 80 ℃ and the system hydrogen pressure is 1.2MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in Table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:2.8, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is 1350:1.

preparation example 6

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 1 into a fixed bed reaction device, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 78 ℃ and the system hydrogen pressure is 1.2MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in Table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:2.7, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is 1300:1.

preparation example 7

loading a noble metal catalyst with the mass percent of 0.05% of platinum prepared in the example 1 into a fixed bed reaction device, then adding 4-aminodiphenylamine and 4-methyl-2-pentanone, reacting to synthesize an anti-aging agent 6PPD under the condition that the temperature is 105 ℃ and the system hydrogen pressure is 0.9MPa, and analyzing the reaction liquid by adopting gas chromatography after the reaction is finished, wherein the results are counted in Table 2; wherein, the mole ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1:3.0, the ratio of the mass of hydrogen to the total mass of 4-aminodiphenylamine and 4-methyl-2-pentanone is 2000:1.

preparation example 8

The preparation example further provides a preparation method of the anti-aging agent 6PPD

The preparation method of preparation example 1 was employed, except that the noble metal catalyst prepared in example 6 was employed with a mass percentage of platinum of 0.04%.

Preparation example 9

The preparation method of preparation example 1 was employed, except that the noble metal catalyst having a mass percentage of platinum of 0.10% was employed as prepared in example 7.

Comparative example 3

The comparative example further provides a method for preparing the anti-aging agent 6PPD.

The preparation method of preparation example 1 was employed, except that the noble metal catalyst prepared in comparative example 1 was employed.

Comparative example 4

The preparation method of preparation example 1 was employed, except that the noble metal catalyst prepared in comparative example 2 was employed.

To further illustrate the advancement of the noble metal catalysts prepared according to the present invention, the following tests were now performed;

test 1: the specific surface areas, the total pore volumes and the mesoporous volumes of the activated carbon and the activated carbon are prepared in the preparation process of the activated carbon in examples 1-7 and comparative examples 1-2 according to GB/T7702.20-2008 respectively; and the compressive strength and ash content of the activated carbon were measured according to GB/T12496.3-1999, wherein the compressive strength refers to the ultimate load that the activated carbon can withstand per unit area at room temperature.

The specific results are counted in table 1;

TABLE 1 comparison of performance parameters of the preliminary activated carbon and activated carbon prepared in examples 1-7 and comparative examples 1-2

Test 2: respectively titrating the contents of the surface functional groups of the activated carbon prepared in the preparation process of the activated carbon in examples 1-7 and comparative examples 1-2 according to a boehm titration method; and the pH of the preliminary activated carbon and activated carbon was determined according to GB/T12496.7-1999, wherein RCOOH represents carboxyl group, RCOOCO represents lactone group, arOH represents phenolic hydroxyl group, and RCOR represents carbonyl group.

The surface functional group content changes and pH value changes of the prepared activated carbon and activated carbon prepared in examples 1 to 7 and comparative examples 1 to 2 are counted in Table 2;

TABLE 2

Test 3: the noble metal catalysts prepared in examples 1 to 7 and comparative examples 1 to 2 were used in the preparation of the antioxidant 6PPD, and the catalytic activity of the active component platinum at different mass percentages was measured, and the conversion of 4-aminodiphenylamine, the selectivity of the antioxidant 6PPD, and the mass ratio of 4-methyl-2-pentanone to 4-methyl-2-pentanol were counted, respectively, and the specific results are shown in table 3; wherein, 4-aminodiphenylamine conversion = (total 4-aminodiphenylamine concentration-remaining 4-aminodiphenylamine concentration)/total 4-aminodiphenylamine concentration × 100%, antioxidant 6PPD selectivity = (yield/conversion of antioxidant 6 PPD) × 100%;

TABLE 3 Table 3

It should be noted that the above-described embodiments are only for explaining the present invention and do not constitute any limitation of the present invention. The invention has been described with reference to exemplary embodiments, but it is understood that the words which have been used are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as defined in the appended claims, and the invention may be modified without departing from the scope and spirit of the invention. Although the invention is described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all other means and applications which perform the same function.

Claims

1. The catalyst comprises a carrier and an active component, and is characterized in that the mass percentages of the carrier and the active component are respectively: 99.90 to 99.96 percent and 0.04 to 0.10 percent; the active component is platinum and/or palladium; the carrier is activated carbon; the specific surface area of the activated carbon is 928.8m ² /g～1486m ² Per g, total pore volume of 0.69m ³ /g～1.10m ³ Per g, mesoporous volume of 0.62m ³ /g～0.98m ³ /g。

2. The catalyst according to claim 1, wherein the activated carbon is spherical with a plurality of spikes on the outer surface;

and/or the specific surface area of the activated carbon is 1161m ² /g～1238m ² Per g, total pore volume of 0.86m ³ /g～0.92m ³ Per g, mesoporous volume of 0.77m ³ /g～0.82m ³ /g；

and/or the ratio of platinum and/or palladium grains with the grain diameter of 2-20 nm in the catalyst to the total number of grains is more than or equal to 88 percent, preferably more than or equal to 90.5 percent.

3. The catalyst according to claim 1 or 2, wherein the activated carbon is subjected to an oxidative modification treatment.

4. A catalyst according to claim 3, characterized in that the preparation method of activated carbon before the oxidative modification treatment comprises: carbonizing and activating walnut shells under the condition of isolating air;

preferably, before the carbonization, the method further comprises the steps of drying, crushing and screening the walnut shells;

and/or the carbonization is carried out to obtain a carbonized substance, wherein the carbonization temperature is 350-650 ℃, and the carbonization time is 0.5-5.5 h;

and/or, the activation is carried out to obtain the preparation activated carbon, in the activation process, steam is introduced into the carbide, and the mass ratio of the carbide to the steam is (0.10-0.35): 1, a step of; the temperature of the water vapor is 150-280 ℃; preferably, the activation temperature is 700-1000 ℃ and the activation time is 6-10 h;

and/or the oxidation is selected from any one of air oxidation, oxygen oxidation, hydrogen peroxide oxidation and sulfuric acid oxidation; preferably, when air oxidation or oxygen oxidation is selected, the oxidation temperature is 300-550 ℃ and the oxidation time is 2-3 h; when hydrogen peroxide or sulfuric acid is selected for oxidization, the oxidization temperature is 10-60 ℃ and the time is 1-4 hours, and further preferably, when hydrogen peroxide is selected for oxidization, the mass ratio of the activated carbon to the hydrogen peroxide is 1: (2.0 to 4.0); the mass concentration of the hydrogen peroxide is 10% -33%; when sulfuric acid is selected for oxidation, the mass ratio of the active carbon to the sulfuric acid is 1: (1.8-3.5); the mass concentration of the sulfuric acid is 70% -98%;

and/or, after the oxidation, a step of compression molding is further included; preferably, an adhesive is added in the compression molding process, the addition amount of the adhesive is preferably 1.5-4.5% of the mass of the activated carbon, and the adhesive is preferably one selected from silica sol, alumina sol, polyvinyl alcohol, polyacrylate, polystyrene, furfural resin, coal tar and asphalt; further preferably, the pressure of the press molding is 20MPa to 35MPa, and the temperature is 150 ℃ to 250 ℃.

5. A method for preparing the catalyst according to any one of claims 1 to 4, comprising the step of mixing the active ingredient-containing precursor solution with a carrier and reducing under a hydrogen atmosphere.

6. The method according to claim 5, wherein the mass ratio of the active ingredient precursor-containing solution to the carrier is (5 to 50): 1, a step of; preferably, the active ingredient-containing precursor solution is a platinum salt solution and/or a palladium salt solution; further preferably, the platinum salt solution is one or more of platinum chloride solution, platinum acetate solution, platinum nitrate solution and chloroplatinic acid solution; the palladium salt solution is one or more of palladium chloride solution, palladium acetate solution and palladium nitrate solution; still further preferably, the active ingredient-containing precursor solution has a mass concentration of 0.01% to 0.15%;

and/or, the mixing is specifically impregnating the support with an active ingredient-containing precursor solution; preferably, the temperature of the impregnation is 15-45 ℃ and the time is 2-8 hours;

and/or the temperature of the reduction is 80-250 ℃, the time is 0.5-8 h, and the pressure is 0.5-5.0 MPa;

and/or the reduction further comprises the steps of washing and drying.

7. The preparation method of the anti-aging agent 6PPD is characterized by comprising the step of reacting 4-aminodiphenylamine, 4-methyl-2-pentanone and hydrogen in the presence of a catalyst to obtain the anti-aging agent 6 PPD;

the catalyst is selected from any one of the catalysts described in claims 1-4 or the catalysts prepared by the preparation methods described in claims 5 or 6.

8. The preparation method according to claim 7, wherein the molar ratio of the 4-aminodiphenylamine to the 4-methyl-2-pentanone is 1: (2.7-3.5), the ratio of the mass of the hydrogen to the total mass of the 4-aminodiphenylamine and the 4-methyl-2-pentanone is (1300-2000): 1;

and/or the reaction temperature is 78-105 ℃ and the hydrogen pressure is 0.9-1.2 MPa.