WO2017076282A1

WO2017076282A1 - Electrolytic tank apparatus using oxygen reduction cathode

Info

Publication number: WO2017076282A1
Application number: PCT/CN2016/104284
Authority: WO
Inventors: 卢善富; 梁大为; 相艳
Original assignee: 北京航空航天大学; 卢善富; 梁大为; 相艳
Priority date: 2015-11-06
Filing date: 2016-11-01
Publication date: 2017-05-11
Also published as: CN105461023A; CN105461023B

Abstract

An electrolytic tank apparatus using an oxygen reduction cathode is characterized by comprising: a separation chamber (7), an anode chamber at one side of the separation chamber (7), and a cathode chamber at the other side of the separation chamber (7), the anode chamber comprising an anode terminal plate (1), a porous anode supporting material (4), and an anode catalyst layer (5). An anode flow field tank (2) is provided at one side, facing the separation chamber (7), of the anode terminal plate (1), an anode water inlet (101) is provided at a water inlet end of the anode flow field tank (2), and an anode water outlet (102) is provided at a water outlet of the anode flow field tank (2). The anode catalyst layer (5) is located between the separation chamber (7) and the porous anode supporting material (4). The cathode chamber comprises a cathode terminal plate (11) and a gas diffusion electrode (9). A cathode flow field tank (10) is provided at one side, facing the separation chamber (7), of the cathode terminal plate (11), a cathode gas inlet (201) is provided at a gas inlet end of the cathode flow field tank (10), and a cathode gas outlet (202) is provided at a gas outlet of the cathode flow field tank (10). The porous gas diffusion electrode (9) is disposed between the cathode terminal plate (11) and the separation chamber (7). A cavity of the separation chamber (7) is filled with glass fiber fillers.

Description

Electrolytic cell device using oxygen reduction cathode

Technical field

The invention relates to an electrolytic cell device using an oxygen reducing cathode based on a porous gas diffusion electrode, and belongs to the water treatment industrial technology in the field of environmental protection.

Background technique

Many industrial wastewaters have poor biodegradability, and contain a large amount of inorganic or organic aromatic poisons such as ammonia, cyanogen, phenols, pyridine, quinoline, etc., which are difficult to biodegrade. Electrochemical advanced oxidation is an effective method for treating such industrial wastewater. Electrochemical oxidation can effectively oxidize and degrade water by using free radicals generated on the surface of the electrode (such as direct oxidation of hydroxyl radicals) or generated oxidants (such as indirect oxidation of hypochlorous acid). Organic Pollutants. The method has the characteristics of high processing efficiency, simple operation, environmental friendliness, and the like, and is convenient for technology. However, higher energy consumption has been a bottleneck that has plagued the application of electro-oxidation technology to wastewater treatment.

The conventional electrochemical oxidation method uses a hydrogen-producing cathode to generate hydrogen in the electrocatalytic reduction of protons in the cathode. Moreover, since the reaction is carried out in an open electrolytic cell, the hydrogen production of the cathode is not effectively recovered, and the mixing of the by-product oxygen of the anode with the hydrogen production of the cathode is also potentially dangerous. The oxygen cathode used in the present invention has been widely used in industrial production of fuel cells and chlor-alkali. In a oxyhydrogen fuel cell, oxygen is reduced at the cathode to form water, and the cathode includes a gas diffusion layer whose main body is a carbon material and a catalytic layer containing a noble metal catalyst. In the chlor-alkali industry, Beijing University of Chemical Technology and Bluestar (Beijing) Chemical Machinery Co., Ltd. have successfully applied oxygen cathodes to the chlor-alkali industry. The results have been transformed into several patents (publication numbers 202730249U, 202730250U, 102925917A, 103014748A). The use of an oxygen cathode in an electrolysis device can greatly reduce the cell voltage from the fundamental level of the electrode reaction, and avoids the mixing problem of cathode hydrogen production and anode oxygen production in the conventional open cell, and at the same time improves economic efficiency and safety.

Summary of the invention

The invention provides an efficient and economical treatment process for changing traditional refractory organic wastewater. The invention utilizes an electrolytic cell based on an oxygen reduction cathode, and under the condition of an applied voltage of 1-5 volts, the anode is highly mineralized to decompose organic pollutants and ammonia nitrogen in the organic wastewater, and the cathode reduces the oxygen which is introduced into water. The invention is unique in that it is more conventional to use oxygen to reduce the cathode. The higher electrode potential of the hydrogen producing cathode reduces the occurrence of reversible reduction of organic pollutants at the cathode and improves current efficiency. In addition, compared with the energy consumption of the conventional electrolytic cell, the invention effectively reduces the electrode plate spacing and simultaneously increases the cathode potential, resulting in a significant reduction in the electrolytic cell voltage, greatly improving the economics of the electrochemical oxidation process for treating wastewater.

In order to achieve the above object, the technical solution adopted by the present invention is as follows:

An electrolytic cell device using a porous gas diffusion electrode as a cathode, comprising an anode chamber, a separation chamber and a cathode chamber;

The anode chamber includes an anode end plate, a separation chamber, a porous anode support material and an anode catalytic layer, the lower end of the water flow chamber is provided with a water inlet, and the upper end is provided with a water outlet; the anode catalytic layer and the porous anode support a material disposed between the anode end plate and the separation chamber; the anode catalytic layer is located on a side of the porous anode support material facing the separation chamber; the porous anode support material is provided An anode current collector, the anode current collector sealing out of the anode end plate;

The compartment is made of foamed plastic, PMMA or silica gel material, and the hollow portion is filled with a porous glass fiber material. The anode chamber and the cathode chamber are separated by a compartment.

According to an aspect of the invention, there is provided an electrolytic cell apparatus using an oxygen reduction cathode, comprising:

Separate the chamber,

In the anode chamber on the side of the separation chamber,

In the cathode chamber on the other side of the separation chamber,

among them

The anode chamber includes an anode end plate, a porous anode support material and an anode catalytic layer, and an anode flow field groove is disposed on a side of the anode end plate facing the separation chamber, and an inlet end of the anode flow field groove is provided There is an anode water inlet, and an anode water outlet is arranged at the water outlet end of the anode flow field tank.

The anode catalytic layer is located between the separation chamber and the porous anode support material,

The cathode chamber includes a cathode end plate and a gas diffusion electrode, and a cathode flow field groove is disposed on a side of the cathode end plate facing the separation chamber, and a cathode air inlet is provided at an inlet end of the cathode flow field groove a gas outlet end of the cathode flow field groove is provided with a cathode gas outlet; the porous gas diffusion electrode is disposed between the cathode end plate and the separation chamber,

The compartment of the compartment is filled with a glass fiber filler.

The cathode chamber includes a cathode end plate and a porous gas diffusion electrode, the porous gas diffusion electrode sealing is disposed between the cathode end plate and the separation chamber; and the cathode end plate faces the porous gas diffusion electrode One side is provided with a cathode flow field groove, and the cathode flow field a cathode inlet is disposed at an inlet end of the tank, a cathode outlet is disposed at an outlet end of the cathode flow field groove, a cathode current collector is disposed in the porous gas diffusion electrode, and the cathode current collector is sealed Outside the cathode end plate;

The anode end plate is made of polymethyl methacrylate (PMMA).

The porous male support material is a corrosion resistant wire mesh having a mesh number of 50-400 mesh, a wire diameter of 10-500 micrometers, and a wire mesh thickness of 100-1000 micrometers.

The anode catalytic layer is RuO ₂ -TiO ₂ , PbO ₂ , SnO ₂ -Sb ₂ O ₃ , Nb ₂ O ₅ -SnO ₂ , SnO ₂ -In ₂ O ₃ , IrO ₂ -Ta ₂ O ₅ , or rare earth metal oxide / Sb ₂ or a mixture of a medium ₂ O ₅ -SnO more.

The corrosion resistant wire comprises a tungsten wire, a titanium wire, a molybdenum wire or a twisted wire.

The corrosion resistant wire forming mesh is a foamed titanium mesh having a thickness of 300 micrometers to 2000 micrometers;

Or the corrosion-resistant wire forming mesh is a porous titanium plate having a thickness of 500 micrometers to 3000 micrometers and a porosity of more than 40%.

The anode flow field groove is designed to be a lateral bottom wide groove and a longitudinal narrow groove, the wide groove width is 3-6 mm, the narrow groove width is 1-3 mm, and the groove depth is 0.5-2.0 mm.

The cathode end plate is made of PMMA.

The porous gas diffusion electrode is composed of a gas diffusion layer, a hydrophobic skeleton, and a catalyst. Materials constituting the gas diffusion layer include carbon black, graphite, carbon nanotubes, and carbon nanofibers. The materials constituting the hydrophobic skeleton include polytetrafluoroethylene (PTFE), paraffin wax, polyethylene, polypropylene, and wax, and are added in the form of a dry powder additive, a liquid suspension (including a special dispersant), or a spherical shape. In the form of a film on a fiber or a porous substrate. The catalyst is a Pt catalyst suitable for an oxygen reduction reaction.

The cathode flow field groove is designed to be a horizontal or vertical serpentine shape and a comb groove arrangement, the groove width is 1-3 mm, the groove depth is 0.5-2.0 mm, and two or three flow channel grooves are arranged in parallel, and the flow field channel is arranged. From the beginning of the water inlet to the end of the water outlet;

The cathode chamber and the anode chamber are separated by the separation chamber.

Also included is a silicon or foam seal that is sealed by the silicone seal between the anode end plate, the separation chamber, and the porous gas diffusion electrode.

Advantageous effects of the present invention include:

(1) The present invention employs an oxygen-reducing cathode, and oxygen is reduced at the cathode to form water. Compared with the conventional hydrogen-producing cathode, the voltage of the electrolytic cell can be greatly reduced due to changes in the electrode reaction.

(2) Oxygen reduction cathode has higher potential than traditional hydrogen production cathode, effectively avoiding pollutants A reversible redox reaction occurs at the yin and yang poles to improve current efficiency.

(3) The cathode no longer generates hydrogen, which avoids the potential danger of mixing the anode oxygen production with the cathode hydrogen production in the conventional electrolytic cell. In addition, the electrolytic cell designed in the present invention can greatly reduce the plate spacing and reduce the solution potential drop compared to the conventional open electrolytic cell.

(4) Replacing the Ni and Fe metal material cathodes with a porous gas diffusion electrode whose main body is a carbon material can greatly reduce the inherent cost of sewage treatment.

DRAWINGS

1 is a diagram showing the structure of an oxygen cathode electrooxidation system according to an embodiment of the present invention.

See the schematic.

Figure 2 is a development view of the oxygen cathode electrooxidation system of the embodiment shown in Figure 1.

Figure 3 is a front elevational view of an anode in accordance with one embodiment of the present invention.

Figure 4 is a left side view of the anode shown in Figure 3.

Reference mark:

1. anode end plate; 2. anode flow field groove; 3. foam plastic seal; 4. porous anode support material; 5. anode catalytic layer; 6. anode current collector; 7. separation chamber (filled with fiberglass or Solid electrolyte); 8. cathode current collector; 9. porous gas diffusion electrode; 10. cathode flow field tank; 11. cathode end plate; 101. anode water inlet (waste water); 102. anode water outlet (treated water); Cathode inlet (air/oxygen); 202. cathode outlet.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, an electrolytic cell apparatus using an oxygen-reducing cathode according to an embodiment of the present invention includes a partitioning chamber 7 and a glass fiber filled therein and a cavity therein. An anode chamber and a cathode chamber on both sides of the chamber 7; the anode chamber includes an anode end plate 1, a porous anode support material 4, and an anode catalytic layer 5, the anode end plate 1 facing the side of the separation chamber 7 There is an anode flow field tank 2, the inlet end of the anode flow field tank 2 is provided with an anode water inlet 101, and the water outlet end of the anode flow field tank 2 is provided with an anode water outlet 102; the anode catalytic layer 5 is located at the Between the separation chamber 7 and the porous anode support material 4, and is in close contact with the porous anode support material 4; the porous anode support material 4 is provided with an anode current collector 6, the anode current collector 6 Sealing out of the anode end plate 1 and the separation chamber 7; the cathode chamber includes a cathode end plate 11 and a gas diffusion electrode 9, the side of the cathode end plate 11 facing the separation chamber 7 With yin a cathode flow field tank 10, a cathode inlet port 201 is disposed at an inlet end of the cathode flow field tank 10, a cathode gas outlet port 202 is disposed at an outlet end of the cathode flow field tank 10; and the porous gas diffusion electrode 9 is disposed Between the cathode end plate 11 and the separation chamber 7; a cathode current collector 8 is disposed on the porous gas diffusion electrode 9, and the cathode current collector 8 seals out the cathode end plate 11 and the Separate from the chamber 7. The cavity of the compartment 7 is filled with a glass fiber filler.

In a preferred embodiment, the porous male support material 4 is a corrosion resistant wire mesh having a mesh number of 50-400 mesh, a wire diameter of 10-500 micrometers, and a wire mesh thickness of 100- 1000 micrometers; the anode catalytic layer 5 is RuO ₂ -TiO ₂ , PbO ₂ , SnO ₂ -Sb ₂ O ₃ , Nb ₂ O ₅ -SnO ₂ , SnO ₂ -In ₂ O ₃ , IrO ₂ -Ta ₂ O ₅ or / Sb one kind of rare earth metal oxide or a mixture of ₂ ₂ O ₅ -SnO more.

In a more preferred embodiment, the wire of the corrosion resistant wire mesh is one or more selected from the group consisting of tungsten wire, titanium wire, molybdenum wire or wire.

In a more preferred embodiment, the corrosion-resistant wire forming mesh is a foamed titanium mesh having a thickness of 300 micrometers to 2000 micrometers; or the corrosion-resistant wire mesh is porous titanium. The plate has a thickness of from 500 micrometers to 3000 micrometers and a porosity of greater than 40%.

In a more preferred embodiment, the cathode end plate 11 is made of polymethyl methacrylate (PMMA); the cathode flow field groove 10 is designed as a lateral or longitudinal serpentine, combed groove arrangement, The groove width is 1-3 mm, the groove depth is 0.5-2.0 mm, and two or three flow channel grooves are arranged in parallel to form a flow field channel from the air inlet to the end of the gas outlet; the catalyst of the porous gas diffusion electrode 9 is a Pt catalyst .

In a more preferred embodiment, the oxygen reduction cathode electrolyzer device further comprises a foam seal 3, the anode end plate 1 and the separation chamber 7 being sealed by the foam seal 3 The cathode end plate 11 and the separation chamber 7 are also sealed by the foam sealing ring 3.

In a specific embodiment:

The anode chamber includes an anode end plate 1, an anode flow field groove 10, a foam sealing ring 3, an anode current collector 6, a porous anode support material 4, and an anode catalytic layer 5. The anode end plate 1 is made of PMMA, and the anode flow field groove is formed by a lateral bottom wide groove and a longitudinal narrow groove, the wide groove width is 3-6 mm, the narrow groove width is 1-3 mm, and the groove depth is 0.5-2.0. Millimeter. The porous male support material is a wire mesh, and is made of corrosion-resistant metal wire such as tungsten wire, titanium wire, molybdenum wire, and/or silk wire, and the mesh number is 50-400 mesh, and the wire diameter is 10- 500 microns, the thickness of the wire mesh is from 100 microns to 1000 microns; in one embodiment, a titanium foam mesh is used as the anode support material having a thickness of from about 300 microns to about 2000 microns; in another embodiment, porous titanium is used. a support material made plate having a thickness of 500-3000 microns, a porosity greater than 40%; the anode catalyst layer 5 _{_{_{RuO 2 -TiO 2, PbO 2,}}} SnO 2 -Sb 2 O 3, Nb 2 O 5 -SnO 2, SnO ₂ -In ₂ O ₃ , IrO ₂ -Ta ₂ O ₅ , or a mixture of one or more of rare earth metal oxides/Sb ₂ O ₅ -SnO ₂ . The cathode includes a cathode end plate 11, a cathode flow field groove 10, a foam sealing ring 3, a gas diffusion electrode 9, a cathode current collector 8, a cathode end plate 11 made of PMMA material, and a cathode flow field 10 design different from the anode flow field 2. It is a horizontal or vertical serpentine, comb-groove arrangement with a groove width of 1-3 mm and a groove depth of 0.5-2.0 mm. Two or three flow channel grooves are arranged in parallel, and the flow field channel starts from the air inlet to the outlet. The gas port ends; the gas diffusion electrode 9 is made of PTFE, acetylene black, and Pt catalyst. The cathode chamber and the anode chamber of the electrolytic cell are separated by the partition chamber 7. The partition chamber 7 used is filled with glass fiber and has a thickness of 500-2000 micrometers; the working voltage applied to the electrolytic cell is 1-5 volts, and the electrolytic cell The working current density is 1-120 mA/cm2; the water inlet 101 on the anode plate 1 is connected to the beginning of the anode flow field 2 at the bottom of the electrode plate; the water outlet 102 on the anode plate 1 is disposed on the side of the plate upper portion, and The ends of the anode flow field 2 are connected. The gas inlet port 201 on the cathode plate 11 is connected to the beginning of the cathode flow field 10 at the bottom of the electrode plate; the water outlet port 202 on the anode plate 11 is disposed on the side of the plate upper portion and is connected to the end of the cathode flow field 10. The organic wastewater enters from the water inlet 101 on the anode plate 1 of the oxygen reduction cathode electrolysis cell at a flow rate of 0.02-0.20 ml/(cm 2 ·min), and is degraded and mineralized under the electrooxidation of the anode, and the treated water is discharged from the anode. The water outlet 102 on the plate 1 is discharged.

The present invention has been described in detail above by way of specific and preferred embodiments thereof, but those skilled in the art should understand that the invention is not limited to the above described embodiments, any of which is within the spirit and scope of the invention Modifications, equivalent substitutions, etc., are intended to be included within the scope of the invention.

Claims

An electrolytic cell device using an oxygen reduction cathode, comprising:

Separate the chamber (7),

In the anode chamber on the side of the separation chamber (7),

In the cathode chamber on the other side of the separation chamber (7),

among them

The anode chamber comprises an anode end plate (1), a porous anode support material (4) and an anode catalytic layer (5), the anode end plate (1) being provided with an anode facing one side of the separation chamber (7) a flow field tank (2), an inlet of the anode flow field tank (2) is provided with an anode water inlet (101), and an outlet of the anode flow field tank (2) is provided with an anode water outlet (102).

The anode catalytic layer (5) is located between the separation chamber (7) and the porous anode support material (4),

The cathode chamber includes a cathode end plate (11) and a gas diffusion electrode (9), and a cathode flow field groove (10) is disposed on a side of the cathode end plate (11) facing the separation chamber (7). a cathode inlet (201) is disposed at an inlet end of the cathode flow field tank (10), a cathode outlet (202) is disposed at an outlet end of the cathode flow field tank (10); and the porous gas diffusion electrode is 9) disposed between the cathode end plate (11) and the separation chamber (7),

The cavity of the compartment (7) is filled with a glass fiber filler.
The electrolytic cell device using an oxygen reduction cathode according to claim 1, wherein:

An anode current collector (6) is disposed on the porous anode support material (4), and the anode current collector (6) is sealed out of the anode end plate (1) and the separation chamber (7).

A cathode current collector (8) is disposed on the porous gas diffusion electrode (9), and the cathode current collector (8) is sealed out of the cathode end plate (11) and outside the separation chamber (7).
The electrolytic cell device using an oxygen reduction cathode according to claim 1, wherein:

The porous male support material (4) is a mesh of corrosion resistant metal wire.

The wire mesh has a mesh number of 50-400 mesh, the wire has a diameter of 10-500 micrometers, and the wire mesh has a thickness of 100-1000 micrometers.
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, characterized in that:

The anode catalytic layer (5) is RuO 2 -TiO 2 , PbO 2 , SnO 2 -Sb 2 O 3 , Nb 2 O 5 -SnO 2 , SnO 2 -In 2 O 3 , IrO 2 -Ta 2 O 5 , A mixture of one or more selected from the group consisting of rare earth metal oxides/Sb 2 O 5 -SnO 2 .
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, characterized in that:

The wire of the corrosion resistant wire mesh is one or more selected from the group consisting of tungsten wire, titanium wire, molybdenum wire or wire.
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, characterized in that:

In a more preferred embodiment, the corrosion resistant wire forming mesh is a titanium foam mesh having a thickness of from 300 micrometers to 2000 micrometers.
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, characterized in that:

Or the corrosion-resistant wire forming mesh is a porous titanium plate having a thickness of 500 micrometers to 3000 micrometers and a porosity of more than 40%.
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, characterized in that:

The cathode end plate (11) is made of polymethyl methacrylate; the cathode flow field groove (10) is designed to be horizontal or longitudinal serpentine, comb-groove arrangement, groove width 1-3 mm, groove The depth is 0.5-2.0 mm, and two or three flow channel slots are arranged in parallel to the flow field channel from the air inlet to the end of the air outlet.

The catalyst of the porous gas diffusion electrode (9) is a Pt catalyst.
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, further comprising:

a first foam sealing ring, the anode end plate (1) and the separation chamber (7) being sealed by the first foam sealing ring,

A second foam seal is sealed between the cathode end plate (11) and the separation chamber (7) by the second foam seal.
An electrolytic cell apparatus using an oxygen reduction cathode according to any one of claims 1 to 3, characterized in that:

The cathode flow field groove (10) is different from the anode flow field groove (2). The cathode flow field groove (10) is a horizontal or longitudinal serpentine shape, and the combing groove is arranged, the groove width is 1-3 mm, and the groove depth is 0.5-2.0. Millimeter, two or three flow channel slots are arranged in parallel, and the flow field channel starts from the air inlet to the end of the air outlet.

The gas diffusion electrode (9) is made of polytetrafluoroethylene, acetylene black and Pt catalyst.

The separation chamber (7) is filled with glass fiber, the thickness of the filled glass fiber is 500-2000 microns, the working voltage applied to the electrolytic cell is 1-5 volts, and the working current density of the electrolytic cell is 1-120 mA/square. cm,

The water inlet (101) on the anode plate end (1) is connected to the beginning of the anode flow field (2) at the bottom of the anode plate end; the water outlet (102) on the anode end plate (1) is provided on the upper side of the anode end plate. , connected to the end of the anode flow field groove (2),

An inlet (201) on the cathode end plate (11) is connected to the beginning of the cathode flow field groove (10) at the bottom of the cathode end plate (11).

The water outlet (202) on the cathode end plate (11) is disposed on the upper side of the cathode end plate (11) and connected to the end of the cathode flow field groove (10).

The organic wastewater enters from the water inlet (101), is degraded and mineralized under the electrooxidation of the anode chamber, and is discharged from the water outlet (102) on the anode end plate (1).