JP2011038145A - Electrolytic apparatus and electrolytic method - Google Patents

Abstract

Electrode degradation is reduced as compared with the prior art.
An electrolysis apparatus A1 for electrolyzing a predetermined electrolytic solution, a liquid contact surface immersed in an electrolyte solution 2, an air contact surface forming a gas flow path, and a liquid contact surface and an air contact surface And a plurality of electrolysis with a plurality of through-holes whose wall surfaces are lyophobic with respect to the electrolyte and whose pore diameter is set to a size that allows the decomposition gas to selectively pass through the electrolyte Electrodes B1, B2 and a polarity switching power supply 3 for supplying a potential at which the polarity is alternately switched over time to the plurality of electrolysis electrodes B1, B2.
[Selection] Figure 1

Description

  The present invention relates to an electrolysis apparatus and an electrolysis method.

  In Patent Document 1 below, a solution containing a KF-HF mixed molten salt in which potassium fluoride (KF) and hydrogen fluoride (HF) are mixed is used as an electrolytic solution, and the electrolytic solution is electrolyzed to obtain high purity. A fluorine gas generator that stably generates fluorine gas is disclosed. This fluorine gas generator collects fluorine gas generated at the anode electrode for use in cleaning a semiconductor manufacturing apparatus. In such a fluorine gas generator, a nickel (Ni) electrode is used as an anode electrode that converts fluorine ions into fluorine gas by desorbing electrons.

JP 2002-339090 A

  By the way, the nickel (Ni) electrode has a problem in that nickel (Ni), which is a material, dissolves into the electrolyte due to dissolution due to application of an electric potential, and as a result, the anode deteriorates. That is, the conventional fluorine gas generator (electrolysis device) needs to replace the anode electrode periodically in order to cope with the deterioration of the anode, so that continuous operation is difficult. Therefore, in the fluorine gas generation device (electrolysis device), extending the life of the anode electrode is a serious technical problem.

  In addition, high purity fluorine gas is required for use in cleaning semiconductor manufacturing equipment. The conventional fluorine gas generator has a problem that the anode electrode has a short life, although a sufficiently pure fluorine gas can be obtained.

The present invention has been made in view of the above-described circumstances, and has the following objects.
(1) Deterioration of the electrode is reduced as compared with the conventional case.
(2) Deterioration of the electrode is reduced as compared with the prior art while ensuring the purity of the generated gas.

  In order to achieve the above object, in the present invention, as a first solving means related to the electrolysis method, an electrolysis apparatus for electrolyzing a predetermined electrolytic solution, the wetted surface immersed in the electrolytic solution, The air contact surface forming the gas flow path, the liquid contact surface and the air contact surface communicate with each other, the wall surface is lyophobic with respect to the electrolyte, and the pore diameter selectively passes the decomposition gas with respect to the electrolyte. A plurality of electrolysis electrodes provided with a plurality of through-holes set to a size to be provided, and a polarity switching power source for supplying a potential at which the polarity is alternately switched over time to the plurality of electrolysis electrodes. Adopt means.

  As the second solving means relating to the electrolysis apparatus, in the first solving means, means is adopted in which each electrolysis electrode is arranged in the electrolyte so that each liquid contact surface is vertical and faces each other. To do.

  As a third solving means relating to the electrolysis apparatus, in the first solving means, a means is adopted in which each electrolysis electrode is disposed in the electrolytic solution with the liquid contact surface on the upper side.

  As a fourth solving means related to the electrolysis apparatus, in any one of the first to third solving means, the polarity switching power supply is configured such that the cathode area is the same as the anode area or the cathode area is larger than the anode area. A means of setting the polarity and supplying a potential to each electrolysis electrode is adopted.

  As a fifth solving means related to the electrolysis apparatus, in any one of the first to fourth solving means, the electrolytic solution uses a fluorine compound as a molten salt, and the fluorine compound is electrolyzed to generate fluorine gas. The method of generating is adopted.

  Further, in the present invention, as a first solving means related to the electrolysis method, an electrolysis method for electrolyzing a predetermined electrolytic solution, wherein a wetted surface immersed in the electrolytic solution and a gas flow path are formed. The air contact surface, the liquid contact surface and the air contact surface communicate with each other, the wall surface is lyophobic with respect to the electrolyte, and the pore size is set to a size that allows the decomposition gas to selectively pass through the electrolyte. A plurality of electrolysis electrodes having a plurality of through-holes are immersed in an electrolytic solution, and a potential at which the polarity is alternately switched over time is supplied to each electrolysis electrode.

  As the second solving means related to the electrolysis method, in the first solving means, a means is adopted in which each electrolysis electrode is disposed in the electrolyte so that each liquid contact surface is in a vertical posture and faces each other.

  As a third solving means related to the electrolysis method, a means is adopted in which, in the first solving means, each electrolysis electrode is arranged in the electrolytic solution with the liquid contact surface on the upper side.

  As a fourth solving means related to the electrolysis method, in any of the first to third solving means, the polarity is set so that the cathode area is the same as the anode area or the cathode area is larger than the anode area. A means of supplying a potential to each electrolysis electrode is adopted.

  As a fifth solving means related to the electrolysis method, in any one of the first to fourth solving means, an electrolytic solution using a fluorine compound as a molten salt is used, and the fluorine compound is electrolyzed to generate fluorine gas. , Is adopted.

According to the present invention, since the potential at which the polarity is alternately switched over time is supplied to each electrolysis electrode, the deterioration of the electrodes, particularly the anode, is improved as compared with the conventional technique in which the polarity supplied to each electrolysis electrode is fixed. Can be reduced.
Further, according to the present invention, the decomposition gas generated on the liquid contact surface is effectively removed from the liquid contact surface and moves into the through hole, and from the liquid contact surface to the inside of the through hole to the electrolyte. Therefore, it is possible to reduce the time for the decomposition gas to stay on the liquid contact surface compared to the conventional method, and this also reduces the deterioration of the electrode compared to the conventional method. In addition, it is possible to improve the decomposition efficiency of the electrolyte (decomposition gas generation efficiency) as compared with the conventional case.
Furthermore, according to the present invention, since the electrolyte selectively enters the inside of the through-hole from the liquid contact surface and moves to the air contact surface, it is possible to collect the high purity decomposition gas in the gas flow path. Is possible.

The structure of the electrolyzer A1 which concerns on 1st Embodiment of this invention is shown, (a) is a front view, (b) is an arrow line view of the X1-X1 line | wire in a front view. The structure of the electrode unit B (1st electrode unit B1 and cathode electrode unit B2) in the electrolyzer A1 which concerns on 1st Embodiment of this invention is shown, (a) is a front view, (b) is a front view. FIG. 4C is a side view of the Y1-Y1 line in FIG. FIG. 2 shows a configuration of an electrode plate of an electrode unit B in the electrolysis apparatus A1 according to the first embodiment of the present invention, where (a) is a front view and (b) is a view taken along the line Z1-Z1 in the front view. (C) is a side view. It is a characteristic view which shows the voltage pattern of 1st electric potential V1 and 2nd electric potential V2 in electrolyzer A1 which concerns on 1st Embodiment of this invention. The structure of the electrolyzer A2 which concerns on 2nd Embodiment of this invention is shown, (a) is a front view, (b) is an arrow line view of the X2-X2 line in a front view. It is an arrow line view which shows the structure of the electrolyzer A3 which concerns on the modification of 2nd Embodiment of this invention. It is a front view which shows the structure of electrolyzer A4 which concerns on 3rd Embodiment of this invention. It is a characteristic view which shows the voltage pattern of the 1st-3rd electric potential V1, V2, V3 in the electrolyzer A4 which concerns on 3rd Embodiment of this invention. The structure of the electrolyzer A5 which concerns on 4th Embodiment of this invention is shown, (a) is a front view, (b) is an arrow line view of the X3-X3 line in a front view. It is an arrow line view which shows the structure of electrolyzer A6 which concerns on the modification of 5th Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
First, the first embodiment will be described. As shown in FIG. 1, the electrolyzer A1 according to the first embodiment includes an electrolytic cell 1, an electrolytic solution 2, a first electrode unit B1, a second electrode unit B2, and a polarity switching power source 3. The electrolytic cell 1 is a box-shaped container in which an upper end is released and an electrolytic solution 2 is stored inside.

The electrolytic solution 2 contains a predetermined compound (electrolysis object) in a predetermined solvent. Various electrolytic solutions 2 are selected depending on the purpose of the electrolysis apparatus A1, that is, what kind of gas is recovered by electrolysis. For example, when the purpose is to generate and recover fluorine gas (F ₂ ), the electrolyte 2 is a mixture of potassium fluoride (KF) and hydrogen fluoride (HF), which is a molten salt (KF · nHF). (1 ≦ n ≦ 3)) is selected. The first electrode unit B1 and the second electrode unit B2 are configured identically, and are immersed in the electrolytic solution 2 in a vertical posture so that the electrode surfaces f1 and f2 face each other in parallel.

  The polarity switching power source 3 is a kind of AC power source having a pair of output terminals and having a function of alternately switching the electrical polarity of each output terminal over time. Of the pair of output ends, one output end is connected to the first electrode unit B1, and the other output end is connected to the second electrode unit B2. In other words, the polarity switching power supply 3 supplies the first potential V1 to the first electrode unit B1 through one output terminal, and the second potential V2 to the second electrode unit B2 through the other output terminal. Supply.

  Accordingly, the first electrode unit B1 and the second electrode unit B2 in the present electrolysis apparatus A1 function as anode electrodes or cathode electrodes because potentials having different polarities are applied from the polarity switching power supply 3 over time.

  FIG. 2 shows the configuration of the first electrode unit B1 and the second electrode unit B2 as an electrode unit B. As shown in the figure, the electrode unit B includes a porous electrode plate 4, a conducting wire 5, an electrode holder 6, a gas conduit 7, an electrode cover 8, and a fastening screw 9.

  As shown in FIG. 3, the porous electrode plate 4 is formed between the liquid contact surface 4b and the air contact surface 4c between the liquid contact surface 4b and the air contact surface 4c of the square and constant thickness conductor plate 4a. A large number of through-holes 4d are formed. The conductor plate 4a is a flat plate made of a predetermined metal such as nickel (Ni). The liquid contact surface 4b of the porous electrode plate 4 is the electrode surfaces f1 and f2 in the first electrode unit B1 and the second electrode unit B2.

  As shown in the figure, the through-hole 4d is formed by forming a lyophobic coating 4e (a lyophobic film) on the wall surface, and a liquid contact surface 4b and an air contact surface 4c whose cross-sectional shapes are parallel to each other. They are formed so as to be orthogonal and have a constant cross-sectional area. The diameter of the through hole 4d is, for example, 500 μm or less, and more preferably 10 μm to 500 μm. The diameter of the through-hole 4d is optimized so that the electrolyte does not enter the through-hole 4d as described in detail below.

The arrangement pitch of the through holes 4d is not particularly limited, but is preferably about 10 μm to 500 μm. That is, the arrangement pitch of the through holes 4d is preferably about the same as the diameter of the through holes 4d.
3 is formed in a state in which the through holes 4d are arranged like a grid, the arrangement of the through holes 4d is not limited to this. It may be in a lattice form or an array state without regularity. Further, the cross-sectional shape of the through-hole 4d shown in FIG. 3 is a shape having a constant cross-sectional area in the axial direction, but may be a shape in which the cross-sectional area changes in the axial direction. Such a porous electrode plate 4 can be easily formed by, for example, laser processing the flat conductor plate 4a.

  The liquid contact surface 4b of the porous electrode plate 4 is surface-treated so as to be lyophilic with respect to the electrolytic solution. The porous electrode plate 4 is formed using the conductor plate 4a as a base material, but the wall surface of each through-hole 4d has a lyophobic film 4e which is a lyophobic film against the electrolyte on the surface of the conductive material. It is formed entirely. Each such film is formed by applying a lyophilic material or a lyophobic material by various coating methods such as spray coating, flow coating, spin coating, dip coating, roll coating, and pressure coating.

Here, “lyophilic” means a state in which the angle (contact angle) between the gas-liquid interface and the solid-liquid interface of the droplet is smaller than 90 ° when a certain amount of the droplet is placed on the solid surface. In addition, “liquidphobic” means that the contact angle is greater than 90 °. When the liquid contact surface 4b (lyophilic surface) and the lyophobic film 4e (liquid lyophobic surface) of each through hole 4d are viewed as the contact angle, the contact angle α of the liquid contact surface 4b (lyophilic surface) with respect to the electrolytic solution (Α <90 °) and the contact angle β (90 ° <β) of the lyophobic film 4e (lyophobic surface) with respect to the electrolyte satisfy the following relational expression (1). That is, the contact angle α of the liquid contact surface 4b is set smaller than the contact angle β of the lyophobic film 4e of each through hole 4d.
α <90 ° <β (1)

  That is, in the porous electrode plate 4, the diameter of the through-hole 4d is set to 500 μm or less, and the contact angles of the liquid contact surface 4b (lyophilic surface) and the liquid-phobic film 4e (liquid-phobic surface) of each through-hole 4d. α and β are configured to satisfy the relational expression (1). For each contact angle α, β, it is more preferable to satisfy the condition of α + 10 ° <90 ° <β or α + 25 ° <90 ° <β instead of the relational expression (1). The contact angle of the air contact surface 4c is not particularly limited, but is preferably set to be larger than 90 ° (that is, lyophobic).

  The conducting wire 5 is an electric wire having one end connected to the air contact surface 4c of the porous electrode plate 4 and the other end connected to an output end of an external power source (not shown). This is for supplying a potential for decomposition to the porous electrode plate 4. The electrode holder 6 is a cubic non-conductive member having a recess formed therein. As shown in the figure, the above-mentioned flat porous electrode plate 4 is mounted on the electrode holder 6 so as to close the hollow portion from one side. A cavity surrounded by the recess of the electrode holder 6 and the porous electrode plate 4 is a gas chamber 6a. Such a gas chamber 6a communicates with the liquid contact surface 4b through a plurality of through holes 4d as shown.

  The gas conduit 7 is a hollow cylindrical non-conductive member having one end fixed to the upper part of the electrode holder 6, and the internal cavity is a gas channel 7a communicating with the gas chamber 6a. Although not shown, the other end of the gas conduit 7 is connected to a gas recovery device. The electrode cover 8 is a square non-conductive member having a square opening 8a formed at the center. The electrode cover 8 is for holding the porous electrode plate 4 in a part of the electrode holder 6 so that the liquid contact surface 4b is exposed to the outside through the opening 8a. The fastening screws 9 are for fastening and fixing the electrode cover 8 to the electrode holder 6, and are provided in the vicinity of the respective portions of the electrode cover 8.

Next, the operation of the electrolyzer A1 thus configured will be described in detail with reference to the voltage patterns of the first potential V1 and the second potential V2 shown in FIG.
In the following description, in order to generate and recover fluorine gas (F ₂ ), a mixture of potassium fluoride (KF) and hydrogen fluoride (HF) is used as a molten salt (KF · nHF (1 ≦ n The case where the electrolytic solution 2 is set to ≦ 3)) will be described.

  During the operation of the electrolyzer A1, the polarity switching power source 3 supplies the first potential V1 having the voltage pattern shown in FIG. 4A to the first electrode unit B1, and supplies the second potential V2 to the second potential V2. Supply to electrode unit B2. The first potential V1 and the second potential V2 are potentials in a voltage pattern in which the voltage changes between the positive electrode operating potential + Va and the negative electrode operating potential 0 in a square waveform with a constant period. Note that the negative electrode potential is not necessarily zero and may be a negative potential.

  Further, as shown in the figure, the first potential V1 and the second potential V2 have voltage patterns set so that the positive electrode operating potential + Va does not overlap each other, that is, at the same time, does not become the positive electrode operating potential + Va. Yes. The positive electrode operating potential + Va is set as a voltage exceeding the positive electrode gas generation potential + Vg at which electrolysis can occur.

  The first potential V1 and the second potential V2 are such that when the first potential V1 is the positive electrode operating potential + Va, the second potential V2 is the negative electrode operating potential 0. In contrast, when the second potential V2 is the positive electrode operating potential + Va, the first potential V1 is the negative electrode operating potential 0. Therefore, when the positive electrode operating potential + Va is applied to the first electrode unit B1, that is, when the first electrode unit B1 functions as an anode curved electrode, the negative electrode operating potential 0 is applied to the second electrode unit B2 and the anode curved. Functions as an electrode.

  The voltage pattern of the first potential V1 and the second potential V2 may be the voltage pattern shown in FIG. 4B instead of the pattern shown in FIG. The voltage pattern of FIG. 4B is a multi-stage change in voltage from the negative electrode operating potential 0 to the positive electrode operating potential + Va of the first potential V1 and the second potential V2 in contrast to the pattern of FIG. It is different in that it is changed sequentially (intermediate is 3 steps). The number of stages in this voltage change is not limited to the middle three stages. Further, the voltage change is not multi-stage, and may be a linear change with a constant inclination, such as a ramp waveform, or a smooth curve.

Now, when the first electrode unit B1 is at the positive electrode operating potential + Va and the second electrode unit B2 is at the negative electrode operating potential 0, the liquid contact surface 4b of the porous electrode plate 4 of the first electrode unit B1 in contact with the electrolyte 2 ( The chemical reaction shown in the following reaction formula (2) occurs on the electrode surface f1), and fluorine gas (F ₂ ) is generated as bubbles on the electrode surface f1. Further, a chemical reaction shown in the following reaction formula (3) occurs on the liquid contact surface 4b (electrode surface f2) of the porous electrode plate 4 of the second electrode unit B2, and hydrogen gas (H ₂ ) is bubbled on the electrode surface f2. Occurs as.
Anode: 2F ⁻ → F ₂ + 2e ⁻ (2)
Cathode: 2H ⁺ + 2e ⁻ → H ₂ (3)

Here, since the liquid contact surface 4b of the first electrode unit B1 is lyophilic, the liquid contact surface 4b is well-familiar with the electrolytic solution 2, so that fluorine gas (F ₂ ) is efficiently generated. In addition, since the liquid contact surface 4b is covered with a lyophilic film, it is not familiar with fluorine gas (F ₂ ) which is a bubble (gas). On the other hand, since the lyophobic film 4e of the through holes 4d formed in large numbers on the liquid contact surface 4b is covered with a lyophobic film, the familiarity with the electrolyte 2 is poor, but bubbles (gas) Familiarity with fluorine gas (F ₂ ) is good.

That is, in the porous electrode plate 4 of the first electrode unit B1, the relational expression (1) is established between the contact angle α of the liquid contact surface 4b and the contact angle β of the lyophobic film 4e of the through hole 4d. The bubbles of fluorine gas (F ₂ ) generated in the vicinity of the through hole 4d on the liquid contact surface 4b of the first electrode unit B1 are excluded from the liquid contact surface 4b (lyophilic surface), and the lyophobic film 4e in the through hole 4d. Move to (lyophobic surface). The bubbles of fluorine gas (F ₂ ) generated in the vicinity of the through hole 4d on the liquid contact surface 4b move from the liquid contact surface 4b to the through hole 4d by the action of this force.

When the surface tension γ [N / m] of the electrolytic solution 2, the contact angle α [deg] of the liquid contact surface 4 b with respect to the electrolytic solution 2, and the radius r [m] of the through hole 4 d, the electrolytic solution 2 is in the through hole 4 d. The pressure (Young-Laplace pressure) ΔP required to enter the interior is expressed by the following equation (4).
ΔP = −2γ (cos α) / r (4)
Therefore, if the pressure of the electrolytic solution 2 at the inlet of the through hole 4d (depending on the depth of the through hole 4d with respect to the electrolytic solution 2) does not exceed the Young Laplace pressure ΔP, the electrolytic solution 2 is placed inside the through hole 4d. It cannot be infiltrated.

As described above, the porous electrode plate 4 of the first electrode unit B1 has such a size that the electrolytic solution 2 cannot enter inside, that is, a size that allows the fluorine gas (F ₂ ), which is a decomposition gas (gas), to selectively pass through ( The diameter of the through-hole 4d is set so as to be equal to or less than the above-mentioned diameter of 500 μm, and a lyophobic film 4e having a contact angle β larger than the contact angle α of the liquid-contact surface 4b is provided on the wall surface of the through-hole 4d. Therefore, the fluorine gas (F ₂ ) bubbles generated on the liquid contact surface 4b are effectively excluded from the liquid contact surface 4b and move to the inside of the through hole 4d, and from the liquid contact surface 4b to the through hole. 4d selectively enters the electrolyte 2 and moves to the air contact surface 4c.

That is, in the first electrode unit B1 of the electrolyzer A1, the fluorine gas (F ₂ ) that is a bubble (gas) is effectively separated from the liquid electrolyte 2 and the electrolyte 2 passes through the through-hole 4d. Without passing through, the electrolytic solution 2 is selectively collected through the through hole 4d and collected in the gas chamber 6a. Then, the fluorine gas (F ₂ ) in the gas chamber 6 a is recovered to the outside through the gas channel 7 a formed by the gas conduit 7. Therefore, according to this electrolyzer A1, it is possible to increase the effective area in electrolysis by removing gas from the portion previously covered with bubbles, and the decomposition efficiency of the electrolytic solution 2, that is, fluorine gas The generation efficiency of (F ₂ ) can be improved.

In contrast to such an action in the first electrode unit B1, in the second electrode unit B2, the porous electrode plate 4 is configured in exactly the same manner as the porous electrode plate 4 of the first electrode unit B1, but the liquid contact surface 4b. Since the gas generated at (electrode surface f2) is bubbles of hydrogen gas (H ₂ ) instead of fluorine gas (F ₂ ), the bubbles of hydrogen gas (H ₂ ) are transferred from the liquid contact surface 4b to the through hole 4d. The liquid contact surface 4b is lyophilic and unfamiliar with bubbles (gas), and is quickly removed from the liquid contact surface 4b according to the buoyancy and floats in the electrolyte 2. . That is, the hydrogen gas (H ₂ ) is not collected in the gas chamber 6a like the fluorine gas (F ₂ ), but is collected in a gas collector separately provided above the second electrode unit B2. .

Subsequently, from such a state that the first electrode unit B1 is at the positive electrode operating potential + Va and the second electrode unit B2 is at the negative electrode operating potential 0, the first electrode unit B1 is at the negative electrode operating potential -Va and the second electrode unit B2 is at the second electrode unit B2. When the state is switched to the positive electrode operating potential + Va, hydrogen gas (H ₂ ) is generated on the electrode surface f1 of the first electrode unit B1, and fluorine gas (F ₂ ) is generated on the electrode surface f2 of the second electrode unit B2. .

In this state, the hydrogen gas (H ₂ ) generated on the electrode surface f1 of the first electrode unit B1 passes through the through-hole 4d of the first electrode unit B1 as in the case of the second electrode unit B2 described above. It is not collected in the gas chamber 6a, but is recovered by floating in the electrolytic solution 2 according to buoyancy. On the other hand, the fluorine gas (F ₂ ) generated on the electrode surface f2 of the second electrode unit B2 enters the through hole 4d and is collected in the gas chamber 6a as described above.

  According to the electrolyzer A1 as described above, the first potential V1 applied to the first electrode unit B1 and the second potential V2 applied to the second electrode unit B2 are alternately switched to change the first potential. Since the electrode unit B1 and the second electrode unit B2 function alternately as anode electrodes, it is possible to greatly suppress the elution of the metal plate 4a, and thus the deterioration of the first electrode unit B1 and the second electrode unit B2. Can be greatly suppressed.

Further, according to the electrolyzer A1, in the first electrode unit B1 and the second electrode unit B2, the fluorine gas (F ₂ ) and the hydrogen gas (H ₂ ) are switched by alternately switching between the anode electrode and the cathode electrode. Are generated alternately, but fluorine gas (F ₂ ) and hydrogen gas (H ₂ ) are collected separately, so that high purity fluorine gas (F ₂ ) and hydrogen gas (H ₂ ) must be collected. Is possible.

Furthermore, according to the present electrolysis apparatus A1, since the postures of the first electrode unit B1 and the second electrode unit B2 are set so that the electrode surfaces f1 and f2 face each other in parallel, the electrode surfaces f1 and f2 are set. The distances between the electrode surfaces f1 and f2 are the same at each of the regions, so that a uniform electric field is generated between the electrode surfaces f1 and f2. If the electrode surfaces f1 and f2 are not parallel to each other, the distance between the electrode surfaces f1 and f2 at each part of the electrode surfaces f1 and f2 is not constant, and thus differs depending on the part of the electrode surfaces f1 and f2. An electric field is generated. According to this electrolysis apparatus A1, since a uniform electric field is generated between the electrode surfaces f1 and f2, fluorine gas (F ₂ ) and hydrogen gas (H ₂ ) can be generated efficiently.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. In FIG. 5, the same components as those of the electrolyzer A1 according to the first embodiment described above are denoted by the same reference numerals. In the following, such identical components are duplicated and will not be described.

  The electrolyzer A2 according to the second embodiment includes an electrolytic cell 1A, an electrolytic solution 2, a first electrode unit B1, a second electrode unit B2, and a polarity switching power source 3 (not shown). The electrolyzer A2 includes an electrolytic cell 1A for accommodating the first electrode unit B1 and the second electrode unit B2 in the electrolytic cell 1A in a horizontal posture as shown in the figure. This electrolytic cell 1A has a larger area and a shallower depth as viewed from the front than the electrolytic cell 1 in the electrolyzer A1 according to the first embodiment. Further, as shown in the drawing, the first electrode unit B1 and the second electrode unit B2 are disposed in the electrolytic solution 2 in the electrolytic cell 1A so that the electrode surfaces f1 and f2 are oriented upward and have the same depth. Soaked.

  As a modification of the electrolyzer A2, an electrolyzer A3 as shown in FIG. 6 can be considered. The electrolyzer A3 according to this modified example includes the first electrode unit B1 and the electrode units f1 and f2 in a posture in which the electrode surfaces f1 and f2 are directed downward and the electrode surfaces f1 and f2 are slightly inclined with respect to the horizontal. The second electrode unit B2 is immersed in the electrolytic solution 2 in the electrolytic cell 1A.

In each of the electrolyzers A2 and A3, the same occurred on the electrode surfaces f1 and f2 of the first electrode unit B1 and the second electrode unit B2 as in the electrolyzer A1 according to the first embodiment described above. Fluorine gas (F ₂ ) enters the through-hole 4d, moves into the gas chamber 6a and is recovered, while hydrogen generated on the electrode surfaces f1 and f2 of the first electrode unit B1 and the second electrode unit B2. The gas (H ₂ ) floats in the electrolytic solution 2 according to the buoyancy and is collected without the through holes 4d of the first electrode unit B1 and the second electrode unit B2.

Moreover, according to each electrolyzer A2, A3, since the polarity of 1st electric potential V1 applied to 1st electrode unit B1 and 2nd electric potential V2 applied to 2nd electrode unit B2 is switched alternately, fluorine gas (F ₂ ) is alternately generated in the first electrode unit B1 and the second electrode unit B2. Therefore, the elution of the metal plate 4a in the first electrode unit B1 and the second electrode unit B2 can be significantly suppressed.

In addition, according to the present electrolysis apparatus A2, since the electrode surfaces f1 and f2 are oriented in the upward direction and in the horizontal posture, the depth of the electrolyte solution 2 at each part of the electrode surfaces f1 and f2 is the same. Therefore, an equal buoyancy is generated in the hydrogen gas (H ₂ ) generated at each part of the electrode surfaces f1 and f2. Therefore, according to the present electrolyzer A2, the uniformity of the electric field generated between the electrode surfaces f1 and f2 described above is impaired, but the hydrogen gas (H ₂ ) generated at each part of the electrode surfaces f1 and f2 is impaired. Can be effectively levitated.

  On the other hand, in the electrolysis apparatus A1 according to the first embodiment, since the electrode surfaces f1 and f2 are set in a vertical posture, the deep portions in the liquid depth directions of the electrode surfaces f1 and f2 are Since a larger fluid pressure is applied, when a fluid pressure greater than the Young Lavras pressure that forms the gas-liquid interface is applied, the electrolytic solution 2 enters the inside of the through hole 4d.

  Also, according to the electrolysis apparatus A3 according to the modified example, since the electrode surfaces f1 and f2 are directed downward, sludge (precipitate) generated slightly on the electrode surfaces f1 and f2 is lowered by the action of gravity. To do. Therefore, according to the electrolyzer A3, it is possible to prevent sludge (precipitate) from being deposited on the electrode surfaces f1 and f2.

[Third Embodiment]
Next, a third embodiment will be described. In FIG. 7, the same components as those in FIG. 1 are denoted by the same reference numerals. In the following, the same components as those in FIG.

  As shown in the figure, the electrolyzer A4 according to the third embodiment includes first to third electrode units B1 to B3, and a polarity switching power source 3A corresponding to the first to third electrode units B1 to B3. Is provided. In other words, the first to third electrode units B1 to B3 are disposed in the electrolytic solution 2 in the electrolytic cell 1 so that the electrode surfaces f1, f2, and f3 (liquid contact surfaces) face each other at an angle of 60 degrees. Soaked. In the present embodiment, the case of 60 degrees is illustrated, but the present invention is not limited to this, and may have an arbitrary angle.

  The polarity switching power supply 3A outputs first to third potentials V1 to V3 corresponding to the first to third electrode units B1 to B3 as shown in the voltage pattern of FIG. That is, the polarity switching power supply 3A outputs the first to third potentials V1 to V3 having a voltage pattern in which the voltage changes in a square wave shape between the positive electrode operating potential + Va and the negative electrode operating potential 0 alternately at a constant cycle. .

  Further, as shown in the figure, the first to third potentials V1 to V3 are set to have a voltage pattern so that the positive electrode operating potentials + Va do not overlap each other, that is, not to simultaneously become the positive electrode operating potential + Va. . That is, when the first to third potentials V1 to V3 are applied with the positive electrode operating potential + Va to any one of the first to third electrode units B1 to B3, the other two are applied with the negative electrode operating potential 0. It is set to be.

  The voltage pattern of the first to third potentials V1 to V3 is controlled so that the anode area becomes smaller than the cathode area. This prevents the electrochemical reaction occurring on the cathode from being rate-limiting and lowering the fluorine gas generation efficiency at the anode. That is, the polarity switching power source 3A sets the polarities of the first to third potentials V1 to V3 so that the reaction area of the cathode electrode is effectively larger than the reaction area of the anodic decomposition electrode. A potential is supplied to the electrode units B1 to B3.

  The polarity switching power supply 3A outputs the first to third potentials V1 to V3 having a voltage pattern as shown in FIG. 8B instead of the voltage pattern as shown in FIG. May be. The voltage pattern of FIG. 8B is a multi-stage change in voltage from the negative electrode operating potential −Va to the positive electrode operating potential + Va of the first to third potentials V1 to V3 in contrast to the pattern of FIG. 8A. It is different in that it is changed sequentially.

In the present electrolyzer A4, when the polarity switching power source 3A outputs the first to third potentials V1 to V3 having a voltage pattern as shown in FIG. 8A, for example, the first to third electrode units B1 are used. When the positive electrode operating potential + Va is applied to any of .about.B3, the negative electrode operating potential 0 is applied to the other two. That is, when any one of the first to third electrode units B1 to B3 functions as an anode electrode, the other functions as a cathode electrode. Then, fluorine gas (F ₂ ) is generated at the anode electrode to which the positive electrode operating potential + Va is applied, and hydrogen gas (H ₂ ) is generated at the cathode electrode to which the negative electrode operating potential 0 is applied.

In this electrolyzer A4 as well, the first to third electrode units are applied when the positive electrode operating potential + Va is applied, just like the electrolyzers A1 to A3 according to the first and second embodiments described above. The fluorine gas (F ₂ ) generated on the electrode surfaces f1 to f3 of B1 to B3 moves to the gas chamber 6a through the through-hole 4d and is recovered, and on the other hand, when the negative electrode operating potential 0 is applied. The hydrogen gas (H ₂ ) generated on the electrode surfaces f1 to f3 of the first to third electrode units B1 to B3 is generated in the electrolyte 2 according to the buoyancy without forming the through holes 4d of the first to third electrode units B1 to B3. Is levitated and recovered.

Further, according to the electrolyzer A4, the first potential V1 applied to the first electrode unit B1, the second potential V2 applied to the second electrode unit B2, and the third potential applied to the third electrode unit B3. since switching the polarity of the potential V3 alternately, fluorine gas (F ₂₎ is alternately generated in the first to third electrode units B1 to B3. Therefore, the elution of the metal plate 4a in the first to third electrode units B1 to B3 can be significantly suppressed.

The overall reaction rate of the electrolyzer A4 is determined by the decomposition rate of the electrolyte 2 at the anode electrode (fluorine gas (F ₂ ) generation rate). That is, the decomposition rate of the electrolytic solution 2 at the anode electrode is the reaction rate limiting rate of the electrolyzer A4.

According to the electrolyzer A4, when the positive electrode operating potential + Va is applied to one electrode unit, the negative electrode operating potential 0 is applied to the other two electrode units. Can be increased. Therefore, according to the present electrolyzer A4, the electrochemical reaction occurring at the cathode is not rate-determining, and therefore the generation efficiency of fluorine gas (F ₂ ) can be improved.

In addition, according to the electrolyzer A4, the electrode surfaces f1 to f3 of the first to third electrode units B1 to B3 are provided at equal distances from each other, so that the electric fields between the electrode surfaces f1 to f3 are the same. It is. Therefore, according to the present electrolyzer A4, the generation amounts of fluorine gas (F ₂ ) and hydrogen gas (H ₂ ) in the first to third electrode units B1 to B3 can be made uniform.

[Fourth Embodiment]
Next, a fourth embodiment will be described with reference to FIG. In addition, in FIG. 9, the same code | symbol is attached | subjected about the component same as electrolysis apparatus A1-A4 which concerns on 1st-3rd embodiment mentioned above. In the following, such identical components are duplicated and will not be described.

  The electrolyzer A5 according to the fourth embodiment includes an electrolytic cell 1B, an electrolytic solution 2, first to third electrode units B1 to B3, and a polarity switching power source 3A (not shown). The electrolyzer A5 includes an electrolytic cell 1B that accommodates the first to third electrode units B1 to B3 in the horizontal direction in the electrolytic cell 1A as shown in the figure. The electrolytic cell 1B has a first and front area larger than the electrolytic cell 1A of the electrolyzer A2 according to the second embodiment in which the second electrode units B1 and B2 are accommodated in a horizontal posture. It is equivalent to the electrolytic cell 1A. Further, as shown in the figure, the first to third electrode units B1 to B3 are immersed in the electrolytic solution 2 in the electrolytic cell 1B so that the electrode surfaces f1 to f3 face upward and have the same depth. Has been.

  Further, as a modification of the present electrolyzer A5, an electrolyzer A6 as shown in FIG. 10 can be considered. In the electrolysis apparatus A6 according to this modification, the first to first electrode surfaces f1 to f3 are oriented so that the electrode surfaces f1 to f3 are directed downward, and the electrode surfaces f1 to f3 are slightly inclined with respect to the horizontal. The third electrode units B1 to B3 are immersed in the electrolytic solution 2 in the electrolytic cell 1B.

  That is, the electrolyzer A5 according to the fourth embodiment has a horizontal area of the electrolytic cell 1A in the electrolyzer A2 according to the second embodiment so that the first to third electrode units B1 to B3 can be accommodated. It is a big one. Therefore, the electrolysis apparatus A2 according to the second embodiment in which the first and second electrode units B1, B2 are immersed in the electrolytic solution 2 so that the electrode surfaces f1, f2 are directed upward and have the same depth. And the effects of the electrolysis apparatus A3 according to the third embodiment in which the first to third electrode units B1 to B3 are immersed in the electrolytic solution 2.

  Further, the electrolyzer A6 according to the modified example has a horizontal area of the electrolytic cell 1A in the electrolyzer A3 according to the modified example of the second embodiment so that the first to third electrode units B1 to B3 can be accommodated. It is a big one. Therefore, the first electrode unit B1 and the second electrode unit B2 are arranged so that the electrode surfaces f1, f2 are directed downward and the electrode surfaces f1, f2 are slightly inclined with respect to the horizontal. The third embodiment in which the effect of the electrolysis apparatus A3 according to the modification of the second embodiment immersed in the electrolytic solution 2 in the electrolytic cell 1A and the first to third electrode units B1 to B3 are immersed in the electrolytic solution 2 The effects of the electrolyzer A3 according to the present invention are exhibited.

In addition, this invention is not limited to said each embodiment, For example, the following further modifications can be considered.
(1) In each of the above embodiments, a configuration in which two or three electrode units are combined is adopted, but the present invention is not limited to this. Four or more electrode units may be combined. In each of the above embodiments, all the electrode units have the same configuration, but electrode units having different configurations may be combined as necessary.

(2) Moreover, when combining three or more electrode units, it is not necessary to supply an electric potential to all the electrode units. That is, for example, in the case of using the first to third electrode units B1 to B3 as in the third and fourth embodiments, the potential is supplied to any two electrode units and the potential is applied to the other one electrode unit. Operation that does not supply is also conceivable.

(3) In each of the above embodiments, nickel (Ni) is selected as the material of the porous electrode plate 1 (metal plate 1a) of the first electrode unit A1p. However, the present invention is not limited to this. The following materials may be used instead of nickel (Ni). That is, as a metal electrode, platinum (Pt), gold (Au), silver (Ag), palladium (Pb), rhodium (Rh), iridium (Ir), tungsten (W) alone, or these as a main component Alloy or nickel (Ni) -copper (Cu) alloy, nickel (Ni) -chromium (Cr) -iron (Fe) alloy, nickel (Ni) -molybdenum (Mo) alloy, nickel (Ni) -chromium (Cr) -Molybdenum (Mo) alloy, etc. may be used.

Also, as the carbon electrode, glassy carbon, pyrolytic graphite, basal plain pyrolytic graphite, carbon paste, HOPG (Highly Oriented Pyrolytic Graphite), carbon fiber, conductive diamond, BDD (Boron Doped Diamond), conductive DLC (Diamond) Like Carbon) electrodes may be used. Further, Nesa (tin oxide doped with antimony (Sb) (SnO ₂ )), Nesatoron (indium oxide doped with tin (Sn) (In ₂ O ₃ )), or the like may be used as the transparent electrode. As the oxide electrode, titanium oxide (TiO ₂ ), manganese oxide (MnO ₂ ), lead dioxide (PbO ₂ ), perovskite oxide, bronze oxide, or the like may be used.

As the semiconductor electrode, silicon (Si), germanium (Ge), zinc oxide (ZnO), cadmium sulfide (CdS), gallium arsenide (GaAs), titanium oxide (TiO ₂ ), or the like may be used. Further, a polymer solid electrolyte electrode may be used. Furthermore, as the combination of the anode electrode and the cathode electrode, each of the above materials may be used alone or a combination of two or more materials may be employed.

(4) In each of the above embodiments, each electrode unit is configured such that only fluorine gas (F ₂ ) out of the fluorine gas (F ₂ ) and hydrogen gas (H ₂ ) passes through the through hole. Is not limited to this. It seems possible to realize a state in which hydrogen gas (H ₂ ) passes through the through hole by appropriately adjusting the hole diameter of the through hole and / or the lyophobic property of the inner wall.
The fluorine gas generated on the lyophilic surface of the anode moves to the lyophobic surface through the through hole. On the other hand, hydrogen gas generated on the lyophilic surface of the cathode may move through the through hole to the lyophobic surface, or may move through the electrolyte without passing through the through hole. In this case, if fluorine gas and hydrogen gas come into contact with each other, there is a possibility of causing an explosive reaction.

Thus, both the fluorine gas (F ₂₎ and hydrogen gas (H ₂₎ may be configured each electrode unit so as to pass through the through hole. Even when the electrode unit configured as described above is used, a high-purity fluorine gas (F) can be obtained by devising a method for recovering fluorine gas (F ₂ ) and hydrogen gas (H ₂ ) from each electrode unit. ₂ ) and hydrogen gas (H ₂ ) can be collected.

  A1 to A6 ... electrolysis apparatus, B ... electrode unit, B1 ... first electrode unit, B2 ... second electrode unit, B3 ... third electrode unit, f1-f3 ... electrode surface, 1, 1A, 1B ... electrolytic cell, 2 ... Electrolyte, 3, 3A ... Polarity switching power supply, 4 ... Porous electrode plate, 4a ... Metal plate, 4b ... Liquid contact surface, 4c ... Air contact surface, 4d ... Through hole, 4e ... Wall surface, 5 ... Conductor, 6 ... Electrode holder, 7 ... Gas conduit, 8 ... Electrode cover, 9 ... Fastening screw

Claims (8)

An electrolysis apparatus for electrolyzing a predetermined electrolyte solution,
The liquid contact surface immersed in the electrolyte, the air contact surface that forms the gas flow path, and the liquid contact surface and the air contact surface communicate with each other. The wall surface is lyophobic with respect to the electrolyte solution and the pore size is decomposed. A plurality of electrolysis electrodes comprising a plurality of through-holes set to a size that allows gas to selectively pass through the electrolyte;
An electrolysis apparatus comprising: a polarity switching power source for supplying a potential at which the polarity is alternately switched over time to the plurality of electrolysis electrodes.   2. The electrolysis apparatus according to claim 1, wherein each electrolysis electrode is disposed in the electrolyte so that each liquid contact surface is in a vertical posture and faces each other.   The electrolysis apparatus according to claim 1, wherein each electrolysis electrode is disposed in the electrolytic solution with a liquid contact surface on an upper side.   The electrolytic solution according to any one of claims 1 to 3, wherein the electrolytic solution uses a fluorine compound as a molten salt, and the fluorine compound is electrolyzed to generate fluorine gas. An electrolysis method for electrolyzing a predetermined electrolyte solution,
The liquid contact surface immersed in the electrolyte, the air contact surface that forms the gas flow path, and the liquid contact surface and the air contact surface communicate with each other. The wall surface is lyophobic with respect to the electrolyte solution and the pore size is decomposed. A plurality of electrolysis electrodes having a plurality of through-holes set to a size that allows gas to selectively pass through the electrolyte solution are immersed in the electrolyte solution,
An electrolysis method comprising supplying each electrolysis electrode with a potential that switches alternately with time.   6. The electrolysis method according to claim 5, wherein each electrolysis electrode is disposed in the electrolyte so that each liquid contact surface is vertical and faces each other.   6. The electrolysis method according to claim 5, wherein each electrolysis electrode is disposed in the electrolytic solution with the wetted surface facing upward.   The electrolysis method according to any one of claims 5 to 7, wherein an electrolytic solution containing a fluorine compound as a molten salt is used to electrolyze the fluorine compound to generate fluorine gas.

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