阅读说明：本技术 一种膨胀石墨碳基固体酸催化剂的制备方法 (Preparation method of expanded graphite carbon-based solid acid catalyst ) 是由 胡勋 高志然 张丽君 贾鹏 邵月文 马德龙 高连信 徐晴 田红利 杨晓鹏 李岳 于 2019-05-28 设计创作，主要内容包括：本发明具体提供了一种固体酸催化剂的制备方法,该方法以膨胀石墨为原料,将其均匀分散于硫酸水溶液,然后于高温下进行水热反应进行酸化处理,抽滤、洗涤和干燥后得到固体酸催化剂,制备的固体酸催化剂催化糠醇具有较高的乙酰丙酸乙酯产率。本发明提供的这种制备方法原料廉价易得,合成方法简单,对于碳基固体酸催化剂的制备提供了一种新思路。并且分析测试结果表明制备的固体酸催化剂的性能较好,应用前景广阔,有商业价值。(The invention specifically provides a preparation method of a solid acid catalyst, which takes expanded graphite as a raw material, uniformly disperses the expanded graphite in a sulfuric acid aqueous solution, then carries out hydrothermal reaction at high temperature for acidification treatment, and obtains the solid acid catalyst after suction filtration, washing and drying. The preparation method provided by the invention has the advantages of cheap and easily-obtained raw materials and simple synthesis method, and provides a new idea for the preparation of the carbon-based solid acid catalyst. And the analysis and test result shows that the prepared solid acid catalyst has better performance, wide application prospect and commercial value.)

1. A preparation method of an expanded graphite carbon-based solid acid catalyst is characterized by comprising the following steps:

(1) mixing, namely uniformly mixing the expanded graphite with sulfuric acid solutions with different concentrations, and stirring for 1 ~ 2 h at room temperature;

(2) hydrothermal reaction: transferring the mixture of the expanded graphite and the sulfuric acid into a hydrothermal kettle, and reacting at different temperatures for different times;

(3) washing: washing the catalyst obtained after the reaction with deionized water by using a suction filtration device until the catalyst is neutral;

(4) and (3) drying, namely drying the washed solid in an oven at the temperature of 80 ~ 100 ℃ for 8 ~ 12 h to obtain the solid acid catalyst.

2. The method for preparing a solid acid catalyst according to claim 1, wherein the concentration of the sulfuric acid solution in the step (1) is 0 ~ 15.0.0 mol/L.

3. The method for preparing a solid acid catalyst according to claim 1, wherein the mass ratio of the expanded graphite to the sulfuric acid solution in the step (1) is 1:10 ~ 1: 18.

4. The method for preparing a solid acid catalyst according to claim 1, wherein the hydrothermal reaction temperature in the step (2) is 150 ℃ ~ 250 ℃.

5. The method for preparing a solid acid catalyst according to claim 1, wherein the hydrothermal reaction time in the step (2) is 0 ~ 16 h.

Technical Field

The invention relates to a preparation method of a solid acid catalyst, in particular to a preparation method of a catalyst for acid catalytic conversion of furfuryl alcohol, and belongs to the field of catalyst preparation.

Background

Acid is a very important catalyst in the conversion reaction of biomass, and the catalytic effect is obvious. At present, liquid acid catalysts such as sulfuric acid, hydrochloric acid and the like are commonly used in industrial application, but the liquid acid catalysts as homogeneous acids have the problems of difficult separation from reactants and products, difficult recycling and the like, and the treatment of waste liquid after reaction is also a great problem, thereby causing great pollution to the environment.

The solid acid catalyst has the advantages of effective separation and reutilization, which causes wide attention in academia and industry, and at present, the solid acid catalyst mainly comprises heteropolyacids such as H3PW12O40 and phosphomolybdic acid, cation exchange resins such as A70 and A15, zeolite molecular sieve solid acids such as ZSM-5 zeolite and X zeolite, and carbon-based solid acid catalysts, and the carbon-based catalysts are the hot points of research due to wide raw material sources and simple preparation.

The carbon carrier adopted by the catalyst prepared by the invention is expanded graphite which is a novel functional carbon material and has the characteristics of large volume, softness, compression resilience and the like, and the expanded graphite is used as the carrier for preparing the solid acid catalyst, so that a novel method is provided for selecting the carrier for preparing the carbon-based catalyst.

Disclosure of Invention

The invention aims to prepare a novel carbon-based solid acid catalyst and apply the carbon-based solid acid catalyst to the acid catalytic conversion reaction of furfuryl alcohol, and therefore, the invention provides a preparation method of the solid acid catalyst, which is simple and comprises the following steps as shown in figure 1:

(1) mixing, namely uniformly mixing the expanded graphite with sulfuric acid solutions (0, 2.5, 5, 7.5, 10, 12.5 and 15 mol/L) with different concentrations, and stirring at room temperature for 1 ~ 2 hours;

(2) hydrothermal reaction, namely transferring the mixture of the expanded graphite and sulfuric acid into a hydrothermal kettle, and reacting for 10 hours at the temperature of 150 ~ 250 ℃;

(3) washing: washing the catalyst obtained after the reaction with deionized water by using a suction filtration device until the catalyst is neutral;

(4) drying, namely drying the washed solid in an oven at the temperature of 80 ~ 100 ℃ for 8 ~ 12 h to obtain a solid acid catalyst;

evaluation of solid acid catalytic performance: adding 0.04 g of solid acid catalyst into 1.0 wt.% ethanol solution of furfuryl alcohol, and reacting in a Heler kettle at 150 deg.C and N₂The pressure was 4.0 MPa, and liquid product analysis and yield calculation were performed by GC-MS.

The experimental results show that: the optimal hydrothermal temperature is 200 ℃, the optimal hydrothermal time is 10h, and the optimal concentration of the sulfuric acid solution is 5 mol/L.

The invention has the beneficial effects that:

(1) the invention provides a new method for preparing a carbon-based solid acid catalyst by using expanded graphite as a raw material and a hydrothermal method, and the preparation method is simple, easy for industrial production, cheap in raw materials and easy to obtain;

(2) the carbon-based solid acid catalyst prepared by the invention has good glycolic acid catalytic conversion performance.

Drawings

FIG. 1 is a flow chart of the preparation process of an expanded graphite carbon-based solid catalyst.

FIG. 2 shows the furfuryl alcohol acid catalytic activity of the carbon-based solid acid catalyst prepared according to the present invention.

FIG. 3 is a gas chromatogram of the liquid obtained in example 2 after the solid acid catalyst catalyzes the furfuryl alcohol conversion reaction.

Detailed Description

Blank example

In the blank example, the acid catalysis performance of the expanded graphite is directly evaluated: 0.04 g of a solid acid catalyst was added to a 1.0 wt.% ethanol solution of furfuryl alcohol by mass, and the reaction was carried out in a Hull kettle, N₂The pressure was 4.0 MPa, and the yield of ethyl levulinate was 30.1% by liquid product analysis and calculation of yield by GC-MS, and the results are shown in FIG. 2.

Comparative example

In the comparative example, the expanded graphite is placed in deionized water, and after hydrothermal reaction is carried out for 10 hours at 200 ℃, the acid catalysis performance is evaluated, and the specific operation steps are as follows:

(1) mixing, namely mixing 1.0 g of expanded graphite with 60 mL of deionized water, and stirring at room temperature for 1 ~ 2 h;

(2) hydrothermal reaction: transferring the mixture of the expanded graphite and the deionized water into a hydrothermal kettle, and reacting for 10 hours at 200 ℃;

(3) washing: washing the catalyst obtained after the hydrothermal reaction by using deionized water by using a suction filtration device until the catalyst is neutral;

(4) drying, namely drying the washed solid in an oven at the temperature of 80 ~ 100 ℃ for 8 ~ 12 h to obtain a solid acid catalyst;

(5) evaluation of solid acid catalytic performance: adding 0.04 g of solid acid catalyst into 1.0 wt.% ethanol solution of furfuryl alcohol, and reacting in a Heler kettle at 150 deg.C and N₂The pressure was 4.0 MPa, and the liquid product analysis and yield calculation were carried out by GC-MS, ethyl levulinateThe yield of the ester was 5.2%, and the results are shown in FIG. 2.