WO2024090472A1 - Hydrogen gas concentration sensor - Google Patents
Hydrogen gas concentration sensor Download PDFInfo
- Publication number
- WO2024090472A1 WO2024090472A1 PCT/JP2023/038496 JP2023038496W WO2024090472A1 WO 2024090472 A1 WO2024090472 A1 WO 2024090472A1 JP 2023038496 W JP2023038496 W JP 2023038496W WO 2024090472 A1 WO2024090472 A1 WO 2024090472A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- hydrogen gas
- electrode
- container
- electrode piece
- electrolyte
- Prior art date
Links
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 116
- 239000003792 electrolyte Substances 0.000 claims abstract description 31
- 239000007772 electrode material Substances 0.000 claims abstract description 16
- 239000000126 substance Substances 0.000 claims abstract description 15
- 239000001257 hydrogen Substances 0.000 claims description 26
- 229910052739 hydrogen Inorganic materials 0.000 claims description 26
- 239000000463 material Substances 0.000 claims description 18
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 12
- 239000011148 porous material Substances 0.000 claims description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 4
- 229910000838 Al alloy Inorganic materials 0.000 claims description 3
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 3
- 229910000640 Fe alloy Inorganic materials 0.000 claims description 3
- 229910000990 Ni alloy Inorganic materials 0.000 claims description 3
- 229910001260 Pt alloy Inorganic materials 0.000 claims description 3
- 229910001069 Ti alloy Inorganic materials 0.000 claims description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 229910001080 W alloy Inorganic materials 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 239000010936 titanium Substances 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 239000010937 tungsten Substances 0.000 claims description 3
- 239000007788 liquid Substances 0.000 abstract description 9
- 239000007789 gas Substances 0.000 abstract description 5
- 239000011800 void material Substances 0.000 abstract description 3
- 230000001747 exhibiting effect Effects 0.000 abstract 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 13
- 239000000919 ceramic Substances 0.000 description 5
- 230000007613 environmental effect Effects 0.000 description 4
- 238000005421 electrostatic potential Methods 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- YZCKVEUIGOORGS-UHFFFAOYSA-N Hydrogen atom Chemical compound [H] YZCKVEUIGOORGS-UHFFFAOYSA-N 0.000 description 1
- MZUSCVCCMHDHDF-UHFFFAOYSA-N P(=O)(=O)[W] Chemical compound P(=O)(=O)[W] MZUSCVCCMHDHDF-UHFFFAOYSA-N 0.000 description 1
- AUKPHARRMFSIIN-UHFFFAOYSA-K P(=O)([O-])([O-])[O-].[W+4].[Cs+] Chemical compound P(=O)([O-])([O-])[O-].[W+4].[Cs+] AUKPHARRMFSIIN-UHFFFAOYSA-K 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000000502 dialysis Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 239000002001 electrolyte material Substances 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 210000003734 kidney Anatomy 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- IYDGMDWEHDFVQI-UHFFFAOYSA-N phosphoric acid;trioxotungsten Chemical compound O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.O=[W](=O)=O.OP(O)(O)=O IYDGMDWEHDFVQI-UHFFFAOYSA-N 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229920005597 polymer membrane Polymers 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000001225 therapeutic effect Effects 0.000 description 1
- -1 tungsten Chemical compound 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/406—Cells and probes with solid electrolytes
- G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
Definitions
- the present invention relates to a hydrogen gas concentration sensor.
- Conventional hydrogen gas concentration sensors are based on detection methods such as semiconductor, ionization, and combustion.
- the measurement principle of these is to detect the amount of hydrogen indirectly as an "extensive physical quantity” such as “carrier concentration (semiconductor type),” “ion concentration (ionization type),” or “reaction heat (combustion type or burning and measuring the water vapor pressure),” and convert these into electrical quantities to use as sensors.
- a hydrogen gas sensor As an example of a hydrogen gas concentration sensor that shortens the detection time, a hydrogen gas sensor has been proposed that includes a first electrode and a second electrode made of materials with different chemical potentials relative to hydrogen, and an electrolyte in contact with these electrodes, and detects hydrogen gas based on the electromotive force value generated between these electrodes (Patent Document 1).
- the first electrode, second electrode, and electrolyte are covered with an outer skin, so in order to use the hydrogen gas sensor to measure the concentration of dissolved hydrogen gas in a liquid, at least the first electrode, which is the detection electrode, needs to be exposed from the outer skin and immersed in the liquid, while the electrolyte needs to be sealed from the liquid.
- the first electrode which is the detection electrode
- the sealing method poses technical and economic challenges.
- the present invention aims to provide a hydrogen gas concentration sensor with a novel configuration that can detect the concentration of hydrogen gas present in environments such as high temperature and high humidity environments, and in special gases and liquids in the chemical industry.
- a hydrogen gas concentration sensor comprising a first electrode piece and a second electrode piece, an electrolyte in which the electrodes are disposed apart from each other, and a container for accommodating the first electrode piece, the second electrode piece, and the electrolyte, the first electrode piece comprising a first electrode material having a standard electromotive force value of 0.8 V or more in a cell constituted of H 2 (-)
- a hydrogen gas concentration sensor characterized in that hydrogen gas diffuses into the container through the gap to form a three-phase interface of hydrogen gas/electrolyte/first electrode piece.
- the hydrogen gas sensor according to (3) characterized in that the gap is formed by pores of a porous material that closes the container end of the container.
- the second electrode material includes at least one of tungsten, a tungsten alloy, nickel, a nickel alloy, titanium, a titanium alloy, copper, a copper alloy, iron, an iron alloy, aluminum, an aluminum alloy, and a material containing these.
- the present invention provides a hydrogen gas concentration sensor with a novel configuration that can detect the hydrogen gas concentration present in special gases and liquids in high temperature and high humidity environments, such as those used in the chemical industry, and is used as a hydrogen concentration sensor for controlling hydrogen fuel cells.
- FIG. 1 is a schematic diagram of a hydrogen gas concentration sensor according to an embodiment.
- 11 is a graph showing EMF values when a platinum wire is used as a first electrode piece of a hydrogen gas concentration sensor in an example.
- Figure 1 is a schematic diagram of a hydrogen gas concentration sensor in this embodiment.
- the hydrogen gas concentration sensor 10 of this embodiment includes a linear first electrode piece 11, a linear second electrode piece 12, an electrolyte 14 in which the electrodes are arranged at a distance from each other, and a container 15 having an opening 15A formed at one end (container end) that contains the first electrode piece 11, the second electrode piece 12, and the electrolyte 14.
- the end of the first electrode piece 11, i.e., the electrode end piece 11A, is exposed to the outside from the opening piece 15A.
- a gap H is formed between the first electrode piece 11 and the opening piece 15A, which is the end of the container.
- the exposed length of the first electrode end piece 11A is extremely short, and may be, for example, several ⁇ m to several tens of ⁇ m, and a porous material that is permeable to hydrogen gas and the like may be disposed on the first electrode end piece 11A.
- the tip of the container 15, i.e., the hydrogen gas concentration sensor 10, specifically the opening 15A, is inserted into the system to be measured, i.e., the hydrogen gas-containing medium, the hydrogen gas to be measured and other gases depending on the environment are diffused into the container 15. As a result, a three-phase interface of hydrogen gas/electrolyte/first electrode piece is formed inside the container 15.
- the first electrode piece 11 functions as a detection electrode for hydrogen gas, and when it comes into contact with hydrogen gas, the chemical potential of (atomic) hydrogen changes significantly.
- the second electrode piece 12 functions as a reference electrode for hydrogen gas, and when it comes into contact with hydrogen gas, its chemical potential changes very little, or if it does change, it is very small.
- the first electrode piece 11 can be made of a first electrode material having a relatively high chemical potential, specifically including a first electrode material having a standard electromotive force value of 0.8 V or more when made of H 2 (-)
- the above-mentioned materials include platinum, platinum alloys, and other materials that have a relatively high adsorption activity for hydrogen gas.
- the first electrode piece 11 can be made of these materials themselves, but these materials can also be used by supporting them on a specified substrate. However, as long as it does not deviate from the scope of the present invention and functions as a detection electrode for hydrogen gas, it can be used in any form.
- the first electrode piece 11 When the first electrode piece 11 is made of a platinum-based material, hydrogen molecules are dissociated, so the hydrogen gas adsorbed on the first electrode piece 11 is quickly released, making it suitable as a detection electrode for a fast-response hydrogen gas concentration sensor, such as a fuel cell control sensor or a hydrogen gas concentration sensor for hydrogen gas dissolved in medical fluids.
- a fast-response hydrogen gas concentration sensor such as a fuel cell control sensor or a hydrogen gas concentration sensor for hydrogen gas dissolved in medical fluids.
- the second electrode piece 12 can be made of a material with a relatively low chemical potential, specifically, a second electrode material in which the standard electromotive force value of a cell made of H 2 (-)
- the above-mentioned materials include materials with relatively low adsorption activity for hydrogen gas, such as tungsten, tungsten alloys, nickel, nickel alloys, titanium, titanium alloys, copper, copper alloys, iron, iron alloys, aluminum, aluminum alloys, and organic conductive materials.
- the second electrode piece 12 can be made of these materials themselves, but these materials can also be used by supporting them on a specified substrate. However, as long as it does not deviate from the scope of the present invention and functions as a reference electrode for hydrogen gas, it can be used in any manner.
- the electrolyte 14 can be composed of an electrolyte that has excellent adhesion to the first electrode 21 and the second electrode 22, such as phosphotungstic acid.
- the electrolyte 14 can contain a structural reinforcing material such as glass wool in addition to an electrolyte material such as phosphotungsten. In this case, the strength of the electrolyte 14 can be increased, and the adhesion to the first electrode piece 11 and the second electrode piece 12 can be further increased.
- the container 15 is preferably made of glass, resin, ceramics, etc. to ensure insulation between the first electrode piece 11 and the second electrode piece 12.
- the container 15 is made of an electrically conductive material such as metal, it is preferable to insulate the first electrode piece 11 from the container 15 by coating it with resin or ceramic.
- the hydrogen gas concentration sensor 10 of this embodiment includes a first electrode piece 11 and a second electrode piece 12, an electrolyte 14 between which the electrodes are spaced apart, and a container 15 for accommodating the first electrode piece 11, the second electrode piece 12, and the electrolyte 14.
- the first electrode piece 11 includes a first electrode material having a standard electromotive force value of 0.8 V or more when the cell is composed of H 2 (-)
- the second electrode piece 12 includes a second electrode material having a standard electromotive force value of less than 0.8 V when the cell has the same configuration.
- the first electrode piece 11 penetrates the electrolyte 14, and an end of the first electrode piece 11 is exposed to the outside from the container 15.
- Hydrogen gas from the hydrogen gas-containing medium to be measured diffuses into the container 15, and a three-phase interface of hydrogen gas/electrolyte/first electrode piece is formed in the container 15.
- the exposed length of the first electrode end 11A may be as short as possible, for example, on the order of microns, and a porous material that allows hydrogen gas and the like to permeate may be disposed on the first electrode end 11A.
- the hydrogen gas concentration in the hydrogen gas-containing medium can be detected.
- the opening 15A of the container 15 into the hydrogen gas-containing medium, the hydrogen gas in the medium, and other gases depending on the environment, diffuse into the container 15, and the concentration of the hydrogen gas can be measured.
- the opening 15A is not sealed by the first electrode piece 11, but a gap H must be formed between the opening 15A and the first electrode piece 11 as described above.
- the size of the gap H is not particularly limited, but it is preferable that, for example, when the opposite side 15B of the container 15 to the opening 15A, which is the container end, is opened to atmospheric pressure, and when the inside of the opposite side 15B of the container 15 is at atmospheric pressure and the hydrogen concentration is 85 vol%, the equilibrium hydrogen gas concentration of the hydrogen gas that diffuses through the gap H and leaks out of the container 15 from the opening 15A is 0.01 vol% or more and 10 vol% or less. This allows the amount of hydrogen gas present in the container 15 to be set within a range in which the hydrogen gas concentration sensor 10 of the present invention operates appropriately.
- the void H as described above can be formed, for example, by utilizing the difference in thermal expansion between the material constituting the container 15 and the first electrode material constituting the first electrode piece 11. Other methods include making grooves on the side of the first electrode piece 11, or preparing multiple first electrode pieces 11 and twisting them together. It can also be formed by applying porous plating to the surface of the first electrode piece 11, or coating the surface of the first electrode piece 11 with porous ceramics/zeolite or ceramic fine particles. On the other hand, the void H can be formed from pores of a porous material that blocks the opening 15A of the container 15. Examples of such materials include polymer membranes, porous ceramics, and zeolites.
- a linear temperature compensation third electrode 13 is provided to eliminate the influence of the environmental temperature.
- This third electrode 13 is also provided so as to be separated from the first electrode 11 and the second electrode 12 with respect to the electrolyte 14.
- the third electrode 13 is a temperature compensation electrode, and is provided to offset the environmental temperature of the hydrogen gas concentration sensor 10, i.e., the environmental temperature change of the first electrode 11, which is the detection electrode, so it is preferable to make the third electrode from the same material as the first electrode 11.
- the third electrode can also function to detect the concentration of hydrogen gas diffused within the container 15B.
- the first electrode 11, the second electrode 12, and the third electrode 13 are arranged to extend outward from the rear end opening of the container 15 on the side opposite the sealed portion of the container 15 in order to measure the electromotive force associated with the detection of hydrogen gas concentration.
- the hydrogen concentration of the hydrogen gas concentration sensor 10 of this embodiment is detected by the electromotive force generated between the first electrode piece 11 and the second electrode piece 12, and this electromotive force is generated based on the following relational expression:
- E is the EMF value
- ⁇ I represents the electrostatic potential of the first electrode
- ⁇ II represents the electrostatic potential of the second electrode.
- the temperature compensation by the third electrode piece 13 is expressed as follows: ( ⁇ : adsorption energy, k: Boltzmann constant, T: temperature, n: hydrogen concentration), and this can be implemented by subtracting this E value from the above-mentioned EMF value.
- n is 0.01 or more
- the above-mentioned E value becomes extremely small, so there is no need to consider temperature compensation, and the third electrode piece 13 itself can be omitted.
- a hydrogen gas concentration sensor 10 as shown in Figure 1 was prepared, and a simple hydrogen gas detection test was carried out.
- the first electrode piece 11 was made of platinum wire with a diameter of 0.2 mm
- the second electrode piece 12 was made of tungsten wire with a diameter of 0.2 mm.
- the third electrode piece 13 was omitted.
- the first electrode piece 11 and the second electrode piece 12 were then placed in an electrolyte 14 made of cesium tungsten phosphate with a gap of 0.2 mm between them.
- the first electrode piece 11, the second electrode piece 12 and the electrolyte 14 were then placed in a glass tube 15 with a diameter of 6 mm and a length of 25 mm, and the first electrode piece 11 was exposed at a length of 3 mm from the opening 15A of the glass tube 15.
- FIG 2 shows the detection voltage (V) when a platinum wire is used as the first electrode piece 11.
- V the detection voltage
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Oxygen Concentration In Cells (AREA)
Abstract
[Problem] The present invention provides a hydrogen gas concentration sensor which has a novel configuration and is capable of sensing the concentration of a hydrogen gas that is present in a gas or in a liquid. [Solution] The present invention comprises a first electrode piece, a second electrode piece, an electrolyte in which the electrode pieces are disposed apart from each other, and a container which houses the first electrode piece, the second electrode piece and the electrolyte. The first electrode piece contains a first electrode material exhibiting a standard electromotive force value of 0.8 V or more in a cell having the configuration of H2(-) |50 mol/m3 H2SO4| a substance sample (+); the second electrode contains a second electrode material exhibiting a standard electromotive force value of less than 0.8 V in a cell having the same configuration; the first electrode piece penetrates through the electrolyte and has an end that is exposed to the outside from the container; and a void space is formed between the first electrode piece and the container end.
Description
本発明は、水素ガス濃度センサに関する。
The present invention relates to a hydrogen gas concentration sensor.
今後の水素エネルギー利用社会において水素爆発の危険性を払拭し安全性が高く、利便性に優れた水素エネルギー利用システムの構築が望まれる。水素ガスセンサの仕様は、大気中に漏れた水素量を瞬時に高精度で検出でき、構造がきわめて単純、信頼性が高いことが求められる。
As hydrogen energy becomes more widely used in the future, it is desirable to build a hydrogen energy utilization system that eliminates the risk of hydrogen explosions and is both safe and convenient. The specifications for the hydrogen gas sensor must be able to instantly detect the amount of hydrogen that has leaked into the atmosphere with high accuracy, have an extremely simple structure, and be highly reliable.
一方で、自動車・重機などの水素燃料電池の制御用水素濃度センサ（水素ガスの効率利用）、発電機軸受用の潤滑油やトランスオイルなど液中用の水素濃度センサ（水素ガスの溶解量やオイル劣化による水素ガス量の検知）や腎臓透析などの医療薬液中の水素濃度センサ（水素を溶存することで治療効果を促進）、水素水など溶液中の水素濃度センサ、化学工業などでのプロセス制御用水素濃度センサの開発が望まれている。
On the other hand, there is a demand for the development of hydrogen concentration sensors for controlling hydrogen fuel cells in automobiles and heavy machinery (efficient use of hydrogen gas), hydrogen concentration sensors for liquids such as lubricating oil for generator bearings and transformer oil (detecting the amount of hydrogen gas dissolved and the amount of hydrogen gas due to oil deterioration), hydrogen concentration sensors in medical fluids such as kidney dialysis (dissolving hydrogen promotes therapeutic effects), hydrogen concentration sensors in solutions such as hydrogen water, and hydrogen concentration sensors for process control in the chemical industry, etc.
従来の水素ガス濃度センサは半導体型、電離型、燃焼型などの検出方法に基づいている。これらの測定原理は「示量性の物理量」である"キャリア濃度（半導体型）"、"イオン濃度（電離型）"、あるいは"反応熱（燃焼型または燃焼させてその水蒸気圧を測定する）"として間接的な検出方法で水素量を検知し、それらを電気的な量に変換してセンサとするものであった。
Conventional hydrogen gas concentration sensors are based on detection methods such as semiconductor, ionization, and combustion. The measurement principle of these is to detect the amount of hydrogen indirectly as an "extensive physical quantity" such as "carrier concentration (semiconductor type)," "ion concentration (ionization type)," or "reaction heat (combustion type or burning and measuring the water vapor pressure)," and convert these into electrical quantities to use as sensors.
したがって、高温高湿度環境下での水素濃度検知やオイルや薬液などの液体に適用することはできず、当然にこれら液体中に溶存した水素ガスの濃度の検出に適用することはできなかった。
Therefore, it cannot be used to detect hydrogen concentration in high temperature and humidity environments, or in liquids such as oil or chemical solutions, and naturally cannot be used to detect the concentration of hydrogen gas dissolved in these liquids.
検出時間を短縮化する水素ガス濃度センサとしては、例えば、互いに水素に対する化学ポテンシャルが異なる材料からなる第１の電極及び第２の電極と、これらの電極と接触する電解質とを備え、これら電極間に発生する起電力値に基づいて水素ガスを検出する水素ガスセンサが提案されている（特許文献１）。
As an example of a hydrogen gas concentration sensor that shortens the detection time, a hydrogen gas sensor has been proposed that includes a first electrode and a second electrode made of materials with different chemical potentials relative to hydrogen, and an electrolyte in contact with these electrodes, and detects hydrogen gas based on the electromotive force value generated between these electrodes (Patent Document 1).
しかしながら、特許文献１に記載の当該水素ガスセンサは、第１電極、第２電極及び電解質が外皮で覆われているため、当該水素ガスセンサを液体中の溶存水素ガス濃度を測定するようにするためには、少なくとも検出電極である第１電極を外皮から露出させて上記液体中に浸漬させる必要がある一方、電解質は液体からシールしなければならない。したがって、水素ガスセンサの構造が複雑になるとともに、シール方法に技術的及び経済的な課題があった。
However, in the hydrogen gas sensor described in Patent Document 1, the first electrode, second electrode, and electrolyte are covered with an outer skin, so in order to use the hydrogen gas sensor to measure the concentration of dissolved hydrogen gas in a liquid, at least the first electrode, which is the detection electrode, needs to be exposed from the outer skin and immersed in the liquid, while the electrolyte needs to be sealed from the liquid. This makes the structure of the hydrogen gas sensor complex, and the sealing method poses technical and economic challenges.
本発明は、高温高湿度環境下、化学工業などでの特殊ガス中や液体中などの環境に存在する水素ガス濃度を検出することが可能な新規な構成の水素ガス濃度センサを提供することを目的とする。
The present invention aims to provide a hydrogen gas concentration sensor with a novel configuration that can detect the concentration of hydrogen gas present in environments such as high temperature and high humidity environments, and in special gases and liquids in the chemical industry.
本発明は、以下に示す通りである。（１）第１電極片及び第２電極片と、これら電極片が離隔して配設された電解質と、前記第１電極片、前記第２電極片及び前記電解質を収容する容器と、を備え、 前記第１電極片は、Ｈ2（－）｜５０ｍｏｌ／ｍ3Ｈ2ＳＯ4｜物質試料（＋）で構成したセルの標準起電力値が０．８Ｖ以上の値を示す第１電極材料を含み、 前記第２電極は、同構成でのセルでの標準起電力値が０．８Ｖ未満の値を示す第２電極材料を含み、 前記第１電極片は、前記電解質を貫通し、前記第1電極片の電極端部が前記容器の容器端部から外部に露出しており、 前記第１電極片と前記容器端部との間には空隙が形成されていることを特徴とする、水素ガス濃度センサ。（２）前記空隙を介して、前記容器内に水素ガスが拡散することにより、水素ガス／電解質／第１電極片の３相界面が形成されていることを特徴とする、（１）に記載の水素ガス濃度センサ。（３）前記空隙の大きさは、前記容器の、前記容器端部の反対側を大気圧に開放した際に、前記容器の当該反対側の容器内を大気圧及び８５ｖｏｌ％の水素濃度としたとき、前記空隙を拡散して容器外部に漏洩する水素ガスの平衡水素ガス濃度量が０．０１ｖｏｌ％以上１０ｖｏｌ％以下となることを特徴とする（１）又は（２）に記載の水素ガス濃度センサ。（４）前記空隙は、前記容器の前記容器端部を閉塞する多孔質材料の気孔によって形成されていることを特徴とする（３）に記載の水素ガスセンサ。（５）前記第１電極材料は、白金、白金合金及びこれらを含む材料の少なくとも１つを含むことを特徴とする、（１）ないし（４）のいずれか一つに記載の水素ガス濃度センサ。（６）前記第２電極材料は、タングステン、タングステン合金、ニッケル、ニッケル合金、チタン、チタン合金、銅、銅合金、鉄、鉄合金、アルミニウム、アルミニウム合金及びこれらを含む材料の少なくとも１つを含むことを特徴とする、（１）ないし（５）のいずれか一つに記載の水素ガス濃度センサ。（７）前記容器内に収容され、前記電解質に配設された第３電極片を備えることを特徴とする、（１）ないし（６）のいずれか一つに記載の水素ガス濃度センサ。
The present invention is as follows. (1) A hydrogen gas concentration sensor comprising a first electrode piece and a second electrode piece, an electrolyte in which the electrodes are disposed apart from each other, and a container for accommodating the first electrode piece, the second electrode piece, and the electrolyte, the first electrode piece comprising a first electrode material having a standard electromotive force value of 0.8 V or more in a cell constituted of H 2 (-)|50 mol/m 3 H 2 SO 4 |substance sample (+), the second electrode comprising a second electrode material having a standard electromotive force value of less than 0.8 V in a cell of the same constitution, the first electrode piece penetrating the electrolyte, an electrode end of the first electrode piece being exposed to the outside from an end of the container, and a gap being formed between the first electrode piece and the end of the container. (2) A hydrogen gas concentration sensor according to (1), characterized in that hydrogen gas diffuses into the container through the gap to form a three-phase interface of hydrogen gas/electrolyte/first electrode piece. (3) The hydrogen gas concentration sensor according to (1) or (2), characterized in that, when the opposite side of the container end of the container is opened to atmospheric pressure, the equilibrium hydrogen gas concentration of hydrogen gas diffusing through the gap and leaking to the outside of the container is 0.01 vol% or more and 10 vol% or less when the inside of the container on the opposite side of the container is at atmospheric pressure and the hydrogen concentration is 85 vol%. (4) The hydrogen gas sensor according to (3), characterized in that the gap is formed by pores of a porous material that closes the container end of the container. (5) The hydrogen gas concentration sensor according to any one of (1) to (4), characterized in that the first electrode material includes at least one of platinum, a platinum alloy, and a material containing these. (6) The hydrogen gas concentration sensor according to any one of (1) to (5), characterized in that the second electrode material includes at least one of tungsten, a tungsten alloy, nickel, a nickel alloy, titanium, a titanium alloy, copper, a copper alloy, iron, an iron alloy, aluminum, an aluminum alloy, and a material containing these. (7) A hydrogen gas concentration sensor according to any one of (1) to (6), further comprising a third electrode piece housed in the container and disposed in the electrolyte.
本発明によれば、水素燃料電池の制御用水素濃度センサで用いられる高温高湿度環境下、化学工業などの特殊ガス中や液体中に存在する水素ガス濃度を検出することが可能な新規な構成の水素ガス濃度センサを提供することができる。
The present invention provides a hydrogen gas concentration sensor with a novel configuration that can detect the hydrogen gas concentration present in special gases and liquids in high temperature and high humidity environments, such as those used in the chemical industry, and is used as a hydrogen concentration sensor for controlling hydrogen fuel cells.
図１は、本実施形態における水素ガス濃度センサの概略構成図である。
Figure 1 is a schematic diagram of a hydrogen gas concentration sensor in this embodiment.
図１に示すように、本実施形態の水素ガス濃度センサ１０は、線状の第１電極片１１及び線状の第２電極片１２と、これら電極片が離隔して配設された電解質１４と、第１電極片１１、第２電極片１２及び電解質１４とを収容する、一端（容器端部）に開口部１５Ａが形成された容器１５とを備えている。第１電極片１１の端部、すなわち電極端部１１Ａは、開口部１５Ａから外部に露出している。また、第1電極片１１と容器端部である開口部１５Ａとの間には空隙Hが形成されている。ここで、第１電極端部１１Ａの露出させる長さは限りなく短く、例えば数μｍから数十μｍ程度であってもよく、第１電極端部１１Ａに水素ガスなどを透過する多孔質材料が配設されていてもよい。
As shown in FIG. 1, the hydrogen gas concentration sensor 10 of this embodiment includes a linear first electrode piece 11, a linear second electrode piece 12, an electrolyte 14 in which the electrodes are arranged at a distance from each other, and a container 15 having an opening 15A formed at one end (container end) that contains the first electrode piece 11, the second electrode piece 12, and the electrolyte 14. The end of the first electrode piece 11, i.e., the electrode end piece 11A, is exposed to the outside from the opening piece 15A. A gap H is formed between the first electrode piece 11 and the opening piece 15A, which is the end of the container. Here, the exposed length of the first electrode end piece 11A is extremely short, and may be, for example, several μm to several tens of μm, and a porous material that is permeable to hydrogen gas and the like may be disposed on the first electrode end piece 11A.
したがって、容器１５、すなわち水素ガス濃度センサ１０は、その先端部、具体的には開口部１５Ａを測定したい系、すなわち水素ガス含有媒体中に挿入した際において、容器１５内には測定したい水素ガス、及び環境に応じてその他のガスが拡散するようになっている。この結果、容器１５内には、水素ガス／電解質／第１電極片の３相界面が形成されるようになる。
Therefore, when the tip of the container 15, i.e., the hydrogen gas concentration sensor 10, specifically the opening 15A, is inserted into the system to be measured, i.e., the hydrogen gas-containing medium, the hydrogen gas to be measured and other gases depending on the environment are diffused into the container 15. As a result, a three-phase interface of hydrogen gas/electrolyte/first electrode piece is formed inside the container 15.
第１電極片１１は、水素ガスに対する検出電極として機能し、水素ガスと接触することによって、（原子状）水素の化学ポテンシャルが大きく変化する。第２電極片１２は、水素ガスに対する基準電極として機能し、水素ガスと接触することによって、その化学ポテンシャルがほとんど変化しないか、変化するとしても極微小である。
The first electrode piece 11 functions as a detection electrode for hydrogen gas, and when it comes into contact with hydrogen gas, the chemical potential of (atomic) hydrogen changes significantly. The second electrode piece 12 functions as a reference electrode for hydrogen gas, and when it comes into contact with hydrogen gas, its chemical potential changes very little, or if it does change, it is very small.
第１電極片１１は、相対的に化学ポテンシャルの高い第１電極材料から構成することができ、具体的にはＨ2（－）｜５０ｍｏｌ／ｍ3Ｈ2ＳＯ4｜物質試料（＋）で構成したセルの標準起電力値が０．８Ｖ以上の値を示す第１電極材料を含む。
The first electrode piece 11 can be made of a first electrode material having a relatively high chemical potential, specifically including a first electrode material having a standard electromotive force value of 0.8 V or more when made of H 2 (-) | 50 mol/m 3 H 2 SO 4 | substance sample (+).
上述した材料としては、白金、白金合金等の、相対的に水素ガスに対する吸着活性度の高い材料を挙げることができる。第１電極片１１は、これら材料自身から構成することもできるが、これらの材料を所定の基体上に担持させて用いることができる。但し、本発明の範疇を逸脱せず、水素ガスに対する検出電極として機能する限り、任意の態様で使用することができる。
The above-mentioned materials include platinum, platinum alloys, and other materials that have a relatively high adsorption activity for hydrogen gas. The first electrode piece 11 can be made of these materials themselves, but these materials can also be used by supporting them on a specified substrate. However, as long as it does not deviate from the scope of the present invention and functions as a detection electrode for hydrogen gas, it can be used in any form.
第１電極片１１を白金系の材料から構成した場合は、水素分子を解離することから、第１電極片１１に吸着した水素ガスの離脱が早く、燃料電池の制御用センサや医療薬液等に溶存する水素ガス濃度センサなど、応答性の早い水素ガス濃度センサの検出電極として適している。
When the first electrode piece 11 is made of a platinum-based material, hydrogen molecules are dissociated, so the hydrogen gas adsorbed on the first electrode piece 11 is quickly released, making it suitable as a detection electrode for a fast-response hydrogen gas concentration sensor, such as a fuel cell control sensor or a hydrogen gas concentration sensor for hydrogen gas dissolved in medical fluids.
第２電極片１２は、相対的に化学ポテンシャルの低い材料から構成することができ、具体的には、Ｈ2（－）｜５０ｍｏｌ／ｍ3Ｈ2ＳＯ4｜物質試料（＋）で構成したセルの標準起電力値が０．８Ｖ未満の値を示す第２電極材料を含む。
The second electrode piece 12 can be made of a material with a relatively low chemical potential, specifically, a second electrode material in which the standard electromotive force value of a cell made of H 2 (-) | 50 mol/m 3 H 2 SO 4 | substance sample (+) is less than 0.8 V.
上述した材料としては、タングステン、タングステン合金、ニッケル、ニッケル合金、チタン、チタン合金、銅、銅合金、鉄、鉄合金、アルミニウム、アルミニウム合金及び有機導電材料などの、相対的に水素ガスに対する吸着活性度合いの低い材料を挙げることができる。第２電極片１２は、これら材料自身から構成することもできるが、これらの材料を所定の基体上に担持させて用いることができる。但し、本発明の範疇を逸脱せず、水素ガスに対する基準電極として機能する限り、任意の態様で使用することができる。
The above-mentioned materials include materials with relatively low adsorption activity for hydrogen gas, such as tungsten, tungsten alloys, nickel, nickel alloys, titanium, titanium alloys, copper, copper alloys, iron, iron alloys, aluminum, aluminum alloys, and organic conductive materials. The second electrode piece 12 can be made of these materials themselves, but these materials can also be used by supporting them on a specified substrate. However, as long as it does not deviate from the scope of the present invention and functions as a reference electrode for hydrogen gas, it can be used in any manner.
電解質１４は、燐タングステン酸などの、第１電極２１及び第２電極２２との密着性に優れた電解質から構成することができる。電解質１４は、燐タングステンなどの電解質材料に加えてグラスウールなどの構造補強材を含むことができる。この場合、電解質１４の強度を増大させることができるとともに、第１電極片１１及び第２電極片１２との密着性をさらに増大させることができる。
The electrolyte 14 can be composed of an electrolyte that has excellent adhesion to the first electrode 21 and the second electrode 22, such as phosphotungstic acid. The electrolyte 14 can contain a structural reinforcing material such as glass wool in addition to an electrolyte material such as phosphotungsten. In this case, the strength of the electrolyte 14 can be increased, and the adhesion to the first electrode piece 11 and the second electrode piece 12 can be further increased.
容器１５は、第１電極片１１及び第２電極片１２との絶縁を担保すべく、ガラスや樹脂、セラミックス等から構成することが好ましい。
The container 15 is preferably made of glass, resin, ceramics, etc. to ensure insulation between the first electrode piece 11 and the second electrode piece 12.
なお、容器１５を金属等の電気伝導性の材料から構成した場合は、第１電極片１１を樹脂やセラミック被覆等して容器１５と絶縁することが好ましい。
If the container 15 is made of an electrically conductive material such as metal, it is preferable to insulate the first electrode piece 11 from the container 15 by coating it with resin or ceramic.
本実施形態の水素ガス濃度センサ１０によれば、第１電極片１１及び第２電極片１２と、これら電極片が離隔して配設された電解質１４と、第１電極片１１、第２電極片１２及び電解質１４を収容する容器１５と、を備え、第１電極片１１は、Ｈ2（－）｜５０ｍｏｌ／ｍ3Ｈ2ＳＯ4｜物質試料（＋）で構成したセルの標準起電力値が０．８Ｖ以上の値を示す第１電極材料を含む。第２電極片１２は、同構成でのセルでの標準起電力値が０．８Ｖ未満の値を示す第２電極材料を含み、第１電極片１１は、電解質１４を貫通し、端部が容器１５から外部に露出している。また、容器１５内には測定したい水素ガス含有媒体からの水素ガスが拡散し、容器１５内には、水素ガス／電解質／第１電極片の３相界面が形成されている。上述のように、第１電極端部１１Ａの露出させる長さは限りなく短く、例えばミクロン程度であってもよく、第１電極端部１１Ａに水素ガスなどを透過する多孔質材料が配設されていてもよい。
The hydrogen gas concentration sensor 10 of this embodiment includes a first electrode piece 11 and a second electrode piece 12, an electrolyte 14 between which the electrodes are spaced apart, and a container 15 for accommodating the first electrode piece 11, the second electrode piece 12, and the electrolyte 14. The first electrode piece 11 includes a first electrode material having a standard electromotive force value of 0.8 V or more when the cell is composed of H 2 (-)|50 mol/m 3 H 2 SO 4 |substance sample (+). The second electrode piece 12 includes a second electrode material having a standard electromotive force value of less than 0.8 V when the cell has the same configuration. The first electrode piece 11 penetrates the electrolyte 14, and an end of the first electrode piece 11 is exposed to the outside from the container 15. Hydrogen gas from the hydrogen gas-containing medium to be measured diffuses into the container 15, and a three-phase interface of hydrogen gas/electrolyte/first electrode piece is formed in the container 15. As described above, the exposed length of the first electrode end 11A may be as short as possible, for example, on the order of microns, and a porous material that allows hydrogen gas and the like to permeate may be disposed on the first electrode end 11A.
したがって、容器１５内において、第１電極片１１及び第２電極片１２の起電力差を計測することにより、水素ガス含有媒体中の水素ガス濃度を検出することができる。換言すれば、容器１５の開口部１５Ａを水素ガス含有媒体中に挿入するのみで、当該媒体中の水素ガス、及び環境に応じてその他のガスが容器１５内に拡散し、当該水素ガスの濃度を測定することができる。
Therefore, by measuring the electromotive force difference between the first electrode piece 11 and the second electrode piece 12 in the container 15, the hydrogen gas concentration in the hydrogen gas-containing medium can be detected. In other words, simply by inserting the opening 15A of the container 15 into the hydrogen gas-containing medium, the hydrogen gas in the medium, and other gases depending on the environment, diffuse into the container 15, and the concentration of the hydrogen gas can be measured.
なお、開口部１５Ａは、第１電極片１１で密封するのではなく、上述のように第１電極片１１との間で空隙Ｈを形成する必要がある。空隙Ｈの大きさは特に限定されるものではないが、例えば、容器１５の、容器端部である開口部１５Ａの反対側１５Ｂを大気圧に開放した際に、容器１５の反対側１５Ｂ内を大気圧及び８５ｖｏｌ％の水素濃度としたとき、空隙Ｈを拡散して開口部１５Ａから容器１５の外部に漏洩する水素ガスの平衡水素ガス濃度量が０．０１ｖｏｌ％以上１０ｖｏｌ％以下となるようにすることが好ましい。これによって、容器１５内に存在する水素ガ
スの量を、本発明の水素ガス濃度センサ１０が適切に駆動する範囲に設定することができる。 The opening 15A is not sealed by the first electrode piece 11, but a gap H must be formed between the opening 15A and the first electrode piece 11 as described above. The size of the gap H is not particularly limited, but it is preferable that, for example, when the opposite side 15B of the container 15 to the opening 15A, which is the container end, is opened to atmospheric pressure, and when the inside of the opposite side 15B of the container 15 is at atmospheric pressure and the hydrogen concentration is 85 vol%, the equilibrium hydrogen gas concentration of the hydrogen gas that diffuses through the gap H and leaks out of the container 15 from the opening 15A is 0.01 vol% or more and 10 vol% or less. This allows the amount of hydrogen gas present in the container 15 to be set within a range in which the hydrogen gas concentration sensor 10 of the present invention operates appropriately.
スの量を、本発明の水素ガス濃度センサ１０が適切に駆動する範囲に設定することができる。 The opening 15A is not sealed by the first electrode piece 11, but a gap H must be formed between the opening 15A and the first electrode piece 11 as described above. The size of the gap H is not particularly limited, but it is preferable that, for example, when the opposite side 15B of the container 15 to the opening 15A, which is the container end, is opened to atmospheric pressure, and when the inside of the opposite side 15B of the container 15 is at atmospheric pressure and the hydrogen concentration is 85 vol%, the equilibrium hydrogen gas concentration of the hydrogen gas that diffuses through the gap H and leaks out of the container 15 from the opening 15A is 0.01 vol% or more and 10 vol% or less. This allows the amount of hydrogen gas present in the container 15 to be set within a range in which the hydrogen gas concentration sensor 10 of the present invention operates appropriately.
上述のような空隙Hは、例えば、容器１５を構成する材料と、第１電極片１１を構成する第１電極材料との熱膨張の差異を利用して形成することができる。また、第１電極片１１の側面に溝をつけることや、複数の第１電極片１１を準備し、これらを撚り合わせる方法がある。また、第１電極片１１の表面に多孔質メッキを施すことや、第１電極片１１の表面を多孔質セラミックス・ゼオライト被覆でしたり、セラミックス微粒子被覆したりすることでも形成することができる。他方、空隙Ｈは、容器１５の開口部１５Ａを閉塞するような多孔質材料の気孔から構成することができる。このような材料として、高分子膜、多孔質セラミックスやゼオライトなどがある。
The void H as described above can be formed, for example, by utilizing the difference in thermal expansion between the material constituting the container 15 and the first electrode material constituting the first electrode piece 11. Other methods include making grooves on the side of the first electrode piece 11, or preparing multiple first electrode pieces 11 and twisting them together. It can also be formed by applying porous plating to the surface of the first electrode piece 11, or coating the surface of the first electrode piece 11 with porous ceramics/zeolite or ceramic fine particles. On the other hand, the void H can be formed from pores of a porous material that blocks the opening 15A of the container 15. Examples of such materials include polymer membranes, porous ceramics, and zeolites.
なお、本発明の水素ガス濃度センサ１０は、環境温度に依存して検出感度が変化するので、当該環境温度による影響を除去すべく、線状の温度補償用第３電極片１３が配設されている。この第３電極片１３も電解質１４に対して、第１電極片１１及び第２電極片１２と離隔するようにして配設されている。第３電極片１３は、温度補償用の電極片であり、水素ガス濃度センサ１０の環境温度、すなわち検出電極である第１電極片１１の環境温度変化を相殺するために配設されているものであるので、第１電極片１１と同じ材料から構成することが好ましい。なお、第３電極片は、上述のような温度補償用電極片以外に、容器１５Ｂ内に拡散した水素ガス濃度検知の機能にも奏することができる。
In addition, since the detection sensitivity of the hydrogen gas concentration sensor 10 of the present invention changes depending on the environmental temperature, a linear temperature compensation third electrode 13 is provided to eliminate the influence of the environmental temperature. This third electrode 13 is also provided so as to be separated from the first electrode 11 and the second electrode 12 with respect to the electrolyte 14. The third electrode 13 is a temperature compensation electrode, and is provided to offset the environmental temperature of the hydrogen gas concentration sensor 10, i.e., the environmental temperature change of the first electrode 11, which is the detection electrode, so it is preferable to make the third electrode from the same material as the first electrode 11. In addition to functioning as a temperature compensation electrode as described above, the third electrode can also function to detect the concentration of hydrogen gas diffused within the container 15B.
第１電極片１１、第２電極片１２及び第３電極片１３は、水素ガス濃度の検出に伴う起電力を測定すべく、容器１５の密閉部と反対側の容器１５の後端開口部より、容器１５の外方に延在するようにして配設されている。
The first electrode 11, the second electrode 12, and the third electrode 13 are arranged to extend outward from the rear end opening of the container 15 on the side opposite the sealed portion of the container 15 in order to measure the electromotive force associated with the detection of hydrogen gas concentration.
なお、本実施形態の水素ガス濃度センサ１０の水素濃度は、第１電極片１１及び第２電極片１２間に発生する起電力によって検出することになるが、当該起電力は以下の関係式に基づいて生成される。
The hydrogen concentration of the hydrogen gas concentration sensor 10 of this embodiment is detected by the electromotive force generated between the first electrode piece 11 and the second electrode piece 12, and this electromotive force is generated based on the following relational expression:
以下に実施例を挙げて本発明をより具体的に説明するが、本発明はこれらに限定されない。
The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these.
図１に示す水素ガス濃度センサ１０を準備し、簡易的に水素ガスの検出試験を実施した。なお、第１電極片１１は直径０，２ｍｍの白金線を使用し、第２電極片１２は直径０．２ｍｍのタングステン線を使用した。また、簡略化のために第３電極片１３は省略した。
A hydrogen gas concentration sensor 10 as shown in Figure 1 was prepared, and a simple hydrogen gas detection test was carried out. The first electrode piece 11 was made of platinum wire with a diameter of 0.2 mm, and the second electrode piece 12 was made of tungsten wire with a diameter of 0.2 mm. For simplicity, the third electrode piece 13 was omitted.
次いで、第１電極片１１及び第２電極片１２を燐タングステン酸セシウムからなる電解質１４に０．２ｍｍの間隔をあけて配設し、さらに、第１電極片１１，第２電極片１２及び電解質１４を、直径６ｍｍ及び長さ２５ｍｍのガラス管１５内に収納して配設し、当該ガラス管１５の開口部１５Ａより、第１電極片１１を３ｍｍの長さで露出させた。
The first electrode piece 11 and the second electrode piece 12 were then placed in an electrolyte 14 made of cesium tungsten phosphate with a gap of 0.2 mm between them. The first electrode piece 11, the second electrode piece 12 and the electrolyte 14 were then placed in a glass tube 15 with a diameter of 6 mm and a length of 25 mm, and the first electrode piece 11 was exposed at a length of 3 mm from the opening 15A of the glass tube 15.
なお、容器１５の開口部１５Ａにおける空隙Hは、容器端部である開口部１５Ａの反対側１５Ｂを大気圧に開放した際に、容器１５の反対側１５Ｂ内を大気圧及び８５ｖｏｌ％の水素濃度としたとき、空隙Ｈを拡散して開口部１５Ａから容器１５の外部に漏洩する水素ガスの平衡水素ガス濃度量が０．０１ｖｏｌ％以上１０ｖｏｌ％以下となっていることを確認した。
It has been confirmed that when the opposite side 15B of the opening 15A of the container 15, which is the end of the container, is opened to atmospheric pressure, and when the inside of the opposite side 15B of the container 15 is at atmospheric pressure and the hydrogen concentration is 85 vol%, the equilibrium hydrogen gas concentration of the hydrogen gas that diffuses through the gap H and leaks from the opening 15A to the outside of the container 15 is 0.01 vol% or more and 10 vol% or less.
図２は、第１電極片１１として白金線を用いた場合の検出電圧（Ｖ）である。図２に示すように、第１電極片１１として白金線を用いた場合は、水素ガスの検出濃度が０ｖｏｌ％から１００ｖｏｌ％まで増加するにつれて、検出電圧が低下していることが分かるすなわち、応答性の早い水素ガス濃度センサの検出電極として適していることが分かる。
Figure 2 shows the detection voltage (V) when a platinum wire is used as the first electrode piece 11. As shown in Figure 2, when a platinum wire is used as the first electrode piece 11, it can be seen that the detection voltage decreases as the detected hydrogen gas concentration increases from 0 vol% to 100 vol%, which means that it is suitable as a detection electrode for a hydrogen gas concentration sensor with fast response.
以上、本発明のいくつかの実施形態を説明したが、これらの実施形態は例として掲示したものであり、発明の範囲を限定することは意図していない。これら新規な実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれるとともに、特許請求の範囲に記載された発明とその均等の範囲に含まれる。
Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.
１０ 水素ガス濃度センサ １１ 第１電極片 １２ 第２電極片 １３ 第３電極片 １４ 電解質 １５ 容器 １５Ａ 開口部 １５Ｂ 開放端
REFERENCE SIGNS LIST 10 Hydrogen gas concentration sensor 11 First electrode 12 Second electrode 13 Third electrode 14 Electrolyte 15 Container 15A Opening 15B Open end
REFERENCE SIGNS LIST 10 Hydrogen gas concentration sensor 11 First electrode 12 Second electrode 13 Third electrode 14 Electrolyte 15 Container 15A Opening 15B Open end
Claims (7)
- 第１電極片及び第２電極片と、これら電極片が離隔して配設された電解質と、前記第１電極片、前記第２電極片及び前記電解質を収容する容器と、を備え、 前記第１電極片は、Ｈ2（－）｜５０ｍｏｌ／ｍ3Ｈ2ＳＯ4｜物質試料（＋）で構成したセルの標準起電力値が０．８Ｖ以上の値を示す第１電極材料を含み、 前記第２電極は、同構成でのセルでの標準起電力値が０．８Ｖ未満の値を示す第２電極材料を含み、 前記第１電極片は、前記電解質を貫通し、前記第１電極片の電極端部が前記容器の容器端部から外部に露出しており、 前記第１電極片と前記容器端部との間には空隙が形成されていることを特徴とする、水素ガス濃度センサ。 A hydrogen gas concentration sensor comprising: a first electrode piece and a second electrode piece, an electrolyte in which the electrodes are arranged at a distance from each other, and a container for accommodating the first electrode piece, the second electrode piece, and the electrolyte, wherein the first electrode piece comprises a first electrode material having a standard electromotive force value of 0.8 V or more in a cell constituted of H 2 (-) | 50 mol/m 3 H 2 SO 4 | substance sample (+), the second electrode comprises a second electrode material having a standard electromotive force value of less than 0.8 V in a cell of the same constitution, the first electrode piece penetrates the electrolyte, and an electrode end of the first electrode piece is exposed to the outside from the container end, and a gap is formed between the first electrode piece and the container end.
- 前記空隙を介して、前記容器内に水素ガスが拡散し、水素ガス／電解質／第１電極片の３相界面が形成されていることを特徴とする、請求項１に記載の水素ガス濃度センサ。 The hydrogen gas concentration sensor of claim 1, characterized in that hydrogen gas diffuses into the container through the gap, forming a three-phase interface of hydrogen gas/electrolyte/first electrode piece.
- 前記空隙の大きさは、前記容器の、前記容器端部の反対側を大気圧に開放した際に、前記容器の当該反対側の容器内を大気圧及び８５ｖｏｌ％の水素濃度としたとき、前記空隙を拡散して容器外部に漏洩する水素ガスの平衡水素ガス濃度量が０．０１ｖｏｌ％以上１０ｖｏｌ％以下となることを特徴とする、請求項１又は２に記載の水素ガス濃度センサ。 The hydrogen gas concentration sensor according to claim 1 or 2, characterized in that the size of the gap is such that when the opposite side of the container to the container end is opened to atmospheric pressure, and the inside of the container on the opposite side of the container is at atmospheric pressure and a hydrogen concentration of 85 vol%, the equilibrium hydrogen gas concentration of hydrogen gas that diffuses through the gap and leaks outside the container is 0.01 vol% or more and 10 vol% or less.
- 前記空隙は、前記容器の前記容器端部を閉塞する多孔質材料の気孔によって形成されていることを特徴とする、請求項３に記載の水素ガスセンサ。 The hydrogen gas sensor of claim 3, characterized in that the gap is formed by pores in a porous material that blocks the container end of the container.
- 前記第１電極材料は、白金、白金合金及びこれらを含む材料の少なくとも１つを含むことを特徴とする、請求項１又は２に記載の水素ガス濃度センサ。 The hydrogen gas concentration sensor according to claim 1 or 2, characterized in that the first electrode material includes at least one of platinum, a platinum alloy, and a material containing these.
- 前記第２電極材料は、タングステン、タングステン合金、ニッケル、ニッケル合金、チタン、チタン合金、銅、銅合金、鉄、鉄合金、アルミニウム、アルミニウム合金及びこれらを含む材料の少なくとも１つを含むことを特徴とする、請求項１又は２に記載の水素ガス濃度センサ。 The hydrogen gas concentration sensor according to claim 1 or 2, characterized in that the second electrode material includes at least one of tungsten, tungsten alloy, nickel, nickel alloy, titanium, titanium alloy, copper, copper alloy, iron, iron alloy, aluminum, aluminum alloy, and materials containing these.
- 前記容器内に収容され、前記電解質に配設された第３電極片を備えることを特徴とする、請求項１又は２に記載の水素ガス濃度センサ。
3. The hydrogen gas concentration sensor according to claim 1, further comprising a third electrode piece housed in the container and disposed in the electrolyte.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022-172754 | 2022-10-27 | ||
| JP2022172754A JP2024064282A (en) | 2022-10-27 | 2022-10-27 | Hydrogen Gas Concentration Sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2024090472A1 true WO2024090472A1 (en) | 2024-05-02 |
Family
ID=90830919
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2023/038496 WO2024090472A1 (en) | 2022-10-27 | 2023-10-25 | Hydrogen gas concentration sensor |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2024064282A (en) |
| WO (1) | WO2024090472A1 (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005080957A1 (en) * | 2004-02-19 | 2005-09-01 | Niigata Tlo Corporation | Hydrogen gas sensor |
| JP2007047124A (en) * | 2005-08-12 | 2007-02-22 | Niigata Tlo:Kk | Hydrogen gas sensor |
| JP2012163506A (en) * | 2011-02-09 | 2012-08-30 | Gunze Ltd | In-oil hydrogen detection sensor |
| JP2017096659A (en) * | 2015-11-18 | 2017-06-01 | 三菱重工業株式会社 | Hydrogen concentration measurement device |
| JP2018084478A (en) * | 2016-11-24 | 2018-05-31 | 東京窯業株式会社 | Gas concentration detection method and solid electrolyte sensor |
| JP2022065582A (en) * | 2020-10-15 | 2022-04-27 | 株式会社新潟Tlo | Hydrogen gas concentration sensor for fuel cell |
| WO2022259883A1 (en) * | 2021-06-09 | 2022-12-15 | 株式会社新潟Tlo | Hydrogen gas concentration sensor |
-
2022
- 2022-10-27 JP JP2022172754A patent/JP2024064282A/en active Pending
-
2023
- 2023-10-25 WO PCT/JP2023/038496 patent/WO2024090472A1/en unknown
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005080957A1 (en) * | 2004-02-19 | 2005-09-01 | Niigata Tlo Corporation | Hydrogen gas sensor |
| JP2007047124A (en) * | 2005-08-12 | 2007-02-22 | Niigata Tlo:Kk | Hydrogen gas sensor |
| JP2012163506A (en) * | 2011-02-09 | 2012-08-30 | Gunze Ltd | In-oil hydrogen detection sensor |
| JP2017096659A (en) * | 2015-11-18 | 2017-06-01 | 三菱重工業株式会社 | Hydrogen concentration measurement device |
| JP2018084478A (en) * | 2016-11-24 | 2018-05-31 | 東京窯業株式会社 | Gas concentration detection method and solid electrolyte sensor |
| JP2022065582A (en) * | 2020-10-15 | 2022-04-27 | 株式会社新潟Tlo | Hydrogen gas concentration sensor for fuel cell |
| WO2022259883A1 (en) * | 2021-06-09 | 2022-12-15 | 株式会社新潟Tlo | Hydrogen gas concentration sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2024064282A (en) | 2024-05-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4264424A (en) | Hydrogen ion sensor having a membrane sheath of an oxygen ion conducting ceramic | |
| CA1295219C (en) | Method and apparatus for detecting hydrogen-containing or hydrogen-reactive gases | |
| US4632746A (en) | Electrochemical cell with thin wire electrode | |
| JP4627037B2 (en) | Contact combustion type gas sensor | |
| US4795533A (en) | Gas detection apparatus and method with novel three-component membrane | |
| CN206470229U (en) | A kind of hydrogen gas sensor for quick detection low-concentration hydrogen | |
| WO2022259883A1 (en) | Hydrogen gas concentration sensor | |
| WO2024090472A1 (en) | Hydrogen gas concentration sensor | |
| JP4538640B2 (en) | Hydrogen sensor | |
| JPH01129156A (en) | Electrochemical sensor for hydrogen | |
| WO2022079925A1 (en) | Fuel cell hydrogen gas concentration sensor | |
| JP4124536B2 (en) | Hydrogen sensor | |
| RU2483299C1 (en) | Solid-electrolyte sensor for amperometric measurement of hydrogen concentration in gas mixtures | |
| US6073478A (en) | Hydrogen sensor using a solid hydrogen ion conducting electrolyte | |
| US5556534A (en) | Electrochemical oxygen and PH sensors employing fluoride based solid-state electrolytes | |
| TWI359946B (en) | Electrochemical sensor | |
| US20060254908A1 (en) | Electrochemical solid electrolyte sensor for the detection of oxygen, hydrocarbons and moisture in vacuum environments | |
| TW200525146A (en) | Electrochemical sensor | |
| CN108680617B (en) | Hydrogen sensor | |
| RU187673U1 (en) | Electrochemical sensor for measuring hydrogen in a metal melt | |
| JP4686726B2 (en) | Hydrogen sensor | |
| GB2168159A (en) | Electrochemical cell with thin wire electrode | |
| US7677082B2 (en) | Solid state gas sensors based on tunnel junction geometry | |
| Guillory | A potentiometric gaseous hydrogen sensor | |
| Woo et al. | Humidity Tolerance of Electrochemical Hydrogen Safety Sensors Based on Yttria-Stabilized Zirconia (YSZ) and Tin-doped Indium Oxide (ITO) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 23882677 Country of ref document: EP Kind code of ref document: A1 |