阅读说明：本技术 一种木质素基有序介孔碳催化剂及其制备方法和应用 (Lignin-based ordered mesoporous carbon catalyst and preparation method and application thereof ) 是由 漆新华 王晓琦 仇茉 于 2020-06-19 设计创作，主要内容包括：本发明属于催化剂技术领域,特别涉及一种木质素基有序介孔碳催化剂及其制备方法和应用。本发明提供的木质素基有序介孔碳催化剂的制备方法,包括以下步骤：将木质素、芳香酚和有机溶剂混合,得到前驱体溶液；将所述前驱体溶液与三嵌段共聚物的有机溶液混合,得到胶束；所述三嵌段共聚物为聚氧乙烯-聚氧丙烯-聚氧乙烯共聚物；将所述胶束与可溶性金属盐混合,得到金属-有机混合液；将所述金属-有机混合液与醛混合后,依次进行溶剂蒸发、交联处理和焙烧,得到所述木质素基有序介孔碳催化剂。测试结果表明,本发明提供的木质素基有序介孔碳催化剂在糠醛加氢反应中进行催化,糠醛转化率为70～92％,糠醇选择性为85～98％。(The invention belongs to the technical field of catalysts, and particularly relates to a lignin-based ordered mesoporous carbon catalyst and a preparation method and application thereof. The preparation method of the lignin-based ordered mesoporous carbon catalyst provided by the invention comprises the following steps: mixing lignin, aromatic phenol and an organic solvent to obtain a precursor solution; mixing the precursor solution with an organic solution of a triblock copolymer to obtain a micelle; the triblock copolymer is polyoxyethylene-polyoxypropylene-polyoxyethylene copolymer; mixing the micelle with soluble metal salt to obtain a metal-organic mixed solution; and mixing the metal-organic mixed solution with aldehyde, and then sequentially performing solvent evaporation, crosslinking treatment and roasting to obtain the lignin-based ordered mesoporous carbon catalyst. Test results show that the lignin-based ordered mesoporous carbon catalyst provided by the invention is used for catalyzing furfural hydrogenation reaction, the furfural conversion rate is 70-92%, and the furfuryl alcohol selectivity is 85-98%.)

1. A preparation method of a lignin-based ordered mesoporous carbon catalyst comprises the following steps:

mixing lignin, aromatic phenol and an organic solvent to obtain a precursor solution;

mixing the precursor solution with an organic solution of a triblock copolymer to obtain a micelle; the triblock copolymer is polyoxyethylene-polyoxypropylene-polyoxyethylene copolymer;

mixing the micelle with soluble metal salt to obtain a metal-organic mixed solution;

and mixing the metal-organic mixed solution with aldehyde, and then sequentially performing solvent evaporation, crosslinking treatment and roasting to obtain the lignin-based ordered mesoporous carbon catalyst.

2. The preparation method according to claim 1, wherein the mass ratio of the lignin to the aromatic phenol is (1-4): 1.

3. the method according to claim 1 or 2, wherein the ratio of the total mass of the lignin and the aromatic phenol to the mass of the triblock copolymer is 1: (0.5 to 3).

4. The production method according to claim 1, wherein the soluble metal salt is a metal nitrate;

the metal nitrate is one or more of copper nitrate, nickel nitrate and cobalt nitrate.

5. The method according to claim 1, wherein the aldehyde is glyoxal and/or glutaraldehyde.

6. The method according to claim 1, 4 or 5, wherein the mass ratio of the triblock copolymer, aldehyde and soluble metal salt is 1.7: (0.3-0.5): (0-0.4), the soluble metal salt is not 0.

7. The method according to claim 1, wherein the temperature of the crosslinking treatment is 80 to 120 ℃ and the time is 12 to 36 hours.

8. The preparation method according to claim 1, wherein the roasting temperature is 500-900 ℃ and the roasting time is 2-3 h; the firing is carried out in a protective gas atmosphere.

9. The lignin-based ordered mesoporous carbon catalyst prepared by the preparation method of any one of claims 1 to 8, which comprises ordered mesoporous carbon and metal loaded in pore channels of the ordered mesoporous carbon.

10. The application of the lignin-based ordered mesoporous carbon catalyst as a catalyst in furfural hydrogenation reaction according to claim 9, wherein in the furfural hydrogenation reaction, the mass of the lignin-based ordered mesoporous carbon catalyst is 0.5-1.5% of that of the liquid raw material; the furfural hydrogenation reaction conditions comprise: the temperature is 100-200 ℃, and the hydrogen pressure is less than or equal to 4.0 MPa.

Technical Field

The invention belongs to the technical field of catalysts, and particularly relates to a lignin-based ordered mesoporous carbon catalyst and a preparation method and application thereof.

Background

Ordered Mesoporous Carbon (OMCs) has large specific surface area, highly ordered pore distribution and high mechanical stability, and has wide application in the fields of catalysis, adsorption, separation, energy storage, electrochemistry and the like. However, compared with the traditional reverse replication method using a silicon-based mesoporous material as a hard template, the conventional ordered mesoporous carbon is a simple, convenient and easy soft template method using induced evaporation self-assembly of a block copolymer and a polymer precursor, and becomes an effective method for synthesizing the ordered mesoporous carbon material.

The classical soft template method utilizes phenolic resin and block copolymer to carry out self-assembly, and obtains the ordered mesoporous carbon material by removing a template agent, but the method completely adopts poisonous phenol and formaldehyde as precursors, and the prepared ordered mesoporous carbon can not effectively encapsulate metal active sites with catalytic activity in the ordered mesoporous carbon, so that the catalytic activity of the catalyst is low. Therefore, finding alternative precursors that are sustainable and less toxic is one of the most important challenges at present; moreover, how to encapsulate the metal active sites in the ordered mesoporous carbon at the same time is a problem to be faced at present in order to improve the catalytic activity of the ordered mesoporous carbon catalyst.

Disclosure of Invention

In view of the above, the present invention aims to provide a lignin-based ordered mesoporous carbon catalyst and a preparation method thereof, the preparation method provided by the present invention is low in toxicity, and the lignin-based ordered mesoporous carbon catalyst obtained by the preparation method provided by the present invention has the characteristics of high catalytic activity, high selectivity to a target product, and stable catalytic performance; the invention also provides application of the lignin-based ordered mesoporous carbon catalyst.

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

the invention provides a preparation method of a lignin-based ordered mesoporous carbon catalyst, which comprises the following steps:

mixing lignin, aromatic phenol and an organic solvent to obtain a precursor solution;

mixing the precursor solution with an organic solution of a triblock copolymer to obtain a micelle; the triblock copolymer is polyoxyethylene-polyoxypropylene-polyoxyethylene copolymer;

mixing the micelle with soluble metal salt to obtain a metal-organic mixed solution;

and mixing the metal-organic mixed solution with aldehyde, and then sequentially performing solvent evaporation, crosslinking treatment and roasting to obtain the lignin-based ordered mesoporous carbon catalyst.

Preferably, the mass ratio of the lignin to the aromatic phenol is (1-4): 1.

preferably, the ratio of the total mass of the lignin and the aromatic phenol to the mass of the triblock copolymer is 1: (0.5 to 3).

Preferably, the soluble metal salt is a metal nitrate; the metal nitrate is one or more of copper nitrate, nickel nitrate and cobalt nitrate.

Preferably, the aldehyde is glyoxal and/or glutaraldehyde.

Preferably, the mass ratio of the triblock copolymer, aldehyde and soluble metal salt is 1.7: (0.3-0.5): (0-0.4), the soluble metal salt is not 0.

Preferably, the temperature of the cross-linking treatment is 80-120 ℃, and the time is 12-36 h.

Preferably, the roasting temperature is 500-900 ℃, and the roasting time is 2-3 h; the firing is carried out in a protective gas atmosphere.

The invention also provides the lignin-based ordered mesoporous carbon catalyst prepared by the preparation method in the technical scheme, which comprises ordered mesoporous carbon and metal loaded in the pore canal of the ordered mesoporous carbon.

The invention also provides an application of the lignin-based ordered mesoporous carbon catalyst in the technical scheme as a catalyst in furfural hydrogenation reaction, wherein the mass of the lignin-based ordered mesoporous carbon catalyst in the furfural hydrogenation reaction is 0.5-1.5% of that of the liquid raw material; the catalytic conditions in the furfural hydrogenation reaction include: the temperature is 100-200 ℃, and the hydrogen pressure is less than or equal to 4.0 MPa.

The invention provides a preparation method of a lignin-based ordered mesoporous carbon catalyst, which comprises the following steps: mixing lignin, aromatic phenol and an organic solvent to obtain a precursor solution; mixing the precursor solution with an organic solution of a triblock copolymer to obtain a micelle; the triblock copolymer is polyoxyethylene-polyoxypropylene-polyoxyethylene copolymer; mixing the micelle with soluble metal salt to obtain a metal-organic mixed solution; and mixing the metal-organic mixed solution with aldehyde, and then sequentially performing solvent evaporation, crosslinking treatment and roasting to obtain the lignin-based ordered mesoporous carbon catalyst. According to the invention, lignin and aromatic phenol are used as carbon precursors, the toxicity of completely using phenol as a precursor substance is reduced, a triblock copolymer is used as a surfactant, a soluble metal salt is used as a catalyst active component, aldehyde is used as a cross-linking agent, metal is loaded in the material by an induced evaporation self-assembly one-step method, the surfactant is removed and the metal is reduced under the condition of containing C by roasting, and the metal-loaded ordered mesoporous carbon material is obtained without further reduction. The preparation method provided by the invention can be used for obtaining the lignin-based ordered mesoporous carbon material with higher specific surface area, and controlling metal in the pore channel by utilizing the threshold limiting effect of the ordered mesoporous carbon material, so that the metal is not easy to agglomerate or run off, the obtained lignin-based ordered mesoporous carbon catalyst still has higher dispersity and activity after multiple catalytic reactions, and the catalytic activity and the catalytic stability of the metal are greatly improved.

Drawings

FIG. 1 is a TEM image of the lignin-based ordered mesoporous carbon catalyst obtained in example 1;

FIG. 2 is a TEM image of the lignin-based ordered mesoporous carbon catalyst obtained in example 1;

FIG. 3 is a small angle XRD pattern of the lignin-based ordered mesoporous carbon catalyst obtained in example 1;

FIG. 4 is a wide-angle XRD pattern of the lignin-based ordered mesoporous carbon catalyst obtained in example 1;

FIG. 5 is a TEM image of the lignin-based ordered mesoporous carbon catalyst obtained in example 3;

FIG. 6 is a TEM image of the lignin-based ordered mesoporous carbon catalyst obtained in example 5.

The test results of the embodiment show that the lignin-based ordered mesoporous carbon catalyst provided by the invention is used for catalyzing furfural hydrogenation reaction, the furfural conversion rate is 70-92%, the furfuryl alcohol selectivity is 85-98%, and the catalyst has high catalytic activity and selectivity.