JP2936933B2 - Limit current type nitrogen oxide sensor - Google Patents
Limit current type nitrogen oxide sensorInfo
- Publication number
- JP2936933B2 JP2936933B2 JP5001596A JP159693A JP2936933B2 JP 2936933 B2 JP2936933 B2 JP 2936933B2 JP 5001596 A JP5001596 A JP 5001596A JP 159693 A JP159693 A JP 159693A JP 2936933 B2 JP2936933 B2 JP 2936933B2
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- JP
- Japan
- Prior art keywords
- electrode film
- solid electrolyte
- oxygen
- electrolyte plate
- cathode
- Prior art date
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- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、空気中の窒素酸化物と
酸素の濃度を同時に計測する限界電流式窒素酸化物セン
サに関するものであるBACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a limiting current type nitrogen oxide sensor for simultaneously measuring nitrogen oxide and oxygen concentrations in air.
【０００２】[0002]
【従来の技術】空気中の酸素濃度を計測できる従来の限
界電流式センサの断面斜視図を図５に示す。１は酸素イ
オン伝導性固体電解質板であり、対となる白金電極膜３
ａと３ｂ（記載せず）が両面に対で形成されている。こ
の固体電解質板１の片側上部にカソード側電極膜３ａを
囲み、始端と終端がお互いに間隔を有するように配置さ
れた螺旋型スペーサ４が配置されている。そして螺旋型
スペーサ４の上部にシール板５を配置して、酸素拡散孔
６が螺旋型スペーサ４の相対向する隔壁と固体電解質板
１とシール板５で囲まれる螺旋型の空間で形成されてい
る。一方、シール板５の上部には加熱部７が配置されセ
ンサ素子を加熱している。電極膜３ａと３ｂはリード線
（記載せず）により直流電圧源（記載せず）と接続され
ており、直流電圧が印加されている。酸素は酸素拡散孔
６を経由してカソード側電極膜３ａへ拡散し、電場によ
り低電圧でも簡単に酸素イオンに変化し酸素イオン伝導
性固体電解質板をアノード電極膜３ｂに向かって移動
し、アノード電極膜３ｂで電子を奪われて再び酸素にな
り空気中に拡散する挙動を示す。一方、窒素酸化物も酸
素拡散孔６を経由してカソード側電極膜３ａへ拡散し、
直流電圧により高電圧側で電気分解して酸素と窒素に分
解する。そして生成物の酸素はさらに酸素イオンに変化
し酸素イオン伝導性固体電解質板１をアノード電極膜３
ｂに向かって移動し、アノード電極膜３ｂで電子を奪わ
れて再び酸素になり空気中に拡散する挙動を示す。2. Description of the Related Art FIG. 5 is a sectional perspective view of a conventional limiting current type sensor capable of measuring the oxygen concentration in air. Reference numeral 1 denotes an oxygen ion conductive solid electrolyte plate, and a platinum electrode film 3 serving as a pair.
a and 3b (not shown) are formed in pairs on both sides. A helical spacer 4 surrounding the cathode-side electrode film 3a and having a start end and an end spaced from each other is disposed on one upper side of the solid electrolyte plate 1. Then, a seal plate 5 is disposed above the spiral spacer 4, and oxygen diffusion holes 6 are formed in a spiral space surrounded by the opposing partition walls of the spiral spacer 4, the solid electrolyte plate 1, and the seal plate 5. I have. On the other hand, a heating section 7 is disposed above the seal plate 5 to heat the sensor element. The electrode films 3a and 3b are connected to a DC voltage source (not shown) by lead wires (not shown), and a DC voltage is applied. Oxygen diffuses through the oxygen diffusion holes 6 to the cathode-side electrode film 3a, easily changes to oxygen ions even at a low voltage by an electric field, and moves the oxygen ion conductive solid electrolyte plate toward the anode electrode film 3b. Electrons are deprived by the electrode film 3b, become oxygen again, and diffuse into the air. On the other hand, nitrogen oxides also diffuse into the cathode-side electrode film 3a through the oxygen diffusion holes 6,
It is electrolyzed on the high voltage side by DC voltage and decomposed into oxygen and nitrogen. The product oxygen is further changed to oxygen ions, and the oxygen ion conductive solid electrolyte plate 1 is placed on the anode electrode film 3.
b, the electrons are removed by the anode electrode film 3b, become oxygen again, and diffuse into the air.
【０００３】また、銅系超伝導金属酸化物は、電気抵抗
が非常に小さいとともに窒素酸化物を選択的に吸着する
ことが最近知られつつある。In addition, it has recently been known that copper-based superconducting metal oxides have very low electric resistance and selectively adsorb nitrogen oxides.
【０００４】[0004]
【発明が解決しようとする課題】図６に、動作温度４５
０℃での従来構成の白金電極におけるヘリウム中の各ガ
ス濃度における電圧電流特性を示す。一酸化窒素（Ｎ
Ｏ）や二酸化窒素（ＮＯ2）は、０．５Ｖ前後から分解
を開始して２．０Ｖ前後から限界電流が得られ始め、さ
らに２．２Ｖ前後になると電子伝導の影響で限界電流が
得られない。この窒素酸化物の分解電流は、窒素酸化物
が電気分解することで発生する電流が小さいため限界電
流が高電圧側で得られることとなるが、あまり高電圧に
なると電子伝導が顕著になるため限界電流が得られなく
なる弊害がある。そのため動作温度が低いと平坦な限界
電流が得られにくく一酸化窒素の濃度が正確に測定でき
ない。そこでこのことを回避して明確な限界電流を得て
一酸化窒素の濃度を正確に測定するためにセンサの動作
温度を上昇させているが、このことはセンサの寿命を短
くする課題がある。FIG. 6 shows an operating temperature of 45.
5 shows voltage-current characteristics of a platinum electrode having a conventional configuration at 0 ° C. for various gas concentrations in helium. Nitric oxide (N
O) and nitrogen dioxide (NO 2 ) start to decompose at about 0.5 V, and a limit current starts to be obtained at about 2.0 V. At about 2.2 V, a limit current is obtained due to electron conduction. Absent. As for the decomposition current of this nitrogen oxide, the current generated by electrolysis of the nitrogen oxide is small, so that the limit current is obtained on the high voltage side, but when the voltage is too high, the electron conduction becomes remarkable. There is an adverse effect that a limit current cannot be obtained. Therefore, when the operating temperature is low, a flat limit current is hardly obtained, and the concentration of nitric oxide cannot be measured accurately. To avoid this, the operating temperature of the sensor is raised in order to obtain a clear limit current and accurately measure the concentration of nitric oxide. However, this has the problem of shortening the life of the sensor.
【０００５】本発明はかかる従来の問題点を解消するも
ので、センサの動作温度を上昇させることなく低い動作
温度で窒素酸化物の濃度を正確に測定するものである。The present invention solves such a conventional problem, and is intended to accurately measure the concentration of nitrogen oxide at a low operating temperature without increasing the operating temperature of the sensor.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するため
に本発明の限界電流式窒素酸化物センサは、対となる第
１電極膜および第２電極膜を両面に２対形成した酸素イ
オン伝導性固体電解質板と、前記固体電解質板の片側の
２個のカソード電極膜を各々囲み始端と終端がお互いに
間隔を有するように配置された２個の螺旋型スペーサ
と、前記螺旋型スペーサの相対向する隔壁と前記固体電
解質板とで囲まれる第１酸素拡散孔および第２酸素拡散
孔を内部に形成するために前記螺旋型スペーサの上部に
配置したシール板とで構成され、前記第１電極膜のカソ
ード電極膜が貴金属と銅系超伝導金属酸化物の混合物か
らなり前記第２電極膜のカソード電極膜が貴金属からな
る構成とした。In order to solve the above-mentioned problems, a limiting current type nitrogen oxide sensor according to the present invention comprises an oxygen ion conductor having two pairs of a first electrode film and a second electrode film formed on both surfaces. A solid electrolyte plate, two helical spacers each surrounding two cathode electrode films on one side of the solid electrolyte plate and arranged so that a start end and an end are spaced from each other; A sealing plate disposed above the helical spacer to form therein first oxygen diffusion holes and second oxygen diffusion holes surrounded by the solid electrolyte plate, and the first electrode The cathode electrode film of the film was made of a mixture of a noble metal and a copper-based superconducting metal oxide, and the cathode electrode film of the second electrode film was made of a noble metal.
【０００７】また、両面に対となる第１電極膜を形成し
た第１酸素イオン伝導性固体電解質板と、前記固体電解
質板の片側の電極膜を囲み始端と終端がお互いに間隔を
有するように配置された螺旋型スペーサと、前記螺旋型
スペーサの上部に配置されており両面に対となる第２電
極膜を形成した第２酸素イオン伝導性固体電解質板とで
構成され、前記第１電極膜のカソード電極膜が貴金属と
銅系超伝導金属酸化物の混合物からなり、前記第２電極
膜のカソード電極膜が貴金属からなる構成とした。Further, a first oxygen ion conductive solid electrolyte plate having a pair of first electrode films formed on both surfaces thereof, and a first end and a second end surrounding the electrode film on one side of the solid electrolyte plate are spaced from each other. The first electrode film, comprising: a spiral spacer disposed thereon; and a second oxygen ion conductive solid electrolyte plate disposed on the spiral spacer and having a pair of second electrode films formed on both surfaces thereof. Is made of a mixture of a noble metal and a copper-based superconducting metal oxide, and the cathode electrode film of the second electrode film is made of a noble metal.
【０００８】[0008]
【作用】上記構成により、窒素酸化物は第１酸素拡散孔
を経由して、貴金属と銅系超伝導金属酸化物の混合物か
らなるカソード側第１電極膜へ拡散する。そしてカソー
ド側第１電極膜において銅系超伝導金属酸化物により吸
着され、さらに貴金属と直流電圧により簡単に分解して
酸素イオンに変化し酸素イオン伝導性固体電解質板をア
ノード電極膜に向かって移動する。そのため、第１酸素
拡散孔において低印加電圧から窒素酸化物に関する限界
電流が得られる。一方、第２酸素拡散孔においては貴金
属からなる第２電極膜において酸素の限界電流が得られ
る。従って、センサの動作温度を上昇させることなく低
い動作温度で一酸化窒素と酸素の濃度を２つの電極を用
いて同時に正確に測定できる。With the above arrangement, the nitrogen oxide diffuses through the first oxygen diffusion holes into the first cathode electrode film made of a mixture of a noble metal and a copper-based superconducting metal oxide. Then, it is adsorbed by the copper-based superconducting metal oxide on the cathode-side first electrode film, and is easily decomposed by the noble metal and the DC voltage to change into oxygen ions, and the oxygen ion-conductive solid electrolyte plate moves toward the anode electrode film. I do. Therefore, a critical current relating to nitrogen oxide can be obtained from the low applied voltage in the first oxygen diffusion hole. On the other hand, in the second oxygen diffusion hole, a limiting current of oxygen is obtained in the second electrode film made of a noble metal. Therefore, the concentration of nitric oxide and oxygen can be simultaneously and accurately measured using the two electrodes at a low operating temperature without increasing the operating temperature of the sensor.
【０００９】また上記構成により、窒素酸化物は酸素拡
散孔を経由して、貴金属と銅系超伝導金属酸化物の混合
物からなるカソード側第１電極膜へ拡散する。そしてカ
ソード側第１電極膜において銅系超伝導金属酸化物によ
り吸着され、さらに貴金属と直流電圧により簡単に分解
して酸素イオンに変化し酸素イオン伝導性固体電解質板
をアノード電極膜に向かて移動する。そのため、第１電
極膜において低印加電圧から窒素酸化物に関する限界電
流が得られる。一方、貴金属からなる第２電極膜におい
て酸素の限界電流が得られる。従って、センサの動作温
度を上昇させることなく低い動作温度で一酸化窒素と酸
素の濃度を２つの電極を用いて同時に正確に測定でき
る。[0009] Further, with the above configuration, the nitrogen oxide diffuses into the cathode-side first electrode film made of a mixture of a noble metal and a copper-based superconducting metal oxide through the oxygen diffusion holes. Then, it is adsorbed by the copper-based superconducting metal oxide on the cathode-side first electrode film, and is further easily decomposed by the noble metal and the DC voltage to change into oxygen ions, and the oxygen ion-conductive solid electrolyte plate is moved toward the anode electrode film. Moving. Therefore, a limit current regarding nitrogen oxide can be obtained from the low applied voltage in the first electrode film. On the other hand, a limiting current of oxygen is obtained in the second electrode film made of a noble metal. Therefore, the concentration of nitric oxide and oxygen can be simultaneously and accurately measured using the two electrodes at a low operating temperature without increasing the operating temperature of the sensor.
【００１０】[0010]
【実施例】以下、本発明の実施例を図面にもとづいて説
明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１１】図１は、発明の第１の実施例である限界電
流式窒素酸化物センサの断面斜視図である。図１におい
て、１は酸素イオン伝導性固体電解質板であり、対とな
る第１電極膜２ａと２ｂ（記載せず）および第２電極膜
３ａと３ｂ（記載せず）が両面に２対形成されている。
この固体電解質板１の片側上部にカソード側第１電極膜
２ａおよびカソード側第２電極膜３ａを各々囲み、始端
と終端がお互いに間隔を有するように配置された第１螺
旋型スペーサ４ａ−１および第２螺旋型スペーサ４ａ−
２が配置されている。そして螺旋型スペーサ４ａ−１、
４ａ−２の上部にシール板５を配置した。そのため、第
１酸素拡散孔６ａ−１および第２酸素拡散孔６ａ−２が
螺旋型スペーサ４ａ−１、４ａ−２の相対向する隔壁と
固体電解質板１とシール板５で囲まれる螺旋型の空間で
形成されている。一方、シール板５の上部には加熱部７
が配置されセンサ素子を加熱している。カソード側第１
電極膜２ａは貴金属と銅系超伝導金属酸化物の混合物か
らなり、カソード側第２電極膜３ａは貴金属からなる。FIG. 1 is a sectional perspective view of a limiting current type nitrogen oxide sensor according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an oxygen ion conductive solid electrolyte plate, and two pairs of first electrode films 2a and 2b (not shown) and second electrode films 3a and 3b (not shown) are formed on both surfaces. Have been.
A first helical spacer 4a-1 surrounding the cathode-side first electrode film 2a and the cathode-side second electrode film 3a on one side of the upper part of the solid electrolyte plate 1 and having a start end and an end spaced from each other. And the second helical spacer 4a-
2 are arranged. And the spiral spacer 4a-1,
The seal plate 5 was arranged on the upper part of 4a-2. Therefore, the first oxygen diffusion hole 6a-1 and the second oxygen diffusion hole 6a-2 are surrounded by the partition walls of the spiral spacers 4a-1 and 4a-2, the solid electrolyte plate 1, and the seal plate 5 in a spiral shape. The space is formed. On the other hand, a heating unit 7 is provided above the seal plate 5.
Are arranged to heat the sensor element. Cathode side first
The electrode film 2a is made of a mixture of a noble metal and a copper-based superconducting metal oxide, and the cathode-side second electrode film 3a is made of a noble metal.
【００１２】次に具体的実験例にもとづいて説明する。
図１の限界電流式窒素酸化物センサにおいて固体電解質
板１としてＺｒＯ2、Ｙ2Ｏ3（Ｙ2Ｏ3８mol％添加）、第
１電極膜２ａ、２ｂとして白金とＹＢａ2Ｃｕ3Ｏ7系超
伝導金属酸化物の混合物、第２電極膜３ａ、３ｂとして
白金、螺旋型スペーサ４ａ−１、４ａ−２として硝子
（熱膨脹係数はＺｒＯ2、Ｙ2Ｏ3と概略同一であり、所
定粒径の耐熱性粒子を微量含有）、シール板５としてフ
ォルステライト、加熱部７として白金ヒータを用いた。
製法について説明する。まず白金とＹＢａ2Ｃｕ3Ｏ7系
超伝導金属酸化物を３：１の重量比で混合し、酸化銅系
硝子フリットや有機溶剤を添加して第１電極膜２ａ、２
ｂのペーストを試作した。次に、第１電極膜２ａ、２ｂ
および第２電極膜３ａ、３ｂを固体電解質板１の上に、
さらに螺旋型スペーサ４ａ−１、４ａ−２を固体電解質
板１の上に厚膜印刷技術および焼成技術を用いて形成し
た。一方、シール板５の上には加熱部７を厚膜印刷技術
および焼成技術を用いて形成した。次に、固体電解質板
１上の螺旋型スペーサ４ａ−１、４ａ−２とシール板５
とを積層し加熱溶融することで酸素拡散孔６ａ−１、６
ａ−２を形成した。そしてリード線（記載せず）を取り
つけて完成である。完成品素子の寸法は１２×１２×
０．９mmである。Next, a description will be given based on specific experimental examples.
In the limiting current type nitrogen oxide sensor of FIG. 1, ZrO 2 and Y 2 O 3 (8 mol% addition of Y 2 O 3 ) are used as the solid electrolyte plate 1, and platinum and YBa 2 Cu 3 O 7 are used as the first electrode films 2a and 2b. A mixture of a superconducting metal oxide, platinum as the second electrode films 3a and 3b, and glass as the helical spacers 4a-1 and 4a-2 (the thermal expansion coefficients are substantially the same as those of ZrO 2 and Y 2 O 3 , and a predetermined particle size. , Forsterite as the seal plate 5 and a platinum heater as the heating unit 7.
The production method will be described. First, platinum and a YBa 2 Cu 3 O 7 -based superconducting metal oxide are mixed at a weight ratio of 3: 1, and a copper oxide-based glass frit or an organic solvent is added to the first electrode film 2 a, 2.
The paste of b was made as a trial. Next, the first electrode films 2a, 2b
And the second electrode films 3a, 3b on the solid electrolyte plate 1,
Further, spiral spacers 4a-1 and 4a-2 were formed on the solid electrolyte plate 1 by using a thick film printing technique and a baking technique. On the other hand, the heating section 7 was formed on the seal plate 5 by using a thick film printing technique and a baking technique. Next, the spiral spacers 4a-1, 4a-2 on the solid electrolyte plate 1 and the seal plate 5
And melted by heating to form oxygen diffusion holes 6a-1, 6a.
a-2 was formed. Then, lead wires (not shown) are attached to complete the process. The dimensions of the finished device are 12 × 12 ×
0.9 mm.
【００１３】図２に、動作温度４５０℃での酸素２．５
％と二酸化窒素（ＮＯ2）５．０％における電圧電流特
性を示す。白金とＹＢａ2Ｃｕ3Ｏ7系超伝導金属酸化物
（略称でＹＢＣ吸着材）の混合物からなるカソード側第
１電極膜２ａを有する酸素拡散孔６ａ−１（第１酸素拡
散孔）は、二酸化窒素の限界電流が１．５Ｖ〜２．２５
Ｖ前後で得られている。一方、白金からなるカソード側
第２電極膜３ａを有する酸素拡散孔６ａ−２（第２酸素
拡散孔）は、酸素の限界電流が０．７５Ｖ〜１．２５Ｖ
前後で得られ、この２つの限界電流から酸素と二酸化窒
素の計測が可能となった。また、この実施例において二
酸化窒素の限界電流が１．５Ｖ〜２．２５Ｖ前後で得ら
れることは、従来の白金電極における２．０Ｖ〜２．２
５Ｖに比較して低電圧側にシフトしており、ＹＢａ2Ｃ
ｕ3Ｏ7系超伝導金属酸化物の吸着効果によりものであ
る。FIG. 2 shows oxygen 2.5 at an operating temperature of 450 ° C.
% And nitrogen dioxide (NO 2 ) 5.0%. The oxygen diffusion holes 6a-1 (first oxygen diffusion holes) having the cathode-side first electrode film 2a made of a mixture of platinum and a YBa 2 Cu 3 O 7 -based superconducting metal oxide (abbreviated as YBC adsorbent) The limit current of nitrogen is 1.5V to 2.25
It is obtained around V. On the other hand, the oxygen diffusion hole 6a-2 (second oxygen diffusion hole) having the cathode-side second electrode film 3a made of platinum has a limiting current of oxygen of 0.75V to 1.25V.
Obtained before and after, and it became possible to measure oxygen and nitrogen dioxide from these two limit currents. Further, the fact that the limit current of nitrogen dioxide can be obtained at around 1.5 V to 2.25 V in this embodiment means that the conventional platinum electrode has a limit current of 2.0 V to 2.2 V.
It is shifted to a lower voltage side compared to 5V, and YBa 2 C
This is due to the adsorption effect of the u 3 O 7 -based superconducting metal oxide.
【００１４】なお、第１電極膜における２．２５Ｖ以上
の電流挙動は電子伝導のため、第２電極膜における１．
２５Ｖ以上の電流挙動は二酸化窒素の分解電流のためで
あり、これら影響のため限界電流が得られなかった。Since the current behavior of 2.25 V or more in the first electrode film is electron conduction, the current behavior in the second electrode film is not less than 1.25 V.
The current behavior of 25 V or more is due to the decomposition current of nitrogen dioxide, and no limit current was obtained due to these effects.
【００１５】また、白金とＹＢａ2Ｃｕ3Ｏ7伝導金属酸
化物との混合比であるが、ＰｔをＹＢａ2Ｃｕ3Ｏ7に対
して９９〜０．１倍の範囲で混合しても効果が得られ
た。この混合割合は、Ｐｔが多いと酸素の吸着特性に優
れ、ＹＢａ2Ｃｕ3Ｏ7が多いと窒素酸化物の吸着特性に
優れることの相関で決められると推定される。The mixing ratio of platinum to YBa 2 Cu 3 O 7 conductive metal oxide is effective even if Pt is mixed in a range of 99 to 0.1 times that of YBa 2 Cu 3 O 7 . was gotten. It is presumed that this mixing ratio is determined by the correlation that when the amount of Pt is large, the oxygen adsorption characteristics are excellent, and when the amount of YBa 2 Cu 3 O 7 is large, the nitrogen oxide adsorption characteristics are excellent.
【００１６】図３は、本発明の第２の実施例である限界
電流式窒素酸化物センサの断面斜視図である。図３にお
いて、１ａ−１は第１の酸素イオン伝導性固体電解質板
であり、対となる第１電極膜２ａと２ｂ（記載せず）が
形成されている。この第１固体電解質板１ａ−１の片側
上部にカソード側第１電極膜２ａを囲み、始端と終端が
お互いに間隔を有するように配置された螺旋型スペーサ
４が配置されている。一方、１ａ−２は第２酸素イオン
伝導性固体電解質板であり、対となる第２電極膜３ａ
（記載せず）と３ｂが形成されている。そして螺旋型ス
ペーサ４の上部に第２の酸素イオン伝導性固体電解質板
１ａ−２を配置し、酸素拡散孔６が螺旋型スペーサ４の
相対向する隔壁と第１固体電解質板１ａ−１と第２固体
電解質板１ａ−２で囲まれる螺旋型の空間で形成されて
いる。そのため、第１電極膜２ａ、２ｂと第２電極膜３
ａ、３ｂで１個の酸素拡散孔６を共有している。第１カ
ソード側電極膜２ａは貴金属と銅系超伝導金属酸化物の
混合物からなり、第２カソード側電極膜３ａは貴金属か
らなる。FIG. 3 is a sectional perspective view of a limiting current type nitrogen oxide sensor according to a second embodiment of the present invention. In FIG. 3, reference numeral 1a-1 denotes a first oxygen ion conductive solid electrolyte plate, on which a pair of first electrode films 2a and 2b (not shown) are formed. A helical spacer 4 surrounding the cathode-side first electrode film 2a and having a start end and an end spaced from each other is disposed above one side of the first solid electrolyte plate 1a-1. On the other hand, reference numeral 1a-2 denotes a second oxygen ion conductive solid electrolyte plate, and a pair of second electrode films 3a.
(Not shown) and 3b are formed. Then, a second oxygen ion conductive solid electrolyte plate 1a-2 is disposed on the upper part of the spiral spacer 4, and the oxygen diffusion holes 6 are arranged opposite to the partition wall of the spiral spacer 4, the first solid electrolyte plate 1a-1 and the second solid electrolyte plate 1a-1. It is formed of a spiral space surrounded by two solid electrolyte plates 1a-2. Therefore, the first electrode films 2a and 2b and the second electrode film 3
a, 3b share one oxygen diffusion hole 6. The first cathode-side electrode film 2a is made of a mixture of a noble metal and a copper-based superconducting metal oxide, and the second cathode-side electrode film 3a is made of a noble metal.
【００１７】次に具体的実験例にもとづいて説明する。
図３の限界電流式窒素酸化物センサにおいて固体電解質
板１ａ−１および１ａ−２としてＺｒＯ2、Ｙ2Ｏ3（Ｙ2
Ｏ3８mol％添加）、第１電極膜２ａ、２ｂとして白金と
ＧａＢａ2Ｃｕ3Ｏ7系超伝導金属酸化物の混合物、第２
電極膜３ａ、３ｂとして白金、螺旋型スペーサ４として
硝子（熱膨脹係数はＺｒＯ2、Ｙ2Ｏ3と概略同一であ
り、所定粒径の耐熱性粒子を微量含有）を用いた。製法
について説明する。まず白金とＧａＢａ2Ｃｕ3Ｏ 7系超
伝導金属酸化物を３：１の重量比で混合し、酸化銅系硝
子フリットや有機溶剤を添加して第１電極膜２ａ、２ｂ
のペーストを試作した。次に、電極膜２ａ、２ｂを第１
固体電解質板１ａ−１の上に、第２電極膜３ａ、３ｂを
第２固体電解質板１ａ−２の上に厚膜印刷技術および焼
成技術を用いて各々形成した。さらに螺旋型スペーサ４
を第１固体電解質板１ａ−１の上に厚膜印刷技術および
焼成技術を用いて形成した。最後に第１固体電解質板１
ａ−１の上に第２固体電解質板１ａ−２とを積層し加熱
溶融することで酸素拡散孔６を形成した。そしてリード
線（記載せず）を取りつけて完成である。完成品素子の
寸法は１２×１２×０．９mmである。Next, a description will be given based on specific experimental examples.
The solid electrolyte in the limiting current type nitrogen oxide sensor of FIG.
ZrO as plates 1a-1 and 1a-2Two, YTwoOThree(YTwo
OThree8 mol%), and platinum as the first electrode films 2a and 2b.
GaBaTwoCuThreeO7Of superconducting metal oxides, second
Platinum for the electrode films 3a and 3b, and for the spiral spacer 4
Glass (Coefficient of thermal expansion is ZrOTwo, YTwoOThreeIs almost identical to
And a small amount of heat-resistant particles having a predetermined particle size). Manufacturing method
Will be described. First, platinum and GaBaTwoCuThreeO 7System
A conductive metal oxide is mixed at a weight ratio of 3: 1 and copper oxide-based
The first electrode films 2a, 2b
Was made as a prototype. Next, the electrode films 2a and 2b are
The second electrode films 3a and 3b are formed on the solid electrolyte plate 1a-1.
Thick film printing technology and printing on the second solid electrolyte plate 1a-2.
Each was formed using a forming technique. Furthermore, spiral spacer 4
Thick film printing technology on the first solid electrolyte plate 1a-1 and
It was formed using a firing technique. Finally, the first solid electrolyte plate 1
A second solid electrolyte plate 1a-2 is laminated on a-1 and heated.
The oxygen diffusion holes 6 were formed by melting. And lead
Attach a line (not shown) to complete. Completed element
The dimensions are 12 × 12 × 0.9 mm.
【００１８】図４に、動作温度４５０℃での酸素２．５
％と二酸化窒素（ＮＯ2 ）５．０％における電圧電流特
性を示す。白金とＧａＢａ2Ｃｕ3Ｏ7系超伝導金属酸化
物（略称でＧＢＣ吸着材）の混合物からなるカソ−ド側
第１電極膜２ａは、二酸化窒素の限界電流が１．５Ｖ〜
２．２５Ｖ前後で得られている。一方、白金からなるカ
ソ−ド側第２電極膜３ａは、酸素の限界電流が０．７５
Ｖ〜１．２５Ｖ前後で得られ、この２つの限界電流から
酸素と二酸化窒素の計測が可能となった。また、この実
施例において二酸化窒素の限界電流が１．５Ｖ〜２．２
５Ｖ前後で得られることは、従来の白金電極における
２．０Ｖ〜２．２５Ｖに比較して低電圧側にシフトして
おり、ＧａＢａ2Ｃｕ3Ｏ7系超伝導金属酸化物の吸着効
果によりものである。FIG. 4 shows oxygen 2.5 at an operating temperature of 450 ° C.
% And nitrogen dioxide (NO 2 ) 5.0%. Platinum and GaBa 2 Cu 3 O 7-based superconducting metal oxide consists of a mixture of (GBC adsorbent in abbreviation) cathode - the first electrode layer 2a de side, limiting current of nitrogen dioxide 1.5V~
It is obtained around 2.25V. On the other hand, the cathode-side second electrode film 3a made of platinum has a limiting current of oxygen of 0.75.
V was obtained at about 1.25 V, and oxygen and nitrogen dioxide could be measured from these two limit currents. In this embodiment, the limit current of nitrogen dioxide is 1.5 V to 2.2.
What is obtained at about 5 V is shifted to a lower voltage side as compared with 2.0 V to 2.25 V in the conventional platinum electrode, and is due to the adsorption effect of the GaBa 2 Cu 3 O 7 -based superconducting metal oxide. It is.
【００１９】なお、第１電極膜における２．２５Ｖ以上
の電流挙動は電子伝導のため、第２電極膜における１．
２５Ｖ以上の電流挙動は二酸化窒素の分解電流のためで
あり、これら影響のため限界電流が得られなかった。Since the current behavior of 2.25 V or more in the first electrode film is electron conduction, the current behavior in the second electrode film is not less than 1.25 V.
The current behavior of 25 V or more is due to the decomposition current of nitrogen dioxide, and no limit current was obtained due to these effects.
【００２０】また、白金とＧａＢａ2Ｃｕ3Ｏ7系超伝導
金属酸化物との混合比であるが、ＰｔをＧａＢａ2Ｃｕ3
Ｏ7に対して９９〜０．１倍の範囲で混合しても効果が
得られた。この割合は、Ｐｔが多いと酸素の吸着特性に
優れ、ＧａＢａ2Ｃｕ3Ｏ7多いと窒素酸化物の吸着特性
に優れることの相関で決められると推定される。The mixing ratio of platinum to GaBa 2 Cu 3 O 7 -based superconducting metal oxide is such that Pt is GaBa 2 Cu 3
Be mixed with respect to O 7 in the range of 99 to 0.1 fold effect was obtained. It is presumed that this ratio is determined by the correlation that when the content of Pt is large, the oxygen adsorption property is excellent, and when the content of GaBa 2 Cu 3 O 7 is large, the nitrogen oxide adsorption property is excellent.
【００２１】銅系超伝導金属酸化物として、ＹＢａ2Ｃ
ｕ3Ｏ7およびＧａＢａ2Ｃｕ3Ｏ7以外にＢａ2ＣｕＯ3.5
やＬａＣｕＯ4、ＢｉｚＣａＳｒ2Ｃｕ2Ｏ10、Ｔｌ2Ｃａ
ＢａＣｕ2Ｏ9、ＢａＣｕ3Ｏ5、ＹａＢａＣｕＯ5、Ｂａ
Ｃｕ3Ｏ5も検討したが同様な効果が得られ、低電圧側か
ら二酸化窒素の限界電流が観察された。また、白金との
混合割合も白金を銅系超伝導金属酸化物に対して９９〜
０．１倍の範囲で混合すると良好な特性が得られた。As a copper-based superconducting metal oxide, YBa 2 C
u 3 O 7 and GaBa 2 Cu 3 O 7 Ba 2 CuO 3.5 in addition
And LaCuO 4 , BizCaSr 2 Cu 2 O 10 , Tl 2 Ca
BaCu 2 O 9 , BaCu 3 O 5 , YaBaCuO 5 , Ba
Although Cu 3 O 5 was also examined, a similar effect was obtained, and a limiting current of nitrogen dioxide was observed from the low voltage side. Further, the mixing ratio of platinum to copper-based superconducting metal oxide is 99 to
Good characteristics were obtained by mixing in a range of 0.1 times.
【００２２】[0022]
【発明の効果】以上のように本発明の限界電流式窒素酸
化物センサによれば、次の効果が得られる。As described above, according to the limiting current type nitrogen oxide sensor of the present invention, the following effects can be obtained.
【００２３】（１）対となる第１電極膜および第２電極
膜を両面に２対形成した酸素イオン伝導性固体電解質板
と、固体電解質板の片側の２個のカソ−ド電極膜を各々
囲み始端と終端がお互いに間隔を有するように配置され
た２個の螺旋型スペ−サと、螺旋型スペーサの相対向す
る隔壁と固体電解質板とで囲まれる第１酸素拡散孔およ
び第２酸素拡散孔を内部に形成するために螺旋型スペー
サの上部に配置したシール板とで構成され、第１電極膜
のカソ−ド電極膜が貴金属と銅系超伝導金属酸化物の混
合物からなり、第２電極膜のカソ−ド電極膜が貴金属か
らなる。窒素酸化物は第１酸素拡散孔を経由して拡散
し、カソ−ド側第１電極膜において銅系超伝導金属酸化
物により吸着され、さらに貴金属と直流電圧により分解
して酸素イオンに変化し、酸素イオン伝導性固体電解質
板をアノ−ド電極膜に向かって移動する。そのため、第
１酸素拡散孔において低印加電圧から窒素酸化物に関す
る限界電流が得られる。一方、第２酸素拡散孔において
は貴金属からなる第２電極膜において酸素の限界電流が
得られる。従って、センサの動作温度を上昇させること
なく低い動作温度で一酸化窒素と酸素の濃度を同時に測
定できる。(1) An oxygen ion conductive solid electrolyte plate in which two pairs of a first electrode film and a second electrode film are formed on both surfaces, and two cathode electrode films on one side of the solid electrolyte plate, respectively. A first oxygen diffusion hole and a second oxygen surrounded by two spiral spacers arranged so that the enclosing start end and the end end are spaced from each other, and opposing partition walls of the spiral spacer and the solid electrolyte plate. A cathode plate disposed above the helical spacer to form a diffusion hole therein, wherein the cathode electrode film of the first electrode film comprises a mixture of a noble metal and a copper-based superconducting metal oxide; The cathode electrode film of the two-electrode film is made of a noble metal. The nitrogen oxides diffuse through the first oxygen diffusion holes, are adsorbed by the copper-based superconducting metal oxide in the cathode-side first electrode film, and further decompose with the noble metal by a DC voltage to change into oxygen ions. Then, the oxygen ion conductive solid electrolyte plate is moved toward the anode electrode film. Therefore, a critical current relating to nitrogen oxide can be obtained from the low applied voltage in the first oxygen diffusion hole. On the other hand, in the second oxygen diffusion hole, a limiting current of oxygen is obtained in the second electrode film made of a noble metal. Therefore, the concentrations of nitric oxide and oxygen can be measured simultaneously at a low operating temperature without increasing the operating temperature of the sensor.
【００２４】（２）両面に対となる第１電極膜を形成し
た第１酸素イオン伝導性固体電解質板と、固体電解質板
の片側の電極膜を囲み始端と終端がお互いに間隔を有す
るように配置された螺旋型スペーサと、螺旋型スペーサ
の上部に配置されており両面に対となる第２電極膜を形
成した第２酸素イオン伝導性固体電解質板とで構成さ
れ、第１電極膜のカソ−ド電極膜が貴金属と銅系超伝導
金属酸化物の混合物からなり第２電極膜のカソ−ド電極
膜が貴金属からなる。窒素酸化物は酸素拡散孔を経由し
て拡散しカソ−ド側第１電極膜において銅系超伝導金属
酸化物により吸着され、さらに貴金属と直流電圧により
分解して酸素イオンに変化し酸素イオン伝導性固体電解
質板をアノ−ド電極膜に向かて移動する。そのため、第
１電極膜において低印加電圧から窒素酸化物に関する限
界電流が得られる。一方、貴金属からなる第２電極膜に
おいては酸素の限界電流が得られる。従って、センサの
動作温度を上昇させることなく低い動作温度で一酸化窒
素と酸素の濃度を同時に正確に測定できる。(2) A first oxygen ion-conductive solid electrolyte plate having a pair of first electrode films formed on both surfaces, and an electrode film on one side of the solid electrolyte plate is surrounded so that the start end and the end are spaced from each other. And a second oxygen ion conductive solid electrolyte plate which is disposed above the spiral spacer and has a pair of second electrode films formed on both sides thereof. The cathode electrode film is made of a mixture of a noble metal and a copper-based superconducting metal oxide, and the cathode electrode film of the second electrode film is made of a noble metal. Nitrogen oxide diffuses through the oxygen diffusion holes and is adsorbed by the copper-based superconducting metal oxide in the cathode-side first electrode film, and further decomposes with the noble metal by a DC voltage to change into oxygen ions, thereby causing oxygen ion conduction. The conductive solid electrolyte plate is moved toward the anode electrode film. Therefore, a limit current regarding nitrogen oxide can be obtained from the low applied voltage in the first electrode film. On the other hand, in the second electrode film made of a noble metal, a limiting current of oxygen is obtained. Therefore, the concentrations of nitric oxide and oxygen can be simultaneously and accurately measured at a low operating temperature without increasing the operating temperature of the sensor.
【図１】本発明の第１の実施例である限界電流式窒素酸
化物センサの断面斜視図FIG. 1 is a sectional perspective view of a limiting current type nitrogen oxide sensor according to a first embodiment of the present invention.
【図２】図１の限界電流式窒素酸化物センサの効果特性
図FIG. 2 is an effect characteristic diagram of the limiting current type nitrogen oxide sensor of FIG.
【図３】本発明の第２の実施例である限界電流式窒素酸
化物センサの断面斜視図FIG. 3 is a sectional perspective view of a limiting current type nitrogen oxide sensor according to a second embodiment of the present invention.
【図４】図３の限界電流式窒素酸化物センサの効果特性
図4 is an effect characteristic diagram of the limiting current type nitrogen oxide sensor of FIG.
【図５】従来の限界電流式窒素酸化物センサの断面斜視
図FIG. 5 is a sectional perspective view of a conventional limiting current type nitrogen oxide sensor.
【図６】従来の限界電流式窒素酸化物センサの効果特性
図FIG. 6 is an effect characteristic diagram of a conventional limiting current type nitrogen oxide sensor.
１ 酸素イオン伝導性固体電解質板 １ａ−１ 第１酸素イオン伝導性固体電解質板 １ａ−２ 第２酸素イオン伝導性固体電解質板 ２ａ カソ−ド側第１電極膜 ３ａ カソ−ド側第２電極膜 ３ｂ アノ−ド側第２電極膜 ４ 螺旋型スペーサ ４ａ−１ 第１螺旋型スペーサ ４ａ−２ 第２螺旋型スペーサ ５ シール板 ６ 酸素拡散孔 ６ａ−１ 第１酸素拡散孔 ６ａ−２ 第２酸素拡散孔 DESCRIPTION OF SYMBOLS 1 Oxygen ion conductive solid electrolyte board 1a-1 1st oxygen ion conductive solid electrolyte board 1a-2 2nd oxygen ion conductive solid electrolyte board 2a Cathode side 1st electrode film 3a Cathode side 2nd electrode film 3b Anode-side second electrode film 4 Spiral spacer 4a-1 First spiral spacer 4a-2 Second spiral spacer 5 Seal plate 6 Oxygen diffusion hole 6a-1 First oxygen diffusion hole 6a-2 Secondary oxygen Diffusion hole
───────────────────────────────────────────────────── フロントページの続き (72)発明者 梅田 孝裕 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (72)発明者 黄地 謙三 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (56)参考文献 特開 平６−160344（ＪＰ，Ａ) 特表 平６−511560（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) G01N 27/416 G01N 27/41 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takahiro Umeda 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (56) References JP-A-6-160344 (JP, A) JP-A-6-511560 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) G01N 27/416 G01N 27/41
Claims (2)
面に２対形成した酸素イオン伝導性固体電解質板と、前
記固体電解質板の片側の２個のカソード電極膜を各々囲
み始端と終端がお互いに間隔を有するように配置された
２個の螺旋型スペーサと、前記螺旋型スペーサの相対向
する隔壁と前記固体電解質板とで囲まれる第１酸素拡散
孔および第２酸素拡散孔を内部に形成するために前記螺
旋型スペーサの上部に配置したシール板とで構成され、
前記第１電極膜のカソード電極膜が貴金属と銅系超伝導
金属酸化物の混合物からなり、前記第２電極膜のカソー
ド電極膜が貴金属からなる限界電流式窒素酸化物セン
サ。1. An oxygen ion-conductive solid electrolyte plate having two pairs of a first electrode film and a second electrode film formed on both surfaces thereof, and two cathode electrode films on one side of the solid electrolyte plate, each surrounding a starting end. And two helical spacers whose ends are spaced from each other, first oxygen diffusion holes and second oxygen diffusion holes surrounded by opposing partitions of the helical spacer and the solid electrolyte plate. A seal plate disposed above the helical spacer to form the inside,
A limiting current type nitrogen oxide sensor, wherein the cathode electrode film of the first electrode film is made of a mixture of a noble metal and a copper-based superconducting metal oxide, and the cathode electrode film of the second electrode film is made of a noble metal.
酸素イオン伝導性固体電解質板と、前記固体電解質板の
片側の電極膜を囲み始端と終端がお互いに間隔を有する
ように配置された螺旋型スペーサと、前記螺旋型スペー
サの上部に配置されており両面に対となる第２電極膜を
形成した第２酸素イオン伝導性固体電解質板とで構成さ
れ、前記第１電極膜のカソード電極膜が貴金属と銅系超
伝導金属酸化物の混合物からなり、前記第２電極膜のカ
ソード電極膜が貴金属からなる限界電流式窒素酸化物セ
ンサ。2. A first electrode having a pair of first electrode films formed on both surfaces.
An oxygen ion conductive solid electrolyte plate, a helical spacer surrounding the electrode film on one side of the solid electrolyte plate, and a start end and an end arranged so as to be spaced from each other, and are disposed above the helical spacer. A second oxygen ion conductive solid electrolyte plate having a pair of second electrode films formed on both surfaces, wherein the cathode electrode film of the first electrode film is made of a mixture of a noble metal and a copper-based superconducting metal oxide; A limiting current type nitrogen oxide sensor wherein the cathode electrode film of the second electrode film is made of a noble metal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5001596A JP2936933B2 (en) | 1993-01-08 | 1993-01-08 | Limit current type nitrogen oxide sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5001596A JP2936933B2 (en) | 1993-01-08 | 1993-01-08 | Limit current type nitrogen oxide sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06201644A JPH06201644A (en) | 1994-07-22 |
| JP2936933B2 true JP2936933B2 (en) | 1999-08-23 |
Family
ID=11505888
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5001596A Expired - Fee Related JP2936933B2 (en) | 1993-01-08 | 1993-01-08 | Limit current type nitrogen oxide sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2936933B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19930636A1 (en) * | 1999-07-02 | 2001-01-18 | Bosch Gmbh Robert | Electrochemical gas sensor and method for determining gas components |
| DE10048240B4 (en) * | 2000-09-29 | 2007-02-08 | Robert Bosch Gmbh | Gas sensor element and method for determining the concentration of a gas component in a gas mixture |
-
1993
- 1993-01-08 JP JP5001596A patent/JP2936933B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06201644A (en) | 1994-07-22 |
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