JP2010197075A - Hydrogen gas sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact inexpensive hydrogen gas sensor capable of properly detecting hydrogen gas even if oxygen gas is absent and even not in a heating environment and having good hydrogen gas selectivity. <P>SOLUTION: The hydrogen gas sensor has a detection section that is formed with a catalyst layer 3 at least on one side of a base material 2 composed of a solid polymer electrolyte S where a single or a plurality of types of carbon C selected from carbon nanotube, fullerene, graphite, nanocarbon, carbon black, nanodiamond, and nanoporous carbon are dispersed and can detect hydrogen gas while oxygen gas is being absent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydrogen gas sensor that detects a hydrogen gas concentration in a gas phase or a liquid phase.

  In configuring a hydrogen energy system typified by a fuel cell, the necessity of a hydrogen gas sensor that accurately detects the concentration of hydrogen is extremely high, and various hydrogen gas sensors have been proposed.

  As a typical example, in Patent Document 1, a heater coil is embedded in a heat conductive layer, and a surface of the heat conductive layer is covered with a combustion catalyst layer for burning a detection target gas by contact. A sensing element for a catalytic combustion type gas sensor has been proposed in which the conductive layer is made of a fired material mainly composed of tin oxide.

JP 2007-271556 A

  However, the detection element for a contact combustion type gas sensor described in Patent Document 1 embeds a heater coil in a heat conduction layer and covers the surface of the heat conduction layer with a combustion catalyst layer that burns the detection target gas by contact. In this configuration, the change in electrical resistance associated with the reaction between oxygen adsorbed on the surface of the combustion catalyst layer and the target gas is detected, so that the target gas cannot be detected in the absence of oxygen. was there.

  In addition, since it is necessary to provide a heater coil that heats the element temperature of the sensitive part to several hundred degrees in order to cause sufficient adsorption and desorption of oxygen molecules, there is a problem that the power consumption increases for that purpose, and it is necessary to provide a heat-resistant structure. In addition to the hydrogen gas, there is also a problem that it has no gas selectivity in response to flammable gases such as methane gas and carbon monoxide gas.

  In view of the above-mentioned problems, the object of the present invention is to detect hydrogen gas properly even in the absence of oxygen gas or in a heating environment, and to achieve a small size and good hydrogen gas selectivity. The object is to provide an inexpensive hydrogen gas sensor.

  In order to achieve the above object, the first characteristic configuration of the hydrogen gas sensor according to the present invention is composed of a solid polymer electrolyte in which conductive particles are dispersed as described in claim 1 of the claims. And a catalyst layer formed on at least one side of the substrate constitutes a detection unit capable of detecting hydrogen gas in the absence of oxygen gas.

  By forming a catalyst layer made of a metal having a catalytic function by contacting hydrogen gas on at least one side surface of a substrate composed of a solid polymer electrolyte, the catalyst layer is directed to the catalyst layer in the absence of oxygen gas. It has been confirmed by the inventors of the present invention that a detection unit that exhibits power generation characteristics when hydrogen gas is supplied can be configured.

  However, when the substrate is composed only of a solid polymer electrolyte, an unstable phenomenon is observed in which the output characteristics in the absence of hydrogen gas fluctuate due to some factor, and low concentration hydrogen gas is efficiently used. In addition, there is a problem in that it is difficult to accurately detect the hydrogen gas concentration because the output level when the hydrogen gas is detected varies due to such a phenomenon.

  Therefore, the inventors of the present application, as a result of earnest research, by dispersing conductive particles in a base material composed of a solid polymer electrolyte, the output characteristics in the absence of hydrogen gas is extremely stable, It has been found that an excellent characteristic is obtained that the hydrogen gas concentration can be accurately detected in the absence of oxygen gas.

  As the conductive particles dispersed in the solid polymer electrolyte, a carbon material can be suitably adopted, and a single or plural types are selected from carbon nanotube, fullerene, graphite, nanocarbon, carbon black, nanodiamond, and nanoporous carbon. The carbon material can be used, and excellent stability is exhibited in any case.

  In addition, it is preferable that at least the catalyst layer has an air-permeable electrode, so that the generated voltage can be taken out simultaneously while supplying hydrogen gas to the detection unit. As such an electrode, for example, carbon paper can be used.

  A catalyst layer is formed on a part of one side surface of the substrate, and an electrode is separated from each of a region covering at least a part or all of the catalyst layer formation region and a non-formation region of the catalyst layer. It is preferable that the catalyst layer and both electrodes are formed on one side surface of the base material, so that the manufacturing process can be simplified, for example, if such a detection unit is configured on the substrate, It becomes possible to reduce the film thickness without impairing the shape retention.

  Furthermore, it is preferable that an electrode is bonded to the upper surface of the catalyst layer formed on one side surface of the base material, and an electrode is bonded to the other side surface of the base material. For example, since it is a base material provided with flexibility, the degree of freedom when assembled to the hydrogen gas detection site is increased.

  Preferably, the catalyst layer is supported on the base material by sputtering and is made of a metal or alloy having a catalytic function by contacting with hydrogen gas, or an organometallic or organic substance having catalytic activity. The particle size distribution and supported amount of the catalyst supported on the catalyst support can be suitably controlled.

  As described above, according to the present invention, hydrogen gas can be properly detected even in the absence of oxygen gas or in a heating environment, and it is small and inexpensive with good hydrogen gas selectivity. A hydrogen gas sensor can be provided.

Configuration of a hydrogen gas sensor according to the present invention Configuration diagram of a hydrogen gas sensor showing another embodiment Configuration diagram of a hydrogen gas sensor showing another embodiment Configuration diagram of a hydrogen gas sensor showing another embodiment Configuration diagram of a hydrogen gas sensor showing another embodiment Explanatory drawing of characteristic test of hydrogen gas sensor in the absence of oxygen gas Sensitivity characteristics diagram of hydrogen gas sensor in the absence of oxygen gas (A) is a sensitivity characteristic diagram of the hydrogen gas sensor with respect to different hydrogen gas concentrations in the absence of oxygen gas, and (b) is an explanatory diagram of a calibration curve of the peak value of the hydrogen gas sensor at that time. Operation diagram of the hydrogen gas sensor

  Hereinafter, a hydrogen gas sensor according to the present invention will be described. As shown in FIG. 1, in the hydrogen gas sensor 1, a catalyst layer 3 having a catalytic function is formed on one side surface of a base material 2 made of a solid polymer electrolyte S in which carbon C is dispersed by contacting with hydrogen gas. The electrodes 4 (4a, 4b) are bonded to both surfaces of the substrate 2.

  The solid polymer electrolyte S is not particularly limited as long as it exhibits proton conductivity. However, perfluorosulfonic acid-based and perfluorocarboxylic acid-based perfluoropolymers having high proton conductivity, poly (styrene), and the like. -ran-ethylene), sulfonated, and other solid polymer electrolyte membranes made of partially sulfonated styrene-olefin copolymer are preferably used, such as Nafion (DuPont registered trademark: NAFION) and Aciplex (Asahi Kasei Corporation registered trademark: ACIPLEX). Etc. can be used suitably.

  The carbon C dispersed in the solid polymer electrolyte S can be selected from carbon nanotubes (hereinafter also referred to as “CNT”), fullerene, graphite, nanocarbon, carbon black, nanodiamond, and nanoporous carbon. . Specific examples of carbon black include furnace black, channel black, and graft carbon.

  The size (particle diameter, length, or diameter) of carbon C (CNT, graphite, etc.) is not particularly limited, but a higher aspect ratio is preferable, and in particular, the length is 1 μm to 500 μm, and the diameter is 5 to 200 nm. Is preferred.

  Furthermore, the carbon C dispersed in the solid polymer electrolyte S is not limited to one type of carbon, and different types of carbon, such as different types of CNT or CNT and graphite, may be mixed.

  That is, the base material 2 is made of a carbon-containing solid material in which a solid polymer electrolyte is mixed with one or more carbon materials selected from carbon nanotubes, fullerenes, graphite, nanocarbon, carbon black, nanodiamond, and nanoporous carbon. It is composed of molecular electrolyte.

  The base material 2 is made of, for example, a carbon nanotube, fullerene, graphite, nanocarbon, carbon black, nanodiamond, nanoporous carbon in a solid polymer electrolyte solution obtained by dissolving a solid polymer electrolyte in an alcohol solvent such as water-propanol. A step of mixing a predetermined amount of carbon C selected from any of the above, a dispersion treatment step of dispersing the carbon C in the solid polymer electrolyte solution, a molding step of forming the carbon C into a predetermined shape by casting or the like after the dispersion treatment, It is manufactured through a heating and drying process in which the molded substrate is dried by heating to remove the solvent.

  Instead of the alcohol solvent, an organic solvent having polarity such as water-dimethylformamide (DMF) can be used. In any case, the dispersibility of carbon C differs depending on the combination of the solvent and the carbon material mixed in the solvent.

  In the heating and drying step, in order to heat and dry while maintaining the dispersion state of carbon C, it is important to adjust the heating time and heating temperature based on the composition of the solvent, the weight ratio of the solid polymer electrolyte and carbon, and the like. .

  If the state where carbon C is dispersed in the electrolyte membrane can be secured, the blending ratio of the solid polymer electrolyte and carbon is not particularly limited, but is preferably 100: 1 to 10:10.

  As described above, the catalyst layer 3 is configured such that the catalyst 3a made of a metal having a catalytic function by being brought into contact with hydrogen gas is supported on one side surface of the base material 2 by sputtering. That is, the base material 2 also functions as a carrier for the catalyst 3a.

The sputtering treatment time is preferably less than 90 seconds, and more preferably 60 seconds or less. The DC and RF output values during sputtering are not particularly limited, but are preferably 1.2 W / cm ² or more.

As the catalyst 3a, platinum Pt or a platinum alloy is suitably used. Besides, gold Au, silver Ag, iridium Ir, palladium Pd, ruthenium Ru, osmium Os, cobalt Co, nickel Ni, tungsten W, molybdenum Mo, manganese A metal containing at least one selected from Mn, yttrium Y, vanadium V, niobium Nb, titanium Ti, rare earth metal can be used, and a carbide such as molybdenum carbide Mo ₂ C can be used instead of the metal catalyst. Is also possible. These catalysts may be used alone or in combination, or some or all of them may be used in the form of an alloy.

  Further, the catalyst layer 3 may be configured by supporting a catalyst 3a made of an organic metal or an organic substance having catalytic activity by contacting with hydrogen gas on one side surface of the substrate 2.

  Examples of such organometallic catalysts include N, N'-Bis (salicylidene) ethylene-diamino-metal (= Ni, Fe, V, etc.), N, N'-mono-8-quinoly-σ-phenylenediamino-metal. (= Ni, Fe, V, etc.) can be used, and examples of organic substances include pyrrolopyrrole red pigments and dipyridyl derivatives.

  The electrode 4 only needs to have a configuration in which at least hydrogen gas can be in contact with the detection portion in which the catalyst layer 3 is formed on one side surface of the substrate 2, such as a copper-nickel alloy thin film in which a large number of pores are formed, It is also possible to form a metal porous sintered body having a good conductivity.

  Furthermore, the electrode 4 is not limited to being composed of a metal that is a good conductor, but may be composed of carbon paper or carbon cloth having electrical conductivity and air permeability.

  When hydrogen gas flows into the electrode 4a on the catalyst layer 3 side of the hydrogen gas sensor 1 described above, hydrogen is decomposed into hydrogen ions and electrons by the action of the catalyst, and the electrons are supplied to an external circuit connected to the electrode 4a. That is, the electrode 4a on the side where the catalyst layer 3 is formed becomes a negative electrode. At this time, the hydrogen gas concentration can be detected by detecting a current value or a voltage value having a correlation with the hydrogen gas concentration by an external circuit.

  9 (a) and 9 (b), the catalyst layer 3 is formed on one side surface of the base material 2 composed only of the solid polymer electrolyte containing no carbon material, and the electrodes 4 are formed on both side surfaces of the base material 2. A bonded hydrogen gas sensor is shown. When the base material 2 is composed only of the solid polymer electrolyte, a local potential is generated inside the base material 2 depending on the material of the solid polymer electrolyte and the film formation state, or in the absence of hydrogen gas. A slight voltage (Vo) is detected between the two electrodes 4a and 4b, and the value becomes unstable due to some influence such as temperature and humidity.

  When hydrogen gas is supplied to the electrode 4 on the catalyst layer 3 side in such an unstable state, even if the hydrogen gas concentration is the same, the detection voltage (Vo + ΔV) varies from time to time, and an accurate value is detected. There are cases where it is not possible.

  However, as shown in FIG. 9C, when a hydrogen gas sensor is configured using a base material 2 in which carbon (indicated by CNT in the figure) is dispersed in a solid polymer electrolyte, the conductivity of carbon in the base material 2 is determined. The detection voltage in the absence of hydrogen gas is stabilized at approximately 0 V because the local potential caused by the partial non-uniformity inside the film is eliminated by the sexual action. As a result, as shown in FIG. 9D, it is estimated that the output voltage ΔV having a correlation with the concentration of the hydrogen gas supplied to the catalyst layer 3 side can be accurately detected.

  The hydrogen gas sensor 1 described above is arranged so that at least the electrode 4a side on which the catalyst layer 3 is formed is aerated with hydrogen gas, and the voltage detection circuit 6 is provided between the electrodes 4a and 4b, thereby being included in the detection target gas. The hydrogen gas concentration can be measured.

  Further, as shown in FIGS. 2 (a) and 2 (b), carbon paper or carbon cloth is provided on the front or back surface of the electrode 4a on which the catalyst layer 3 is formed so that the detection target gas is uniformly supplied to the electrode 4a. A gas diffusion layer 7 made of or the like may be provided. Furthermore, it is preferable to interpose carbon paper 8 or the like between the counter electrode 4b of the electrode 4a and the substrate 2 from the viewpoint of the corrosion resistance of the electrode 4b. Similarly, interposing carbon paper 8 or the like between the electrode 4a and the substrate 2 is preferable from the viewpoint of the corrosion resistance of the electrode 4a.

  In the above-described embodiment, the catalyst layer 3 is formed by directly sputtering the catalyst 3a on the base material 2. However, for example, the catalyst layer 3 is formed by applying carbon fiber, carbon nanotube, or the like on one side surface of the base material 2. Alternatively, the catalyst 3a may be supported on the upper surface of the coated layer. When carbon nanotubes are used, the characteristics of the catalyst support are extremely excellent because of the specific surface area.

  Furthermore, in addition to forming the catalyst layer 3 by sputtering, known methods such as vacuum deposition, electron irradiation, CVD, PVD, impregnation, spray coating, spray pyrolysis, kneading, spraying, coating with a roll or iron, It is also possible to form the catalyst layer 3 by employing screen printing, kneading method, photoelectrolysis method, coating method, sol-gel method, dipping method or the like.

  In the above-described embodiment, the hydrogen gas sensor 1 has been described as a self-supporting example in which the hydrogen gas sensor 1 itself has shape retention. However, the hydrogen gas sensor 1 according to the present invention uses a thin film formation process on a substrate. It can also be configured.

  For example, as shown in FIG. 3, a thin film electrode 4b is formed on a substrate 10 by screen printing or the like, and a solid polymer electrolyte solution in which carbon C is dispersed is dropped on the upper surface and dried by heating. The hydrogen gas sensor 1 can be configured by forming the base material 2 and further forming the catalyst layer 3 and the air-permeable electrode 4a on the upper surface thereof in order. The catalyst layer 3 and the air permeable electrode 4a can be formed by employing a known film forming technique such as sputtering or vapor deposition.

  Further, as shown in FIG. 4, a thin film base material 2 is formed by dropping a solid polymer electrolyte solution in which carbon C is dispersed on a substrate 10 and drying by heating, and a catalyst layer is formed in a partial region on the upper surface thereof. 3, a gas-permeable electrode is formed on the upper surface thereof, and an electrode 3 b is formed on the upper surface of the base material 2 in a region different from the region where the catalyst layer 3 is formed, whereby the hydrogen gas sensor 1 is configured. be able to.

  Further, as shown in FIG. 5, two electrodes 4a and 4b separated on the substrate 10 are formed, the catalyst layer 3 is formed on the upper surface of one of the electrodes 4a, and the both electrodes 4a and 4b are covered. In addition, the hydrogen gas sensor 1 can be configured by forming a thin film base material 2 that is heated and dried after the solid polymer electrolyte solution in which carbon C is dispersed is dropped. In this case, the hydrogen gas reaches the catalyst layer 3 through the substrate 2.

  3 to 5, since the catalyst layer 3 and both electrodes 4 are formed on one side surface of the base material 2, not only can the manufacturing process be simplified, but for example, such a detection unit is provided on the substrate. If configured, it is possible to manufacture a small hydrogen gas sensor having a reduced thickness without impairing shape retention.

  In the embodiment described above, the hydrogen gas sensor using the base material in which the carbon material is dispersed as the conductive particle in the solid polymer electrolyte has been described, but instead of the carbon material, the solid polymer electrolyte has a conductive resin, etc. Conductive particles other than carbon materials may be employed.

  As a base material made of a solid polymer electrolyte, a hydrogen gas sensor was prepared by using a solid polymer film obtained by adding 6.9 wt% of CNT to a sulfonated styrene ethylene copolymer. Gas sensitivity characteristics were evaluated.

  First, a sulfonated styrene ethylene copolymer is dissolved in N, N-dimethylformamide (hereinafter referred to as “DMF”) as a solvent so that the solid content ratio is 5 wt%. A polymer solution is prepared.

  Carbon nanotubes (CNT) as a carbon material are dissolved in DMF, mixed with the prepared sulfonated styrene ethylene copolymer solution, dispersed with an ultrasonic homogenizer for 10 minutes, and stirred with a stirrer for 30 minutes.

  10 mL of this sulfonated styrene ethylene copolymer solution is dropped into a casting mold frame and dried at a temperature of 110 ° C. for 6 hours to be cured. The cured electrolyte membrane is peeled from the mold, and a sulfonated styrene ethylene copolymer + CNT 6.9 wt% added electrolyte membrane having a thickness of about 200 μm cured into a sheet is obtained.

  Next, a platinum layer serving as a catalyst layer is deposited on one side surface of the sufficiently cured sulfonated styrene ethylene copolymer + CNT 6.9 wt% added electrolyte film by sputtering. Specifically, platinum is used as a target, an output of 300 mW, a rotation speed of 1.6 rpm, a sputtering treatment time of 30 seconds, and an argon gas atmosphere is formed as an inert gas atmosphere. The gas flow rate is, for example, 20 cc / min.

  The sulfonated styrene ethylene copolymer + CNT 6.9 wt% added electrolyte membrane is cut into a circle having a diameter of 13 mm, and sandwiched between carbon paper as a breathable electrode and a donut-shaped stainless steel washer having the same diameter as the electrode. To obtain a hydrogen gas sensor.

  Furthermore, in order to compare with the hydrogen gas sensor according to the present invention, a hydrogen gas sensor using a base material made of only a solid polymer electrolyte without dispersing carbon was prototyped by the following procedure.

  10 mL of a sulfonated styrene ethylene copolymer solution (Poly (styrene-ran-ethylene), sulfonated, 5 wt.% Solution in 1-propanol manufactured by ALDRICH) is dropped into a casting mold frame and dried at a temperature of 80 ° C. for 6 hours. And let it harden. The cured electrolyte membrane is peeled from the mold, and a sulfonated styrene ethylene copolymer electrolyte membrane having a thickness of about 200 μm cured in a sheet shape is obtained.

  Next, a platinum layer is deposited by sputtering on one side of the sufficiently cured sulfonated styrene ethylene copolymer electrolyte membrane. Specifically, platinum is used as a target, an output of 300 mW, a rotation speed of 1.6 rpm, a sputtering treatment time of 30 seconds, and an argon gas atmosphere is formed as an inert gas atmosphere. For example, the gas flow rate is 20 cc / min.

  A sulfonated styrene-ethylene copolymer electrolyte membrane is cut into a circle having a diameter of 13 mm, and sandwiched between a carbon paper as a breathable electrode and a donut-shaped stainless steel washer having the same diameter as the electrode. can get.

  As shown in FIG. 6, the hydrogen gas sensor 1 according to the present invention is installed in a desiccator 20, and the hydrogen gas sensor 1 and a digital multimeter (MULTIMETER VOAC manufactured by Iwadori Measurement Co., Ltd.) are connected via a lead wire 24 sealed to the casing. 7411) 25.

  The desiccator 20 is connected to the vacuum pump 21 through the valve V1, and is connected to the nitrogen gas cylinder 22 through the valve V2. After the inside of the container is evacuated by the vacuum pump 21, the nitrogen gas is supplied from the nitrogen gas cylinder 22 to the atmospheric pressure. The gas filling operation is repeated three times to remove oxygen gas from the container.

  Next, a nitrogen gas cylinder 23 containing hydrogen gas with a concentration of 4% is connected to the valve V2, and after the inside of the container is evacuated by the vacuum pump 21, the valve V2 is opened and hydrogen gas with a concentration of 4% is placed in the container. The nitrogen gas contained was filled to atmospheric pressure, and the output voltage of the hydrogen gas sensor 1 at that time was measured with a digital multimeter.

  Next, the hydrogen gas sensor 1A for comparison was installed inside the desiccator 20, and the output voltage of the hydrogen gas sensor 1A for comparison was measured with a digital multimeter in the same procedure.

  As shown in FIG. 7, the output voltage of the hydrogen gas sensor 1 according to the present invention is maintained at a stable output voltage of 0 V in a vacuum in which oxygen gas and hydrogen gas do not exist, and is filled with hydrogen gas having a concentration of 4%. An output voltage of about 0.8 V was measured at the peak value.

  On the other hand, the output voltage of the hydrogen gas sensor 1A for comparison is about 0.6V when an output voltage of -0.28V is confirmed in a vacuum in which oxygen gas and hydrogen gas do not exist, and hydrogen gas with a concentration of 4% is filled. The output voltage of was measured.

  When such a measurement was performed a plurality of times, it was confirmed that the same sensitivity characteristic as described above was reproduced. However, the comparison hydrogen gas sensor 1A was in a vacuum in which oxygen gas and hydrogen gas were not present each time measurement was performed. It was confirmed that the output voltage at fluctuated.

  Next, the hydrogen gas sensor 1 according to the present invention is installed inside the desiccator 20, and hydrogen gas is hydrogenated using a nitrogen gas cylinder mixed with hydrogen gas having a concentration of 4%, 2%, and 1% in the same procedure as described above. As a result of measuring the output voltage of the gas sensor 1, the sensitivity characteristic as shown in FIG. 8A was obtained, and the correlation between the hydrogen gas concentration and the output voltage of the peak value as shown in FIG. 8B was obtained.

  Furthermore, the same experiment was performed on methane gas and carbon monoxide gas as the gas to be detected, but no change in output appeared. From this, it was confirmed that the gas selectivity was also provided.

  The hydrogen gas sensor according to the present invention is extremely useful for a fuel cell system using hydrogen gas as an energy source, and detects the hydrogen gas concentration in the absence of oxygen gas, such as detection of hydrogen concentration in a hydrogen gas tank or a hydrogen gas supply pipe or detection of leakage. It can be suitably used when it is necessary to detect.

  Moreover, it can be suitably used for hydrogen concentration monitoring and hydrogen gas leak detection in a heat treatment apparatus of a semiconductor manufacturing plant. For example, it can be used for monitoring the hydrogen gas concentration in a heat treatment process for interfacial treatment using hydrogen gas or a mixed gas of hydrogen gas and nitrogen gas.

1: Hydrogen gas sensor 2: Base material 3: Catalyst layer 3a: Catalysts 4, 4a, 4b: Electrode 6: Measuring instrument (voltage detection circuit)
7, 8: Gas diffusion layer C: Carbon S: Solid polymer electrolyte

Claims (7)

  A detection unit capable of detecting hydrogen gas in the absence of oxygen gas by a base composed of a solid polymer electrolyte in which conductive particles are dispersed and a catalyst layer formed on at least one side of the base. Configured hydrogen gas sensor.   The hydrogen gas sensor according to claim 1, wherein the conductive particles are a carbon material.   3. The hydrogen gas sensor according to claim 1, wherein the conductive particles are a carbon material selected from single or plural kinds of carbon nanotubes, fullerenes, graphites, nanocarbons, carbon blacks, nanodiamonds, and nanoporous carbons.   The hydrogen gas sensor according to any one of claims 1 to 3, wherein an electrode having air permeability is bonded to at least the catalyst layer.   A catalyst layer is formed on a part of one side surface of the substrate, and an electrode is separated from each of a region covering at least a part or all of the catalyst layer formation region and a non-formation region of the catalyst layer. The hydrogen gas sensor according to any one of claims 1 to 4, wherein the hydrogen gas sensor is bonded to the base.   The hydrogen gas sensor according to any one of claims 1 to 4, wherein an electrode is bonded to an upper surface of a catalyst layer formed on one side surface of the base material, and an electrode is bonded to the other side surface of the base material.   The said catalyst layer is carry | supported by the said base material by sputtering, and when it contacts with hydrogen gas, it is comprised with the metal or alloy which has a catalytic function, or the organometallic or organic substance which has a catalytic activity. The hydrogen gas sensor described in 1.

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