阅读说明：本技术 一种磁性CNx催化剂及其制备方法和在垃圾腐臭气中的应用 (Magnetic CNxCatalyst, preparation method thereof and application of catalyst in garbage rancidity ) 是由 张震威 乐传俊 魏雪姣 吴泽颖 邓瑶瑶 向梅 张微 于 2020-05-11 设计创作，主要内容包括：本发明涉及一种磁性CN<Sub>x</Sub>催化剂及其制备方法好应用,制备方法如下：(1)将含酸酐的表面活性剂溶于水中,再加入胺类化合物,搅拌,加热,反应3h～4h后得到混合液A；将铁盐化合物溶于水中形成铁盐溶液；将所述混合液A与所述铁盐溶液混合,搅拌反应1h～24h,得到混合液B；(2)调节所述混合液B的pH值为酸性,继续搅拌反应2h～12h,得到沉淀物,过滤,多次洗涤所述沉淀物,干燥得到前驱体；(3)将所述前驱体置于气氛炉中,在惰性气体中通入氢气,于300℃～500℃下进行加氢还原反应,最终制得磁性CN<Sub>x</Sub>催化剂。本发明方法制得磁性CN<Sub>x</Sub>催化剂对所述有机硫化合物和有机胺化合物的催化降解率大于60％。(The invention relates to a magnetic CN x The catalyst and the preparation method thereof are easy to apply, and the preparation method comprises the following steps: (1) dissolving a surfactant containing anhydride in water, adding an amine compound, stirring, heating, and reacting for 3-4 hours to obtain a mixed solution A; dissolving an iron salt compound in water to form an iron salt solution; mixing the mixed solution A with the mixed solution AMixing the ferric salt solutions, and stirring and reacting for 1-24 h to obtain a mixed solution B; (2) adjusting the pH value of the mixed solution B to be acidic, continuously stirring and reacting for 2-12 h to obtain a precipitate, filtering, washing the precipitate for multiple times, and drying to obtain a precursor; (3) putting the precursor into an atmosphere furnace, introducing hydrogen into inert gas, and carrying out hydrogenation reduction reaction at 300-500 ℃ to finally prepare magnetic CN x A catalyst. The method of the invention prepares the magnetic CN x The catalytic degradation rate of the catalyst to the organic sulfur compound and the organic amine compound is more than 60 percent.)

1. Magnetic CN_xThe preparation method of the catalyst is characterized by comprising the following steps:

(1) dissolving a surfactant containing anhydride in water, adding an amine compound, stirring, heating, and reacting for 3-4 hours to obtain a mixed solution A; dissolving an iron salt compound in water to form an iron salt solution; mixing the mixed solution A with the ferric salt solution, and stirring and reacting for 1-24 h to obtain a mixed solution B;

(2) adjusting the pH value of the mixed solution B to be acidic, continuously stirring and reacting for 2-12 h to obtain a precipitate, filtering, washing the precipitate for multiple times, and drying to obtain a precursor;

(3) putting the precursor into an atmosphere furnace, introducing hydrogen into inert gas, and carrying out hydrogenation reduction reaction at 300-500 ℃ to finally prepare magnetic CN_xA catalyst.

2. A magnetic CN according to claim 1_xThe preparation method of the catalyst is characterized in that the ferric salt compound in the step (1) is one of ferric nitrate, ferric chloride and potassium ferricyanate; the surface active agent containing the anhydride is styrene-maleic anhydride block copolymer.

3. A magnetic CN according to claim 1_xThe preparation method of the catalyst is characterized in that the amine compound in the step (1) is strong ammonia water with the mass fraction of 25 wt% -28 wt%.

4. A magnetic CN according to claim 1_xThe preparation method of the catalyst is characterized in that the heating temperature in the step (1) is 60-120 ℃.

5. A magnetic CN according to claim 1_xThe preparation method of the catalyst is characterized in that the mass ratio of the surface active agent containing the acid anhydride, the amine compound and the iron salt compound in the step (1) is (4-8): (1-2): 0.5-10); the concentration of the surface active agent containing the anhydride in water is 0.1 g/mL-0.5 g/mL; the concentration of the iron salt compound in the solution B is 0.1 g/mL-0.3 g/mL.

6. A magnetic CN according to claim 1_xPreparation method of catalystThe method is characterized in that the pH value of the acidity in the step (2) is 1-6, the acidity is adjusted by adopting nitric acid or hydrochloric acid with the mass concentration of 10%, and the dropping speed of the nitric acid or hydrochloric acid is 1-10 mL/min; the temperature of the stirring reaction in the step (1) and the step (2) is 30-100 ℃, and the stirring speed is 500-30000 rpm.

7. A magnetic CN according to claim 1_xThe preparation method of the catalyst is characterized in that in the step (3), the mass concentration of the hydrogen in the inert gas is 5-95%, and the inert gas is argon; the time of the hydrogenation reduction reaction is 3-8 h.

8. Magnetic CN prepared by the preparation method of any one of claims 1 to 7_xA catalyst.

9. Magnetic CN prepared by the preparation method of any one of claims 1 to 7_xThe application of the catalyst in the garbage rotting odor is characterized in that the magnetic CN_xThe catalyst is used for catalyzing and degrading organic sulfur compounds and organic amine compounds in garbage odor, and the magnetic CN_xThe catalytic degradation rate of the catalyst to the organic sulfur compound and the organic amine compound is more than 60 percent.

Technical Field

The invention relates to the technical field of inorganic catalysts, in particular to a magnetic CN_xA catalyst, a preparation method thereof and application thereof in garbage rancidity.

Background

With the improvement of living standard of people, a great amount of garbage is generated in various domestic big cities. The foul gas generated in the processes of garbage collection, stacking and transportation is one of the main problems troubling urban residents, and influences the health and daily life of people all the time. Aiming at the requirements of efficient and green reduction of odor at the disposal end of perishable garbage, novel degradation equipment needs to be researched for carrying out photocatalytic degradation on the odor after ventilation and air exchange collection, molecules such as hydrogen sulfide, methyl mercaptan and the like in the odor can be completely converted into odorless compounds such as sulfate ions, carbon dioxide, water and the like through photocatalysis, and finally organic molecules such as ammonia and the like are converted into odorless and harmless substances after water absorption, so that the purpose of completely reducing and purifying the odor is achieved.

Wherein, nitrogen is doped with Carbon (CN)_x) The nano material synthesis technology is developed quickly, and the performance is excellent and reliable. The material has wide application in the fields of catalysis, sensors, photoelectricity, environmental protection and the like, and has great commercial value. In recent years, various methods for preparing CN have been developed_xPhysical and chemical methods of nanomaterials. Low cost, simple process, high efficiency, controllable grain size and specific surfaceCN_xThe preparation method of the nano material is always the focus of research in the field. Particularly shows good reaction performance in the reaction of catalyzing and oxidizing VOCs, and has important industrial significance.

Because the components of the garbage rancidity odor are complex and can change along with weather, seasons and stacking time, no effective catalyst can be used for better catalyzing and degrading the garbage rancidity odor at present. Therefore, the development of a catalyst for catalyzing and degrading garbage rotten odor based on nitrogen-doped carbon is urgently needed.

Disclosure of Invention

In order to solve the technical problem that no effective catalyst can perform better catalytic degradation on garbage odor in the prior art, a magnetic CN is provided_xA catalyst, a preparation method thereof and application thereof in garbage rancidity. Magnetic CN prepared by the method of the invention_xThe catalyst is of a nano-sheet structure, and is convenient to recycle and reuse by utilizing external magnetic field force.

In order to achieve the purpose, the invention is realized by the following technical scheme:

magnetic CN_xThe preparation method of the catalyst comprises the following steps:

(1) dissolving a surfactant containing anhydride in water, adding an amine compound, stirring, heating, and reacting for 3-4 hours to obtain a mixed solution A; dissolving an iron salt compound in water to form an iron salt solution; mixing the mixed solution A with the ferric salt solution, and stirring and reacting for 1-24 h to obtain a mixed solution B;

(2) adjusting the pH value of the mixed solution B to be acidic, continuously stirring and reacting for 2-12 h to obtain a precipitate, filtering, washing the precipitate for multiple times, and drying to obtain a precursor;

(3) putting the precursor into an atmosphere furnace, introducing hydrogen into inert gas, and carrying out hydrogenation reduction reaction at 300-500 ℃ to finally prepare magnetic CN_xA catalyst.

Under the action of the amine compound in the step (1), on one hand, the solubility of the surfactant containing the anhydride can be increased, namely, the anhydride in the surfactant containing the anhydride reacts with the amino group in the amine compound, so that the solubility of the surfactant in water can be increased, and on the other hand, a substance formed after the anhydride in the surfactant containing the anhydride reacts with the amino group in the amine compound can form a complex with Fe ions in iron salt, so that iron-containing polymer colloid particles are formed in a system; the acidity adjustment in the step (2) is to reduce the solubility of the iron-containing polymer colloidal particles formed in the step (1) in an aqueous solution system, so that precursors (carbon and nitrogen elements, a carbon source which is a surfactant containing acid anhydride, and a nitrogen source which is an amine compound) can be precipitated from the solution.

Further, the ferric salt compound in the step (1) is one of ferric nitrate, ferric chloride and potassium ferricyanate; the surface active agent containing the anhydride is styrene-maleic anhydride block copolymer. The molecular structure of the copolymer is characterized by having a styrene rigid structure which can enhance the mechanical strength and carboxylic acid groups which are convenient for modification to meet different use requirements.

Further, the amine compound in the step (1) is concentrated ammonia water with the mass fraction of 25 wt% -28 wt%. The concentrated ammonia water can accelerate the reaction between the acid anhydride in the acid anhydride-containing surfactant and the amino in the concentrated ammonia water, so that substances generated by the acid anhydride and the amino in the concentrated ammonia water can be dissolved quickly, and the reaction efficiency is improved.

Further, the heating temperature in the step (1) is 60-120 ℃. In order to accelerate the dissolution, the reaction between the acid anhydride and the amino group in the amine compound in the acid anhydride-containing surfactant in the step (1) is more convenient.

Further, the mass ratio of the surface active agent containing the acid anhydride, the amine compound and the iron salt compound in the step (1) is (4-8): (1-2): 0.5-10); the concentration of the surface active agent containing the anhydride in water is 0.1 g/mL-0.5 g/mL; the concentration of the iron salt compound in the solution B is 0.1 g/mL-0.3 g/mL.

Further, the pH value of the acidity in the step (2) is 1-6, nitric acid or hydrochloric acid with the mass concentration of 10% is adopted for adjusting the acidity, the dripping speed of the nitric acid or hydrochloric acid is 1-10 mL/min, the acidity is adjusted, the system is converted from the original alkalinity to the acidity, the precipitation of a precursor is facilitated, and the dripping speed can influence the structure, porosity, specific surface area and other properties of the precursor; the temperature of the stirring reaction in the step (1) and the step (2) is 30-100 ℃, and the stirring speed is 500-30000 rpm.

Further, in the step (3), the mass concentration of the hydrogen in the inert gas is 5-95%, and the inert gas is argon; the time of the hydrogenation reduction reaction is 3-8 h. The concentration of hydrogen has influence on the crystal form of the formed magnetic substance, the generated ferroferric oxide magnetic substance is generated under the low-concentration hydrogen content, and the simple substance ferromagnetic substance is easily generated under the high-concentration hydrogen content; further, the hydrogen concentration increases, and the specific surface area of the formed catalyst increases and then decreases.

The invention also provides a magnetic CN prepared by the preparation method_xA catalyst.

In a final aspect of the present invention, there is provided the above-mentioned magnetic CN_xApplication of catalyst in garbage odor and magnetic CN_xThe catalyst is used for catalyzing and degrading organic sulfur compounds and organic amine compounds in garbage odor, and the magnetic CN_xThe catalytic degradation rate of the catalyst to the organic sulfur compound and the organic amine compound is more than 60 percent.

The beneficial technical effects are as follows:

due to CN_xThe nanometer material has low recovery and utilization rate, and the simple substance iron and the Fe₃O₄All have magnetism, can utilize the magnetic field to carry out rapid recovery, and the invention leads the magnetic substance to be simple substance iron and/or Fe₃O₄And CN_xAre combined, improve CN_xThe method can adjust the dosage of the surfactant containing anhydride, the ferric salt compound and the amine compound and the pH value of a reaction system to obtain the final product, namely the magnetic CN_xThe component, shape, specific surface area and pore size of each element in the catalyst are regulated and controlled, and the magnetic CN prepared by the method_xThe catalyst is of a nano-sheet structure, the specific surface area, the morphology and the crystal form of the catalyst are all improved, and the catalytic oxidation performance of organic sulfur compounds and organic amine compounds is improvedCN is caused by the intervention of Fe simple substance and/or ferroferric oxide thereof_xThe energy level bandwidth of (2) is narrowed, the photoelectron and hole relaxation time is improved, and the CN can be enhanced_xPhotocatalytic activity of (a); the catalyst can utilize external magnetic field force to be conveniently recycled and reused; the invention prepares the magnetic CN_xThe catalyst has a catalytic degradation rate of 70% or more for organic sulfur; has a catalytic degradation rate of 60% or more for an organic amine compound; the invention prepares the magnetic CN_xThe method of the catalyst is controllable and simple, the operation requirement is low, the target product is easy to form, extreme accurate control is not needed, and the prepared catalyst has more excellent physical and chemical properties.

Drawings

FIG. 1 shows the magnetic CN obtained in example 1_xTransmission electron microscopy of the catalyst.

FIG. 2 shows magnetic CN formed in example 1_xX-ray diffraction pattern of the catalyst.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless specifically stated otherwise, the numerical values set forth in these examples do not limit the scope of the invention. Techniques, methods known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that the use of "a" and "B" to define the solution formed after mixing or stirring to homogeneity is merely for the purpose of distinguishing the mixed solution formed in each step, and the above-mentioned words do not have any special meaning unless otherwise stated, and therefore, should not be construed as limiting the scope of the present invention.

Brief description of related chemical terms: ferric nitrate Fe (NO)₃)₃FeCl, iron chloride₃Potassium ferricyanate K₃[Fe(CN)₆]Styrene-maleic anhydride Block copolymer SMA (SMA1000P, Kleviley France), Hydrogen H₂Argon Ar;

transmission electron microscope TEM, X-ray diffraction XRD.