JPH10123093A - Solid electrolytic hydrogen sensor - Google Patents
Solid electrolytic hydrogen sensorInfo
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- JPH10123093A JPH10123093A JP8297185A JP29718596A JPH10123093A JP H10123093 A JPH10123093 A JP H10123093A JP 8297185 A JP8297185 A JP 8297185A JP 29718596 A JP29718596 A JP 29718596A JP H10123093 A JPH10123093 A JP H10123093A
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- Prior art keywords
- hydrogen
- zno
- sensor
- sensitivity
- solid electrolyte
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Abstract
Description
【０００１】[0001]
【発明の利用分野】この発明は、安定化ジルコニア等の
固体電解質を用いた水素センサの改良に関し、特に高温
での水素の選択的検出に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hydrogen sensor using a solid electrolyte such as stabilized zirconia, and more particularly to a selective detection of hydrogen at a high temperature.
【０００２】[0002]
【従来技術】発明者らは、安定化ジルコニア等の酸素イ
オン導電性固体電解質を用いて、各種の可燃性ガスやＮ
Ｏｘ等のガスを検出することを研究してきた。これらの
検出には混成電位を用い、例えば可燃性ガスの検出の場
合、検出極での可燃性ガスの酸化電流と酸素の還元電流
とを平衡させ、酸化電流と還元電流とが等しい際の混成
電位から検出を行う。そして発明者らは、検知極にＷＯ
3を用いると硫化水素を選択的に検出し得ることを見い
出した（ケミストリーレターズ（CHEMISTRY LETTERS）
1994,1733-1736）。また検知極にＣｄＭn2Ｏ4を用いる
と、ＮＯｘを選択的に検出し得ることを見い出した（ジ
ャーナルオブザエレクトロケミカルソサイエティー (J.
Electrochem. Soc.), 143 (2), L33-L35 (1996)）。2. Description of the Related Art The inventors of the present invention have used various oxygen-conducting solid electrolytes such as stabilized zirconia and various kinds of combustible gases and N
We have been studying the detection of gases such as Ox. For these detections, a hybrid potential is used.For example, in the case of detecting a combustible gas, the oxidation current of the combustible gas at the detection electrode and the reduction current of oxygen are balanced, and the hybrid current when the oxidation current and the reduction current are equal is detected. Detection is performed from the potential. Then, the inventors added WO to the detection electrode.
It has been found that hydrogen sulfide can be selectively detected when 3 is used (CHEMISTRY LETTERS).
1994, 1733-1736). It has also been found that NOx can be selectively detected by using CdMn2O4 for the detection electrode (Journal of the Electrochemical Society (J.
Electrochem. Soc.), 143 (2), L33-L35 (1996)).
【０００３】ところで水素の検出に関して、Ｓｂ2Ｏ5等
のプロトン導電体を用い、室温〜１００℃程度の温度で
水素を検出することが知られている。また同様に金属酸
化物半導体ガスセンサ材料のＳnＯ2をシリコーン蒸気で
被毒し、水素以外のガスへの感度を消滅させて水素選択
性を得ることが知られている。しかしながらこれらのセ
ンサはいずれも室温〜２００℃程度で作動するものであ
り、高温での水素の検出には適してない。As for the detection of hydrogen, it has been known to detect hydrogen at a temperature of about room temperature to about 100 ° C. using a proton conductor such as Sb 2 O 5. Similarly, it is known that SnO2 of a metal oxide semiconductor gas sensor material is poisoned with silicone vapor to extinguish sensitivity to gases other than hydrogen to obtain hydrogen selectivity. However, all of these sensors operate at room temperature to about 200 ° C., and are not suitable for detecting hydrogen at a high temperature.
【０００４】[0004]
【発明の課題】この発明の課題は、高温で水素選択的で
高感度かつ高速応答の固体電解質水素センサを得ること
にある。SUMMARY OF THE INVENTION An object of the present invention is to provide a solid electrolyte hydrogen sensor having high sensitivity at high temperature and high sensitivity and high speed response.
【０００５】[0005]
【発明の構成】この発明の固体電解質水素センサは、酸
素イオン導電性固体電解質の表面に、ＺnＯ，ＳnＯ2，
Ｉn2Ｏ3からなる群の少なくとも一員の金属酸化物半導
体を用いた検知極と、ＺnＯ，ＳnＯ2，Ｉn2Ｏ3をいずれ
も含有しない参照極とを設けたことを特徴とする。好ま
しくは、金属酸化物半導体をＺnＯとする。ここにＺnＯ
やＳnＯ2，Ｉn2Ｏ3には、水素以外のガスへの感度を発
現させない範囲で添加物を加えても良い。そして検知極
材料として最も好ましいのは、水素感度の高いＺnＯで
ある。参照極には例えばＰt，Ａu，Ｉr，Ｒh等の貴金属
や、ＷＯ3，ＴiＯ2，ＣuＯ等の金属酸化物半導体を用い
る。また固体電解質は、安定化ジルコニアに限らず、Ｃ
eＯ2系等の他の酸素イオン導電性固体電解質でも良い。DETAILED DESCRIPTION OF THE INVENTION The solid electrolyte hydrogen sensor according to the present invention has a structure in which ZnO, SnO2,
A detection electrode using a metal oxide semiconductor of at least one member of the group consisting of In2O3 and a reference electrode containing none of ZnO, SnO2, and In2O3 are provided. Preferably, the metal oxide semiconductor is ZnO. Here ZnO
Additives may be added to SnO2 and In2O3 as long as they do not exhibit sensitivity to gases other than hydrogen. The most preferable sensing electrode material is ZnO having high hydrogen sensitivity. For the reference electrode, a noble metal such as Pt, Au, Ir, and Rh, or a metal oxide semiconductor such as WO3, TiO2, and CuO is used. The solid electrolyte is not limited to stabilized zirconia,
Other oxygen ion conductive solid electrolytes such as eO2 may be used.
【０００６】[0006]
【発明の作用と効果】発明者は検知極の材料について実
験を繰り返し、ＺnＯとＳnＯ2並びにＩn2Ｏ3からなる群
の少なくとも一員の金属酸化物半導体を検知極材料とす
ると、例外的に水素選択性が得られることを見い出し
た。そしてこのような水素選択性は４５０〜６００℃程
度の高温域において得られ、しかも水素に対する起電力
の変化は大きく、かつ応答性能も優れている。この結
果、従来困難であった、高温域において水素選択的でか
つ応答に優れ、高感度な固体電解質水素センサが得られ
る。The inventor has repeated experiments on the material of the sensing electrode, and when at least one member of a metal oxide semiconductor of the group consisting of ZnO, SnO2 and In2O3 is used as the sensing electrode material, exceptional hydrogen selectivity is obtained. I found something to be done. Such hydrogen selectivity is obtained in a high temperature range of about 450 to 600 ° C., and the change in electromotive force with respect to hydrogen is large and the response performance is excellent. As a result, a high-sensitivity solid electrolyte hydrogen sensor that is hydrogen-selective and has excellent response in a high temperature range, which has been difficult in the past, can be obtained.
【０００７】[0007]
【０００８】[0008]
【センサの作製と構造】図１に実施例の固体電解質水素
センサの構造を示す。２は固体電解質水素センサで、４
は８ｍｏｌ％のＹ2Ｏ3で安定化したＺrＯ2（イットリア
安定化ジルコニア：ＹＳＺ）チューブで、その一端が閉
じている。ＹＳＺチューブ４は長さが３０ｃｍ、内径が
５ｍｍかつ外径が８ｍｍである。６はＹＳＺチューブ４
の先端に設けたＺnＯ層で、８はリード取り付け用のＰt
金網で、ＺnＯ層６の外側に設け、これらを合わせて検
知極１０と呼ぶ。なお検知極１０におけるＰt網８の役
割はリードと検知極１０との電気的接触であり、Ｐtに
限らず任意の金網や導電性ペースト等を用いても良い。
１２はＹＳＺチューブ４の内面先端に塗布したＰt層
で、１４は同様のＰt金網である。Ｐt層１２とＰt金網
１４とを総称して参照極１６と呼ぶ。検知極１０と参照
極１６にはそれぞれリード１８，１８を取り付け、ＹＳ
Ｚチューブ４の内部には例えばヒータ２０を収容して、
４５０〜６００℃程度の動作温度に加熱できるようにす
る。[Production and Structure of Sensor] FIG. 1 shows the structure of the solid electrolyte hydrogen sensor of the embodiment. 2 is a solid electrolyte hydrogen sensor and 4
Is a ZrO2 (yttria-stabilized zirconia: YSZ) tube stabilized with 8 mol% of Y2 O3, one end of which is closed. The YSZ tube 4 has a length of 30 cm, an inner diameter of 5 mm, and an outer diameter of 8 mm. 6 is YSZ tube 4
Is a ZnO layer provided at the tip of the lead, and 8 is a Pt for lead attachment.
A wire mesh is provided outside the ZnO layer 6, and these are collectively referred to as a sensing electrode 10. The role of the Pt net 8 in the detection electrode 10 is the electrical contact between the lead and the detection electrode 10, and is not limited to Pt, and any wire net or conductive paste may be used.
Reference numeral 12 denotes a Pt layer applied to the tip of the inner surface of the YSZ tube 4, and reference numeral 14 denotes a similar Pt wire mesh. The Pt layer 12 and the Pt wire net 14 are collectively called a reference electrode 16. Leads 18 are attached to the detection electrode 10 and the reference electrode 16, respectively, and YS
For example, a heater 20 is housed inside the Z tube 4,
It can be heated to an operating temperature of about 450 to 600 ° C.
【０００９】水素センサ２を以下のようにして作製し
た。ＹＳＺチューブ４の内面先端にＰtペーストを塗布
し、１２００℃で３０分間焼成した。これとは別にＺn
Ｃｌ2等の金属塩化物の水溶液をアンモニア水で中和
し、得られた沈澱を６００℃で空気中５時間焼成し、Ｚ
nＯ等の酸化物とした。得られた酸化物を粉砕し、α−
テルピネオールとエチルセルロースとを混合してペース
ト状にし、ＹＳＺチューブ４の先端に塗布し、６００℃
で４時間空気中で焼成して膜厚約３０μｍのＺnＯ層等
６とした。次にＺnＯ層６等とＰt層１２とにＰt金網
８，１４等を取り付け、これらにリード１８，１８を取
り付けてセンサ２を完成した。なお発明者はＺnＯ以外
の金属酸化物半導体材料も用いたが、以下特に断らない
限り、検知極６の材料にＺnＯを用いたものとして説明
する。The hydrogen sensor 2 was manufactured as follows. A Pt paste was applied to the tip of the inner surface of the YSZ tube 4 and baked at 1200 ° C. for 30 minutes. Apart from this, Zn
An aqueous solution of a metal chloride such as Cl2 is neutralized with aqueous ammonia, and the resulting precipitate is calcined at 600 ° C. in air for 5 hours.
An oxide such as nO was used. The obtained oxide is pulverized, and α-
Terpineol and ethyl cellulose are mixed to form a paste, applied to the tip of a YSZ tube 4,
For 4 hours to form a ZnO layer 6 having a thickness of about 30 μm. Next, Pt wire meshes 8 and 14 were attached to the ZnO layer 6 and the Pt layer 12, and leads 18 and 18 were attached to these to complete the sensor 2. Although the inventor used a metal oxide semiconductor material other than ZnO, the following description will be made assuming that ZnO is used as the material of the sensing electrode 6 unless otherwise specified.
【００１０】図２は変形例の固体電解質水素センサ２２
を示し、２４は同様のＹＳＺ板で、２６はＺnＯ層であ
り、２８，３２，３６はＰt層、３４は膜状のヒータで
ある。そしてＺnＯ層２６とＰt層２８とで検知極３０を
構成し、Ｐt層３２で参照極を構成する。図２の変形例
の作用や特性は、特に断らない限り図１の実施例と同様
である。以下に図１の固体電解質水素センサ２の特性を
示す。FIG. 2 shows a modified solid electrolyte hydrogen sensor 22.
24 is a similar YSZ plate, 26 is a ZnO layer, 28, 32 and 36 are Pt layers, and 34 is a film heater. The ZnO layer 26 and the Pt layer 28 constitute a detection electrode 30, and the Pt layer 32 constitutes a reference electrode. The operation and characteristics of the modification of FIG. 2 are the same as those of the embodiment of FIG. 1 unless otherwise specified. The characteristics of the solid electrolyte hydrogen sensor 2 of FIG. 1 are shown below.
【００１１】[0011]
【結果】検知極の材質を種々に変化させて２００ｐｐｍ
の水素とＣＯとに対する起電力を測定した。測定ではヒ
ータ２０を用いずセンサ２を流通系におき、センサや雰
囲気の温度を４５０〜６００℃程度に保って、起電力を
測定した。結果を表１に示す。なおセンサ２の構造は図
１のもので、この場合の測定温度は６００℃である。さ
て表１から明らかなように、ＺnＯやＳnＯ2並びにＩn2
Ｏ3では水素に対して高い感度が得られ、これ以外の金
属酸化物では水素に対する起電力の変化は極めて小さ
い。また検知極材料を貴金属とすると、６００℃では水
素感度は極めて小さかった。これに対してＺnＯやＳnＯ
2，Ｉn2Ｏ3では水素感度は高く、またＣＯ感度は小さ
く、センサは水素選択性を示す。これらのことから、水
素センサ材料として用い得る検知極の材質はＺnＯ，Ｓn
Ｏ2，Ｉn2Ｏ3のいずれかに限られる。そしてこれらの内
で最も水素感度が高かったのはＺnＯで、以下にＺnＯつ
いて特性を示す。[Results] 200 ppm by changing the material of the sensing electrode in various ways
The electromotive force for hydrogen and CO was measured. In the measurement, the sensor 2 was placed in a circulation system without using the heater 20, and the electromotive force was measured while maintaining the temperature of the sensor and the atmosphere at about 450 to 600 ° C. Table 1 shows the results. The structure of the sensor 2 is that of FIG. 1, and the measurement temperature in this case is 600 ° C. As is clear from Table 1, ZnO, SnO2 and In2
O3 has high sensitivity to hydrogen, and other metal oxides have a very small change in electromotive force with respect to hydrogen. When the detection electrode material was a noble metal, the hydrogen sensitivity at 600 ° C. was extremely small. On the other hand, ZnO and SnO
2, In2O3 has high hydrogen sensitivity and low CO sensitivity, and the sensor shows hydrogen selectivity. From these facts, the material of the sensing electrode that can be used as a hydrogen sensor material is ZnO, Sn.
It is limited to either O2 or In2O3. Among them, ZnO had the highest hydrogen sensitivity, and the characteristics of ZnO are shown below.
【００１２】[0012]
【表１】検知極の材質と水素感度 △ＥＭＦ材質 ２００ｐｐｍ Ｈ2 ２００ｐｐｍ ＣＯ ＺnＯ −１３６ −９ ＳnＯ2 −９５ −１ Ｉn2Ｏ3 −５５ −７ ＷＯ3 −７ −７ ＴiＯ2 −７ 〜０ ＣuＯ −１ 〜０ Ｆe2Ｏ3 −１ 〜０ Ｍn3Ｏ4 〜０ 〜０ Ｃo3Ｏ4 〜０ 〜０ Ｃr2Ｏ3 〜０ 〜０ ＮiＯ 〜０ 〜０ ＊ 測定温度は６００℃．[Table 1] Detection electrode material and hydrogen sensitivity △ EMF material 200 ppm H2 200 ppm CO ZnO -136-9 SnO2 -95 -1 In2O3 -55 -7 WO3 -7 -7 TiO2 -7 to 0 CuO -1 to 0 Fe2O3- 1 to 0 Mn3 O4 to 0 to 0 Co3 O4 to 0 to 0 Cr2 O3 to 0 to 0 Nio to 0 to 0 * Measurement temperature is 600 ° C.
【００１３】図３に。検知極にＺnＯを用いた場合（以
下同様）の、水素濃度と起電力との関係を示す。図３に
示すように、起電力は４５０〜６００℃で５０〜５００
ｐｐｍの範囲で、水素濃度の対数に対して直線的に変化
した。測定温度を低下させるほど、水素中の起電力の空
気中での値（起電力０）からの変化は増加するが、水素
濃度に対する起電力の勾配は僅かに緩やかになる。６０
０℃では空気中に対する５０ｐｐｍの水素での起電力の
変化は約−７５ｍＶで、水素濃度が１桁変化すると起電
力は約−１００ｍＶ変化する。５００℃や６００℃での
空気中と２００ｐｐｍの水素中との間の応答波形を図４
に示す。６００℃では、２００ｐｐｍの水素に対する９
０％応答時間は、空気中から水素中へで約５秒、水素中
から空気中へで約１０秒である。FIG. The relationship between the hydrogen concentration and the electromotive force when ZnO is used for the detection electrode (the same applies hereinafter) is shown. As shown in FIG. 3, the electromotive force is 50 to 500 ° C. at 450 to 600 ° C.
It changed linearly with the logarithm of the hydrogen concentration in the ppm range. As the measured temperature decreases, the change of the electromotive force in hydrogen from the value in air (electromotive force 0) increases, but the gradient of the electromotive force with respect to the hydrogen concentration becomes slightly gentler. 60
At 0 ° C., the change in electromotive force at 50 ppm of hydrogen relative to air is about −75 mV, and when the hydrogen concentration changes by one digit, the electromotive force changes by about −100 mV. FIG. 4 shows a response waveform between air in 500 ° C. or 600 ° C. and 200 ppm of hydrogen.
Shown in At 600 ° C., 9 ppm for 200 ppm hydrogen
The 0% response time is about 5 seconds from air to hydrogen and about 10 seconds from hydrogen to air.
【００１４】図５に、ＺnＯを検知極に用いたセンサで
の、各種ガスに対する起電力を示す。測定温度は６００
℃で、Ｈ2，ＣＨ4，ＣＯ，ＮＯ2，及びＮＯに対してガ
ス濃度を２００ｐｐｍとし，ＣＯ2に対して８０００ｐ
ｐｍとし、Ｈ2Ｏに対して３５６５Ｐａとした。図５か
ら明らかなように、水素選択性は極めて高い。FIG. 5 shows the electromotive force for various gases in a sensor using ZnO as a detection electrode. Measurement temperature is 600
At 200C, the gas concentration was 200 ppm for H2, CH4, CO, NO2, and NO, and 8000 p
pm and 3565 Pa with respect to H2O. As is clear from FIG. 5, the hydrogen selectivity is extremely high.
【００１５】図６に、６００℃で（検知極材料はＺn
Ｏ）２００ｐｐｍの水素と空気中との間で、雰囲気を繰
り返し切り替えた際の応答波形を示す。雰囲気の切り替
えを繰り返し行っても応答波形は一定で、検出の繰り返
しに伴う感度の劣化は見られない。FIG. 6 shows that at 600 ° C. (the detection electrode material is Zn
O) Response waveforms when the atmosphere is repeatedly switched between 200 ppm hydrogen and air. Even when the atmosphere is repeatedly switched, the response waveform is constant, and there is no deterioration in sensitivity due to the repeated detection.
【００１６】図７に、実施例のセンサ２（検知極にＺn
Ｏを使用）を、４３０時間６００℃に加熱した際の特性
を示す。空気中での起電力と２００ｐｐｍの水素中での
起電力は共に極めて安定で、センサの信頼性は高い。FIG. 7 shows a sensor 2 of the embodiment (Zn is added to the detection electrode).
O) is heated at 600 ° C. for 430 hours. The electromotive force in air and the electromotive force in 200 ppm hydrogen are both extremely stable, and the reliability of the sensor is high.
【００１７】センサの動作機構を検討する。実施例の固
体電解質水素センサは、式(1)の電池からなるものと見
なすことができる。 ａir, Ｐt｜ＹＳＺ｜ＺnＯ，Ｐt，Ｈ２（＋ａir） (1) 即ちイットリア安定化ジルコニア（ＹＳＺ）は参照極で
Ｐtに接触し、検知極でＺnＯに直接接触してＰtには接
触しない。このためＹＳＺとＺnＯとの界面には非ネル
ンスト型の挙動が生じ、ＺnＯが検知極材料として作用
し、Ｐt金網は単なる集電体として作用する。さて空気
と水素とが共存していると、ＹＳＺとＺnＯとの界面に
は式(2)の酸素の電気化学的還元反応と、式(3)の水素の
電気化学的酸化反応とが進行する。 Ｏ2 ＋ ４ｅ- → ２Ｏ2- (2) Ｈ2 ＋ Ｏ2- → Ｈ2Ｏ ＋ ２ｅ- (3) これらの２つの電気化学反応の混成電位が検知極１０の
電位となり、検知極１０と参照極１６間に電流が流れな
いものとすると、式(2)の反応電流と式(3)の反応電流は
等しく、これらの電流が平衡することから、検知極１０
の電位が定まる。これらの内で水素感度の発現に寄与す
るのは(3)の水素の電気化学的酸化反応であり、検知極
で上記の電気化学反応とは別個に水素の接触的酸化反応
が進行する場合、感度は減少する。また同様に検知極の
式(3)の反応に対する活性が低い場合も、水素感度は低
下する。Consider the operation mechanism of the sensor. The solid electrolyte hydrogen sensor of the embodiment can be regarded as comprising a battery of the formula (1). air, Pt | YSZ | ZnO, Pt, H2 (+ air) (1) That is, yttria-stabilized zirconia (YSZ) contacts Pt at the reference electrode, directly contacts ZnO at the detection electrode, and does not contact Pt. For this reason, non-Nernst-type behavior occurs at the interface between YSZ and ZnO, ZnO acts as a sensing electrode material, and the Pt wire mesh acts as a mere current collector. Now, when air and hydrogen coexist, the electrochemical reduction reaction of oxygen of formula (2) and the electrochemical oxidation reaction of hydrogen of formula (3) proceed at the interface between YSZ and ZnO. . O2 + 4e - → 2O 2- ( 2) H2 + O 2- → H2O + 2e - (3) mixed potential of these two electrochemical reaction becomes the potential of the sensing electrode 10, while the reference electrode 16 and sensing electrode 10 Assuming that no current flows through the sensing electrode 10, the reaction current of equation (2) is equal to the reaction current of equation (3), and these currents are balanced.
Is determined. Among these, it is the electrochemical oxidation reaction of hydrogen (3) that contributes to the development of hydrogen sensitivity.If the catalytic oxidation reaction of hydrogen proceeds separately from the above electrochemical reaction at the sensing electrode, Sensitivity decreases. Similarly, when the activity of the detection electrode for the reaction of the formula (3) is low, the hydrogen sensitivity also decreases.
【００１８】図８に、検知極材料にＺnＯを用いた際
の、酸素濃度の変化に対する起電力の変化を示す。なお
水素濃度は０ｐｐｍと２００ｐｐｍとの２種類とし、測
定温度は６００℃である。FIG. 8 shows a change in electromotive force with respect to a change in oxygen concentration when ZnO is used as a material for the sensing electrode. The hydrogen concentration was set to two types, 0 ppm and 200 ppm, and the measurement temperature was 600 ° C.
【００１９】図９に、５５０℃での空気中，空気＋５０
ｐｐｍの水素中，及び空気＋２００ｐｐｍの水素中での
分極特性を示す。即ち各雰囲気で、検知極と参照極間の
電圧とその間の電流との関係を示したものが図９で、例
えば空気中で両極間の電圧を０とすると、雰囲気が等し
いため分極電流は０となる。さて図９の結果を整理する
と、各雰囲気で水素の電気化学的酸化反応（式(3)）に
対する分極特性を求めることができる。これらを図１０
にプロットしなおした。ここで水素の酸化電流と酸素の
還元電流とが一致する点が混成電位となる。この図か
ら、５０ｐｐｍの水素に対する酸化電流と酸素の還元電
流とが一致する混成電位は−１３５ｍＶであり、センサ
起電力の実測値−１３４ｍＶとよく一致する。同様に２
００ｐｐｍの水素に対する酸化電流と酸素の還元電流が
一致する電位は−１９０ｍＶであり、センサ起電力の測
定値−１８８ｍＶとよく一致する。従って実施例での水
素の検出機構は、式(2)，(3)の同時進行に伴う混成電位
モデルで説明できることが明らかである。FIG. 9 shows that in air at 550 ° C., air +50
9 shows the polarization characteristics in ppm of hydrogen and in air + 200 ppm of hydrogen. That is, FIG. 9 shows the relationship between the voltage between the detection electrode and the reference electrode and the current between them in each atmosphere. For example, if the voltage between both electrodes is 0 in air, the polarization current is 0 because the atmospheres are equal. Becomes By summarizing the results of FIG. 9, the polarization characteristics for the electrochemical oxidation reaction of hydrogen (Equation (3)) can be determined in each atmosphere. These are shown in FIG.
Was re-plotted. Here, the point at which the hydrogen oxidation current and the oxygen reduction current coincide is the hybrid potential. From this figure, the hybrid potential at which the oxidation current with respect to 50 ppm of hydrogen and the reduction current of oxygen coincide with each other is -135 mV, which is in good agreement with the measured value of the sensor electromotive force of -134 mV. Similarly 2
The potential at which the oxidation current with respect to 00 ppm of hydrogen matches the reduction current of oxygen is -190 mV, which is in good agreement with the measured value of the sensor electromotive force of -188 mV. Therefore, it is clear that the hydrogen detection mechanism in the embodiment can be explained by the hybrid potential model accompanying the simultaneous progress of the equations (2) and (3).
【００２０】[0020]
【表２】 混成電位の計算値と起電力の測定値 Ｈ2濃度 混成電位の計算値（mV） 起電力の測定値（mV） ５０ｐｐｍ −１３５ −１３４ ２００ｐｐｍ −１９０ −１８８ ＊ センサは検知極にＺnＯを用い，測定温度は５５０℃．Table 2 Calculated value of hybrid potential and measured value of electromotive force H2 concentration Calculated value of hybrid potential (mV) Measured value of electromotive force (mV) 50 ppm -135 -134 200 ppm -190 -188 * And the measurement temperature was 550 ° C.
【図１】 実施例の固体電解質水素センサの要部断面
図FIG. 1 is a sectional view of a main part of a solid electrolyte hydrogen sensor according to an embodiment.
【図２】 変形例の固体電解質水素センサの断面図FIG. 2 is a cross-sectional view of a modified solid electrolyte hydrogen sensor.
【図３】 ＺnＯを用いた実施例での起電力の水素濃
度依存性を示す特性図FIG. 3 is a characteristic diagram showing a hydrogen concentration dependency of an electromotive force in an example using ZnO.
【図４】 ＺnＯを用いた実施例での、２００ｐｐｍ
の水素に対する応答波形を示す特性図FIG. 4 shows 200 ppm in an example using ZnO.
Diagram showing response waveforms of hydrogen to hydrogen
【図５】 ＺnＯを用いた実施例での、６００℃での
各種ガスに対する起電力変化を示す特性図FIG. 5 is a characteristic diagram showing a change in electromotive force for various gases at 600 ° C. in an example using ZnO.
【図６】 ＺnＯを用いた実施例での、６００℃での
２００ｐｐｍ水素に対する応答波形を示す特性図FIG. 6 is a characteristic diagram showing a response waveform to 200 ppm hydrogen at 600 ° C. in an example using ZnO.
【図７】 ＺnＯを用いた実施例での、６００℃での
約２０日間の経時特性を示す特性図FIG. 7 is a characteristic diagram showing aging characteristics at about 600 ° C. for about 20 days in an example using ZnO.
【図８】 ＺnＯを用いた実施例での、６００℃での
起電力の酸素濃度依存性を示す特性図FIG. 8 is a characteristic diagram showing an oxygen concentration dependency of an electromotive force at 600 ° C. in an example using ZnO.
【図９】 ＺnＯを用いた実施例での、５５０℃での
分極特性を示す特性図FIG. 9 is a characteristic diagram showing polarization characteristics at 550 ° C. in an example using ZnO.
【図１０】 図９のデータを再プロットした特性図FIG. 10 is a characteristic diagram obtained by replotting the data of FIG. 9;
２，２２ 水素センサ ４，２４ ＺrＯ2 ６，２６ ＺnＯ層 ８，１４ Ｐt金網 １０，３０ 検知極 １２，２８，３２，３６ Ｐt層 １６ 参照極 １８ リード ２０，３４ ヒータ 2,22 Hydrogen sensor 4,24 ZrO2 6,26 ZnO layer 8,14 Pt wire mesh 10,30 Detecting electrode 12,28,32,36 Pt layer 16 Reference electrode 18 Lead 20,34 Heater
Claims (2)
ＺnＯ，ＳnＯ2，Ｉn2Ｏ3からなる群の少なくとも一員の
金属酸化物半導体を用いた検知極と、ＺnＯ，ＳnＯ2，
Ｉn2Ｏ3をいずれも含有しない参照極とを設けた固体電
解質水素センサ。1. The method according to claim 1, wherein the surface of the oxygen ion conductive solid electrolyte is
A detection electrode using a metal oxide semiconductor of at least one member of the group consisting of ZnO, SnO2, and In2O3;
A solid electrolyte hydrogen sensor provided with a reference electrode containing no In2O3.
とを特徴とする、請求項１の固体電解質水素センサ。2. The solid electrolyte hydrogen sensor according to claim 1, wherein said metal oxide semiconductor is ZnO.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29718596A JP3775704B2 (en) | 1996-10-18 | 1996-10-18 | Solid electrolyte hydrogen sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29718596A JP3775704B2 (en) | 1996-10-18 | 1996-10-18 | Solid electrolyte hydrogen sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10123093A true JPH10123093A (en) | 1998-05-15 |
| JP3775704B2 JP3775704B2 (en) | 2006-05-17 |
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ID=17843283
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29718596A Expired - Fee Related JP3775704B2 (en) | 1996-10-18 | 1996-10-18 | Solid electrolyte hydrogen sensor |
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| Country | Link |
|---|---|
| JP (1) | JP3775704B2 (en) |
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| WO2007020731A1 (en) * | 2005-08-12 | 2007-02-22 | Niigata Tlo Corporation | Hydrogen gas sensor |
| JP2007071642A (en) * | 2005-09-06 | 2007-03-22 | New Cosmos Electric Corp | Hydrogen gas detection element and hydrogen gas detector |
| JP2007225313A (en) * | 2006-02-21 | 2007-09-06 | Norio Miura | Gas sensing element |
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1996
- 1996-10-18 JP JP29718596A patent/JP3775704B2/en not_active Expired - Fee Related
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007017277A (en) * | 2005-07-07 | 2007-01-25 | Matsushita Electric Works Ltd | Hydrogen pressure sensor |
| WO2007020731A1 (en) * | 2005-08-12 | 2007-02-22 | Niigata Tlo Corporation | Hydrogen gas sensor |
| JP2007071642A (en) * | 2005-09-06 | 2007-03-22 | New Cosmos Electric Corp | Hydrogen gas detection element and hydrogen gas detector |
| JP2007225313A (en) * | 2006-02-21 | 2007-09-06 | Norio Miura | Gas sensing element |
| JP2009243942A (en) * | 2008-03-28 | 2009-10-22 | Kyushu Univ | Hydrocarbon concentration measuring sensor element and hydrocarbon concentration measuring method |
| US9722086B2 (en) | 2009-10-30 | 2017-08-01 | Semiconductor Energy Laboratory Co., Ltd. | Logic circuit and semiconductor device |
| JP2011120222A (en) * | 2009-10-30 | 2011-06-16 | Semiconductor Energy Lab Co Ltd | Logic circuit and semiconductor device |
| JP2011132876A (en) * | 2009-12-24 | 2011-07-07 | Hitachi Plant Technologies Ltd | Hydrogen compression device and hydrogen gas leakage monitoring system |
| US9366646B2 (en) | 2012-03-14 | 2016-06-14 | Korea Advanced Institute Of Science And Technology | Hydrogen measurement sensor having junction structure of solid oxygen ion conductor and solid hydrogen ion conductor in molten metal |
| CN104160267A (en) * | 2012-03-14 | 2014-11-19 | 韩国科学技术院 | Hydrogen measurement sensor having junction structure of solid oxygen ion conductor and solid hydrogen ion conductor in molten metal |
| JP2017044576A (en) * | 2015-08-26 | 2017-03-02 | 国立研究開発法人産業技術総合研究所 | Gas sensor and method of detecting gas |
| RU181283U1 (en) * | 2017-11-09 | 2018-07-09 | Александр Сергеевич Ильин | SEMICONDUCTOR HYDROGEN SENSOR OPERATING AT ROOM TEMPERATURE |
| JP2019138764A (en) * | 2018-02-09 | 2019-08-22 | 株式会社デンソー | Gas sensor |
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