阅读说明：本技术 一种催化剂浆料的制备方法、催化剂浆料、催化剂元件及催化模块 (Preparation method of catalyst slurry, catalyst element and catalytic module ) 是由 郭聪 展宗城 梁鹏 展飞 郭海洋 于 2020-12-30 设计创作，主要内容包括：本发明提供了一种催化剂浆料的制备方法、采用该方法制备的催化剂浆料、采用该催化剂浆料制备的催化剂元件以及采用该种催化剂元件组装而成的催化模块。采用本发明的催化剂浆料的制备方法制备获得的催化剂浆料对含氯及非含氯VOCs去除效率优良,高空速下具有优异催化活性、热稳定性和抗卤素中毒能力。(The invention provides a preparation method of catalyst slurry, the catalyst slurry prepared by the method, a catalyst element prepared by the catalyst slurry and a catalytic module assembled by the catalyst element. The catalyst slurry prepared by the preparation method of the catalyst slurry has excellent removal efficiency on VOCs containing chlorine and VOCs not containing chlorine, and has excellent catalytic activity, thermal stability and halogen poisoning resistance at high airspeed.)

1. A preparation method of catalyst slurry is characterized by comprising the following steps:

(1) mixing a certain amount of first auxiliary agent with a certain amount of acid solution, fully stirring to be viscous, and then adding a binder and deionized water to obtain a mixed solution A;

(2) adding an alumina substrate and a cerium-zirconium oxygen storage material in a certain mass ratio into the mixed solution A obtained in the step (1), and uniformly stirring to obtain a mixed solution B;

(3) adding a certain amount of second aid and/or third aid into the mixed solution B obtained in the step (2), uniformly stirring, and carrying out ball milling for a certain time to obtain a mixed solution C;

(4) and (4) adjusting the pH value of the mixed solution C obtained in the step (3), adding an active component, and continuing ball milling for a certain time to obtain the catalyst slurry.

2. The method for preparing the catalyst slurry according to claim 1, wherein in the step (1), the first assistant comprises one or more of alkali metal salt, alkali metal oxide, and alkali metal comprises one or more of Li, Na, K, Rb and Cs;

preferably, the acid solution comprises one or more of nitric acid, hydrochloric acid, sulfuric acid, oxalic acid and citric acid;

preferably, the binder is one or more of silica sol, aluminum sol, silicon-aluminum sol, titanium sol and pseudo-boehmite;

preferably, the first aid and the binder are added in an amount of 0.1 to 12 wt% and 2 to 25 wt%, respectively, of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material.

3. The method of preparing a catalyst slurry according to claim 1, wherein in the step (2), the mass ratio of the alumina substrate to the cerium-zirconium oxygen storage material is 30-90: 70-10;

preferably, the alumina substrate is r-Al₂O₃The cerium-zirconium oxygen storage material is Ce_xZr_1-xO₂Wherein x is more than 0 and less than 1.

4. The method for preparing the catalyst slurry according to claim 1, wherein in the step (3), the second auxiliary agent comprises one or more of lanthanide metals and oxides thereof, and the lanthanide metals comprise one or more of La, Ce, Nd and Lu; the third auxiliary agent comprises one or more of polyvinyl alcohol, polyethylene glycol, tween 20, polyurethane, butanediol, acrylate, modified acrylate, polyacrylate and cellulose;

preferably, the second auxiliary agent is added in an amount of 0.02 to 15 wt% of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material;

preferably, the third auxiliary agent is added in an amount of 0.1 to 20 wt% of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material;

preferably, the time of ball milling is 0.5 to 2 hours.

5. The method of preparing the catalyst slurry according to claim 1, wherein in the step (4), the mixed solution C is subjected to pH adjustment using an acid, the acid including one or more of nitric acid, hydrochloric acid, sulfuric acid, oxalic acid, and citric acid;

preferably, the pH is adjusted to 4-6; after the active components are added, the ball milling is continued for 0.5 to 2 hours;

preferably, the active component comprises one or more of noble metal, noble metal salt and noble metal oxide, the noble metal comprises one or more of Pd, Pt, Ru and Rh, and the addition amount of the active component is 10-80g/ft of the catalyst slurry calculated by elementary metal³。

6. A catalyst slurry obtained by the method for preparing a catalyst slurry according to any one of claims 1 to 5.

7. A catalyst element prepared using the catalyst ink of claim 6.

8. The catalyst element of claim 7, wherein the catalyst element is prepared by a method comprising:

and coating the catalyst slurry on a catalyst element carrier in a vacuum coating mode, drying and roasting to obtain the catalyst element.

9. A catalytic module assembled using the catalyst element of claim 7 or 8.

10. Use of the catalytic module of claim 9 for the degradation of chlorinated and/or non-chlorinated VOCs.

Technical Field

The invention relates to the technical field of catalysts, in particular to a preparation method of catalyst slurry, the catalyst slurry, a catalyst element and a catalytic module, which are used for degrading chlorine-containing VOCs.

Background

chlorine-Containing Volatile Organic Compounds (CVOCs) are a class of important branches of VOCs, and mainly include methyl Chloride (CM), Dichloromethane (DCM), Vinyl Chloride (VC), Chlorobenzene (CB), 1, 2-Dichloroethane (DCE), Trichloroethylene (TCE), and the like, which have strong toxicity, and under certain conditions in the atmosphere, the compounds undergo a photochemical reaction with nitrogen oxides, which causes an increase in the surface ozone concentration to form photochemical smog, and also can react with some free radicals in the atmosphere to form secondary organic aerosols. Some compounds deplete stratospheric ozone, creating ozone voids, while some generate too much ozone in the troposphere. In addition, some recent research results show that VOCs can cause certain harm to human health. CVOCs are widely used in the industries of chlor-alkali industry, petrochemical industry, pharmacy, pesticide, coating decoration, packaging printing and the like, and have more discharge amount, stronger toxicity and higher treatment difficulty compared with other types of VOCs.

The catalytic oxidation method has the advantages of low ignition temperature, high purification efficiency and the like, but generates a small amount of polychlorinated byproducts during the catalytic oxidation of the CVOCs, thereby improving the emission risk of dioxin.

The industrial organic waste gas treatment technology mainly comprises an adsorption method, a membrane separation method, an absorption method, a condensation method, direct combustion, photocatalysis, catalytic combustion and the like. The adsorption method has a good effect of eliminating low-concentration waste gas, but can cause pollution to be transferred from a gas phase to a solid phase, so that the problem of secondary pollution is caused; the condensation method is mainly used for treating waste gas with high concentration and small air volume, but has the defects of large investment, high operation cost, low benefit and the like for the waste gas with low concentration and large air volume; direct combustion for treating high-concentration waste gasThe temperature is too high (basically higher than 800 ℃), and sip and NO appear in combustion products_xAnd toxic by-products; the catalytic combustion has the characteristics of low energy consumption, no secondary pollution, high efficiency and the like under the condition of low-concentration waste gas, and is one of the most effective treatment methods for treating industrial waste gas in commerce at present.

Catalytic oxidation is a widely used method for eliminating chlorine-containing volatile organic waste gases (CVOCs). However, the existing catalysts for eliminating chlorine-containing organic waste gas have the problems of great challenge, such as high ignition temperature, easy poisoning, generation of toxic by-products, short service life and the like, and most of the existing photocatalytic module framework carriers mostly adopt aluminum-based honeycombs, metal meshes and other supported titanium dioxide catalysts which have large pores, small specific surface area and few active sites, are not beneficial to adsorption of waste gas molecules and coating of products, and have low degradation efficiency.

Chinese patent application CN202010263327.3 discloses a Pt-Ce-USY catalyst for oxidative degradation of chlorine-containing VOCs and a preparation method thereof, which takes platinum tetraammine dichloride, cerous chloride and an ultrastable Y molecular sieve as raw materials and adopts a precipitation-deposition method to load CeO₂And loading Pt by an ion exchange method to prepare the Pt/Ce-USY catalyst. However, the technical scheme loads CeO₂And Pt is complex and tedious in treatment process, and when the coating is loaded, the operation is complex and long in duration, and repeated filtration-washing is needed.

Based on the above problems, there is a need for a method for preparing catalyst slurry, which can effectively degrade chlorine-containing VOCs and has a simple and easy preparation process, and catalyst slurry prepared by the method, a catalyst element prepared by the catalyst slurry, and a catalytic module assembled by the catalyst element.

Disclosure of Invention

The invention aims to provide a preparation method of catalyst slurry, the catalyst slurry prepared by the method, a catalyst element prepared by the catalyst slurry and a catalytic module assembled by the catalyst element, so as to at least solve the technical problems of high ignition temperature, easy poisoning, short service life and the like of a catalyst for degrading chlorine-containing VOCs, complex preparation process, low degradation efficiency and the like in the prior art.

In order to achieve the above object, the present invention provides a method for preparing a catalyst slurry, comprising the steps of: (1) mixing a certain amount of first auxiliary agent with a certain amount of acid solution, fully stirring to be viscous, and then adding a binder and deionized water to obtain a mixed solution A; (2) adding an alumina substrate and a cerium-zirconium oxygen storage material in a certain mass ratio into the mixed solution A obtained in the step (1), and uniformly stirring to obtain a mixed solution B; (3) adding a certain amount of second aid and/or third aid into the mixed solution B obtained in the step (2), uniformly stirring, and carrying out ball milling for a certain time to obtain a mixed solution C; (4) and (4) adjusting the pH value of the mixed solution C obtained in the step (3), adding an active component, and continuing ball milling for a certain time to obtain the catalyst slurry.

Optionally, in step (1), the first auxiliary agent includes one or more of alkali metal salt, alkali metal oxide, and alkali metal includes one or more of Li, Na, K, Rb, and Cs.

Preferably, the acid solution comprises one or more of nitric acid, hydrochloric acid, sulfuric acid, oxalic acid and citric acid.

Preferably, the binder is one or more of silica sol, aluminum sol, silicon-aluminum sol, titanium sol and pseudo-boehmite.

Preferably, the first aid and the binder are added in an amount of 0.1 to 12 wt% and 2 to 25 wt%, respectively, of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material.

Optionally, in the step (2), the mass ratio of the alumina substrate to the cerium-zirconium oxygen storage material is 30-90: 70-10.

Preferably, the alumina substrate is r-Al₂O₃The cerium-zirconium oxygen storage material is Ce_xZr_1-xO₂Wherein x is more than 0 and less than 1.

Optionally, in the step (3), the second auxiliary agent includes one or more of lanthanide metals and oxides thereof, and the lanthanide metals include one or more of La, Ce, Nd and Lu; the third auxiliary agent comprises one or more of polyvinyl alcohol, polyethylene glycol, Tween 20, polyurethane, butanediol, acrylate, modified acrylate, polyacrylate and cellulose.

Preferably, the second aid is added in an amount of 0.02 to 15 wt% of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material.

Preferably, the third auxiliary agent is added in an amount of 0.1 to 20 wt% based on the total mass of the alumina substrate and the cerium-zirconium oxygen storage material.

Preferably, the time of ball milling is 0.5 to 2 hours.

Optionally, in the step (4), the mixed solution C is subjected to pH adjustment using an acid, wherein the acid includes one or more of nitric acid, hydrochloric acid, sulfuric acid, oxalic acid and citric acid.

Preferably, the pH is adjusted to 4-6; after the active components are added, the ball milling is continued for 0.5 to 2 hours.

Preferably, the active component comprises one or more of noble metal, noble metal salt and noble metal oxide, the noble metal comprises one or more of Pd, Pt, Ru and Rh, and the addition amount of the active component is 10-80g/ft of the catalyst slurry calculated by elementary metal³。

The invention also provides the catalyst slurry prepared by the preparation method of the catalyst slurry.

The preparation method of the catalyst slurry comprises the steps of carrying out doping modification on an alumina substrate by utilizing one or more of different alkali metal salts and alkali metal oxides, and/or carrying out doping modification on a cerium-zirconium oxygen storage material by utilizing one or more of different lanthanide metals and oxides thereof, so as to adjust the surface acidity of the material, form a large number of lattice defects in a material phase, improve the stability of a material unit cell structure and inhibit phase change of the material caused by high temperature. In addition, the Redox performance, the oxygen storage performance and the thermal stability of the material are improved by reasonably optimizing the Ce/Zr ratio, so that the prepared VOCs oxidation catalyst has more excellent catalytic performance and thermal stability. Under the action of the active auxiliary agent alkali metal and the binder, the active ingredient can be promoted to be highly dispersed, the strong interaction between the active ingredient and the alumina substrate and the cerium-zirconium oxygen storage material can be enhanced, the size of active particles is controlled, the number of active centers and the exposed area are increased, the use amount of noble metal can be greatly reduced, the cost is saved, less noble metal is reasonably distributed, and a good catalytic effect is achieved on macromolecules with strong oxidation resistance in VOCs, so that the effect of rapid oxidation is achieved. The Ru-based catalyst has higher Deacon reaction activity, can transfer Cl element occupying active sites, and greatly improves the stability and the halogen poisoning resistance of the catalyst.

The invention also provides a catalyst element prepared by the catalyst slurry.

Alternatively, the catalyst element is prepared by adopting the following method: and coating the front side and the back side of the catalyst slurry on a catalyst element carrier in a vacuum coating mode, drying and roasting to obtain the catalyst element.

Optionally, the coating time of the vacuum coating is 1-20 min; the drying adopts hot air drying, the drying temperature is 60-200 ℃, and the drying time is 10-60 min; the roasting adopts a roasting mode in air, the roasting temperature is 300-600 ℃, and the roasting time is 1-8 h; the coating amount of the catalyst slurry is 60-300 g/L.

Optionally, the catalyst element carrier is formed by bonding and compounding corrugated refractory fiber paper and flat refractory fiber paper to form a pore passage for catalyst slurry and gas to pass through. The pore space can be freely adjusted according to the requirement.

Preferably, the corrugated refractory fiber paper is processed from the planar refractory fiber paper.

Preferably, the planar refractory fiber paper is made of high pressure resistant fibers, and the high pressure resistant fibers include one or more of ceramic fibers, basalt fibers, glass fibers, high silica fibers, quartz fibers and mullite fibers.

Optionally, the catalyst element carrier is obtained by bonding and compounding corrugated refractory fiber paper and planar refractory fiber paper, and then rolling the corrugated refractory fiber paper and the planar refractory fiber paper into a cylinder or laminating the corrugated refractory fiber paper and the planar refractory fiber paper into a cube. The corrugated refractory fiber paper can form uniform pore channels with the adjacent planar refractory fiber paper in the winding or stacking process, and the pore channels provide more places for the attachment of catalyst slurry and enable airflow to pass smoothly, so that the corrugated refractory fiber paper and the planar refractory fiber paper can fully react in the pore channels, and the catalytic activity of the catalyst is greatly improved.

The invention also provides a catalytic module assembled by the catalyst element.

Optionally, the catalytic module comprises one or more of the catalyst elements and a module housing in which the catalyst elements are enclosed.

The invention also provides application of the catalytic module in degradation of VOCs containing chlorine and/or non-chlorine.

The preparation method of the catalyst slurry is simple and easy to implement, and toxic byproducts are not generated in the application process; the catalyst slurry prepared by the preparation method of the catalyst slurry has excellent removal efficiency on VOCs containing chlorine and VOCs not containing chlorine, has excellent catalytic activity, thermal stability and halogen poisoning resistance at high airspeed, can save the using amount of the catalyst and reduce the volume of a reactor; the catalyst element has larger geometric surface area and porosity, can provide larger reaction surface, promotes the high dispersion of active components, improves the reaction efficiency, and can freely adjust the pore channel spacing as required; the catalytic module disclosed by the invention is simple in manufacturing process, low in cost, flexible in preparation method and easy to adjust, and can be used for preparing catalyst modules with different shapes and sizes according to actual working condition requirements; in addition, the catalytic module of the present invention, the outside of which is protected by the module case, has excellent wear resistance, durability and impact resistance, and reduces the abrasion of the catalyst elements by the flow of exhaust gas when passing through the catalyst reactor, thereby greatly extending the service life of the catalytic module.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention.

FIG. 1 is a schematic cross-sectional view of an alternative catalyst element support according to an embodiment of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

fig. 3 is a graph of the performance of a catalyst element prepared in example 1 of the present invention in an atmosphere of ethyl acetate and methylene chloride.

Detailed Description

The terms as used herein:

"prepared from … …" is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of … …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of … …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when the range "1 ~ 5" is disclosed, the ranges described should be construed to include the ranges "1 ~ 4", "1 ~ 3", "1 ~ 2 and 4 ~ 5", "1 ~ 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In these examples, the parts and percentages are by mass unless otherwise indicated.

"part by mass" means a basic unit of measure indicating a mass ratio of a plurality of components, and 1 part may represent any unit mass, for example, 1g or 2.689 g. If we say that the part by mass of the component A is a part by mass and the part by mass of the component B is B part by mass, the ratio of the part by mass of the component A to the part by mass of the component B is a: b. alternatively, the mass of the A component is aK and the mass of the B component is bK (K is an arbitrary number, and represents a multiple factor). It is unmistakable that, unlike the parts by mass, the sum of the parts by mass of all the components is not limited to 100 parts.

"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).

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

(1) mixing a certain amount of first auxiliary agent with a certain amount of acid solution, fully stirring to be viscous, and then adding a binder and deionized water to obtain a mixed solution A;

wherein the first auxiliary agent comprises one or more of alkali metal salt and alkali metal oxide, and the alkali metal comprises one or more of Li, Na, K, Rb and Cs; the acid solution comprises one or more of nitric acid, hydrochloric acid, sulfuric acid, oxalic acid and citric acid; the binder is one or more of silica sol, aluminum sol, silicon-aluminum sol, titanium sol and pseudo-boehmite; the addition amounts of the first auxiliary agent and the binder are 0.1-12 wt% and 2-25 wt% of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material, respectively;

(2) adding an alumina substrate and a cerium-zirconium oxygen storage material in a certain mass ratio into the mixed solution A obtained in the step (1), and uniformly stirring to obtain a mixed solution B;

wherein the mass ratio of the alumina substrate to the cerium-zirconium oxygen storage material is 30-90: 70-10; what is needed isThe alumina base material is r-Al₂O₃The cerium-zirconium oxygen storage material is Ce_xZr_1-xO₂Wherein x is more than 0 and less than 1;

(3) adding a certain amount of second aid and/or third aid into the mixed solution B obtained in the step (2), uniformly stirring, and carrying out ball milling for a certain time to obtain a mixed solution C;

wherein the second auxiliary agent comprises one or more of lanthanide metals and oxides thereof, and the lanthanide metals comprise one or more of La, Ce, Nd and Lu; the third auxiliary agent comprises one or more of polyvinyl alcohol, polyethylene glycol, tween 20, polyurethane, butanediol, acrylate, modified acrylate, polyacrylate and cellulose; the addition amount of the second auxiliary agent is 0.02-15 wt% of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material; the addition amount of the third auxiliary agent is 0.1-20 wt% of the total mass of the alumina substrate and the cerium-zirconium oxygen storage material; the ball milling time is 0.5-2 h;

(4) adjusting the pH value of the mixed solution C obtained in the step (3), adding an active component, and continuing ball milling for a certain time to obtain the catalyst slurry;

adjusting the pH of the mixed solution C by using acid, wherein the acid comprises one or more of nitric acid, hydrochloric acid, sulfuric acid, oxalic acid and citric acid; adjusting the pH value to 4-6; after the active components are added, the ball milling is continued for 0.5 to 2 hours; the active component comprises one or more of noble metal, noble metal salt and noble metal oxide, the noble metal comprises one or more of Pd, Pt, Ru and Rh, and the adding amount of the active component accounts for 10-80g/ft of the catalyst slurry calculated by elementary metal³。

The embodiment of the invention also provides the catalyst slurry prepared by the preparation method of the catalyst slurry.

The embodiment of the invention also provides a catalyst element prepared by adopting the catalyst slurry. The catalyst element is prepared by adopting the following method:

coating the front side and the back side of the catalyst slurry on a catalyst element carrier in a vacuum coating mode, drying and roasting to obtain the catalyst element; wherein the content of the first and second substances,

the coating time of the vacuum coating is 1-20 min; the drying adopts hot air drying, the drying temperature is 60-200 ℃, and the drying time is 10-60 min; the roasting adopts a roasting mode in air, the roasting temperature is 300-600 ℃, and the roasting time is 1-8 h; the coating amount of the catalyst slurry is 60-300 g/L;

the catalyst element carrier is formed by bonding and compounding corrugated refractory fiber paper and planar refractory fiber paper to form a pore passage for catalyst slurry and gas to pass through. The pore canal distance can be freely adjusted according to the requirement; the corrugated refractory fiber paper is processed from the planar refractory fiber paper; preferably, the planar refractory fiber paper is made of high pressure resistant fibers, and the high pressure resistant fibers include one or more of ceramic fibers, basalt fibers, glass fibers, high silica fibers, quartz fibers and mullite fibers.

In a preferred embodiment, the catalyst element carrier is obtained by bonding and compounding corrugated refractory fiber paper and flat refractory fiber paper, and then rolling the bonded corrugated refractory fiber paper and flat refractory fiber paper into a cylinder or laminating the bonded corrugated refractory fiber paper and flat refractory fiber paper into a cube. The corrugated refractory fiber paper can form uniform pore channels with the adjacent planar refractory fiber paper in the winding or stacking process, and the pore channels provide more places for the attachment of catalyst slurry and enable airflow to pass smoothly, so that the corrugated refractory fiber paper and the planar refractory fiber paper can fully react in the pore channels, and the catalytic activity of the catalyst is greatly improved.

As shown in fig. 1 and 2, the catalyst element carrier 1 is formed by laminating a corrugated refractory fiber paper 2 and a planar refractory fiber paper 3 after bonding and compounding, and the corrugated refractory fiber paper 2 and the planar refractory fiber paper 3 form uniform cell channels 4 during lamination.

The embodiment of the invention also provides a catalytic module obtained by assembling the catalyst elements, wherein the catalytic module comprises one or more catalyst elements and a module shell, and the catalyst elements are packaged in the module shell.

The embodiment of the invention also provides application of the catalytic module in degradation of chlorine-containing and/or non-chlorine-containing VOCs in the industries of chlor-alkali industry, petrochemical industry, pharmacy, pesticide, coating decoration, packaging printing and the like.

Embodiments of the present invention will be described in detail below with reference to specific examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

This example provides a method for preparing a catalyst slurry:

(1) 0.4g of Na₂CO₃Mixing with a small amount of dilute nitric acid, stirring to paste, adding 4.2g of pseudo-boehmite and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 4-6, adding 0.4g Pd (NO)₃)₂、1.8g Pt(NO₃)₂、1.0g Ru(NO)(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 5min, drying with 120 ℃ hot air for 30min, and roasting in 550 ℃ air atmosphere for 4h to obtain a catalyst element;

the catalyst element carrier is rolled into a cylinder after corrugated refractory fiber paper and planar refractory fiber paper are bonded and compounded, wherein the corrugated refractory fiber paper is processed by planar refractory fiber paper, and the planar refractory fiber paper is made of high silica glass fiber corrugated fiber paper.

The catalyst coating on this catalyst element was tested at 126g/L with a noble metal loading of 0.38g/L Pd, 0.53g/L Pt and 0.32g/L Ru.

The catalyst activity was evaluated using a VOCs oxidation catalyst activity evaluation platform, and the catalyst element obtained in this example, having a diameter of 45mm and a height of 50mm, was placed in a reactor, and a simulated pollutant gas was electrically heated and then introduced into the reactor. Ethyl acetate and dichloromethane are used as simulated pollutants, wherein the concentration of the ethyl acetate is 7-8g/m³The concentration of the dichloromethane is 0.2 to 0.6g/m³，SV＝25000h^-1The conversion rates at different temperature points were measured, and the conversion rates of VOCs were calculated using the concentrations at the inlet and outlet of the catalyst, as shown in fig. 3, and in an environment of two-component pollutants ethyl acetate and dichloromethane, the catalyst slurry obtained in this example was significantly better than the conventional catalyst slurry in T50 ═ 190 ℃, T90 ═ 220 ℃, T98 ═ 230 ℃, and T99 ═ 235 ℃.

Example 2

This example provides a method for preparing a catalyst slurry:

(1) 0.3g of Na₂CO₃Mixing with a small amount of dilute nitric acid, stirring to paste, adding 4.2g of pseudo-boehmite and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃The pH of the mixed solution C was adjusted to 4 to 6, and 3.8g of Pd (NO) was added₃)₂、1.0g Ru(NO)(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 5min, drying with 120 ℃ hot air for 30min, and roasting in 550 ℃ air atmosphere for 4h to obtain a catalyst element;

the catalyst element carrier is rolled into a cylinder after corrugated refractory fiber paper and planar refractory fiber paper are bonded and compounded, wherein the corrugated refractory fiber paper is processed by planar refractory fiber paper, and the planar refractory fiber paper is made of glass fiber corrugated fiber paper.

The coating amount of the catalyst coating on the catalyst element was tested to be 130g/L, and the noble metal loading was 0.72g/L Pd and 0.4g/L Ru.

Example 3

This example provides a method for preparing a catalyst slurry:

(1) 0.35g of Na₂CO₃Mixing with a small amount of dilute nitric acid, stirring to paste, adding 3.8g of pseudo-boehmite and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) adding 6.3gLa2O3 and 5.8g of cellulose into the mixed solution B, fully stirring, and carrying out ball milling for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 4-6, adding 1.0g Ru (NO)₃)₂、2.2g Pd(NO₃)₂、1.2g Pt(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 5min, drying with 120 ℃ hot air for 30min, and roasting in 550 ℃ air atmosphere for 4h to obtain a catalyst element;

the catalyst element carrier is rolled into a cylinder after corrugated refractory fiber paper and planar refractory fiber paper are bonded and compounded, wherein the corrugated refractory fiber paper is processed by planar refractory fiber paper, and the planar refractory fiber paper is made of glass fiber corrugated fiber paper.

The coating amount of the catalyst coating on the catalyst element was tested to be 126g/L, and the noble metal loading was 0.5g/L Ru, 0.53g/L Pd, 0.36g/L Pt.

Example 4

This example provides a method for preparing a catalyst slurry:

(1) 0.45g of Na₂CO₃Mixing with a small amount of dilute nitric acid, stirring to paste, adding 4.2g of pseudo-boehmite and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 4-6, adding 1.5g Pd (NO)₃)₂、0.8g Pt(NO₃)₂、1.2g Ru(NO)(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 5min, drying with 120 ℃ hot air for 30min, and roasting in 550 ℃ air atmosphere for 4h to obtain a catalyst element;

the catalyst element carrier is rolled into a cylinder after corrugated refractory fiber paper and planar refractory fiber paper are bonded and compounded, wherein the corrugated refractory fiber paper is processed by planar refractory fiber paper, and the planar refractory fiber paper is made of glass fiber corrugated fiber paper.

The catalyst coating on the catalyst element was tested at 128g/L, noble metal loading of 0.46g/L Pd, 0.25g/L Pt and 0.5g/L Ru.

Example 5

This example provides a method for preparing a catalyst slurry:

(1) 0.35g of Na₂CO₃Mixing with a small amount of dilute nitric acid, stirring to paste, adding 4.2g of pseudo-boehmite and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 3-5, adding 0.6g Pd (NO)₃)₂、1.6g Pt(NO₃)₂、1.2g Ru(NO)(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 5min, drying with 120 ℃ hot air for 30min, and roasting in 550 ℃ air atmosphere for 4h to obtain a catalyst element;

the catalyst element carrier is rolled into a cylinder after corrugated refractory fiber paper and planar refractory fiber paper are bonded and compounded, wherein the corrugated refractory fiber paper is processed by planar refractory fiber paper, and the planar refractory fiber paper is made of ceramic fiber corrugated fiber paper.

The catalyst coating on this catalyst element was tested to have a coating weight of 127g/L, noble metal loadings of 0.33g/L Pd, 0.52g/L Pt and 0.48g/L Ru.

Example 6

This example provides a method for preparing a catalyst slurry:

(1) 0.35g of KNO₃Mixing with a small amount of dilute nitric acid, stirring to be pasty, adding 4.2g of silica sol and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 3-5, adding 1.0g Ru (NO)₃)₂、0.6g Pt(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 1min, drying with hot air at 60 ℃ for 60min, and roasting in an air atmosphere at 300 ℃ for 8h to obtain a catalyst element;

the catalyst element carrier is formed by laminating a corrugated refractory fiber paper and a planar refractory fiber paper after being bonded and compounded into a cube, wherein the corrugated refractory fiber paper is formed by processing a planar refractory fiber paper, and the planar refractory fiber paper is made of basalt fiber corrugated fiber paper.

The coating amount of the catalyst coating on the catalyst element was tested to be 126g/L, and the noble metal loading was 0.49g/L Ru and 0.28g/L Pt.

Example 7

This example provides a method for preparing a catalyst slurry:

(1) 0.42g of KNO₃Mixing with a small amount of dilute nitric acid, stirring to be pasty, adding 4.2g of silica sol and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 3-5, adding 1.0g Ru (NO)₃)₂、0.6g Pt(NO₃)₂、1.6g Pd(NO₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 20min, drying with hot air at 200 ℃ for 10min, and roasting in an air atmosphere at 600 ℃ for 1h to obtain a catalyst element;

the catalyst element carrier is formed by laminating a corrugated refractory fiber paper and a planar refractory fiber paper after being bonded and compounded into a cube, wherein the corrugated refractory fiber paper is formed by processing a planar refractory fiber paper, and the planar refractory fiber paper is made of mullite fiber corrugated fiber paper.

The coating amount of the catalyst coating on the catalyst element was tested to be 124g/L, and the noble metal loadings were 0.50g/L Ru, 0.42g/L Pt, and 0.53g/L Pd.

Example 8

This example provides a method for preparing a catalyst slurry:

(1) 0.50g of KNO₃Mixing with a small amount of dilute nitric acid, stirring to be pasty, adding 4.2g of silica sol and 120ml of deionized water, and stirring to obtain a mixed solution A;

(2) adding 40g of activated alumina and 20g of cerium-zirconium oxygen storage material into the mixed solution A, and uniformly stirring to obtain a mixed solution B;

(3) mix 6.3gLa₂O₃And 5.8g of cellulose are added into the mixed solution B, fully stirred and ball-milled for 30min to obtain a mixed solution C;

(4) by HNO₃Adjusting pH of the mixed solution C to 3-5, adding 1.2g Ru (NO)₃)₂And continuing ball milling for 1h to obtain catalyst slurry.

The present embodiment also provides a method for preparing a catalyst element:

coating the front and back surfaces of a catalyst element carrier with catalyst slurry by using a vacuum coating machine, coating for 10min, drying with hot air at 100 ℃ for 40min, and roasting in an air atmosphere at 400 ℃ for 5h to obtain a catalyst element;

the catalyst element carrier is formed by laminating a corrugated refractory fiber paper and a planar refractory fiber paper after being bonded and compounded into a cube, wherein the corrugated refractory fiber paper is formed by processing a planar refractory fiber paper, and the planar refractory fiber paper is made of ceramic fiber corrugated fiber paper.

The catalyst coating on the catalyst element was tested at a coating level of 126g/L and a noble metal loading of 0.49g/L Ru.

Comparative example 1

The comparative example is different from example 1 only in that cordierite honeycomb ceramic is used as a catalyst element carrier, and the rest is the same as example 1, and will not be described again.

The catalyst activity was evaluated using a VOCs oxidation catalyst activity evaluation platform, and the catalyst elements prepared in examples 1 to 5 and comparative example 1 having the same volume (diameter of 45mm and height of 50mm) were loaded into a reactor, and a simulated pollutant gas was electrically heated and then introduced into the reactor. Ethyl acetate and dichloromethane are used as simulated pollutants, and the concentration of the ethyl acetate is 7-8g/m³The concentration of the dichloromethane is 0.2 to 0.6g/m³，SV＝25000h^-1And measuring the conversion rate of different temperature points, and calculating the conversion rate of VOCs by using the concentration of the inlet and the outlet of the catalyst. The degradation efficiency of the catalyst elements of examples 1-5 and comparative example 1 for ethyl acetate and dichloromethane under the above test conditions is shown in table 1.

Table 1 degradation efficiency of the catalyst elements of examples 1-5 and comparative example 1 for ethyl acetate and dichloromethane under the above test conditions

	230℃	260℃	290℃	320℃
					Example 1	97.6％	98.2％	99.5％	99.7％
Example 2	97.6％	98.5％	99.2％	99.5％
					Example 3	97.2％	98.6％	99.2％	99.6％
Example 4	97.9％	98.2％	99.5％	99.6％
					Example 5	97.8％	98.8％	99.6％	99.8％
Example 6	97.5％	98.5％	99.1％	99.6％
					Example 7	97.7％	98.5％	99.4％	99.5％
Example 8	97.3％	98.3％	99.1％	99.4％
					Comparative example 1	93.2％	95.6％	97.2％	97.6％

By comparison, the catalyst element of the invention has higher degradation efficiency on ethyl acetate and dichloromethane, because the catalyst element of the invention has larger geometric surface area and porosity, can provide larger reaction surface, promotes high dispersion of active components, and improves reaction efficiency.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.