CN111036197A

CN111036197A - Catalyst and preparation method of 2, 5-furandicarboxylic acid

Info

Publication number: CN111036197A
Application number: CN201811191673.4A
Authority: CN
Inventors: 郑路凡; 孙乾辉; 宗保宁; 杜泽学
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2020-04-21

Abstract

The invention provides a catalyst and a preparation method of 2, 5-furandicarboxylic acid, wherein the preparation method of the catalyst comprises the following steps: mixing a pre-carrier and an alkaline nitrogen-containing compound, putting the mixture into a solvent, heating and stirring the mixture under the condition of water bath, and carrying out alkaline treatment; sequentially drying and roasting the alkali-treated fore-carrier to obtain a carrier; and loading an active component on the carrier to obtain the catalyst; wherein the active component is selected from one or more of ruthenium, palladium, platinum and rhodium; the front carrier is selected from one or more of activated carbon, graphite, fullerene and graphene oxide. The catalyst can realize the high-efficiency conversion of the 5-hydroxymethylfurfural without adding an alkaline auxiliary agent to obtain the high-selectivity 2, 5-furandicarboxylic acid, and has the advantages of simple operation method, mild reaction condition, environmental protection, no pollution and good industrial application prospect.

Description

Catalyst and preparation method of 2, 5-furandicarboxylic acid

Technical Field

The invention relates to the field of chemical industry, in particular to a preparation method of a catalyst and a method for preparing 2, 5-furandicarboxylic acid by applying the prepared catalyst.

Background

Currently, fuels and chemicals needed by society are mainly derived from fossil fuels, and the increase of the cost, the reduction of the supply amount of the fossil fuels and the influence on the environment lead people to generate wide interest in sustainable alternative energy and chemical raw materials, especially biomass resources which have wide sources and high carbohydrate specific gravity and can produce liquid fuels and organic chemicals through processes of selective dehydration or hydrogenation and the like. 5-Hydroxymethylfurfural (HMF) is one of the important biomass-based platform compounds, which can be prepared by acid-catalyzed dehydration of carbohydrates such as fructose, glucose and cellulose, 2, 5-furandicarboxylic acid (FDCA) obtained by catalytic oxidation of 5-hydroxymethylfurfural. The FDCA contains aromatic rings in the molecular structure, can effectively improve the heat resistance and mechanical properties of a bio-based polymer material when used for synthesizing the bio-based polymer material, is considered to be an ideal substitute of petroleum-based monomer terephthalic acid (PTA), and can also be applied to the synthesis of bio-based polymers such as polyester, polyamide and epoxy resin instead of isophthalic acid, adipic acid, succinic acid, bisphenol A and the like. Therefore, the development of the synthetic method of the 2, 5-furandicarboxylic acid has important application value and biomass sustainable utilization significance.

In the process of preparing FDCA by selective oxidation of HMF, the generated FDCA can reduce the activity of a metal catalyst and even deactivate the metal catalyst, so that an alkaline compound is often added to generate a salt with the product FDCA, the catalyst is protected, the ring-opening degradation of the FDCA is prevented, and the selectivity of the product is improved. Some patents and literature reports methods for synthesizing FDCA, such as: CN 101891719A discloses a method for synthesizing 2, 5-furandicarboxylic acid, which adopts a catalyst to catalyze furan substances in an alkaline solution to synthesize the 2, 5-furandicarboxylic acid, but the reaction time is longer, and the alkaline solution is not easy to separate from the product after mixing; gupta et al (Greenchemistry, 2011, 13(4), p 824-827) load Au on alkaline Hydrotalcite (HT) to obtain an Au/HT catalyst, however, as the use frequency increases, the carrier HT gradually dissolves, so that the stability of the catalyst is reduced; CN 104162422a discloses a preparation method of a basic carbonaceous solid catalyst carrier, which is used for catalytic synthesis of FDCA, however, the catalyst has a problem of reduced activity after multiple uses.

Therefore, it is desirable to provide a new catalyst and a method for synthesizing 2, 5-furandicarboxylic acid using the same, which solve the above problems in the prior art.

It is noted that the information disclosed in the foregoing background section is only for enhancement of background understanding of the invention and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

The invention aims to provide a preparation method of a catalyst and a method for preparing 2, 5-furandicarboxylic acid by applying the prepared catalyst, so as to solve the problems that the traditional synthetic method or an alkaline solution is used as an alkali source, which brings difficulty to product separation, and the subsequent acidification treatment is complicated; or using basic compound as carrier, the loss of basic metal ion in the circulation process reduces the stability of catalyst.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a preparation method of a catalyst, which comprises the following steps:

mixing a pre-carrier and an alkaline nitrogen-containing compound, putting the mixture into a solvent, heating and stirring the mixture under the condition of water bath, and carrying out alkaline treatment;

sequentially drying and roasting the alkali-treated fore-carrier to obtain a carrier; and

loading an active component on the carrier to obtain the catalyst;

wherein the active component is selected from one or more of ruthenium (Ru), palladium (Pd), platinum (Pt) and rhodium (Rh); the front carrier is selected from Activated Carbon (AC), graphite (C) and fullerene (C)₆₀) And Graphene Oxide (GO).

According to one embodiment of the invention, the active component is ruthenium and the pre-support is activated carbon.

According to one embodiment of the present invention, the basic nitrogen-containing compound is selected from one or more of a nitrogen-containing heterocyclic compound selected from one or more of pyridine, piperidine, pyrrole, pyrrolidine, piperidine and imidazole, an aliphatic amine selected from one or more of ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, 1, 2-propanediamine, 1, 3-propanediamine and n-butylamine, and an aromatic amine selected from one or more of aniline, benzylamine, phenethylamine, o-aminophenol, m-aminophenol and p-aminophenol.

According to one embodiment of the invention, the mass ratio of the pro-carrier to the basic nitrogen-containing compound is 1: 0.5 to 20; the mass ratio of the pre-carrier to the solvent is 1: 20-150.

According to one embodiment of the present invention, the solvent is a mixed solution of ethanol and water, the ethanol accounts for 10% to 95% of the mass of the mixed solution, the water accounts for 5% to 90% of the mass of the mixed solution, preferably, the ethanol accounts for 20% to 50% of the mass of the mixed solution, and the water accounts for 50% to 80% of the mass of the mixed solution.

According to one embodiment of the invention, the alkaline treatment is carried out at a temperature of 40 ℃ to 95 ℃, preferably 50 ℃ to 75 ℃, for a time of 1h to 12h, preferably 4h to 8 h.

According to one embodiment of the invention, the drying treatment is carried out at a temperature of between 80 ℃ and 200 ℃, preferably between 100 ℃ and 150 ℃; the drying time is 8-24 h, preferably 10-18 h.

According to one embodiment of the invention, the roasting treatment comprises roasting the dried pre-support in nitrogen or inert atmosphere, the roasting treatment being carried out at a temperature of 300 ℃ to 1000 ℃, preferably 400 ℃ to 800 ℃; the roasting treatment time is 1-6 h, preferably 2-4 h.

According to one embodiment of the present invention, the supporting of the active ingredient on the carrier comprises:

mixing the soluble salt solution of the active component with the carrier to obtain a mixture, drying the mixture at the temperature of 60-120 ℃ for 6-24 h, and then reducing the mixture at the temperature of 150-600 ℃ for 2-6 h in a reducing atmosphere, wherein the reducing atmosphere comprises 10-100% of hydrogen and 0-90% of nitrogen or inert gas in percentage by volume;

preferably, the soluble salt solution of the active ingredient is mixed with the carrier in an equal volume impregnation method.

According to one embodiment of the invention, the mass ratio of the active component to the carrier in the catalyst is 0.005-0.08: 1, preferably 0.035-0.08: 1, and more preferably 0.04-0.06: 1.

The invention also provides a catalyst prepared by the method.

The invention also provides a preparation method of 2, 5-furandicarboxylic acid, which comprises the following steps:

contacting an aqueous solution of 5-hydroxymethylfurfural with a catalyst under the condition of air and/or oxygen to perform a catalytic oxidation reaction to prepare the 2, 5-furandicarboxylic acid, wherein the catalyst is the catalyst in claim 11.

According to one embodiment of the invention, the molar ratio of the 5-hydroxymethylfurfural to the active components in the catalyst is 40-200: 1, preferably 70-120: 1.

according to one embodiment of the present invention, the partial pressure of oxygen in the catalytic oxidation reaction is 0.05 to 2MPa, preferably 0.5 to 1 MPa; the reaction temperature is 50-170 ℃, and preferably 90-120 ℃; the reaction time is 0.5 to 24 hours, preferably 1 to 4 hours.

According to the technical scheme, the invention has the beneficial effects that:

according to the catalyst and the preparation method thereof provided by the invention, after the carrier is subjected to alkali treatment, drying treatment and roasting treatment, the catalyst prepared by loading the noble metal on the carrier can catalyze 5-hydroxymethylfurfural to carry out selective oxidation reaction without adding an alkaline auxiliary agent, compared with the carrier which is not subjected to modification treatment, the activity of the catalyst is obviously improved, the stability of the catalyst is better, and no loss of metal components is found in the circulation process;

according to the preparation method of 2, 5-furandicarboxylic acid, the catalyst can be used for realizing efficient conversion of 5-hydroxymethylfurfural under mild conditions to obtain the high-selectivity 2, 5-furandicarboxylic acid, the operation method is simple, the post-treatment step of the product can be simplified without adding an alkaline auxiliary agent, and the condition that a large amount of wastewater is generated in the subsequent acidification process is avoided; in addition, in the preparation process, water is used as a solvent, and oxygen or air is used as an oxygen source, so that the preparation method is low in cost, green, environment-friendly, pollution-free and good in industrial application prospect.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to yield one or more new ranges of values, which ranges of values should be considered as specifically disclosed herein.

loading an active component on the carrier to obtain the catalyst;

Compared with the unmodified carrier, the activity of the catalyst is obviously improved, the catalyst can catalyze 5-hydroxymethylfurfural to carry out selective oxidation reaction under the condition of not adding an alkaline auxiliary agent, the stability of the catalyst is good, and no loss of metal components is found in the recycling process.

In some embodiments, preferably, the active component is ruthenium (Ru) and the pre-support is Activated Carbon (AC). Research shows that the Ru/Ac catalyst can further improve the selectivity of the 2, 5-furandicarboxylic acid.

In some embodiments, the basic nitrogen-containing compound is selected from one or more of a nitrogen-containing heterocyclic compound selected from one or more of pyridine, piperidine, pyrrole, tetrahydropyrrole, piperidine, and imidazole, an aliphatic amine selected from one or more of ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, 1, 2-propanediamine, 1, 3-propanediamine, and n-butylamine, and an aromatic amine selected from one or more of aniline, benzylamine, phenethylamine, o-aminophenol, m-aminophenol, and p-aminophenol.

In some embodiments, the mass ratio of the pre-support to the basic nitrogen-containing compound is 1: 0.5 to 20; the mass ratio of the pre-carrier to the solvent is 1: 20-150.

In some embodiments, the solvent is a mixed solution of ethanol and water, the ethanol accounts for 10% to 95% of the mixed solution, the water accounts for 5% to 90% of the mixed solution, preferably, the ethanol accounts for 20% to 50% of the mixed solution, and the water accounts for 50% to 80% of the mixed solution.

In some embodiments, the alkali treatment is carried out at a temperature of 40 ℃ to 95 ℃, preferably 50 ℃ to 75 ℃, for a time of 1h to 12h, preferably 4h to 8 h.

In some embodiments, the drying treatment is carried out at a temperature of 80 ℃ to 200 ℃, preferably 100 ℃ to 150 ℃; the drying time is 8-24 h, preferably 10-18 h.

In some embodiments, the firing process includes exposing the dried pre-support to nitrogen (N)₂) Or in an inert atmosphere including, but not limited to, helium (He), argon (Ar), etc. The roasting treatment is carried out at the temperature of 300-1000 ℃, preferably 400-800 ℃; the roasting treatment time is 1-6 h, preferably 2-4 h.

In some embodiments, said loading an active ingredient on said carrier comprises:

preferably, the soluble salt solution of the active ingredient is mixed with the carrier in an equal volume impregnation method. It will be understood by those skilled in the art that an isovolumetric impregnation method is one in which the volume of the support (typically the pore volume) is the same as the volume of the impregnating solution, and the impregnating solution is just fully within the pores. The method can conveniently control the loading capacity of the active component, and the loading capacity can be easily calculated.

In some embodiments, the mass ratio of the active component to the carrier in the catalyst is 0.005-0.08: 1, preferably 0.035-0.08: 1, more preferably 0.04-0.06:1. specifically, when a soluble salt solution of the active component is mixed with the carrier, the mass ratio of the metal element in the soluble salt of the active component to the carrier is controlled to be 0.005-0.08: 1, preferably 0.035-0.08: 1, and more preferably 0.04-0.06: 1. Wherein the soluble salt solution of the active component can be chloroplatinic acid (H)₂PtCl₆) An aqueous solution of (1), palladium chloride (PdCl)₂) Aqueous solution of (1), ruthenium chloride (RuCl)₃) Aqueous solution of (A) or rhodium chloride (RhCl)₃) But is not limited thereto.

The invention also provides a catalyst prepared by the method.

It will be appreciated by those skilled in the art that the catalytic oxidation reaction is carried out in a sealed environment.

In some embodiments, the molar ratio of the 5-hydroxymethylfurfural to the active components in the catalyst is from 40 to 200: 1, preferably 70-120: 1.

in some embodiments, the catalytic oxidation reaction has an oxygen partial pressure of 0.05 to 2MPa, preferably 0.5 to 1 MPa; specifically, the air and/or oxygen in the above pressure range can be injected into the reaction kettle at one time, and the operation is simpler and more convenient compared with a continuous aeration mode.

In some embodiments, the reaction temperature in the catalytic oxidation reaction is 50 ℃ to 170 ℃, preferably 90 ℃ to 120 ℃; the reaction time is 0.5 to 24 hours, preferably 1 to 4 hours. It can be seen that the catalyst of the invention is adopted to prepare 2, 5-furandicarboxylic acid, the reaction temperature is relatively mild, the catalytic activity is high, and the reaction time is short.

Therefore, the catalyst can realize the high-efficiency conversion of the 5-hydroxymethylfurfural under mild conditions without adding an alkaline auxiliary agent, and simplifies the post-treatment steps of the product. In addition, the method of the invention fills gas with certain pressure into the reaction kettle at one time, and the operation is simple; as water is used as a solvent and oxygen or air is used as an oxygen source in the whole preparation process, the preparation method is low in cost, green, environment-friendly and pollution-free, and has good industrial application prospects.

The following is illustrated by specific examples:

PREPARATION EXAMPLE 1 preparation of Ru/AC catalyst

(1) Mixing 2g of pre-carrier activated carbon AC, 10g of tetrahydropyrrole, 100g of 30 wt% ethanol and 70 wt% water, carrying out alkali treatment for 6h under the condition of water bath at 65 ℃ by refluxing and stirring, separating the alkali-treated activated carbon, drying for 12h in an oven at 100 ℃, and then drying in an N oven₂Roasting at 800 ℃ for 2h under the atmosphere to obtain the carrier active carbon AC.

(2) RuCl is treated by an equal volume impregnation method₃And (3) mixing the aqueous solution with the carrier activated carbon AC obtained in the step (1), and stirring for 2h, wherein the mass ratio of the metal Ru in the RuCl3 aqueous solution to the carrier activated carbon AC is 0.05: 1. The mixture was then dried at 120 ℃ for 12H at 20% H by volume₂And 80% N₂Is reduced for 4 hours at 400 ℃ in the reducing atmosphere to obtain the catalyst Ru/AC with the active component content of 4.7 wt%.

PREPARATION EXAMPLE 2 preparation of Ru/AC catalyst

(1) Mixing 2g of pre-carrier activated carbon AC, 15g of pyridine, 80g of 20 wt% ethanol and 80 wt% water, carrying out alkali treatment for 8h under the condition of 60 ℃ water bath by refluxing and stirring, then separating the activated carbon AC subjected to alkali treatment, drying in an oven at 120 ℃ for 10h, and then drying in an N oven₂Roasting at 700 ℃ for 2h under the atmosphere to obtain the carrier active carbon AC.

(2) RuCl is treated by an equal volume impregnation method₃Mixing the aqueous solution with the carrier active carbon C obtained in the step (1), and stirring for 2.5h, wherein RuCl is₃The mass ratio of the metal Ru to the carrier active carbon AC in the aqueous solution is 0.06: 1. The mixture was then dried at 110 ℃ for 14H at 30% H by volume₂And 70% N₂Reducing the mixture for 3 hours at the temperature of 400 ℃ in a reducing atmosphere to obtain the catalyst Ru/AC with the active component content of 5.6 wt%.

PREPARATION EXAMPLE 3 preparation of Ru/AC catalyst

(1) Mixing 2g of pre-carrier activated carbon AC, 5g of 1, 2-propane diamine, 150g of 50 wt% ethanol and 50 wt% water, carrying out alkali treatment for 5h under the condition of water bath at 55 ℃ by refluxing and stirring, separating the activated carbon AC subjected to alkali treatment, drying for 14h in a 110 ℃ oven, and then drying in an N oven₂Roasting at 600 ℃ for 2h under the atmosphere to obtain the carrier active carbon AC.

(2) RuCl is treated by an equal volume impregnation method₃And (3) mixing the aqueous solution with the carrier activated carbon AC obtained in the step (1), and stirring for 2h, wherein the mass ratio of the metal Ru in the RuCl3 aqueous solution to the carrier activated carbon AC is 0.04: 1. The mixture was then dried at 100 ℃ for 16H at 25% H by volume₂And 75% N₂Reducing for 4 hours at 450 ℃ in a reducing atmosphere to obtain the catalyst Ru/AC with the active component content of 3.7 wt%.

PREPARATION EXAMPLE 4 preparation of Ru/C catalyst

(1) Mixing 2g of front carrier graphite C, 30g of benzylamine, 120g of 10 wt% ethanol and 90 wt% water, carrying out alkali treatment for 4h under the condition of 75 ℃ water bath by refluxing and stirring, then separating the graphite C subjected to alkali treatment, drying for 16h in a 100 ℃ oven, and then roasting for 2h at 500 ℃ under the atmosphere of He to obtain the carrier graphite C.

(2) RuCl is treated by an equal volume impregnation method₃Mixing the aqueous solution with the carrier graphite C obtained in the step (1), and stirring for 3h, wherein RuCl₃The mass ratio of the metal Ru to the carrier graphite C in the aqueous solution is 0.05: 1. The mixture was then dried at 110 ℃ for 13H at 20% H by volume₂And 80% N₂Reducing for 3 hours at 500 ℃ in a reducing atmosphere to obtain the catalyst Ru/C with the active component content of 4.7 wt%.

PREPARATION EXAMPLE 5 preparation of Rh/GO CATALYST

(1) Mixing 2g of pre-carrier graphene oxide, 5g of ethylamine, 60g of 85 wt% ethanol and 15 wt% water, carrying out alkali treatment on the mixture by refluxing and stirring in a water bath at 55 ℃ for 6 hours, separating the alkali-treated graphene oxide GO, drying the alkali-treated graphene oxide GO in a 100 ℃ oven for 10 hours, and then drying the graphene oxide GO in an N oven₂And (3) roasting at the high temperature of 750 ℃ for 2h under the atmosphere to obtain the graphene oxide GO serving as the carrier.

(2) Adopting an isovolumetric impregnation method to impregnate RhCl₃Mixing the aqueous solution with the carrier graphene oxide obtained in the step (1), and stirring for 2h, wherein RhCl is used as a carrier₃The mass ratio of the metal Rh to the graphene oxide as the carrier in the aqueous solution is 0.04: 1. The mixture was then dried at 110 ℃ for 13H at 25% H by volume₂And reducing for 4h at 400 ℃ in a 75% He atmosphere to obtain a catalyst Rh/GO with the active component content of 3.7 wt%.

PREPARATION EXAMPLE 6 preparation of Ru/AC catalyst

The catalyst Ru/AC was prepared as described in preparation 1, except that the basic compound added was piperidine, RuCl₃The mass ratio of the metal Ru to the carrier active carbon AC in the aqueous solution is 0.08:1, and the catalyst Ru/AC with the active component content of 7.4 wt% is obtained.

PREPARATION EXAMPLE 7 preparation of Ru/AC catalyst

The catalyst Ru/AC was prepared as described in preparation example 1, except that the basic compound added was benzylamine, RuCl₃The mass ratio of the metal Ru to the carrier active carbon AC in the aqueous solution is 0.03:1, and the catalyst Ru/AC with the active component content of 2.8 wt% is obtained.

Preparation example 8 preparation of Pd/AC catalyst

The catalyst Pd/AC was prepared by following the procedure of preparation example 1, except that triethylamine as a basic compound was added and PdCl was used₂Aqueous solution instead of RuCl₃Aqueous solution to obtain the catalyst Pd/AC with the active component content of 4.7 wt%.

PREPARATION EXAMPLE 9 preparation of Pt/AC catalyst

Catalyst Pt/AC was prepared as in preparation 1, except that the basic compound added was imidazole, H₂PtCl₆Aqueous solution instead of RuCl₃And (4) obtaining a catalyst Pt/AC with the active component content of 4.7 wt% by using an aqueous solution.

PREPARATION EXAMPLE 10 preparation of Rh/AC catalyst

A catalyst Rh/AC was prepared as in preparation 1, except that the basic compound added was p-aminophenol and RhCl was used₃Aqueous solution instead of RuCl₃Aqueous solution to obtain catalyst Rh/AC with an active component content of 4.7 wt%.

Preparation example 11

Catalyst Pt/GO was prepared according to the method of preparation 1, except that the basic compound added was n-propylamine, H₂PtCl₆Aqueous solution instead of RuCl₃And (3) obtaining a catalyst Pt/GO with the active component content of 4.7 wt% by using an aqueous solution.

Preparation example 12

Preparation of the catalyst Pd/C according to the method of preparation example 1₆₀In the difference, the basic compound added is pyrrole, with PdCl₂Aqueous solution instead of RuCl₃Aqueous solution to obtain catalyst Pd/C with active component content of 4.7 wt%₆₀。

Comparative preparation example 1

The procedure of preparation example 1 was followed except that step (1) was not conducted and RuCl was directly impregnated by an isometric volume impregnation method₃Mixing the aqueous solution with activated carbon AC which is not subjected to alkali treatment but is subjected to drying and high-temperature roasting treatment, and stirring for 2h, wherein RuCl is added₃The mass ratio of the metal Ru to the active carbon AC in the aqueous solution is 0.05: 1. The mixture was then dried at 120 ℃ for 12H at 20% H by volume₂And 80% N₂Reducing for 4h at 400 ℃ in the atmosphere to obtain the catalyst Ru/AC with the active component content of 4.7 wt%.

Comparative preparation example 2

The procedure of preparation example 1 was followed except that step (1) was not conducted and RuCl was directly impregnated by an isometric volume impregnation method₃Mixing the aqueous solution with activated carbon AC without any treatment, and stirring for 2h, wherein RuCl₃The mass ratio of the metal Ru to the active carbon AC in the aqueous solution is 0.05: 1. The mixture was then dried at 120 ℃ for 12H at 20% H by volume₂And 80% N₂Reducing for 4h at 400 ℃ in the atmosphere to obtain the catalyst Ru/AC with the active component content of 4.7 wt%.

Example 1

This example serves to illustrate the process of the present invention for the synthesis of 2, 5-furandicarboxylic acid.

Adding 0.2g of 5-hydroxymethylfurfural into a 50mL stainless steel high-pressure reaction kettle, adding 10mL deionized water to dissolve the 5-hydroxymethylfurfural, adding 0.034g of Ru/AC (the content of active components is 4.7 wt%, namely the molar ratio of the 5-hydroxymethylfurfural to a catalyst calculated by metal elements is about 100: 1) obtained in the preparation example 1 into a reaction solution, filling oxygen to 0.5MPa without adding an alkaline assistant, sealing the reaction kettle, raising the reaction temperature to 120 ℃ by adopting an automatic temperature control program, keeping the temperature for 3 hours under continuous stirring, and keeping the pressure unchanged in the reaction process. After the reaction was completed, it was cooled to 25 ℃. And filtering and washing the reaction solution to collect the reaction solution. And (3) diluting the reaction solution with deionized water, fixing the volume to 100mL, and sampling for high performance liquid chromatography analysis. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 96.3 percent.

Example 2

Adding 0.2g of 5-hydroxymethylfurfural into a 50mL stainless steel high-pressure reaction kettle, adding 10mL deionized water to dissolve the 5-hydroxymethylfurfural, adding 0.024g of Ru/AC (the active component content is 5.6 wt%, namely the molar ratio of the 5-hydroxymethylfurfural to the catalyst calculated by metal elements is about 120: 1) obtained in the preparation example 2 into a reaction solution, filling oxygen to 1.0MPa without adding an alkaline assistant, sealing the reaction kettle, raising the reaction temperature to 90 ℃ by adopting an automatic temperature control program, keeping the temperature for 4 hours under continuous stirring, and keeping the pressure unchanged in the reaction process. After the reaction was completed, it was cooled to 25 ℃. And filtering and washing the reaction solution to collect the reaction solution. And (3) diluting the reaction solution with deionized water, fixing the volume to 100mL, and sampling for high performance liquid chromatography analysis. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 94.4 percent.

Example 3

Adding 0.2g of 5-hydroxymethylfurfural into a 50mL stainless steel high-pressure reaction kettle, adding 10mL deionized water to dissolve the 5-hydroxymethylfurfural, adding 0.06g of Ru/AC (the content of active components is 3.7 wt%, namely the molar ratio of the 5-hydroxymethylfurfural to a catalyst calculated by metal elements is about 70: 1) obtained in the preparation example 3 into a reaction solution, filling oxygen to 0.8MPa without adding an alkaline assistant, sealing the reaction kettle, raising the reaction temperature to 100 ℃ by adopting an automatic temperature control program, keeping the temperature for 2 hours under continuous stirring, and keeping the pressure unchanged in the reaction process. After the reaction was completed, it was cooled to 25 ℃. And filtering and washing the reaction solution to collect the reaction solution. And (3) diluting the reaction solution with deionized water, fixing the volume to 100mL, and sampling for high performance liquid chromatography analysis. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 91.3 percent.

Example 4

Adding 0.2g of 5-hydroxymethylfurfural into a 50mL stainless steel high-pressure reaction kettle, adding 10mL deionized water to dissolve the 5-hydroxymethylfurfural, adding 0.034g of Ru/C (the content of active components is 4.7 wt%, namely the molar ratio of the 5-hydroxymethylfurfural to a catalyst calculated by metal elements is about 100: 1) obtained in the preparation example 4 into a reaction solution, filling oxygen to 0.6MPa without adding an alkaline assistant, sealing the reaction kettle, raising the reaction temperature to 120 ℃ by adopting an automatic temperature control program, keeping the temperature for 2 hours under continuous stirring, and keeping the pressure unchanged in the reaction process. After the reaction was completed, it was cooled to 25 ℃. And filtering and washing the reaction solution to collect the reaction solution. And (3) diluting the reaction solution with deionized water, fixing the volume to 100mL, and sampling for high performance liquid chromatography analysis. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 89.4 percent.

Example 5

The procedure is as in example 1, except that 0.043g of Rh/GO from preparation 5 (active component content 3.7 wt.%, i.e. the molar ratio of 5-hydroxymethylfurfural to catalyst, calculated as metallic element, is about 100: 1) is used as catalyst. The conversion rate of the 5-hydroxymethylfurfural is 99 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 85.2 percent.

Example 6

The procedure of example 1 was followed except that 0.022g of the Ru/AC obtained in preparation example 6 was used as the catalyst (active component content 7.4% by weight, i.e., the molar ratio of 5-hydroxymethylfurfural to the catalyst on a metal element basis was about 100: 1). The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 92.9 percent.

Example 7

The procedure of example 1 was followed except that 0.058g of the Ru/AC obtained in preparation example 7 (active component content: 2.8% by weight, i.e., the molar ratio of 5-hydroxymethylfurfural to the catalyst on a metal element basis, was about 100: 1) was used as the catalyst. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 90.6 percent.

Example 8

The procedure of example 1 was followed except that the catalyst obtained in preparation example 8, Pd/AC, was used in place of Ru/AC (active component content 4.7% by weight, i.e., the molar ratio of 5-hydroxymethylfurfural to the catalyst, calculated as the metal element, was about 100: 1). The conversion rate of 5-hydroxymethylfurfural is 95% and the selectivity of the product 2, 5-furandicarboxylic acid is 82.4%.

Example 9

The procedure of example 1 was followed except that the catalyst obtained in preparation example 9, Pt/AC, was used in place of Ru/AC (active component content 4.7 wt%, i.e., molar ratio of 5-hydroxymethylfurfural to the catalyst calculated on the metal element was about 100: 1). The conversion rate of the 5-hydroxymethylfurfural is 99 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 85.5 percent.

Example 10

The procedure of example 1 was followed except that the catalyst Rh/AC obtained in preparation example 10 was used in place of Ru/AC (active component content 4.7% by weight, i.e. the molar ratio of 5-hydroxymethylfurfural to catalyst based on the metal element was about 100: 1). The conversion rate of the 5-hydroxymethylfurfural is 97 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 89.3 percent.

Example 11

The procedure of example 1 was followed except that the catalyst obtained in preparation example 11, Pt/GO, was used instead of Ru/AC (active component content 4.7 wt%, i.e. molar ratio of 5-hydroxymethylfurfural to catalyst calculated on metallic elements was about 100: 1). The conversion rate of the 5-hydroxymethylfurfural is 98 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 84.6 percent.

Example 12

The procedure of example 1 was followed, except that the catalyst Pd/C60 obtained in preparation example 11 was used in place of Ru/AC (active component content 4.7% by weight, i.e., the molar ratio of 5-hydroxymethylfurfural to the catalyst based on the metal element was about 100: 1). The conversion rate of the 5-hydroxymethylfurfural is 92 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 80.4 percent.

Comparative example 1

The procedure of example 1 was followed except that the Ru/AC obtained in comparative preparation example 1 was used in place of the Ru/AC in example 1. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 68.9 percent.

Comparative example 2

The procedure of example 1 was followed except that the Ru/AC obtained in comparative preparation 2 was used in place of the Ru/AC in example 1. The conversion rate of the 5-hydroxymethylfurfural is 100 percent, and the selectivity of the product 2, 5-furandicarboxylic acid is 64.6 percent.

Comparing the results of example 1 with those of comparative examples 1 and 2, it can be seen that, when 5-hydroxymethylfurfural is used to synthesize 2, 5-furandicarboxylic acid, 5-hydroxymethylfurfural can be efficiently catalytically oxidized to 2, 5-furandicarboxylic acid without adding an alkaline assistant by using the catalyst of the present invention, and the selectivity of 2, 5-furandicarboxylic acid can be significantly improved.

In addition, the catalyst is recycled by 5 times by the method of example 1, the conversion rate of HMF is 100%, and the selectivity of 2, 5-furandicarboxylic acid is still basically maintained at 96.3%, which shows that the stability and the recycling performance of the catalyst prepared by the method of the invention are improved.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention. It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition. In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. A method of preparing a catalyst comprising:

loading an active component on the carrier to obtain the catalyst;

wherein the active component is selected from one or more of ruthenium, palladium, platinum and rhodium; the front carrier is selected from one or more of activated carbon, graphite, fullerene and graphene oxide.

2. The method according to claim 1, wherein the active component is ruthenium and the pre-support is activated carbon.

3. The method according to claim 1, wherein the basic nitrogen-containing compound is selected from one or more of nitrogen-containing heterocyclic compounds selected from one or more of pyridine, piperidine, pyrrole, tetrahydropyrrole, piperidine and imidazole, aliphatic amines selected from one or more of ethylamine, diethylamine, triethylamine, n-propylamine, isopropylamine, 1, 2-propanediamine, 1, 3-propanediamine and n-butylamine, and aromatic amines selected from one or more of aniline, benzylamine, phenethylamine, o-aminophenol, m-aminophenol and p-aminophenol.

4. The production method according to claim 1, wherein the mass ratio of the fore-carrier to the basic nitrogen-containing compound is 1: 0.5 to 20; the mass ratio of the pre-carrier to the solvent is 1: 20-150.

5. The preparation method according to claim 1, wherein the solvent is a mixed solution of ethanol and water, the ethanol accounts for 10-95% of the mixed solution by mass, the water accounts for 5-90% of the mixed solution by mass, preferably, the ethanol accounts for 20-50% of the mixed solution by mass, and the water accounts for 50-80% of the mixed solution by mass.

6. The process according to claim 1, wherein the alkaline treatment is carried out at a temperature of 40 ℃ to 95 ℃, preferably 50 ℃ to 75 ℃, for a time of 1h to 12h, preferably 4h to 8 h.

7. The method according to claim 1, characterized in that the drying treatment is carried out at a temperature of 80 ℃ to 200 ℃, preferably 100 ℃ to 150 ℃; the drying time is 8-24 h, preferably 10-18 h.

8. The preparation method according to claim 1, wherein the roasting treatment comprises roasting the dried pre-support in a nitrogen or inert atmosphere, the roasting treatment being carried out at a temperature of 300 ℃ to 1000 ℃, preferably 400 ℃ to 800 ℃; the roasting treatment time is 1-6 h, preferably 2-4 h.

9. The method of claim 1, wherein the loading the active ingredient on the carrier comprises:

10. The preparation method according to claim 1, wherein the mass ratio of the active component to the carrier in the catalyst is 0.005-0.08: 1, preferably 0.035-0.08: 1, and more preferably 0.04-0.06: 1.

11. A catalyst prepared by the method of any one of claims 1 to 10.

12. A process for the preparation of 2, 5-furandicarboxylic acid comprising:

13. The preparation method according to claim 12, wherein the molar ratio of the 5-hydroxymethylfurfural to the active components in the catalyst is 40-200: 1, preferably 70-120: 1.

14. the production method according to claim 12, wherein the partial pressure of oxygen in the catalytic oxidation reaction is 0.05 to 2MPa, preferably 0.5 to 1 MPa; the reaction temperature is 50-170 ℃, and preferably 90-120 ℃; the reaction time is 0.5 to 24 hours, preferably 1 to 4 hours.