CN115845602A - Porous catalytic honeycomb for high-voltage electric field synergistic purification module and preparation method thereof - Google Patents

Abstract

The invention discloses a porous catalytic honeycomb for a high-voltage electric field synergistic purification module and a preparation method thereof, wherein the porous catalytic honeycomb consists of an insulating honeycomb, a catalytic layer and electronic slurry; the plurality of through holes of the insulation honeycomb form an air flow channel; a catalytic layer is coated on the inner surface of each through hole; the catalyst layer contains a catalyst capable of generating an active substance for decomposing contaminant molecules under the action of a high-voltage electric field and/or a light field; forming a first conductive area by the electronic paste coated on the first end face, and forming a second conductive area by the electronic paste coated on the second end face; the volume resistivities of the first conductive region and the second conductive region are both less than or equal to 100 omega cm. The porous catalytic honeycomb omits a macroscopic metal electrode, has the characteristics of simple structure and high installation and maintenance efficiency, and can overcome the defects of complex structure, difficult disassembly and assembly and influence on final performance due to easy corrosion and pulverization of the macroscopic electrode in the prior art.

Description

Porous catalytic honeycomb for high-voltage electric field synergistic purification module and preparation method thereof

Technical Field

The invention relates to the technical field of catalytic purification, in particular to a porous catalytic honeycomb for a high-voltage electric field synergistic purification module and a preparation method thereof.

Background

In the field of air catalytic purification technology, the existing catalytic purification devices include the following two types:

1. an ion field catalytic purification device comprises a high-voltage power supply, an ion field catalyst and a pair of electrodes which are respectively arranged at two sides of the ion field catalyst, wherein the high-voltage power supply is respectively connected with the pair of electrodes; the ion field catalyst takes a porous material as a carrier, and the surface of the ion field catalyst is coated with a semiconductor oxide composite coating.

2. A high-voltage electric auxiliary photocatalysis purification module comprises a photocatalyst, an electric insulation porous medium, an ultraviolet lamp set, a high-voltage power supply and a pair of discharge electrodes; the photocatalyst is loaded on the surface of the electrically-insulated porous medium, the electrically-insulated porous medium is placed between the pair of discharge electrodes, and the discharge electrodes are hollow; the ultraviolet lamp set is arranged on the outer side of the discharge electrodes, and the pair of discharge electrodes are respectively connected with the output end of the high-voltage power supply. Irradiating ultraviolet light on the photocatalyst to excite the photocatalyst to generate photocatalysis; meanwhile, a strong electric field is formed between the discharge electrode pairs by utilizing high voltage, the strong electric field is used for cooperatively exciting the photocatalyst to perform photocatalysis, air containing volatile organic matter molecules or peculiar smell gas molecules and free bacteria is contacted with the surface of the photocatalyst and then decomposed, and the strong electric field prevents effective active photoproduction electrons and photoproduction holes in the photocatalysis process from being compounded.

However, the two purification devices in the prior art both need a pair of solid macroscopic metal electrodes, so that the quality of the electrodes affects the purification effect, and the problems of complex structure, high assembly cost and difficult disassembly and maintenance are caused; in addition, the macroscopic metal electrode is easily corroded and pulverized under the condition of a high-voltage electric field, thereby causing the problem of forming an insulating film on the surface.

Disclosure of Invention

In view of the above, the invention provides a porous catalytic honeycomb for a high-voltage electric field synergistic purification module and a preparation method thereof, the porous catalytic honeycomb omits a macroscopic metal electrode, has the characteristics of simple structure and high installation and maintenance efficiency, and can overcome the defects of complex structure, difficulty in disassembly and assembly and influence on final performance due to easy corrosion and pulverization of the macroscopic electrode in the prior art.

The invention adopts the following specific technical scheme:

a porous catalytic honeycomb for a high-voltage electric field synergistic purification module comprises an insulating honeycomb, a catalytic layer and electronic slurry;

the insulation honeycomb is provided with a plurality of through holes, a first end face and a second end face, wherein the first end face and the second end face are positioned at two ends of the through holes; the through holes form airflow channels; the inner surface of each through hole is coated with the catalytic layer;

the catalyst layer contains a catalyst which can generate active substances for decomposing pollution molecules under the action of a high-voltage electric field and/or a light field;

the electronic paste is coated on the first end face and the second end face of the insulating honeycomb, a first conductive area is formed by the electronic paste coated on the first end face, and a second conductive area is formed by the electronic paste coated on the second end face;

the volume resistivity of the first conductive region and the volume resistivity of the second conductive region are both less than or equal to 100 Ω · cm.

Furthermore, the insulating honeycomb is made of cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite or cordierite-aluminum titanate composite matrix;

the cross section of the through hole is in a shape of a circle, a triangle, a square, a pentagon or a hexagon.

Furthermore, the catalytic layer also contains an adhesive and a catalytic promoter;

the catalyst comprises a high-voltage electric field excitation catalyst and a photocatalyst;

the high-voltage electric field excitation catalyst is Pt, pd, ag, ru metal simple substance and oxide thereof, and TiO ₂ 、CeO ₂ 、CuO、Fe ₂ O ₃ And Fe ₃ O ₄ At least one of (a);

the photocatalyst is CeO ₂ 、TiO ₂ 、ZnO、SnO ₂ 、Ga ₂ O ₃ 、BiPO ₄ 、AgNO ₃ At least one of BiOBr and BiOCl;

the adhesive and the catalytic promoter contain polyvinyl alcohol, alumina or cerium-zirconium eutectic.

The photocatalyst is modified by doping graphene and metal ions or nitrogen, so that the light absorption range of the photocatalyst is widened.

Still further, the electronic paste comprises at least one of Ag, pd, ni, al, W, mo, ta, nb, V, cr, ti, and at least one of graphene, carbon nanotubes, or carbon black.

Still further, the insulating honeycomb further comprises a bonding pad for circuit welding, a through hole for electrical bonding or a conductive hole for adhesion, which are arranged on the first end face and the second end face.

In addition, the invention also provides a preparation method of the porous catalytic honeycomb in the technical scheme, which comprises the following steps:

preparing an insulating honeycomb, an electronic paste and a coating component for forming a catalytic layer;

determining the heat treatment temperature of the electronic paste and the coating component, wherein the heat treatment temperature of the electronic paste is Tm, and the heat treatment temperature of the coating component is Tn;

comparing Tm and Tn;

when Tm is less than Tn, firstly coating the coating component on the inner surface of a through hole of the insulating honeycomb to form a catalyst layer, then carrying out heat treatment on the insulating honeycomb with the catalyst layer, then coating electronic slurry on a first end face of the insulating honeycomb to form a first conductive area, coating the electronic slurry on a second end face of the insulating honeycomb to form a second conductive area, and finally carrying out heat treatment on the insulating honeycomb with the catalyst layer, the first conductive area and the second conductive area;

when Tm is greater than Tn, firstly coating electronic slurry on a first end face of an insulating honeycomb to form a first conductive region, coating the electronic slurry on a second end face of the insulating honeycomb to form a second conductive region, then carrying out heat treatment on the insulating honeycomb with the first conductive region and the second conductive region, then shielding the first conductive region and the second conductive region of the insulating honeycomb through a protective layer, coating a coating component on the inner surface of a through hole of the insulating honeycomb through impregnation adsorption or catalysis to form a catalytic layer, removing the protective layer, and finally carrying out heat treatment on the insulating honeycomb with the catalytic layer, the first conductive region and the second conductive region;

when Tm = Tn, a coating composition is first coated on the inner surfaces of the through holes of the insulated honeycomb by a dipping process to form a catalytic layer, then an electronic paste is coated on a first end surface of the insulated honeycomb to form a first conductive region, and an electronic paste is coated on a second end surface of the insulated honeycomb to form a second conductive region, and finally the insulated honeycomb formed with the catalytic layer, the first conductive region, and the second conductive region is subjected to a heat treatment.

Has the advantages that:

1. the porous catalytic honeycomb for the high-voltage electric field synergistic purification module consists of an insulating honeycomb, a catalytic layer and electronic slurry; the plurality of through holes of the insulation honeycomb form an air flow channel; the inner surface of each through hole is coated with a catalyst layer, and the catalyst layer contains a catalyst which can generate an active substance for decomposing pollution molecules under the action of a high-voltage electric field and/or a light field; forming two opposite conductive regions by the electronic paste coated on the first end face and the second end face; the porous catalytic honeycomb forms two electrodes which are oppositely arranged through the electronic slurry coated on the first end face and the second end face of the insulating honeycomb, entity macroscopic metal electrodes are not needed, and the catalytic layer can promote the catalytic layer to decompose active substances for purifying pollution molecules under the synergistic action of a high-voltage electric field and/or light rays formed between the two electrodes, so that the purifying effect of the porous catalytic honeycomb is improved; the porous catalysis honeycomb with the structure integrates the insulation honeycomb and the electrode providing the high-voltage electric field into a whole, simplifies the structure of the high-voltage electric field cooperative purification module, saves the solid metal electrode and reduces the installation process of the electrode, and simultaneously, the catalyst contained in the catalysis layer can purify and treat the pollution molecules under the cooperative action of the high-voltage electric field and/or the light field.

2. The insulating honeycomb material in the porous catalytic honeycomb is one of cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite and cordierite-aluminum titanate composite substrates, and the cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite and cordierite-aluminum titanate composite substrates have the characteristics of good insulating effect, easiness in material obtaining, low manufacturing cost and long service life, so that the porous catalytic honeycomb made of the insulating honeycomb material has the advantages of good insulating effect, low manufacturing cost and long service life.

3. The catalyst layer is coated on the inner surface of the through hole of the porous catalytic honeycomb, the catalyst forming the catalyst layer comprises a high-voltage electric field excitation catalyst and a photocatalyst, the high-voltage electric field excitation catalyst can be used for decomposing active substances of pollution molecules in purified air through a high-voltage electric field formed between the two conductive areas, the photocatalyst can be decomposed into the active substances of the pollution molecules in the purified air through light rays irradiated on the photocatalyst, and the air purification efficiency of the porous catalytic honeycomb is further improved; in addition, the purifying performance of the purifying module can be dynamically regulated and controlled by controlling the coating area and the coating area of the catalytic layer on the inner surface of the through hole.

4. In the above porous catalytic honeycomb, the insulating honeycomb further includes pads for circuit bonding, through-holes for electrical bonding, or conductive holes for adhesion provided at the first end face and the second end face, and connection of the insulating honeycomb to an external power supply is facilitated by the pads, the through-holes, and the conductive holes.

5. The preparation method of the porous catalytic honeycomb comprises the following steps: preparing an insulating honeycomb, an electronic paste and a coating component for forming a catalytic layer; determining and comparing heat treatment temperatures of the electronic paste and the coating component; different procedures are selected according to the heat treatment temperature of the electronic paste and the coating component, so that the formation of the catalyst layer and the electronic paste on the insulating honeycomb is realized, the catalyst layer, the electronic paste and the insulating honeycomb form an integrated porous catalytic honeycomb, the assembly link of an electrode and the insulating honeycomb is omitted, the structure, the disassembly and the maintenance of the porous catalytic honeycomb are simplified, and the installation and maintenance efficiency of the purification module is improved.

Drawings

FIG. 1 is a schematic perspective view of a catalytic honeycomb according to the present invention;

FIG. 2 is a side view of the porous catalytic honeycomb of FIG. 1;

FIG. 3 isbase:Sub>A cross-sectional view A-A ofbase:Sub>A porous catalytic honeycomb;

FIG. 4 is an enlarged partial view of portion B of FIG. 3;

FIG. 5 is an enlarged partial view of the portion B of FIG. 3;

FIG. 6 is a schematic perspective view of another embodiment of a porous catalytic honeycomb of the present invention;

FIG. 7 is a schematic perspective view of another embodiment of a porous catalytic honeycomb of the present invention;

fig. 8 is a partially enlarged structural view of a portion C in fig. 7.

Wherein 1-insulating honeycomb, 2-catalytic layer, 3-via, 4-first conductive region, 5-second conductive region, 6-first connection pad, 7-second connection pad, 8-wire, 9-via

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

Example one

The embodiment provides a porous catalytic honeycomb for a high-voltage electric field synergistic purification module, as shown in the structures of fig. 1, 6 and 7, the porous catalytic honeycomb is composed of an insulating honeycomb 1, a catalytic layer 2 and electronic slurry;

the insulating honeycomb 1 is provided with a plurality of through holes 3, and a first end face and a second end face located at both ends of the plurality of through holes 3; the through holes 3 form airflow channels; the cross-sectional shape of the through holes 3 can be any shape such as a circle, a triangle, a square, a pentagon or a hexagon, for example, the porous catalytic honeycomb in fig. 1 and 2 is provided with a plurality of square through holes 3 distributed in an array, the porous catalytic honeycomb in fig. 6 is provided with a plurality of circular through holes 3 distributed in an array, and the porous catalytic honeycomb in fig. 7 is provided with a plurality of regular hexagon through holes 3 distributed in an array;

as shown in the structures of fig. 3, 4 and 5, a catalyst layer 2 is coated on the inner surface of each through hole 3, the catalyst layer 2 contains a catalyst capable of generating an active substance for decomposing pollution molecules under the action of a high-voltage electric field and/or a light field, and the catalyst layer can prevent the recombination of electrons and holes in the photocatalysis process under the action of the high-voltage electric field to promote the directional movement of the electrons and holes generated in the photocatalysis process; the inner surfaces of the through holes 3 of the porous catalytic honeycomb shown in fig. 4 are completely coated with the catalytic layer 2, the inner surfaces of the through holes 3 of the porous catalytic honeycomb shown in fig. 5 are partially coated with the catalytic layer 2, and the inner surfaces of the through holes 3 of the porous catalytic honeycomb can be coated with the catalytic layer 2 in a gradient manner; the purification performance of the purification module 1 can be dynamically regulated and controlled through different coating positions, areas and distribution; coating electronic paste on both a first end face and a second end face of the insulating honeycomb 1, forming a first conductive region 4 by the electronic paste on the first end face, and forming a second conductive region 5 by the electronic paste on the second end face; as shown in the structures of fig. 3, 4 and 5, coating an electronic paste on a first end face of an insulating honeycomb 1 to form a first conductive region 4, coating an electronic paste on a second end face of the insulating honeycomb 1 to form a second conductive region 5, and insulating between the first conductive region 4 and the second conductive region 5 through the insulating honeycomb 1; the electronic paste comprises at least one of Ag (silver), pd (palladium), ni (nickel), al (aluminum), W (tungsten), mo (molybdenum), ta (tantalum), nb (niobium), V (vanadium), cr (chromium), ti (titanium), and at least one of graphene, carbon nanotubes, or carbon black; the volume resistivities of the first conductive region 4 and the second conductive region 5 are both 100 Ω · cm or less.

When the porous catalytic honeycomb is used in a high-voltage electric field cooperative purification module, the first conductive region 4 and the second conductive region 5 are electrically connected with a high-voltage power supply and used for forming a high-voltage electric field between the first conductive region 4 and the second conductive region 5; meanwhile, a light source is arranged outside the first end face of the porous catalytic honeycomb, such as: an ultraviolet light source.

The porous catalytic honeycomb 1 is composed of an insulating honeycomb 1, a catalytic layer 2 and electronic slurry; the insulating honeycomb 1 has a plurality of through holes 3, and first and second end faces located at both ends of the through holes 3; the through holes 3 form airflow channels; the inner surface of each through hole 3 is coated with a catalyst layer 2, the catalyst layer 2 contains a catalyst which can generate active substances for decomposing pollution molecules under the action of a high-voltage electric field and/or a light field, and the catalyst layer can promote electrons and holes generated in the photocatalysis process to move directionally under the action of the high-voltage electric field so as to prevent the electrons and the holes from being compounded; forming a first conductive area 4 and a second conductive area 5 which are oppositely arranged through the electronic paste coated on the first end face and the second end face; the porous catalytic honeycomb forms two electrodes which are oppositely arranged through the electronic slurry coated on the two end faces of the insulating honeycomb 1, entity macroscopic metal electrodes are not needed, and the catalytic layer 2 can promote the catalytic layer to decompose active substances for purifying pollution molecules under the action of a high-voltage electric field and/or light rays formed between two conductive areas, so that the purification effect of the porous catalytic honeycomb is improved; the porous catalytic honeycomb with the structure integrates the insulating honeycomb 1 and the electrode for providing a high-voltage electric field, simplifies the structure of a high-voltage electric field cooperative purification module, saves solid metal electrodes and reduces the installation process of the electrodes, so the porous catalytic honeycomb has the advantages of simple structure, easy installation and high installation and maintenance efficiency, and simultaneously overcomes the defects of complex structure, difficult disassembly and assembly and influence on final performance due to easy corrosion and pulverization of macroscopic electrodes in the prior art.

In a specific embodiment, the material of the insulating honeycomb 1 in the porous catalytic honeycomb may be cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite, or cordierite-aluminum titanate composite matrix. The insulating honeycomb 1 can be made of one of cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite and cordierite-aluminum titanate composite matrixes, and the cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite and cordierite-aluminum titanate composite matrixes have the characteristics of good insulating effect, easiness in material obtaining, low manufacturing cost and long service life, so that the porous catalytic honeycomb made of the insulating honeycomb material has the advantages of good insulating effect, low manufacturing cost and long service life.

The catalyst layer 2 of the porous catalytic honeycomb can also contain an adhesive and a catalytic assistant; the catalyst comprises a high-voltage electric field excitation catalyst and a photocatalyst; the high-voltage electric field excited catalyst may be Pt, pd, ag, ru, tiO, or their oxides ₂ 、CeO ₂ 、CuO、Fe ₂ O ₃ And Fe ₃ O ₄ At least one of (a); the photocatalyst may be CeO ₂ 、TiO ₂ 、ZnO、SnO ₂ 、Ga ₂ O ₃ 、BiPO ₄ 、AgNO ₃ BiOBr, biOCl, namely: the photocatalyst can be at least one of cerium dioxide, titanium dioxide, zinc oxide, tin dioxide, gallium oxide, bismuth phosphate, bismuth oxybromide and bismuth oxychloride. The catalyst promoter and the adhesive can contain PVA (polyvinyl alcohol) and Al ₂ O ₃ (alumina) or cerium zirconium eutectic. The photocatalyst can also be modified by doping graphene and metal ions or nitrogen so as to widen the light absorption range of the photocatalyst.

According to the porous catalytic honeycomb, the catalytic layer 2 is coated on the inner surface of the through hole 3, the catalyst forming the catalytic layer 2 comprises the high-voltage electric field excitation catalyst and the photocatalyst, the high-voltage electric field excitation catalyst can be used for decomposing active substances of pollution molecules in purified air through the high-voltage electric field formed between the two conductive areas, the photocatalyst can be used for decomposing the active substances of the pollution molecules in the purified air through light irradiating on the photocatalyst, and the air purification efficiency of the porous catalytic honeycomb is further improved.

Furthermore, the insulating honeycomb 1 further includes pads for circuit bonding, through holes for electrical bonding, or conductive holes for bonding, provided on the first end face and the second end face; as shown in fig. 1, the pads may include first connection pads 6 and second connection pads 7 fixedly mounted to the insulating honeycomb 1; the first connection pad 6 is in conduction with the first conductive region 4, the second connection pad 7 is in conduction with the second conductive region 5, and the high voltage power supply can be electrically connected through the first connection pad 6 and the second connection pad 7, so that a high voltage electric field is formed between the first conductive region 4 and the second conductive region 5. The high voltage power supply 6 may be electrically connected to the first conductive area 4 and the second conductive area 5 by a wire 8 by welding, bonding, or gluing. As illustrated in fig. 7 and 8, a connection structure in which a wire 8 is crimped by making a hole in the first conductive region 4 and the second conductive region 5.

In the porous catalytic honeycomb, the insulating honeycomb 1 further comprises a bonding pad for circuit welding, a perforation for electric bonding or a conductive hole for bonding, which are arranged on the first end face and the second end face, and the connection of the insulating honeycomb and an external power supply is facilitated through the bonding pad, the perforation and the conductive hole; meanwhile, the inner surface of the through hole 3 is completely coated, partially coated or gradient-coated with the catalyst layer 2, and the purification performance of the porous catalytic honeycomb can be dynamically controlled by controlling the coating area and the coating area of the catalyst layer 2 on the inner surface of the through hole 3.

Example two

This example provides a method for preparing a porous catalytic honeycomb according to the above example, including the following steps:

preparing an insulating honeycomb 1, an electronic paste, and a coating component forming a catalytic layer 2;

determining the heat treatment temperature of the electronic paste and the coating component, wherein the heat treatment temperature of the electronic paste is Tm, and the heat treatment temperature of the coating component is Tn;

comparing Tm and Tn;

when Tm < Tn, firstly coating a coating component on the inner surface of a through hole 3 of an insulating honeycomb 1 to form a catalyst layer 2, then carrying out heat treatment on the insulating honeycomb 1 with the catalyst layer 2, then coating electronic slurry on a first end face of the insulating honeycomb 1 to form a first conductive region 4, coating the electronic slurry on a second end face to form a second conductive region 5, and finally carrying out heat treatment on the insulating honeycomb 1 with the catalyst layer 2, the first conductive region 4 and the second conductive region 5;

when Tm > Tn, first applying an electronic paste to a first end surface of the insulating honeycomb 1 to form a first conductive region 4, applying an electronic paste to a second end surface of the insulating honeycomb 1 to form a second conductive region 5, then performing heat treatment on the insulating honeycomb 1 on which the first conductive region 4 and the second conductive region 5 are formed, then shielding the first conductive region 4 and the second conductive region 5 of the insulating honeycomb 1 by a protective layer, applying a coating composition to inner surfaces of through holes 3 of the insulating honeycomb 1 by immersion adsorption or catalysis to form a catalytic layer 2, removing the protective layer, and finally performing heat treatment on the insulating honeycomb 1 on which the catalytic layer 2, the first conductive region 4, and the second conductive region 5 are formed;

when Tm = Tn, a coating composition is first applied to the inner surfaces of the through holes 3 of the insulating honeycomb 1 by a dipping process to form the catalytic layer 2, then an electron paste is applied to a first end surface of the insulating honeycomb 1 to form the first conductive region 4, and an electron paste is applied to a second end surface of the insulating honeycomb 1 to form the second conductive region 5, and finally the insulating honeycomb 1 formed with the catalytic layer 2, the first conductive region 4, and the second conductive region 5 is subjected to a heat treatment.

The porous catalytic honeycomb is prepared by the preparation method, so that the catalytic layer 2 and the electronic slurry are integrally formed on the insulating honeycomb 1, the catalytic layer 2, the electrode and the insulating honeycomb 1 are integrally formed into the porous catalytic honeycomb, the assembly link of the electrode and the insulating honeycomb 1 is omitted, the structure, the assembly, the disassembly and the maintenance of the porous catalytic honeycomb are simplified, and the installation and maintenance efficiency of the purification module is improved.

According to different raw materials for preparing the porous catalytic honeycomb, the following embodiments can be provided:

implementation mode one

The main component of the electronic paste is silver paste, and the sintering temperature Tm is 600-850 ℃.

Preparation of catalytic layer 2: dispersing 102g of tetrabutyl titanate precursor into 175mL of anhydrous ethanol dispersing agent, then adding 85mL of anhydrous ethanol into 7mL of dilute hydrochloric acid (37.5 wt%, hydrolysis inhibitor), and stirring at normal temperature for 30-60 min to obtain titanium sol dispersion liquid; the sintering temperature Tn of the catalyst layer 2 is 400 to 500 ℃.

The cordierite honeycomb had a wall thickness of 1.5mm.

Because Tm is more than Tn, firstly coating the first end face and the second end face of the cordierite honeycomb with electronic paste, dipping the paste by using a rolling brush during coating, repeatedly rolling and coating the first end face and the second end face, and then sintering at 850 ℃ for 2h, wherein the thickness of the sintered electronic paste coating is 30-50 mu m;

then covering the first end face and the second end face with covering films with the same pore channel structures, soaking the covering films into titanium sol dispersion liquid, and drying the covering films at 60 ℃; then calcining at 400-500 ℃, wherein the thickness of the sintered catalyst layer 2 is 100-150 μm;

under the combined action of the high-voltage electric field or the high-voltage electric field and the optical field, air can flow through the first end surface to the second end surface and can also flow in the reverse direction, so that the circulating purification is carried out.

Second embodiment

The electronic paste is graphene electronic paste, wherein the components comprise: 90 percent of terpineol, 3 to 4 percent of fumed silica (thixotropic agent), 3 to 4 percent of di-n-octyl phthalate (plasticizer), 2 percent of ethyl cellulose (binder) and 0.05 to 0.14 percent of high-temperature thermal reduction graphene, and the treatment temperature in a planetary mixer is that the Tm of the drying temperature of the organic solvent is lower than 300 ℃.

Catalyst layer 2: firstly, gallium nitrate and urea are reacted to generate a gallium oxide precursor, then the gallium oxide precursor is calcined for 2 hours at the temperature of 600-800 ℃ to obtain gallium oxide, the obtained gallium oxide is dispersed into the low-viscosity epoxy resin of the adhesive, and the treatment temperature Tn is 450 ℃.

And when the Tm is less than Tn, the silicon carbide honeycomb is firstly impregnated with the catalyst layer 2 and then calcined at 450-500 ℃.

In the impregnation process, a mold is used for plugging the pore passages on one side of the silicon carbide honeycomb, so that the impregnation process is only locally carried out to form local impregnation; so as to form a distance between the first end face or the second end face and the surface of the catalyst layer 2, wherein the distance is preferably 1mm-3mm, so that the purification capacity of the high-voltage electric field and the purification module is controlled; the thickness of the coating of the catalyst layer 2 after impregnation is 20-50 μm;

and coating the first end face and the second end face with electronic paste, and drying the solvent to obtain the porous catalytic honeycomb, wherein the thickness of the electronic paste coating is 10-25 mu m.

Third embodiment

The main component of the electronic paste is tungsten, and the sintering temperature Tm is 1300-1600 ℃.

The catalyst layer 2 is used for preparing BiPO by a hydrothermal method ₄ Polyvinyl alcohol dispersion liquid, polyvinyl alcohol is an adhesive, and the sintering temperature Tn is 90 ℃.

The wall thickness of the cordierite-aluminum titanate composite matrix honeycomb was 5mm.

And (3) coating the electronic paste firstly because Tm is more than Tn, dipping the paste on two end faces of the cordierite-aluminum titanate composite matrix honeycomb by using a rolling brush during coating, repeatedly brushing the paste on the two end faces in a rolling way, and then sintering at 1350 ℃ for 2 hours, wherein the thickness of the sintered electronic paste coating is 20-40 mu m.

And in the dipping process, a pore channel is plugged by a mold at one side of the honeycomb, a pinhole with the other end matched with the pore channel is injected into the pore channel, the catalyst layer 2 slurry is pushed out, then the pore channel at the other side is plugged by another mold, the pore channels are placed in parallel and dried to form middle dipping, the distance between one end and two end faces of the catalyst layer 2 is preferably 1mm-5mm, so that the purifying capacity of the high-voltage electric field synergistic purifying module is controlled, and the thickness of the dipped catalyst layer 2 is 30 μm-40 μm.

Embodiment IV

The electronic paste mainly comprises platinum, and the sintering temperature is 950-1200 ℃.

The catalyst layer 2 is a dispersion of a Pd and cerium zirconium eutectic, and the sintering temperature is 600 ℃.

The cordierite-aluminum titanate composite matrix honeycomb has a wall thickness of 5mm.

And (2) coating the catalyst layer 2 firstly, dipping slurry by using a rolling brush when coating the first end face and the second end face of the cordierite-aluminum titanate composite matrix honeycomb, repeatedly brushing the slurry on the two end faces in a rolling way, and then sintering for 2 hours at 950 ℃, wherein the thickness of the sintered electronic slurry coating is 20-40 mu m.

In the dipping process, a specific mould is used for plugging the pore channel on one side of the silicon carbide honeycomb, a pinhole with the other end in accordance with the pore channel is injected into the pore channel, the catalyst layer slurry is pushed out, then the pore channel on the other side is plugged by another specific mould, the pore channels are placed in parallel and dried to form intermediate dipping, and the distance between one end of the catalyst layer and two end faces is preferably 1-5mm, so that the purifying capacity of the purifying module is controlled. The thickness of the catalytic layer coating after impregnation is 30-40 μm.

The purification performance of the high-voltage electric field collaborative purification module and the existing purification module adopting the porous catalytic honeycomb is tested.

1. Odor Performance test

With reference to GB21551.4 Special requirements for refrigerators with antibacterial, sterilizing and purifying functions for household and similar appliances, the volume of a cabin in a sealed environment is tested to be 100L, and the initial concentrations of methyl mercaptan and trimethylamine are both 6mg/m ³ . The two end faces of the insulating honeycomb 1 of the porous catalytic honeycomb are coated with electronic slurry, and the resistivity of the first conductive area 4 and the resistivity of the second conductive area 5 are both less than 100 omega cm; the contrast group has adopted current purification module, applys macroscopic metal electrode in insulating honeycomb both sides, and its mounting means is for hugging closely the honeycomb installation, and in order to contrast purifying effect, applys voltage mode and honeycomb pore inside catalyst homogeneous phase, and the catalyst is for graphite alkene doping TiO ₂ The air volume is consistent by adjusting the fan, so that the influence of other factors is avoided, and the purification result is shown in table 1.

TABLE 1 odor cleaning Performance test results

It can be seen from the above table that the purifying efficiency can be greatly enhanced by coating the electronic paste on the surface of the insulating honeycomb 1, and when the electronic paste is used as methyl mercaptan for example, the photocatalytic purifying efficiency is improved from 50.4% to 95.6% in 30 minutes, and the enhancing effect is remarkable.

2. Ethylene purification Performance test

Ethylene is a widely used ripening agent, can accelerate the ripening of fruits and vegetables, and can also be used as the basis for evaluating the performance by considering the purifying effect of the purifying module on ethylene. In order to test the effect of removing ethylene by adopting the high-voltage electric field synergistic purification module of the porous catalytic honeycomb and the existing purification module, the ethylene purification performance test is carried out, 100ppm of ethylene gas is introduced into a 100L sealed box, then two purification modules are started, and the concentration of the ethylene gas is measured by adopting gas chromatography to determine C _t (ppm), the purification efficiency calculation formula is as follows:

purification efficiency = [ (100-C) _t )/100]×100％；

The test results are shown in table 2:

table 2 ethylene purification performance test results

From the test results in the table, the electronic slurry is coated on the surface of the insulating honeycomb, so that the purification efficiency of ethylene can be greatly enhanced, and taking 6h as an example, the high-voltage electric field synergistic purification module of the porous catalytic honeycomb can improve the removal performance from 24.6% of the existing purification module to 60.3%, and can achieve the purification efficiency of more than 98% in 16h, so that the enhancement effect is obvious.

3. Air sterilization performance test

According to the test method of ' Disinfection technical Specification ' (2002 edition of Ministry of health) ' -2.1.3, the air sterilization effect identification test is carried out by adopting the high-voltage electric field synergistic purification module of the porous catalytic honeycomb and the existing purification module, and the test is carried out at 1m ³ The relative humidity of the test environment was 62% and the temperature was 24 ℃. The high-voltage electric field synergistic purification module of the porous catalytic honeycomb is used as a test group for testing the air sterilization performance, a control group is a natural extinction process, and the test results are shown in table 3:

TABLE 3 air sterilization Performance test results

As can be seen from the results in the table above, the test group has better space sterilization performance, and the sterilization rate of 0.5h reaches more than 99.94%.

Meanwhile, in order to compare with the air sterilization effect of the existing purification module, the existing purification module is used as a comparison experiment group, the comparison group is also a natural extinction process, the test result of the comparison experiment is shown in table 4, the 0.5h bacterial sterilization rate is only 62.91 percent and is less than 70 percent of that of the experiment comparison group, and the sterilization rate of the experiment comparison group is not more than 99.94 percent required by the standard within 1h, so that the sterilization effect can be met within a longer time, and the experiment module has more advantages in space sterilization performance.

TABLE 4 air Sterilization Performance test results

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A porous catalytic honeycomb for a high-voltage electric field synergistic purification module is characterized by consisting of an insulating honeycomb, a catalytic layer and electronic slurry;

the insulating honeycomb is provided with a plurality of through holes, a first end face and a second end face, wherein the first end face and the second end face are positioned at two ends of the through holes; the through holes form airflow channels; the inner surface of each through hole is coated with the catalytic layer;

the catalyst layer contains a catalyst which can generate active substances for decomposing pollution molecules under the action of a high-voltage electric field and/or a light field;

the electronic paste is coated on the first end face and the second end face of the insulating honeycomb, a first conductive area is formed by the electronic paste coated on the first end face, and a second conductive area is formed by the electronic paste coated on the second end face;

the volume resistivities of the first conductive region and the second conductive region are both less than or equal to 100 omega cm.

2. The porous catalytic honeycomb of claim 1, wherein the insulating honeycomb is made of cordierite, silicon carbide, aluminum titanate, zirconia, silicon nitride, cordierite-mullite, or cordierite-aluminum titanate composite matrix;

the cross section of the through hole is in a shape of a circle, a triangle, a square, a pentagon or a hexagon.

3. The porous catalytic honeycomb of claim 1, wherein the catalytic layer further comprises a binder and a promoter;

the catalyst comprises a high-voltage electric field excitation catalyst and a photocatalyst;

the high-voltage electric field excitation catalyst is Pt, pd, ag, ru metal simple substance and oxide thereof, and TiO ₂ 、CeO ₂ 、CuO、Fe ₂ O ₃ And Fe ₃ O ₄ At least one of;

the photocatalyst is CeO ₂ 、TiO ₂ 、ZnO、SnO ₂ 、Ga ₂ O ₃ 、BiPO ₄ 、AgNO ₃ At least one of BiOBr and BiOCl;

the adhesive and the catalytic promoter contain polyvinyl alcohol, alumina or cerium-zirconium eutectic;

the photocatalyst is modified by doping graphene and metal ions or nitrogen, so that the light absorption range of the photocatalyst is widened.

4. The porous catalytic honeycomb of claim 1, wherein the electronic paste comprises at least one of Ag, pd, ni, al, W, mo, ta, nb, V, cr, ti, and at least one of graphene, carbon nanotubes, or carbon black.

5. The porous catalytic honeycomb of any one of claims 1-4, wherein the insulating honeycomb further comprises pads for circuit bonding, perforations for electrical bonding, or electrically conductive holes for bonding disposed on the first end face and the second end face.

6. A method of making a porous catalytic honeycomb according to any of claims 1-5 comprising the steps of:

preparing an insulating honeycomb, an electronic paste and a coating component for forming a catalytic layer;

determining the heat treatment temperature of the electronic paste and the coating component, wherein the heat treatment temperature of the electronic paste is Tm, and the heat treatment temperature of the coating component is Tn;

comparing Tm and Tn;

when Tm is less than Tn, firstly coating the coating component on the inner surface of a through hole of the insulating honeycomb to form a catalyst layer, then carrying out heat treatment on the insulating honeycomb with the catalyst layer, then coating electronic slurry on a first end face of the insulating honeycomb to form a first conductive area, coating electronic slurry on a second end face of the insulating honeycomb to form a second conductive area, and finally carrying out heat treatment on the insulating honeycomb with the catalyst layer, the first conductive area and the second conductive area;

when Tm is greater than Tn, firstly coating electronic paste on a first end face of an insulating honeycomb to form a first conductive region, coating the electronic paste on a second end face to form a second conductive region, then carrying out heat treatment on the insulating honeycomb formed with the first conductive region and the second conductive region, then shielding the first conductive region and the second conductive region of the insulating honeycomb through a protective layer, coating components on the inner surface of a through hole of the insulating honeycomb through immersion adsorption or catalysis to form a catalytic layer, removing the protective layer, and finally carrying out heat treatment on the insulating honeycomb formed with the catalytic layer, the first conductive region and the second conductive region;

when Tm = Tn, a coating composition is first coated on the inner surfaces of the through holes of the insulated honeycomb by a dipping process to form a catalytic layer, then an electronic paste is coated on a first end surface of the insulated honeycomb to form a first conductive region, and an electronic paste is coated on a second end surface of the insulated honeycomb to form a second conductive region, and finally the insulated honeycomb formed with the catalytic layer, the first conductive region, and the second conductive region is subjected to a heat treatment.

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