阅读说明：本技术 一种玄武岩纤维载体的固定床式苯甲醇制醛催化剂及其制备方法 (Fixed bed type benzyl alcohol aldehyde preparation catalyst with basalt fiber carrier and preparation method thereof ) 是由 苗世顶 李静瑶 刘清顺 时雄曦 司集文 张砚 于 2021-08-19 设计创作，主要内容包括：本发明公开一种玄武岩纤维载体的固定床式苯甲醇制醛催化剂及其制备方法,包括玄武岩纤维载体组分和催化浸润剂组分。该催化材料以纤维为载体,直接在生产过程中将具有催化活性的黏土材料负载Pd的分散液以浸润剂形式接枝于纤维表面,通过纺织形成一种三维网状的兼具催化性能和固定床功能的材料,简化了反应装置,暴露了更多Pd的催化活性位点数量,提高了催化剂与反应物质的可及性；同时包覆于纤维表面的无机浸润剂涂层有效的提高了催化网的耐腐蚀性,为工业上苯甲醇的催化氧化提供了更高效、性质稳定、易于回收、抗冲击能力更强、造价低廉、生产工艺简单且催化剂和催化床一体的新型材料。(The invention discloses a fixed bed type benzyl alcohol aldehyde preparation catalyst of a basalt fiber carrier and a preparation method thereof. The catalytic material takes fiber as a carrier, the clay material loaded Pd dispersion liquid with catalytic activity is directly grafted on the surface of the fiber in the form of a wetting agent in the production process, and a three-dimensional reticular material with both catalytic performance and fixed bed function is formed by spinning, so that a reaction device is simplified, the number of catalytic activity sites of more Pd is exposed, and the accessibility of a catalyst and a reaction substance is improved; meanwhile, the inorganic impregnating compound coating coated on the surface of the fiber effectively improves the corrosion resistance of the catalytic net, and provides a novel material which is more efficient, stable in property, easy to recover, stronger in impact resistance, low in manufacturing cost, simple in production process and integrated with a catalyst and a catalytic bed for the catalytic oxidation of industrial benzyl alcohol.)

1. A fixed bed type benzyl alcohol aldehyde preparation catalyst of basalt fiber carrier is characterized in that: the feed consists of the following raw materials: a basalt fiber carrier component and a catalytic impregnating compound component.

2. The fixed bed type benzyl alcohol aldehyde catalyst with the basalt fiber carrier as claimed in claim 1, is characterized in that: the basalt fiber carrier is an inorganic fiber which is prepared by preferably preparing basalt according to a proportion and is formed by drawing and has a micron-sized diameter.

3. The fixed bed type benzyl alcohol aldehyde catalyst with the basalt fiber carrier as claimed in claim 1, is characterized in that: the catalytic impregnating compound is prepared by mixing clay, noble metal precursor solution, sodium borohydride and deionized water in proportion.

4. The fixed bed type benzyl alcohol aldehyde catalyst with the basalt fiber carrier as claimed in claim 3, wherein: the clay can be montmorillonite, hectorite and other clay materials with electrostatic adsorption capacity, ion exchange capacity and expansive surface.

5. The fixed bed type benzyl alcohol aldehyde catalyst with the basalt fiber carrier as claimed in claim 3, wherein: the concentration of the precursor is 0.025mol/L-0.01 mol/L.

6. The fixed bed type benzyl alcohol aldehyde catalyst with the basalt fiber carrier as claimed in claim 3, wherein: the raw material comprises the following components in percentage by mass: 3-5 parts of clay, 15-45 parts of precursor solution, 0.04-0.2 part of sodium borohydride and 50-82 parts of deionized water.

7. The preparation method of the basalt fiber-supported fixed bed type catalyst for preparing aldehyde from benzyl alcohol according to any one of claims 1 to 5, wherein the fixed bed type catalyst comprises: the specific implementation steps are as follows:

(1) uniformly dispersing a certain amount of weighed clay nanoparticles in deionized water, stirring for 2-3h by using a magnetic stirrer, carrying out ultrasonic treatment for 5-10min, and then stirring for 0.5-1h again for later use;

(2) weighing a proper amount of precursor solution, adding the precursor solution into the dispersion liquid obtained in the step (1), stirring for 1-2h, performing ultrasonic treatment for 10-20min, uniformly stirring, centrifuging for 5-10min, and drying in a vacuum drying oven at 60-80 ℃ for 10h for later use;

(3) dispersing the solid sample obtained in the step (2) in deionized water, weighing a proper amount of sodium borohydride particles, dissolving the sodium borohydride particles in 5-15ml of deionized water, slowly adding the sodium borohydride particles into the dispersion liquid, and continuously stirring for 1-2 hours to obtain a catalytic impregnating compound for later use;

(4) melting basalt raw materials at the temperature of 1400-²Standby;

(5) and (4) plying the basalt fiber filaments obtained in the step (4) by a plying machine, and then spinning to form basalt fiber cloth to obtain a basalt fiber catalytic net with the thickness of 2-5mm, so as to obtain the material with both fixed bed and catalytic performance.

Technical Field

The invention discloses a fixed bed type benzyl alcohol aldehyde preparation catalyst with a basalt fiber carrier and a preparation method thereof, which are a catalytic material for preparing benzaldehyde by oxidizing benzyl alcohol and a preparation method thereof, belonging to the technical field of chemical materials.

Background

The aldehydes have high value as high-value components in the flavor industry such as food, medicine, dye, etc. It is usually prepared by hydrolysis of benzyl chloride or oxidation of toluene. But chlorine contamination or more by-products limit its application. Therefore, in order to meet the environmental requirements, the catalytic oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) by taking oxygen or hydrogen peroxide as a green oxidant under the action of a catalyst draws wide attention in laboratories and chemical industries. Noble metal Nanoparticles (NPs) such as Pt, Pd, Ru, Au, etc. have high catalytic activity due to incomplete coordination of surface atoms and size effect. However, since noble metal nanoparticles tend to grow gradually into inactive large particles due to the surface energy, Pd nanoparticles need to be supported on a suitable support. Although the selectivity and conversion rate of the invented material are improved to different degrees, the active site exposure is insufficient and the product and the catalyst are difficult to separate because of the agglomeration effect of the powder catalyst, and the glass fiber loses the carrier skeleton effect in a strong oxidation environment and is difficult to satisfy the industrial catalytic oxidation of benzyl alcohol by taking hydrogen peroxide as an oxidant.

Compared with the carrier, the basalt fiber has extremely high corrosion resistance, impact resistance, heat resistance and the like under the continuous strong oxidizing fluid environment compared with the glass fiber, and has incomparable advantages. The weavability of the basalt fiber enables the basalt fiber to be prepared into a three-dimensional network microstructure, and provides possibility for preparing fixing devices such as a thin folded sheet structure and a packed bed with catalytic performance. Considering the technical problem that the heterogeneous catalyst is damaged by the reduction of mechanical properties due to oxidation corrosion, the inorganic wetting agent with stronger corrosion resistance is adopted as the modified coating, so that the advantage is obvious. The clay particles can form a continuous network structure through crosslinking in an aqueous medium, can form a uniform film due to good thixotropy and swelling property, can react with silicon hydroxyl on the surface of the fiber to form a new-Si-O-Si-bond to be coated on the surface of the fiber to form a coating layer, can effectively resist or slow down the surface erosion effect of the medium, and provides possibility for being used as a fiber modified impregnating compound in the production process. In addition, the clay particles have ion exchange characteristics and surface electronegativity, and Pd is adsorbed on the surface of montmorillonite in situ through static electricity under the action of a reducing agent²⁺Reduction to Pd⁰The dispersibility of the metal nanoparticles is increased, thereby exposing more active sites to be in full contact with the reactant benzyl alcohol. Therefore, the clay also provides a bridge for loading the noble metal nano particles on the fiber. To the best of our knowledge, few reports have been made on the use of basalt fibers modified with inorganic wetting agents as a fixed bed in the field of catalysis or focused on solving the catalyst/solvent separation problem. Therefore, the main material of the clay-loaded Pd inorganic impregnating compound modified basalt fiber catalytic mesh utilizes the economic, non-toxic and harmless inorganic material, controls the pressure drop in a different beneficial mode from other traditional catalysts, solves the problem of catalyst/solvent separation and improves the contact efficiency.

In conclusion, the fixed bed type benzyl alcohol aldehyde preparation catalyst with the basalt fiber carrier is an environment-friendly material which is high in catalytic activity, good in mechanical stability, strong in corrosion resistance, simple in reaction process and low in manufacturing cost, and has good economic benefits and social benefits.

Disclosure of Invention

Technical problem to be solved

1. The invention provides a fixed bed type benzyl alcohol aldehyde preparation catalyst with a basalt fiber carrier, which aims to further improve the catalytic oxidation efficiency of benzyl alcohol.

2. The invention provides a fixed bed type benzyl alcohol aldehyde preparation catalyst with a basalt fiber carrier, which aims to further improve the corrosion resistance of a catalyst bed under the action of continuous corrosive fluid.

3. The invention provides a fixed bed type benzyl alcohol aldehyde preparation catalyst with a basalt fiber carrier, and aims to further solve the problem of separation of a liquid product of benzyl alcohol oxidation from a traditional powder catalyst.

4. The invention provides a fixed bed type benzyl alcohol aldehyde preparation catalyst with a basalt fiber carrier, and aims to further optimize the technical problem that a catalytic bed is required to be arranged in the traditional powdery catalyst.

The technical scheme is as follows:

in order to meet the technical requirements, the invention provides a fixed bed type benzyl alcohol aldehyde preparation catalyst with a basalt fiber carrier and a preparation method thereof, which can replace the traditional reaction mode of a powdery catalyst and a catalytic bed, and have the advantages of simplified reaction device, high catalytic activity, good mechanical stability, strong corrosion resistance, simple production process, low manufacturing cost and the like. The material is realized by the following technical scheme:

a fixed bed type benzyl alcohol aldehyde preparation catalyst of a basalt fiber carrier is composed of the following raw materials: basalt fiber carrier and catalytic impregnating compound

1. Preferably, the basalt fiber carrier is an inorganic fiber which is prepared from basalt according to a certain proportion and is formed by drawing and has a diameter of 8-15 μm.

2. Preferably, the catalytic impregnating compound is prepared by proportionally mixing clay, noble metal precursor solution, sodium borohydride and deionized water

3. Preferably, the clay can be montmorillonite, hectorite and other clay materials with electrostatic adsorption capacity, ion exchange capacity and swelling surface.

4. Preferably, the concentration of the sodium tetrachloropalladate is 0.025mol/L-0.01mol/L,

5. preferably, the mass ratio of the raw material components is as follows: 3-5 parts of clay, 15-45 parts of precursor solution, 0.04-0.2 part of sodium borohydride and 50-82 parts of deionized water.

The preparation method comprises the following steps:

according to the technical scheme of the fixed bed type benzyl alcohol aldehyde preparation catalyst with the basalt fiber carrier, the specific implementation steps are as follows:

(1) uniformly dispersing a certain amount of weighed clay nanoparticles in deionized water, stirring for 2-3h by using a magnetic stirrer, carrying out ultrasonic treatment for 5-10min, and then stirring for 0.5-1h again for later use;

(2) weighing a proper amount of precursor solution, adding the precursor solution into the dispersion liquid obtained in the step (1), magnetically stirring for 1-2h, performing ultrasonic treatment for 10min, uniformly stirring, centrifuging for 5-10min, and drying in a vacuum drying oven at 60-80 ℃ for 10h for later use;

(3) dispersing the solid sample obtained in the step (2) in deionized water, weighing a proper amount of sodium borohydride particles, dissolving the sodium borohydride particles in 5-15ml of deionized water, slowly adding the sodium borohydride particles into the dispersion liquid, and continuously stirring for 1-2 hours to obtain a catalytic impregnating compound for later use;

(4) melting basalt raw materials at the temperature of 1400-²Standby;

(5) and (3) plying the basalt fiber filaments obtained in the step (4) by a plying machine, and then spinning to form basalt fiber cloth to obtain a basalt fiber catalytic net with the thickness of 2-5mm, so as to obtain the Pd @ CLAY/BFCN material with the fixed bed function and the catalytic performance.

The invention has the following positive effects:

compared with the prior art, the invention provides a fixed bed type benzyl alcohol aldehyde preparation catalyst of a basalt fiber carrier and a preparation method thereof, and the positive effects are as follows:

1. the clay is used as a bridge, and the metal Pd nano particles loaded on the three-dimensional basalt fiber mesh structure obtain higher dispersity and expose more active sites;

2. the three-dimensional basalt fiber mesh structure increases the accessibility of the reactant benzyl alcohol and the active sites, thereby increasing the conversion efficiency;

3. the clay is used as an inorganic modified impregnating compound to wrap the basalt fiber, so that the corrosion resistance of the fiber catalytic mesh in a strong oxidation medium is improved;

4. the basalt fiber three-dimensional net is used as a reactor fixed catalytic bed structure, and has very good fluid impact resistance in continuous fluid

5. The clay-loaded Pd inorganic impregnating compound modified basalt fiber catalytic net is used as a reactor fixed catalytic bed structure, so that the problem of separation of a fluid medium and a catalyst can be effectively solved. The oxidation reaction steps are simplified.

Drawings

FIG. 1 is a surface topography of basalt fiber filaments and fabrics after the impregnation of a catalytic coating according to the present invention;

FIG. 2 is a graph of the conversion and strength of the catalytic web of example 2 of the present invention over four cycles;

FIG. 3 is a graph of the change in tensile strength and mass loss of the catalytic web at different impact times for example 2 of the present invention;

FIG. 4 is a graph showing the effect of the catalytic gauze on the conversion and selectivity of the reaction for producing aldehyde from benzyl alcohol under different impact times in example 2 of the present invention;

FIG. 5 is a graph of the change in catalytic web tensile strength and mass loss for different fluid velocities according to example 2 of the present invention;

FIG. 6 is a graph showing the effect of catalytic gauze on the conversion and selectivity of the reaction for producing aldehyde from benzyl alcohol at different flow rates in example 2 of the present invention.

The specific implementation mode is as follows:

the present invention is further illustrated by the following examples, which do not limit the present invention in any way, and any modifications or changes that can be easily made by a person skilled in the art to the present invention will fall within the scope of the claims of the present invention without departing from the technical solution of the present invention.

Example 1:

weighing 3 parts of montmorillonite sample, dissolving in 82 parts of deionized water, fully stirring for 2 hours, then carrying out ultrasonic treatment for 10 minutes, and stirring again for 30 minutes to form montmorillonite dispersion liquid; then adding 15 parts of 0.025mol/L sodium tetrachloropalladate solution, fully stirring for 1.5h and carrying out ultrasonic treatment for 10 min; then 0.1 part of sodium borohydride is weighed and dissolved in 8ml of deionized water, and is slowly added into the dispersion liquid to be stirred for 1 hour, so as to obtain the inorganic impregnating compound; the basalt raw materials are uniformly mixed and then placed into a wire drawing machine, wire drawing is carried out through platinum-rhodium alloy at 1500 ℃, meanwhile, inorganic impregnating compound is poured into an impregnating compound container, the impregnating compound is dripped on the surface of the fiber at a constant speed while wire drawing is carried out, and the prepared fiber bundle is woven into basalt fiber cloth through a strander and a loom.

Example 2:

weighing 5 parts of montmorillonite sample, dissolving in 50 parts of deionized water, fully stirring for 2 hours, performing ultrasonic treatment for 10 minutes, and stirring again for 30 minutes to form montmorillonite dispersion liquid; then adding 45 parts of 0.025mol/L sodium tetrachloropalladate solution, fully stirring for 1.5h and carrying out ultrasonic treatment for 10 min; then 0.1 part of sodium borohydride is weighed and dissolved in 8ml of deionized water, and is slowly added into the dispersion liquid to be stirred for 1 hour, so as to obtain the inorganic impregnating compound; the basalt raw materials are uniformly mixed and then placed into a wire drawing machine, wire drawing is carried out through platinum-rhodium alloy at 1500 ℃, meanwhile, inorganic impregnating compound is poured into an impregnating compound container, the impregnating compound is dripped on the surface of the fiber at a constant speed while wire drawing is carried out, and the prepared fiber bundle is woven into basalt fiber cloth through a strander and a loom.

Example 3:

weighing 3 parts of a hectorite sample, dissolving the hectorite sample in 67 parts of deionized water, fully stirring for 2 hours, performing ultrasonic treatment for 10min, and stirring again for 30min to form a hectorite dispersion liquid; then adding 30 parts of 0.025mol/L sodium tetrachloropalladate solution, fully stirring for 1.5h and carrying out ultrasonic treatment for 10 min; then 0.2 part of sodium borohydride is weighed and dissolved in 8ml of deionized water, and is slowly added into the dispersion liquid to be stirred for 1 hour, so as to obtain the inorganic impregnating compound; the basalt raw materials are uniformly mixed and then placed into a wire drawing machine, wire drawing is carried out through platinum-rhodium alloy at 1500 ℃, meanwhile, inorganic impregnating compound is poured into an impregnating compound container, the impregnating compound is dripped on the surface of the fiber at a constant speed while wire drawing is carried out, and the prepared fiber bundle is woven into basalt fiber cloth through a strander and a loom.

Example 4:

weighing 5 parts of montmorillonite sample, dissolving in 80 parts of deionized water, fully stirring for 2 hours, performing ultrasonic treatment for 10 minutes, and stirring again for 30 minutes to form montmorillonite dispersion liquid; then adding 15 parts of 0.025mol/L sodium tetrachloropalladate solution, fully stirring for 1.5h and carrying out ultrasonic treatment for 10 min; then 0.2 part of sodium borohydride is weighed and dissolved in 8ml of deionized water, and is slowly added into the dispersion liquid to be stirred for 1 hour, so as to obtain the inorganic impregnating compound; the basalt raw materials are uniformly mixed and then placed into a wire drawing machine, wire drawing is carried out through platinum-rhodium alloy at 1500 ℃, meanwhile, inorganic impregnating compound is poured into an impregnating compound container, the impregnating compound is dripped on the surface of the fiber at a constant speed while wire drawing is carried out, and the prepared fiber bundle is woven into basalt fiber cloth through a strander and a loom.

Example 5:

weighing 4 parts of hectorite sample, dissolving in 66 parts of deionized water, fully stirring for 2 hours, performing ultrasonic treatment for 10min, and stirring again for 30min to form a hectorite dispersion liquid; then adding 30 parts of 0.025mol/L sodium tetrachloropalladate solution, fully stirring for 1.5h and carrying out ultrasonic treatment for 10 min; then 0.1 part of sodium borohydride is weighed and dissolved in 8ml of deionized water, and is slowly added into the dispersion liquid to be stirred for 1 hour, so as to obtain the inorganic impregnating compound; the basalt raw materials are uniformly mixed and then placed into a wire drawing machine, wire drawing is carried out through platinum-rhodium alloy at 1500 ℃, meanwhile, inorganic impregnating compound is poured into an impregnating compound container, the impregnating compound is dripped on the surface of the fiber at a constant speed while wire drawing is carried out, and the prepared fiber bundle is woven into basalt fiber cloth through a strander and a loom.

Test example:

a performance experiment was conducted on the fixed bed type benzyl alcohol to aldehyde catalysts of basalt fiber supports prepared in examples 1 to 5. The tensile strength test is carried out according to national standards GB/T3354 and GB/T21490-2008; the catalytic activity test is carried out on the conversion efficiency of oxidizing the benzyl alcohol into the benzaldehyde after 5 hours of reaction when hydrogen peroxide is used as an oxidant through gas chromatography under the condition of condensation reflux; the fluid impact resistance test measures the change of tensile strength and mass loss of the catalytic net impacting for 1-24h when the water flow rate is 0.1-0.6m/s through the self-made laboratory equipment.

Table 1 catalytic activity testing of catalytic nets

Serial number	Conversion (%)	Selectivity (%)	TOF(h-1)	Reaction temperature (. degree.C.)
					Example 1	54	99	12.72	40
Example 2	96	90	22.61	80
					Example 3	86	88	20.64	80
Example 4	90	91	21.2	80
					Example 5	87	84	20.49	80

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