3D printing porous honeycomb ceramic carrier and preparation method and application thereof

Abstract

The embodiment of the invention discloses a 3D printing porous honeycomb ceramic carrier as well as a preparation method and application thereof, relates to the technical field of tail gas treatment materials, and aims to solve the problems of single preparation shape, limited pore structure, small specific surface area, non-uniform catalyst loading, high temperature required by catalysis and the like of the porous honeycomb ceramic carrier in the prior art. The 3D printing porous honeycomb ceramic carrier comprises the following components in parts by weight: 25 to 40 parts of halloysite nanotubes, 5 to 10 parts of a binder, 1 to 5 parts of a dispersant, 5 to 10 parts of a catalyst precursor and 100 to 150 parts of deionized water.

Description

Technical Field

[0001] This application relates to the technical field of tail gas treatment materials, and particularly relates to a 3D printed porous honeycomb ceramic carrier and its preparation method and application. Background Art

[0002] With the rapid development of the automotive industry, automotive tail gas emissions have become one of the main sources of air pollution. Harmful emissions such as nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM) in the tail gas pose a serious threat to human health and the ecological environment.

[0003] As an important supporting material for tail gas treatment catalysts, the performance of porous honeycomb ceramic carriers directly affects the catalytic efficiency and system stability. Most traditional porous honeycomb ceramic carrier materials are prepared by the template method or the extrusion molding method, which have limitations in the preparation of complex shapes and pore size control, and also have problems such as small specific surface area, low surface activity, insufficient thermal stability, uneven catalyst loading, and high temperature required for catalysis.

[0004] Therefore, developing a new type of porous honeycomb ceramic material and its preparation method to improve the tail gas purification efficiency and preparation flexibility has become a research hotspot. Summary of the Invention

[0005] The main purpose of this application is to provide a 3D printed porous honeycomb ceramic carrier and its preparation method and application, aiming to overcome the problems of single preparation shape, limited pore structure, small specific surface area, uneven catalyst loading, and high temperature required for catalysis of the existing porous honeycomb ceramic carriers.

[0006] To achieve the above purpose, the technical solutions adopted in the embodiments of this application are as follows:

[0007] In the first aspect, the embodiments of this application provide a 3D printed porous honeycomb ceramic carrier, which includes the following components in parts by weight: 25 parts to 40 parts of halloysite nanotubes, 5 parts to 10 parts of binder, 1 part to 5 parts of dispersant, 5 parts to 10 parts of catalyst precursor, and 100 parts to 150 parts of deionized water.

[0008] As some optional embodiments of this application, the binder includes at least one of chitosan, sodium alginate, polyvinyl acetate, carboxymethyl chitosan, polyvinyl alcohol, polyethylene glycol, gelatin, starch, polyacrylate, epoxy resin, and acrylic resin.

[0009] As some optional embodiments of this application, the dispersant includes at least one of sodium hexametaphosphate, sodium silicate, sodium carbonate, sodium dodecyl sulfate, and sodium polyacrylate.

[0010] As some optional embodiments of the present application, the catalyst precursor includes at least one of FeCO3, Fe2(CO3)3, Fe(NO3)2, Fe(NO3)3, CoCO3, Co(NO3)2, Co(NO 3)3 , NiCO3, Ni(NO3)2, Ce2(CO3)3, Ce(CO3)2, Ce(NO3)3, Ce(NO3)4, PtCO3, Pt(CO3)2, Pt(NO3)2, Pt(NO3)4, PbCO3, Pb(NO 3)2 , MnCO3, Mn(NO 3)2 , Mn(NO3)3, Cu2(OH)2CO3, Cu(NO3)2, Au2(CO 3)3 , Au(NO 3)3 , Ag2CO3 and AgNO3.

[0011] As some optional embodiments of the present application, the 3D printed porous honeycomb ceramic carrier further includes an acid solution and a weak alkaline solution; the mass ratio of the acid and weak alkaline solutions to the catalyst precursor is both 2-5:1.

[0012] As some optional embodiments of the present application, the acid solution includes at least one of hydrochloric acid solution, nitric acid solution, sulfuric acid solution and phosphoric acid solution, with a concentration of 0.01 mol / L - 0.05 mol / L; the weak alkaline solution includes at least one of ammonia water, ammonium bicarbonate solution and sodium bicarbonate solution, with a concentration of 0.01 mol / L - 0.05 mol / L.

[0013] In a second aspect, an embodiment of the present application provides a method for preparing the 3D printed porous honeycomb ceramic carrier as described above, including the following steps:

[0014] Mix halloysite nanotubes, binder, dispersant and deionized water in proportion and mix them evenly to obtain a ceramic blank.

[0015] Soak the catalyst precursor in the acid solution, and after dissolution, obtain a metal coating solution.

[0016] Spray the ceramic blank on the forming plate through the printing nozzle of a 3D printing forming machine, print and form a green body based on a preset model of the porous honeycomb ceramic, and then perform drying treatment and sintering treatment to obtain a porous honeycomb ceramic precursor.

[0017] Soak the porous honeycomb ceramic precursor in the weak alkaline solution, take it out and dry it to obtain a pretreated porous honeycomb ceramic precursor.

[0018] Immerse the pretreated porous honeycomb ceramic precursor in the metal coating solution. After immersion, wash it with deionized water, and then perform drying treatment and calcination treatment to obtain a 3D printed porous honeycomb ceramic carrier of a coating catalyst precursor based on halloysite clay.

[0019] As some alternative embodiments of the present application, the sintering treatment means that the formed green body is heated to 600°C at a rate of 5°C / min in a high-temperature sintering furnace, held for 1 h, then continuously heated to 1200°C, and held for 2 h.

[0020] As some alternative embodiments of the present application, the soaking time is 5 h to 10 h.

[0021] In a third aspect, an embodiment of the present application provides an application of the 3D printed porous honeycomb ceramic carrier as described above, that is, its application in the preparation of products for treating air pollution; the air pollution includes automobile exhaust.

[0022] Compared with the prior art, the embodiment of the present application uses three-dimensional printing technology to design complex structures and realizes highly customized production. Due to its extremely high specific surface area, halloysite nanotubes provide abundant attachment points and active sites for the catalyst precursor, thus promoting the increase of catalyst loading and the improvement of catalytic activity. Further, the functional groups and pore structures on the surface of halloysite nanotubes can effectively adsorb harmful substances in automobile exhaust, helping to concentrate these substances around the catalyst, and then accelerating the process of catalytic reaction. The ceramic carrier used has excellent specific surface area and adsorption performance. Through structural design by three-dimensional printing technology and the application of catalysts, the carrier has a significant catalytic conversion efficiency for harmful substances in automobile exhaust and shows broad application potential. Detailed Embodiments

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0024] Based on the foregoing content, it can be seen that:

[0025] The first objective of this application is to overcome the problems of the prior art, such as the single preparation shape of the porous honeycomb ceramic carrier, limited pore structure, small specific surface area, uneven catalyst loading, and high temperature required for catalysis. Therefore, a 3D printed porous honeycomb ceramic carrier coated with a catalyst precursor based on halloysite clay is provided. This ceramic carrier uses halloysite nanotubes as the main raw material, prepares a complex porous ceramic carrier through 3D printing technology, and impregnates and precipitates a catalyst precursor coating on the surface and pores of the porous ceramic carrier. The 3D printed porous honeycomb ceramic carrier based on halloysite clay obtained in this application can effectively promote the uniform distribution and thermal stability of the catalyst, ensure the continuous high efficiency of the catalytic conversion process, and can also achieve catalytic conversion at a lower temperature.

[0026] That is, the 3D printed porous honeycomb ceramic carrier includes the following components in parts by weight: 25 to 40 parts of halloysite nanotubes, 5 to 10 parts of binder, 1 to 5 parts of dispersant, 5 to 10 parts of catalyst precursor, and 100 to 150 parts of deionized water.

[0027] Among them, the binder includes at least one of chitosan, sodium alginate, polyvinyl acetate, carboxymethyl chitosan, polyvinyl alcohol, polyethylene glycol, gelatin, starch, polyacrylate, epoxy resin, and acrylic resin.

[0028] Among them, the dispersant includes at least one of sodium hexametaphosphate, sodium silicate, sodium carbonate, sodium dodecyl sulfate, and sodium polyacrylate.

[0029] Among them, the catalyst precursor includes at least one of FeCO3, Fe2(CO3)3, Fe(NO3)2, Fe(NO3)3, CoCO3, Co(NO3)2, Co(NO 3)3 、NiCO3, Ni(NO3)2, Ce2(CO3)3, Ce(CO3)2, Ce(NO3)3, Ce(NO3)4, PtCO3, Pt(CO3)2, Pt(NO3)2, Pt(NO3)4, PbCO3, Pb(NO 3)2 、MnCO3, Mn(NO 3)2 、Mn(NO3)3, Cu2(OH)2CO3, Cu(NO3)2, Au2(CO 3)3 、Au(NO 3)3 、Ag2CO3 and AgNO3.

[0030] Among them, the 3D printed porous honeycomb ceramic carrier further includes an acid solution and a weak alkaline solution; the mass ratio of the acid solution to the catalyst precursor is 2:1.

[0031] Among them, the acid solution includes at least one of hydrochloric acid solution, nitric acid solution, sulfuric acid solution and phosphoric acid solution, with a concentration of 0.01 mol / L to 0.05 mol / L; the weak alkaline solution includes at least one of ammonia water, ammonium bicarbonate solution and sodium bicarbonate solution, with a concentration of 0.01 mol / L to 0.05 mol / L.

[0032] The second object of the present application is to provide a preparation method of the above-mentioned 3D printed porous honeycomb ceramic carrier.

[0033] That is: a preparation method of the 3D printed porous honeycomb ceramic carrier as described above, comprising the following steps:

[0034] Mix halloysite nanotubes, binder, dispersant and deionized water evenly in proportion to obtain a ceramic blank.

[0035] Immerse the catalyst precursor in the acid solution, and obtain a metal coating solution after dissolution.

[0036] Spray the ceramic blank on the forming plate through the printing nozzle of a 3D printing forming machine, print and form a green body based on a preset model of a porous honeycomb ceramic, and then perform drying treatment and sintering treatment to obtain a porous honeycomb ceramic precursor; the sintering treatment refers to heating the green body to 600 °C at a rate of 5 °C / min in a high-temperature sintering furnace, holding for 1 h, then continuing to heat to 1200 °C and holding for 2 h; immerse the porous honeycomb ceramic precursor in the weak alkaline solution for 5 h to 10 h, take it out and dry it to obtain a pretreated porous honeycomb ceramic precursor.

[0037] Immerse the pretreated porous honeycomb ceramic precursor in the metal coating solution for 5 h to 10 h, wash it with deionized water after immersion, and then perform drying treatment and calcination treatment to obtain a 3D printed porous honeycomb ceramic carrier coated with a catalyst precursor based on halloysite clay.

[0038] The third object of the present application is to provide an application of the above-mentioned 3D printed porous honeycomb ceramic carrier.

[0039] That is: an application of the 3D printed porous honeycomb ceramic carrier as described above, namely its application in the preparation of products for treating air pollution; the air pollution includes automobile exhaust, such as carbon monoxide in the automobile exhaust.

[0040] The following will be described in detail with specific examples for better understanding of the technical solutions of the present application by those skilled in the art:

[0041] Example 1

[0042] A preparation method of a 3D printed porous honeycomb ceramic carrier coated with a catalyst precursor based on halloysite clay, comprising the following steps:

[0043] (1) Weigh 25 parts of halloysite nanotubes, 6 parts of polyethylene glycol, 3 parts of sodium silicate and 63 parts of deionized water by mass, mix them evenly to obtain a ceramic blank for standby;

[0044] (2) Weigh 10 parts of the catalyst precursor (calculated according to the mass ratio of Co(NO3)2 and Ce(NO3)3 being 1:1) by mass, soak it in an acid solution, and obtain a metal coating solution after dissolution for standby; the acid solution is a phosphoric acid solution, the concentration of the phosphoric acid solution is 0.05 mol / L, and the mass ratio of the catalyst precursor to the acid solution is 1:2;

[0045] (3) Spray the ceramic blank on a forming plate through a printing nozzle of a 3D printing molding machine, print a formed blank based on a preset model of a porous honeycomb ceramic, then dry it at room temperature and sinter it at a high temperature to obtain a porous honeycomb ceramic based on halloysite clay; the sintering process is to heat the formed blank in a high-temperature sintering furnace at a rate of 5 °C / min to 600 °C, hold for 1 h, then continue to heat to 1200 °C and hold for 2 h;

[0046] (4) Immerse the porous honeycomb ceramic based on halloysite clay prepared in step (3) in a weakly alkaline solution for pretreatment, the immersion time is 5 h, take it out and dry it to obtain a pretreated porous honeycomb ceramic carrier based on halloysite clay; the weakly alkaline solution is ammonia water, and the concentration of the ammonia water solution is 0.1 mol / L;

[0047] (5) Immerse the porous honeycomb ceramic carrier based on halloysite clay prepared in step (4) in the metal coating solution prepared in step (2) for impregnation precipitation, the impregnation time is 5 h, after the impregnation precipitation is completed, wash it with deionized water, dry it, and calcine it to obtain a porous honeycomb ceramic coated with a catalyst precursor.

[0048] Example 2

[0049] A preparation method of a 3D printed porous honeycomb ceramic carrier coated with a catalyst precursor based on halloysite clay, comprising the following steps:

[0050] (1) Weigh 30 parts of halloysite nanotubes, 7 parts of polyethylene glycol, 2 parts of sodium silicate and 58 parts of deionized water by mass, mix them evenly to obtain a ceramic blank for standby;

[0051] (2) Soak 10 parts by mass of the catalyst precursor (Co(NO3)2 and Ce(NO3)3 calculated by a mass ratio of 1:1) in an acid solution. After dissolution, a metal coating solution is obtained and reserved. The acid solution is a phosphoric acid solution with a concentration of 0.03 mol / L, and the mass ratio of the catalyst precursor to the acid solution is 1:2;

[0052] (3) Spray the ceramic blank on the forming plate through the printing nozzle of a 3D printing forming machine, print and form a green body based on a preset model of porous honeycomb ceramics, and then dry at room temperature and sinter at high temperature to obtain porous honeycomb ceramics based on halloysite clay. The sintering process is to heat the green body in a high-temperature sintering furnace at a rate of 5 °C / min to 600 °C, hold for 1 h, then continue to heat to 1200 °C and hold for 2 h;

[0053] (4) Immerse the porous honeycomb ceramics based on halloysite clay prepared in step (3) in a weakly alkaline solution for pretreatment for 6 h, take it out and dry to obtain a pretreated porous honeycomb ceramic carrier based on halloysite clay. The weakly alkaline solution is ammonium bicarbonate with a concentration of 0.03 mol / ;

[0054] (5) Immerse the porous honeycomb ceramic carrier based on halloysite clay prepared in step (4) in the metal coating solution prepared in step (2) for impregnation precipitation for 6 h. After the impregnation precipitation is completed, wash, dry and calcine with deionized water to obtain a porous honeycomb ceramic coated with the catalyst precursor.

[0055] Example 3

[0056] A method for coating a catalyst precursor on a 3D printed porous honeycomb ceramic carrier based on halloysite clay, comprising the following steps:

[0057] (1) Take 35 parts by mass of halloysite nanotubes, 8 parts by mass of polyethylene glycol, 4 parts by mass of sodium silicate and 53 parts by mass of deionized water, mix them evenly to obtain a ceramic blank and reserve it;

[0058] (2) Soak 10 parts by mass of the catalyst precursor (Co(NO3)2 and Ce(NO3)3 calculated by a mass ratio of 1:1) in an acid solution. After dissolution, a metal coating solution is obtained and reserved. The acid solution is a phosphoric acid solution with a concentration of 0.02 mol / L, and the mass ratio of the catalyst precursor to the acid solution is 1:2;

[0059] (3) Spray the ceramic blank onto the forming plate through the printing nozzle of a 3D printing machine, print a formed green body based on a preset model of porous honeycomb ceramics, and then dry it at room temperature and sinter it at high temperature to obtain porous honeycomb ceramics based on halloysite clay; the sintering process is to heat the formed green body in a high-temperature sintering furnace to 600 °C at a rate of 5 °C / min, hold for 1 h, then continue to heat to 1200 °C, and hold for 2 h;

[0060] (4) Immerse the porous honeycomb ceramics based on halloysite clay prepared in step (3) in a weakly alkaline solution for pretreatment for 6 h, take it out and dry it to obtain a pretreated porous honeycomb ceramic carrier based on halloysite clay; the weakly alkaline solution is ammonium bicarbonate, and the concentration of the ammonium bicarbonate solution is 0.05 mol / L;

[0061] (5) Immerse the porous honeycomb ceramic carrier based on halloysite clay prepared in step (4) in the metal coating solution prepared in step (2) for impregnation precipitation for 6.5 h. After the impregnation precipitation is completed, wash, dry, and calcine it with deionized water to obtain a porous honeycomb ceramic coated with a catalyst precursor.

[0062] Example 4

[0063] A preparation method of a 3D printed porous honeycomb ceramic carrier based on halloysite clay and coated with a catalyst precursor, comprising the following steps:

[0064] (1) Weigh 40 parts of halloysite nanotubes, 10 parts of polyethylene glycol, 5 parts of sodium silicate, and 48 parts of deionized water by mass, mix them evenly to obtain a ceramic blank for standby;

[0065] (2) Immerse 10 parts of a catalyst precursor (Co(NO3)2 and Ce(NO3)3 calculated according to a mass ratio of 1:1) by mass in an acid solution, dissolve it to obtain a metal coating solution for standby; the acid solution is a phosphoric acid solution, the concentration of the phosphoric acid solution is 0.04 mol / L, and the mass ratio of the catalyst precursor to the acid solution is 1:2;

[0066] (3) Spray the ceramic blank onto the forming plate through the printing nozzle of a 3D printing machine, print a formed green body based on a preset model of porous honeycomb ceramics, and then dry it at room temperature and sinter it at high temperature to obtain porous honeycomb ceramics based on halloysite clay; the sintering process is to heat the formed green body in a high-temperature sintering furnace to 600 °C at a rate of 5 °C / min, hold for 1 h, then continue to heat to 1200 °C, and hold for 2 h; obtain porous honeycomb ceramics based on halloysite clay;

[0067] (4) Immerse the porous honeycomb ceramics based on halloysite clay prepared in step (3) in a weakly alkaline solution for pretreatment for 7 h, take it out and dry it to obtain the pretreated porous honeycomb ceramics carrier based on halloysite clay; the weakly alkaline solution is an aqueous ammonium bicarbonate solution, and the concentration of the aqueous ammonium bicarbonate solution is 0.02 mol / L;

[0068] (5) Immerse the pretreated porous honeycomb ceramics carrier based on halloysite clay obtained in step (4) in the metal coating solution prepared in step (2) for impregnation precipitation for 7 h. After the impregnation precipitation is completed, wash it with deionized water, dry it, and calcine it to obtain the porous honeycomb ceramics coated with the catalyst precursor.

[0069] Comparative Example 1

[0070] A method for coating a catalyst precursor on a 3D printed porous honeycomb ceramics carrier based on halloysite clay comprises the following steps:

[0071] (1) Weigh 35 parts of halloysite nanotubes, 7 parts of polyethylene glycol, 5 parts of sodium silicate and 53 parts of deionized water by mass, mix them evenly to obtain a ceramic blank for standby;

[0072] (2) Spray the ceramic blank onto the forming plate through the printing nozzle of a 3D printing molding machine, print and form a green body based on the model of the preset porous honeycomb ceramics, and then dry it at room temperature and sinter it at high temperature; the sintering process is to heat the green body in a high-temperature sintering furnace from room temperature to 600 °C at a rate of 5 °C / min, hold for 1 h, then continue to heat to 1200 °C and hold for 2 h.

[0073] Experimental Example 1

[0074] The appropriate viscosity of the blank is crucial for the 3D printing formability. Evaluate the rheological properties of the above Examples 1-4. Measure the rheological behavior of the blank by a rheometer, repeat the experiment 3 times, and calculate the average value. The test results are shown in Table 1.

[0075] Table 1

[0076]

[0077] The structure and complexity of the 3D printed ceramic model are closely related to the rheological properties of the blank. The blank should maintain a viscoelastic behavior with shear thinning behavior, that is, have a sufficiently low viscosity at high shear rates to allow extrusion without clogging the nozzle. At the same time, it is necessary to have a sufficient yield stress at zero shear to avoid the collapse of the model under the action of gravity after filamentous deposition, that is, it must have a certain shape retention ability.

[0078] As can be seen from Table 1, with the increase in the content of halloysite nanotubes, the viscosity of the blank significantly increases. This is mainly because the increase in the content of halloysite nanotubes forms a stronger network structure with sodium silicate and polyethylene glycol. In addition, halloysite nanotubes have strong hydrophilicity, resulting in the formation of hydrogen bonds between the Al-OH and Si-O-Si groups on their surface and water molecules, which hinders the migration of water in the ink. With the increase in the content of halloysite nanotubes in the blank, this water absorption phenomenon increases sharply, leading to an increase in viscosity. In addition, through further oscillatory frequency sweep tests and cyclic strain sweep tests, it can be concluded that the above-mentioned blanks all exhibit corresponding elastic behaviors, and when subjected to high-to-low strain cycles, the blanks exhibit a transition behavior from liquid to solid. At low strains, the blank exhibits solid-like properties, while at high strains, the blank exhibits liquid-like properties with fluidity. The above results all indicate that the ceramic blank has 3D printability.

[0079] Experimental Example 2

[0080] Catalytic performance tests were carried out for different impregnation times. The harmful substances in automobile exhaust account for 1% of the total exhaust volume, and CO accounts for 70% of the harmful substances. CO is the most harmful component with the highest content in automobile exhaust. The test was carried out using a fixed-bed reactor. The porous honeycomb ceramic carrier coated with the prepared catalyst precursor was loaded into the reactor and fixed at both ends with cotton balls. The air in the reactor was exhausted, and a mixed gas with 1% CO was introduced, and the temperature was raised at 2 °C / min to test the conversion temperature of CO at different temperatures.

[0081] Conversion rate of CO = Conversion rate of CO / Content of CO2 in the product + Remaining amount of CO in the product.

[0082] The experiment was repeated 3 times and the average value was calculated. The test results are shown in Table 2.

[0083] Table 2

[0084]

[0085] Note: T0 is the light-off temperature, T50 is the temperature at which CO is converted by 50%, and T100 is the temperature at which CO is completely converted.

[0086] Due to the high specific surface area and good adsorption performance of halloysite nanotubes, when used to prepare a porous honeycomb ceramic carrier, the tiny pores inside can provide more catalytic active sites, which is beneficial to the progress of the catalytic reaction. As can be seen from Table 2, compared with Comparative Example 1 and Examples 1, 2, 3, and 4, the porous honeycomb ceramic coated with the catalyst has better catalytic performance than the porous honeycomb ceramic without the coated catalyst. This is because the catalyst and the porous honeycomb ceramic based on halloysite clay have a synergistic catalytic effect, which accelerates the catalytic conversion of CO. When the catalyst loading is low, a higher reaction temperature is required to compensate for the catalytic activity. At the same time, if the impregnation time is too long and the loaded catalyst is excessive, it will lead to the close packing between the catalyst particles, making it difficult for CO molecules to effectively contact the catalyst active sites, and may also block the pore channels, making it difficult for CO to diffuse into the carrier interior, thus reducing the catalytic efficiency.

[0087] In addition, the time for immersion precipitation in the metal coating solution in step (5) shows a trend of first increasing and then decreasing for the temperature required to convert CO in the range of 5 - 10 h. The lowest conversion temperature is achieved by impregnation for 5 h in Example 1.

[0088] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A 3D printed porous honeycomb ceramic carrier, characterized in that: The invention comprises the following components in parts by weight: 25 to 40 parts of halloysite nanotubes, 5 to 10 parts of a binder, 1 to 5 parts of a dispersant, 5 to 10 parts of a catalyst precursor and 100 to 150 parts of deionized water.

2. The 3D printed porous honeycomb ceramic carrier according to claim 1, characterized in that: The binder includes at least one of chitosan, sodium alginate, polyvinyl acetate, carboxymethyl chitosan, polyvinyl alcohol, polyethylene glycol, gelatin, starch, polyacrylate, epoxy resin and acrylic resin.

3. The 3D printed porous honeycomb ceramic carrier according to claim 1, characterized in that: The dispersant includes at least one of sodium hexametaphosphate, sodium silicate, sodium carbonate, sodium lauryl sulfate and sodium polyacrylate.

4. The 3D printed porous honeycomb ceramic carrier according to claim 1, characterized in that: The catalyst precursor includes FeCO3, Fe2(CO3)3, Fe(NO3)2, Fe(NO3)3, CoCO3, Co(NO3)2, Co(NO 3)3 , NiCO3, Ni(NO3)2, Ce2(CO3)3, Ce(CO3)2, Ce(NO3)3, Ce(NO3)4, PtCO3, Pt(CO3)2, Pt(NO3)2, Pt(NO3)4, PbCO3, Pb(NO 3)2 、MnCO3、Mn(NO 3)2 , Mn(NO3)3, Cu2(OH)2CO3, Cu(NO3)2, Au2(CO 3)3 、Au(NO 3)3 , Ag2CO3 and AgNO3.

5. The 3D printed porous honeycomb ceramic carrier according to claim 1, characterized in that: The 3D printed porous honeycomb ceramic carrier also includes an acid solution and a weak alkaline solution; the mass ratio of the acid solution, the weak alkaline solution and the catalyst precursor is 2 to 5:

1.

6. The 3D printed porous honeycomb ceramic carrier according to claim 1, characterized in that: The acid solution includes at least one of hydrochloric acid solution, nitric acid solution, sulfuric acid solution and phosphoric acid solution, and the concentration is 0.01mol / L to 0.05mol / L; the weak alkaline solution includes at least one of ammonia water, ammonium bicarbonate solution and sodium bicarbonate solution, and the concentration is 0.01mol / L to 0.05mol / L.

7. A method for preparing a 3D printed porous honeycomb ceramic carrier according to any one of claims 1 to 6, characterized in that: The following steps are involved: The halloysite nanotubes, a binder, a dispersant and deionized water are mixed uniformly in proportion to prepare a ceramic blank; The catalyst precursor is immersed in an acid solution and dissolved to obtain a metal coating liquid; The ceramic blank is sprayed onto a forming plate through a printing nozzle of a 3D printing machine, a forming blank is printed based on a preset porous honeycomb ceramic model, and then a drying process and a sintering process are performed to obtain a porous honeycomb ceramic precursor; Soaking the porous honeycomb ceramic precursor in a weak alkaline solution, taking it out and drying it to obtain a pretreated porous honeycomb ceramic precursor; The pretreated porous honeycomb ceramic precursor is immersed in the metal coating liquid, washed with deionized water after immersion, and then dried and calcined to obtain a 3D printed porous honeycomb ceramic carrier coated with a catalyst precursor based on halloysite clay.

8. The method for preparing a 3D printed porous honeycomb ceramic carrier according to claim 7, characterized in that: The sintering treatment refers to heating the formed green body to 600° C. at a rate of 5° C. / min in a high-temperature sintering furnace, keeping the temperature for 1 hour, and then continuing to heat the green body to 1200° C. and keeping the temperature for 2 hours.

9. The method for preparing a 3D printed porous honeycomb ceramic carrier according to claim 7, characterized in that: The soaking time is 5 to 10 hours.

10. An application of a 3D printed porous honeycomb ceramic carrier as claimed in any one of claims 1 to 6, characterized in that: The invention discloses an application of the invention in preparing a product for treating air pollution; the air pollution includes automobile exhaust gas.

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