Honeycomb material and preparation method thereof

Abstract

The invention provides a honeycomb material and a preparation method thereof. The honeycomb material comprises a honeycomb base material and a porous material loaded on the honeycomb base material, and loading is achieved through in-situ conversion of the porous material on the honeycomb base material. The preparation method of the honeycomb material comprises the following steps: simultaneously or sequentially mixing a raw material A and a raw material B of a porous material with a raw material of a honeycomb base material, carrying out an in-situ reaction, and carrying out honeycomb forming, thereby obtaining the honeycomb material, or preparing the porous material from the raw material A and the raw material B of the porous material, mixing the porous material with the raw material of the honeycomb base material, and then carrying out honeycomb forming, the raw material A comprises zinc oxide and / or zinc hydroxide; the raw material B comprises 2-methylimidazole. According to the method, the mode that the honeycomb base material is coated with a powder porous material is avoided, so that waste liquid generated in the porous material production process and many problems related in the forming process are avoided, the porous material is generated on the honeycomb base material in situ, the process is simplified, and pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of material preparation, and in particular relates to a honeycomb material and a preparation method thereof. Background Art

[0002] At present, the porous materials commonly prepared are mostly in the form of powders. When applied in the industrial field, they generally need to be formed and processed, and finally applied in the form of spheres, strips, etc., or coated on profiles in the form of slurry for use.

[0003] A large amount of wastewater will be generated during the preparation of the powder, and the powder form is not conducive to application. Generally, an adhesive needs to be introduced, which may reduce the overall performance of the material. In particular, when the slurry is used for coating, the fluidity, stability, storage and other issues of the slurry need to be considered, and the process is quite complicated. The prior art generally mixes the raw materials for reaction, and then washes, filters, dries, and grinds them multiple times. When applied, the porous material is ground, and a solvent and an additive are added to prepare a coating slurry, which is then coated on the honeycomb substrate. After drying and activation, a honeycomb material coated with a porous material is obtained.

[0004] In order to obtain good dispersion and use effects, porous materials should have small particle size and large surface area, but this will lead to the following problems: 1. Long separation and washing processing time, large amount of wastewater, low production efficiency and high cost; 2. The product is easy to dry into lumps due to strong capillary force during the subsequent drying process, so further grinding is required to make it fine. Although it can also be improved by spraying, freezing, vacuum and other methods, it will increase equipment investment and operating costs; 3. The slurry preparation process has problems such as large surface area of ​​powdered porous materials that are difficult to disperse, low solid content of slurry, poor fluidity, easy sedimentation, and deterioration during storage, which is not conducive to coating and use.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a honeycomb material and a preparation method thereof to solve the above problems.

[0007] In order to achieve the above objectives, the present invention particularly adopts the following technical solutions:

[0008] A honeycomb material comprises a honeycomb substrate and a porous material loaded on the honeycomb substrate, wherein the loading is achieved by in-situ conversion of the porous material on the honeycomb substrate.

[0009] Optionally, the honeycomb substrate includes an extruded honeycomb substrate and / or a fiber honeycomb substrate.

[0010] A method for preparing the honeycomb material comprises: mixing the raw materials A and B of the porous material with the raw materials of the honeycomb substrate simultaneously or sequentially, and performing honeycomb forming after in-situ reaction, to obtain the honeycomb material;

[0011] The raw material A includes oxides or hydroxides of manganese, cobalt, nickel, copper, zinc, and iron;

[0012] The raw material B includes imidazole and its derivatives, pyrimidine and its derivatives.

[0013] The raw material A of the porous material should not be soluble in the system where the raw material B of the porous material is located.

[0014] Optionally, the preparation method includes: preparing raw materials A and B of the porous material into slurry A and slurry B respectively for standby use;

[0015] The slurry A is coated on a honeycomb substrate, and then dried to obtain a precursor material; the precursor material is then impregnated with the slurry B, and dried again to form a honeycomb body;

[0016] The slurry A includes a sol or suspension of the raw material A in water;

[0017] The slurry B includes water, methanol, ethanol, DMF solution of the raw material B or a combination thereof.

[0018] The present invention couples the preparation process of the porous material with the coating process on the honeycomb substrate, thereby eliminating the separate preparation process of the porous material. Therefore, there are no difficulties in separation, washing, drying, and pulping, the process is greatly simplified, energy loss is reduced, and waste emissions are reduced. Moreover, since the raw materials A and B are independently configured, there is no problem of mixing affecting storage and repeated use, which facilitates production management and stable quality.

[0019] Preferably, the solid content of the raw material A in the slurry A is 10-40%.

[0020] The selection of the solid content range of raw material A in slurry A is particularly important. Experiments have shown that if the concentration is too low, the load of a single coating is small, increasing the number of coatings and energy consumption. If the concentration is too high, the fluidity of the slurry deteriorates, defects increase during coating, and this is not conducive to product stability.

[0021] Preferably, the concentration of the slurry B is 5-30%.

[0022] The concentration of slurry B has an important influence on the result of the reaction. It has been verified by experiments that if the concentration is too low, the reaction time will be prolonged and the production efficiency will be reduced. If the concentration is too high, there will be more parts physically attached to the honeycomb substrate, and the raw material utilization rate will be reduced.

[0023] Optionally, the drying method includes hot air, infrared, microwave, and vacuum drying;

[0024] Preferably, the drying temperature is 50-500° C. and the drying time is 0.5-3 h.

[0025] From the perspective of improving efficiency, a higher drying temperature is better, but too high a temperature may damage the structure of the porous material or reduce the adhesion to the substrate. Experiments have verified that within the preferred drying temperature range of the present invention, the overall effect is better.

[0026] Optionally, the immersion time is 1-30 min.

[0027] Optionally, the preparation method further comprises: before the coating, adding porous material seed crystals to the slurry A and stirring evenly;

[0028] The porous material seed crystals include a combination of one or more seed crystals in the porous material composed of the raw material A and the raw material B; preferably, the added mass of the porous material seed crystals is 1-10% of the mass of the raw material A in the slurry A.

[0029] Further preferably, the added mass of the porous material seed crystals is 5% of the mass of the raw material A in the slurry A.

[0030] Experimental verification shows that when the amount of seed crystals added is less than 1%, the specific surface area and pore volume of the material are lower under the same conditions. When the amount of seed crystals added is more than 10%, the cost is higher and the increase in specific surface area and pore volume is limited.

[0031] Optionally, the preparation method further comprises: before the impregnation, adding the porous material seed crystals into the slurry B and stirring evenly.

[0032] The porous material seed crystal is stable in the system of raw material A or raw material B. The seed crystal and raw material A have similar particle sizes and are mixed more evenly; the seed crystal and raw material B belong to different physical phases, which is conducive to the stability of the seed crystal.

[0033] The present invention creatively mixes raw material A for preparing porous material with porous material seed crystals, coats them on a honeycomb substrate and dries them. This process is mainly a physical change, and chemical changes may also occur. That is, raw material A is transferred from the slurry to the honeycomb substrate through physical surface effects such as hydrogen bonds, and may undergo hydrolysis or decomposition reactions during the subsequent drying process, firmly bonding to the honeycomb substrate to form a precursor material.

[0034] Then, the raw material B for preparing the porous material is mixed with the aforementioned precursor material and dried, or the raw material B and the porous material seed crystal are mixed and then impregnated with the precursor material. This process is mainly a chemical change, and there may also be physical changes, that is, the raw material B in the solution or slurry reacts with the raw material A or its chemical reaction product to form a porous material. Since the raw material A or its chemical reaction product is insoluble in the solution or slurry where the raw material B is located, the porous material is firmly bonded to the honeycomb substrate by chemical bonds. It is not ruled out that part of the raw material B is attached to the honeycomb substrate through physical surface effects such as hydrogen bonds, which can be removed in the subsequent drying process.

[0035] According to the method provided by the present invention, the attachment amount of raw material A and raw material B on the honeycomb substrate can be accurately and effectively controlled, and it is set according to the properties of the substrate, actual needs and reaction conditions, and controlled by adjusting the concentration of each system and the number of coatings. Since the stoichiometric molar ratio of raw material A to raw material B in the porous material is 1:2, when the attachment amount of the porous material on the honeycomb substrate is constant, the attachment amount of raw material A and raw material B required is also basically determined.

[0036] Beneficial effects of the present invention:

[0037] The honeycomb material provided by the present invention has the excellent structure of the honeycomb body, can efficiently load porous materials, has a higher specific surface area and pore volume, and thus obtains better adsorption performance.

[0038] The present invention loads porous materials on a honeycomb substrate, and by mixing, coating, and impregnating raw materials required for the porous materials, the raw materials react on the honeycomb substrate to form the porous materials, thereby avoiding waste water generated by preparing the porous materials separately and the trouble of molding, making the preparation process simpler, while saving costs and energy consumption, reducing pollution, being more environmentally friendly and economical, and being suitable for industrial promotion and use. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] The honeycomb material is prepared according to the method provided by the present invention, and the specific steps are as follows:

[0042] S1: Add water and additives to zinc oxide to prepare a slurry with a solid content of 15%, add 5% of the weight of zinc oxide seed, stir evenly and apply it on the honeycomb substrate, then dry it with hot air at 150°C for 1 hour to obtain the precursor material. It is calculated that the zinc oxide loading is 30kg / m 3 ;

[0043] S2: 2-methylimidazole was added with water to prepare a 25% solution. The precursor material obtained in S1 was immersed in the aqueous solution of 2-methylimidazole for 10 min, and then dried under microwave at 120 °C for 1 h to obtain a 2-methylimidazole loading of 60 kg / m 3 of honeycomb material.

[0044] It was calculated that the loading capacity of porous material in the honeycomb material was 84kg / m 3 , with a specific surface area of ​​685m 2 / g, and the pore volume is 0.30ml / g.

[0045] Example 2

[0046] S1: Add water and additives to zinc hydroxide to prepare a slurry with a solid content of 20%, and add 6% of the weight of zinc hydroxide seed crystals. After stirring evenly, apply it on the honeycomb substrate, and then dry it with hot air at 150°C for 1 hour to obtain a precursor material. It is calculated that the zinc hydroxide loading is 37kg / m 3 ;

[0047] S2: 2-methylimidazole was added with water to prepare a 25% solution. The precursor material obtained in S1 was immersed in the aqueous solution of 2-methylimidazole for 10 min, and then dried under microwave at 120 °C for 1 h to obtain a 2-methylimidazole loading of 60 kg / m 3 of honeycomb material.

[0048] It was calculated that the loading capacity of porous material in the honeycomb material was 84kg / m 3 , with a specific surface area of ​​685m 2 / g, and the pore volume is 0.30ml / g.

[0049] Example 3

[0050] S1: Add water and additives to zinc oxide to prepare a slurry with a solid content of 10%, add 5% of the weight of zinc oxide seed, stir evenly and coat it on the honeycomb substrate, then dry it with hot air at 150°C for 1 hour to obtain the precursor material. It is calculated that the zinc oxide loading is 20kg / m 3 ;

[0051] S2: 2-methylimidazole was added with water to prepare a 16% solution. The precursor material obtained in S1 was immersed in the aqueous solution of 2-methylimidazole for 1 min, and then dried under microwave at 120 °C for 1 h to obtain a 2-methylimidazole loading of 40 kg / m 3 of honeycomb material.

[0052] It was calculated that the loading capacity of the porous material in the obtained honeycomb material was 56kg / m 3 , with a specific surface area of ​​540m 2 / g, and the pore volume is 0.23ml / g.

[0053] Example 4

[0054] S1: Add water and additives to zinc oxide to prepare a slurry with a solid content of 15%, stir it evenly and apply it on the honeycomb substrate, then dry it with hot air at 150°C for 1 hour to obtain the precursor material. It is calculated that the zinc oxide loading is 30kg / m 3 ;

[0055] S2: 2-methylimidazole was added with water to prepare a 25% solution. The precursor material obtained in S1 was immersed in the aqueous solution of 2-methylimidazole for 10 min, and then dried under microwave at 120 °C for 1 h to obtain a 2-methylimidazole loading of 60 kg / m 3 of honeycomb material.

[0056] It was calculated that the loading capacity of porous material in the honeycomb material was 84kg / m 3 , with a specific surface area of ​​550m 2 / g, and the pore volume is 0.24ml / g.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that the solid content of the zinc oxide slurry prepared in S1 is 2%. The zinc oxide loading of the precursor material obtained in S1 is calculated to be 5 kg / m 3 The 2-methylimidazole loading in the obtained honeycomb material is 60 kg / m 3 , the loading capacity of porous material is 14kg / m 3 , with a specific surface area of ​​128m 2 / g, and the pore volume is 0.05ml / g.

[0059] Comparative Example 2

[0060] Different from Implementation 1, the solid content of the slurry prepared in S1 was 50%, and pore blockage occurred during the coating process, making subsequent operations impossible.

[0061] Comparative Example 1

[0062] The honeycomb material is prepared according to the prior art method, and the specific steps are as follows:

[0063] The zinc nitrate solution and the 2-methylimidazole solution were mixed and reacted for 2 hours, filtered, washed, dried and ground to obtain a powdery porous material. The powdery porous material was added with water and an additive to prepare a 15% slurry, which was coated on a honeycomb substrate. After being taken out, it was dried in hot air at 150°C for 1 hour to obtain a porous material with an attachment weight of 50 kg / m 3 Honeycomb with a surface area of ​​500m 2 / g, and the pore volume is 0.2ml / g.

[0064] It can be seen from Examples 1-4 that the honeycomb materials prepared by the preparation method provided by the present invention have large specific surface areas and large pore volumes, and the preparation and implementation steps of each raw material are relatively independent and controllable. The loading capacity of the porous material is generally high and relatively flexible, controllable and adjustable.

[0065] By comparing Examples 1-4 with Comparative Example 1, it can be seen that since there is no need to introduce an adhesive, the method provided by the present invention has a higher comprehensive loading capacity of the porous material, the prepared honeycomb material has a larger specific surface area, a larger pore volume, and better adsorption performance, and eliminates the steps of filtering, washing, drying, and grinding in the separate preparation of porous materials. The complex process of preparing the porous material slurry is converted into a simple and easy raw material preparation process, reducing the difficulty of production and storage, and therefore has obvious advantages of saving energy consumption and reducing waste.

[0066] It can be seen from Examples 1 and 4 that even if the amount of seed crystals added is only 5% of raw material A, which is less than 2% of the loading amount of the porous material, the addition of a trace amount of seed crystals has a significant effect on the quality of the porous material, that is, on the specific surface area and pore volume. Although the loading amounts of the two are almost the same, the specific surface area and pore volume of the material obtained in Example 1 are significantly better than those in Example 4.

[0067] It can be seen from Example 1 and Comparative Example 1 that the solid content of zinc oxide in raw material A in slurry A of Comparative Example 1 is relatively low, which is lower than the preferred range of the present invention, so its loading amount is relatively small. Even if the loading amount of raw material B is consistent with that of Example 1, due to the limitation of the stoichiometric ratio of the chemical reaction, the raw material B actually participating in the reaction to form the porous material is only 10 kg / m 3 Therefore, the load of the porous material is only 14kg / m 3 The specific surface area and pore volume of the material are much smaller than those in Example 1, and the performance of the obtained materials is very different.

[0068] It can be seen from Example 1 and Control Example 2 that the higher the solid content of raw material A in slurry A, the better. When the solid content is higher than the preferred range of the present invention, it may even directly lead to pore blockage and inability to carry out subsequent reactions.

[0069] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. A honeycomb material, It is characterized in that The invention comprises a honeycomb substrate and a porous material loaded on the honeycomb substrate, wherein the loading is achieved by in-situ conversion of the porous material on the honeycomb substrate.

2. The honeycomb material according to claim 1, It is characterized in that The honeycomb substrate includes an extruded honeycomb substrate and / or a fiber honeycomb substrate.

3. A method for preparing the honeycomb material according to claim 1 or 2, It is characterized in that include: The raw materials A and B of the porous material are mixed with the raw materials of the honeycomb substrate simultaneously or sequentially, and honeycomb forming is performed after in-situ reaction; The raw material A includes oxides or hydroxides of manganese, cobalt, nickel, copper, zinc, and iron; The raw material B includes imidazole and its derivatives, pyrimidine and its derivatives.

4. The preparation method according to claim 3, It is characterized in that The preparation method comprises: preparing raw materials A and B of the porous material into slurry A and slurry B respectively for standby use; The slurry A is coated on a honeycomb substrate, and then dried to obtain a precursor material; the precursor material is then impregnated with the slurry B, and dried again to form a honeycomb body; The slurry A includes a sol or suspension of the raw material A in water; The slurry B includes water, methanol, ethanol, DMF solution of the raw material B or a combination thereof.

5. The preparation method according to claim 4, It is characterized in that The solid content of the raw material A in the slurry A is 10-40%.

6. The preparation method according to claim 4, It is characterized in that The concentration of the slurry B is 5-30%.

7. The preparation method according to claim 4, It is characterized in that The drying methods include hot air, infrared, microwave and vacuum drying; Preferably, the drying temperature is 50-500° C. and the drying time is 0.5-3 h.

8. The preparation method according to claim 4, It is characterized in that The immersion time is 1-30 minutes.

9. The preparation method according to claim 4, It is characterized in that The preparation method further comprises: before the coating, adding porous material seed crystals into the slurry A and stirring evenly; The porous material seed crystals include a combination of one or more seed crystals in the porous material composed of the raw material A and the raw material B; Preferably, the added mass of the porous material seed crystals is 1-10% of the mass of the raw material A in the slurry A.

10. The preparation method according to claim 4 or 9, It is characterized in that The preparation method further comprises: before the impregnation, adding the porous material seed crystals into the slurry B and stirring the mixture evenly.