A monolithic array electrode device for electrochemical modification of the surface of a honeycomb activated carbon and its use

Abstract

The application discloses a kind of for honeycomb activated carbon surface electrochemical modification integrated array electrode device and its application.The application is directed to the characteristics of honeycomb activated carbon periodic array through-hole, and an integrated array electrode device including honeycomb activated carbon anode, graphite fiber as array graphite fiber cathode through the center of honeycomb hole, porous anode current collector plate, porous insulating plate, porous cathode current collector plate and fixing mechanism is designed, so that electric field is evenly distributed in integrated array electrode device, and the uniformity of honeycomb activated carbon in electrochemical grafting modification process is guaranteed.The integrated array electrode device for honeycomb activated carbon electrochemical modification provided by the application has simple structure and strong universality, and can realize organic amine, olefin polymer monomer, conductive polymer monomer, protein, polypeptide and nucleotide modification on honeycomb activated carbon.

Description

Technical Field

[0001] This invention belongs to the field of surface modification technology for honeycomb activated carbon, specifically relating to an integral array electrode device for electrochemical modification of honeycomb activated carbon and its electrochemical modification method. Background Technology

[0002] Honeycomb activated carbon is a type of molded activated carbon with honeycomb-shaped pores. It has advantages such as large specific surface area, well-developed pores, high adsorption capacity, and low pore resistance. It is widely used in the purification of large volume low-concentration exhaust gas, industrial, agricultural and livestock exhaust gas, catering fume treatment, and wastewater treatment.

[0003] Honeycomb activated carbon can be inorganically modified to introduce catalytically active sites, meeting the application requirements of various occasions. For example, in the prior art, honeycomb activated carbon, after inorganic modification (vanadium oxide, titanium oxide, molybdenum oxide, manganese oxide, copper chloride, etc.), can be used to obtain monolithic denitrification catalysts (CN1597095A, CN107754810B), ozone removal catalysts (CN109926045A), and formaldehyde removal catalysts (CN105597682A). Through organic modification, honeycomb activated carbon can be endowed with new functions by controlling its surface chemistry and pore structure, such as selective and / or specific adsorption, highly selective catalysis, and efficient sensing, which is expected to find applications in high-tech fields such as chemical engineering, environment, electronics, biology, and medicine. For example, patent CN109107527 discloses that honeycomb activated carbon, after impregnation with organic amines and microwave treatment, can obtain a highly efficient adsorbent for ketone-containing organic waste gas.

[0004] There are two common methods for modifying honeycomb activated carbon: co-forming with activated carbon and modifiers, and post-modification methods (impregnation and coating). These two methods are suitable for inorganic modification of honeycomb activated carbon. Impregnation can be used for organic modification, but because the modifier and the honeycomb activated carbon carrier only have intermolecular forces, its stability is poor, and it is prone to detachment and loss during use. Honeycomb activated carbon can be modified using covalent grafting, a common method for carbon materials. However, traditional covalent modification methods require multiple steps of surface group transformation, resulting in low grafting efficiency, poor grafting uniformity, and high material and energy consumption. Electrochemical grafting methods have advantages such as low energy consumption, high efficiency, controllable loading, strong grafting uniformity, and strong method versatility. The efficiency and uniformity of electrochemical grafting are greatly affected by the electric field distribution. However, due to the periodically arranged through-pore structure of honeycomb activated carbon, its electrode arrangement is very difficult. Summary of the Invention

[0005] This invention addresses the technical problem of electrode arrangement during the electrochemical grafting process of honeycomb activated carbon by proposing an integral array electrode device for the electrochemical modification of honeycomb activated carbon.

[0006] The specific technical solution provided by this invention is as follows:

[0007] An integral array electrode device for electrochemical modification of the surface of honeycomb activated carbon, the integral array electrode device comprising a honeycomb activated carbon anode 4, graphite fiber 7, porous anode current collector 3, porous insulating plate 2, porous cathode current collector 1 and fixing mechanism 5.

[0008] The porous anode current collector 3 is made of titanium, nickel or graphite. The array hole spacing of the porous anode current collector 3 is consistent with the honeycomb hole spacing in the honeycomb activated carbon anode 4. The shape of the array holes of the porous anode current collector 3 is consistent with the honeycomb shape in the honeycomb activated carbon anode 4. The array hole diameter of the porous anode current collector 3 is 50%-95% of the honeycomb hole diameter. The porous anode current collector 3 is attached to both ends of the honeycomb activated carbon anode 4 according to the hole array alignment method.

[0009] The porous insulating plate 2 is made of plastic or rubber. The array hole spacing of the porous insulating plate 2 is consistent with the honeycomb hole spacing in the honeycomb activated carbon anode 4. The shape of the array holes of the porous insulating plate 2 is consistent with the shape of the honeycomb in the honeycomb activated carbon anode 4. The array hole diameter of the porous insulating plate 2 is 50%-95% of the hole diameter of the porous anode current collector plate 3. The porous insulating plate 2 is attached to both ends of the porous anode current collector plate 3 according to the hole array alignment method.

[0010] The porous cathode current collector 1 is made of stainless steel, copper, titanium, nickel or graphite. The array hole spacing of the porous cathode current collector 1 is consistent with the honeycomb hole spacing in the honeycomb activated carbon anode 4. The array hole shape of the porous cathode current collector 1 is consistent with the honeycomb in the honeycomb activated carbon anode 4. The array hole diameter of the porous cathode current collector 1 is 50%-95% of the honeycomb hole diameter in the honeycomb activated carbon anode 4. The porous cathode current collector 1 is attached to both ends of the porous insulating plate 2 according to the hole array alignment method.

[0011] The array of graphite fibers 7 penetrating the center of the honeycomb holes is constructed by sewing. The graphite fibers are pulled by long needles and pass through the porous cathode current collector 1, the porous insulating plate 2, the porous anode current collector 3, the honeycomb activated carbon anode 4, the porous anode current collector 3, the porous insulating plate 2, and the porous cathode current collector 1 at the other end in sequence. Then, they are inserted from the nearest hole of the porous cathode current collector 1 at the other end. After all the holes are filled with graphite fibers 7 by sewing, the porous cathode current collector 1, the porous insulating plate 2, the porous anode current collector 3, and the honeycomb activated carbon anode 4 at both ends are aligned with the center, and the graphite fibers 7 are pulled tight and knotted.

[0012] The ribs between adjacent holes of the porous cathode current collector 1, the porous insulating plate 2, and the porous anode current collector 3 form electrical contact with the graphite fiber 7.

[0013] The fixing mechanism 5 is located on the porous cathode current collector 1 and the porous anode current collector 3, and is used to fix the porous cathode current collector 1 at both ends, the porous insulating plate 2 at both ends, the porous anode current collector 3 at both ends, and the honeycomb activated carbon anode 4 to each other.

[0014] Furthermore, the honeycomb activated carbon anode 4 is prepared by heat-treating honeycomb activated carbon at 700-1300℃ for 0.5-20 hours. The honeycomb activated carbon has dimensions of 100*100*50mm~100*100*100mm, a pore size of 1.5-8.0mm, and a bulk density of 0.35-0.60g / cm³. 3 .

[0015] Furthermore, the graphite fiber 7 is a 3-24K high-conductivity graphitized carbon fiber yarn.

[0016] Furthermore, the fixing mechanism 5 is fixed by screws or buckles.

[0017] The monolithic array electrode device described above is used for electrochemical modification of the surface of honeycomb activated carbon.

[0018] An electrolyte containing a modifier is injected into an electrolytic cell, and the surface of honeycomb activated carbon is electrochemically modified using an integral array electrode device.

[0019] The specific process is as follows: the positive terminal of power supply 8 is connected to the porous anode current collector 3, and the negative terminal of power supply 8 is connected to the porous cathode current collector 1. Electrochemical modification is carried out by adjusting the current intensity, reaction time, and electrolyte concentration.

[0020] Furthermore, the electrolyte is sodium hydroxide, sodium bicarbonate, AlCl3, KCl, or FeCl3.

[0021] Furthermore, the modifier is an organic amine, an olefin polymer, a conductive polymer, a protein, a polypeptide, or a nucleotide.

[0022] Furthermore, the modifier accounts for 5-20% of the mass fraction of the electrolyte.

[0023] Furthermore, the electrolyte concentration is 0.2-1 mol / L.

[0024] Furthermore, the current intensity is 0.2-1A, and the reaction time is 10-100min.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. This invention provides an integral array electrode device for electrochemical modification of honeycomb activated carbon. Taking into account the periodic array of through holes in honeycomb activated carbon, a stacked structure of honeycomb activated carbon anode, anode current collector, insulating porous plate, and cathode current collector, and an array of graphite fiber cathodes penetrating the through holes of the honeycomb activated carbon anode are designed. This ensures that the electric field is uniformly distributed in the integral array electrode device, guaranteeing the uniformity of the honeycomb activated carbon during the electrochemical grafting modification process.

[0027] 2. The integral array electrode device for electrochemical modification of honeycomb activated carbon provided by the present invention has a simple structure and strong versatility, and can realize the modification of honeycomb activated carbon with organic amines, olefin polymer monomers, conductive polymer monomers, proteins, peptides and nucleotides. Attached Figure Description

[0028] Figure 1(a) is a schematic diagram of the structure of the monolithic array electrode device modified with honeycomb activated carbon electrochemically.

[0029] Figure 1(b) shows the design of an integral array electrode device modified with honeycomb activated carbon electrochemically.

[0030] Figure 2 A schematic diagram of the construction method of an integral array electrode device for electrochemical modification of honeycomb activated carbon, wherein (a) is an assembly schematic diagram and (b) is a partially enlarged schematic diagram of the construction method.

[0031] Figure 3 This is a schematic diagram of an integrated array electrode device application.

[0032] In the figure: 1 Porous cathode current collector, 2 Porous insulating plate, 3 Porous anode current collector, 3, 4 Honeycomb activated carbon anode, 5 Fixing mechanism, 6 Arrayed graphite fiber cathode, 7 Graphite fiber, 8 Power supply. Detailed Implementation

[0033] Example 1

[0034] As shown in Figures 1(a) and 1(b), in order to solve the technical problem of electrode arrangement in the electrochemical grafting process of honeycomb activated carbon, an integral array electrode device for electrochemical modification of honeycomb activated carbon is proposed, including a porous cathode current collector 1, a porous insulating plate 2, a porous anode current collector 3, a honeycomb activated carbon anode 4, and a fixing mechanism 5. The honeycomb activated carbon anode 4 is made by heat-treating honeycomb activated carbon at 800℃ for 2 hours. The honeycomb activated carbon has a size of 10*10*10cm and a pore diameter of 8.0mm. The porous anode current collector 3 is made of graphite, with an array hole spacing consistent with the honeycomb hole spacing of the honeycomb activated carbon, a hole shape consistent with the honeycomb of the honeycomb activated carbon, and a pore diameter of 6.0mm. The porous anode current collector 3 is attached to both ends of the honeycomb activated carbon anode 4 according to the hole array alignment. The porous insulating plate 2 is made of plastic, with an array hole spacing consistent with the honeycomb hole spacing of the honeycomb activated carbon, and a pore diameter of 3mm. The insulating plate is attached to both ends of the porous anode current collector 2 according to the hole array alignment. The porous cathode current collector 1 is made of graphite, with an array hole spacing consistent with the honeycomb hole spacing of the honeycomb activated carbon, a hole shape consistent with the honeycomb of the honeycomb of the honeycomb activated carbon, and a pore diameter of 6mm. The porous cathode current collector 1 is attached to both ends of the insulating plate 2 according to the hole array alignment. The fixing mechanism 5 is located at both ends of the porous cathode current collector 1 and the porous anode current collector 3, and is fixed by screw clamps.

[0035] Construction method of monolithic array electrode device with honeycomb activated carbon electrochemical modification, such as Figure 2 As shown, a graphite fiber cathode array 6, penetrating the center of the honeycomb holes, is constructed using a sewing method. Graphite fibers 7 are sequentially passed through a porous cathode current collector 1, a porous insulating plate 2, a porous anode current collector 3, a honeycomb activated carbon anode 4, a porous anode current collector 3, a porous insulating plate 2, and a porous cathode current collector 1, guided by long needles. After all holes are filled with graphite fibers, the porous cathode current collector 1, porous insulating plate 2, porous anode current collector 3, honeycomb activated carbon anode 4, porous anode current collector 3, porous insulating plate 2, and porous cathode current collector 1 are aligned with the center of the honeycomb holes, and the graphite fibers are tightened and knotted. The graphite fibers 7 are 24K high-conductivity graphitized carbon fiber yarns. The ribs between adjacent holes of the porous cathode current collector 1, porous insulating plate 2, and porous anode current collector 3 form electrical contact with the graphite fibers 7.

[0036] Applications of monolithic array electrode devices for electrochemical modification of honeycomb activated carbon surfaces, such as... Figure 3As shown, the integrated array electrode device of honeycomb activated carbon is placed in an electrolytic cell. The positive terminal of power supply 8 is connected to the porous anode current collector plate 3, and the negative terminal of power supply 8 is connected to the porous cathode current collector plate 1. The layered structure of honeycomb activated carbon anode 4, anode current collector 3, insulating porous plate 2, and cathode current collector 1, along with the arrayed graphite fiber cathode 6 penetrating the through-holes of the honeycomb activated carbon anode, ensures a uniform electric field distribution in the integrated array electrode device, guaranteeing the uniformity of the honeycomb activated carbon during the electrochemical grafting modification process. Ethanol and deionized water are mixed in a 1:1 ratio in a beaker. Sodium hydroxide is added as an electrolyte at a concentration of 0.6 mol / L, and the mixture is stirred until completely dissolved. 20% (by mass) of tetraethylenepentamine is added to the electrolyte solution, and the mixture is sonicated for 15 minutes to ensure complete dispersion in the electrolyte solution. The above mixed solution is then injected into the electrolytic cell. The power supply is adjusted, and the current is controlled at approximately 1 A. The reaction is carried out for 60 minutes, after which tetraethylenepentamine-grafted honeycomb activated carbon is obtained. Through dynamic CO2 adsorption experiments, the unmodified honeycomb activated carbon showed a saturated adsorption capacity of only 2.3 mg·g⁻¹ for 4000 ppm CO2, which was rapidly and completely penetrated by CO2. The modified honeycomb activated carbon showed a saturated adsorption capacity of 55.7 mg·g⁻¹ and a breakthrough time of 16.5 min. Electrografting tetraethylenepentamine significantly improved the honeycomb activated carbon's ability to capture low-concentration CO2.

[0037] Example 2

[0038] Except that the modifier was replaced with an electrolyte of 10% glycidyl methacrylate and 0.4 mol / L sodium bicarbonate, the current intensity was 0.25 A, and the reaction time was 50 min, everything else was the same as in Example 1.

[0039] Example 3 is identical to Example 1 except that the modifier is replaced with 10% melamine by mass, the electrolyte is replaced with 0.2 mol / L potassium chloride, the current intensity is 0.2 A, and the reaction time is 20 min.

[0040] Example 4 is identical to Example 1 except that the modifier is replaced with 5% polystyrene by mass, the electrolyte is replaced with 0.2 mol / L AlCl3, the current intensity is 1A, and the reaction time is 60 min.

[0041] The embodiments provided in this invention are merely preferred solutions. Any modifications, equivalent changes, and alterations made by those skilled in the art without departing from the essence of this invention are within the scope of protection defined by the claims of this invention.

Claims

1. A monolithic array electrode device for electrochemical modification of the surface of a honeycomb activated carbon, characterized by, The integral array electrode device includes a honeycomb activated carbon anode (4), graphite fiber (7), porous anode current collector (3), porous insulating plate (2), porous cathode current collector (1), and fixing mechanism (5). The porous anode current collector (3) is made of titanium, nickel or graphite. The array hole spacing of the porous anode current collector (3) is consistent with the honeycomb hole spacing in the honeycomb activated carbon anode (4). The shape of the array holes of the porous anode current collector (3) is consistent with the honeycomb shape in the honeycomb activated carbon anode (4). The array hole diameter of the porous anode current collector (3) is 50%-95% of the honeycomb hole diameter. The porous anode current collector (3) is attached to both ends of the honeycomb activated carbon anode (4) according to the hole array alignment method. The porous insulating plate (2) is made of plastic or rubber. The array hole spacing of the porous insulating plate (2) is consistent with the honeycomb hole spacing in the honeycomb activated carbon anode (4). The shape of the array holes of the porous insulating plate (2) is consistent with the shape of the honeycomb in the honeycomb activated carbon anode (4). The array hole diameter of the porous insulating plate (2) is 50%-95% of the hole diameter of the porous anode current collector plate (3). The porous insulating plate (2) is attached to both ends of the porous anode current collector plate (3) according to the hole array alignment method. The porous cathode current collector (1) is made of stainless steel, copper, titanium, nickel or graphite. The array hole spacing of the porous cathode current collector (1) is consistent with the honeycomb hole spacing in the honeycomb activated carbon anode (4). The array hole shape of the porous cathode current collector (1) is consistent with the honeycomb in the honeycomb activated carbon anode (4). The array hole diameter of the porous cathode current collector (1) is 50%-95% of the honeycomb hole diameter in the honeycomb activated carbon anode (4). The porous cathode current collector (1) is attached to both ends of the porous insulating plate (2) according to the hole array alignment method. The array of graphite fibers (7) penetrating the center of the honeycomb holes is constructed by sewing. The graphite fibers are pulled by long needles and pass through the porous cathode current collector (1), the porous insulating plate (2), the porous anode current collector (3), the honeycomb activated carbon anode (4), the porous anode current collector (3), the porous insulating plate (2), and the porous cathode current collector (1) at one end in sequence. Then, they are inserted from the nearest hole of the porous cathode current collector (1) at the other end. After all the holes are filled with graphite fibers (7) by sewing, the porous cathode current collector (1), the porous insulating plate (2), the porous anode current collector (3), and the honeycomb activated carbon anode (4) at both ends are aligned with the center and the graphite fibers (7) are pulled tight and knotted. The ribs between adjacent holes of the porous cathode current collector (1), the porous insulating plate (2), and the porous anode current collector (3) form electrical contact with the graphite fiber (7); The fixing mechanism (5) is located on the porous cathode current collector (1) and the porous anode current collector (3), and is used to fix the porous cathode current collector (1) at both ends, the porous insulating plate (2) at both ends, the porous anode current collector (3) at both ends, and the honeycomb activated carbon anode (4) to each other.

2. The integral array electrode device for electrochemical modification of honeycomb activated carbon surface according to claim 1, characterized in that, The honeycomb activated carbon anode (4) is prepared by heat-treating honeycomb activated carbon at 700-1300℃ for 0.5-20 hours; the size of the honeycomb activated carbon is 100. 100 50mm~100 100 100mm, pore size 1.5-8.0mm, bulk density 0.35-0.60g / cm³ 3 .

3. The integral array electrode device for electrochemical modification of honeycomb activated carbon surface according to claim 1, characterized in that, The graphite fiber (7) is a 3-24K high-conductivity graphitized carbon fiber yarn.

4. A monolithic array electrode device for electrochemically modifying the surface of honeycomb activated carbon according to claim 1, wherein The fixing mechanism (5) is fixed by screws or buckles.

5. Use of the monolithic array electrode device according to any one of claims 1 to 4, characterized in that Used for electrochemical modification of honeycomb activated carbon surfaces.

6. Use according to claim 5, characterized in that, An electrolyte containing a modifier is injected into an electrolytic cell, and the surface of honeycomb activated carbon is electrochemically modified using an integral array electrode device.

7. The application according to claim 5, characterized in that, The positive terminal of the power supply (8) is connected to the porous anode current collector (3), and the negative terminal of the power supply (8) is connected to the porous cathode current collector (1). Electrochemical modification is carried out by adjusting the current intensity, reaction time, and electrolyte concentration.

8. The application according to claim 6, characterized in that, The electrolyte in the electrolyte is sodium hydroxide, sodium bicarbonate, AlCl3, KCl, or FeCl3; the modifier is an organic amine, olefin polymer, conductive polymer, protein, polypeptide, or nucleotide.

9. The application according to claim 6, characterized in that, The modifier accounts for 5-20% of the mass fraction of the electrolyte; the electrolyte concentration in the electrolyte is 0.2-1 mol / L.

10. The application according to claim 7, characterized in that, The current intensity is 0.2-1A, and the reaction time is 10-100min.

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