JPS6137577B2 - - Google Patents
Info
- Publication number
- JPS6137577B2 JPS6137577B2 JP56177629A JP17762981A JPS6137577B2 JP S6137577 B2 JPS6137577 B2 JP S6137577B2 JP 56177629 A JP56177629 A JP 56177629A JP 17762981 A JP17762981 A JP 17762981A JP S6137577 B2 JPS6137577 B2 JP S6137577B2
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor
- gases
- catalyst
- gas
- oxidation catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000007789 gas Substances 0.000 claims description 37
- 239000003054 catalyst Substances 0.000 claims description 22
- 239000004065 semiconductor Substances 0.000 claims description 22
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 18
- 230000003647 oxidation Effects 0.000 claims description 11
- 238000007254 oxidation reaction Methods 0.000 claims description 11
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 claims description 6
- 239000003063 flame retardant Substances 0.000 claims description 6
- 229910044991 metal oxide Inorganic materials 0.000 claims description 6
- 150000004706 metal oxides Chemical class 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 description 13
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 5
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 229910052697 platinum Inorganic materials 0.000 description 4
- 239000001273 butane Substances 0.000 description 3
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 3
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910006404 SnO 2 Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910001111 Fine metal Inorganic materials 0.000 description 1
- 230000010718 Oxidation Activity Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 231100000989 no adverse effect Toxicity 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910001930 tungsten oxide Inorganic materials 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
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Description
【発明の詳細な説明】
この発明はガス感知素子の改良に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION This invention relates to improvements in gas sensing elements.
SnO2等の金属酸化物半導体の抵抗値がガスに
よつて変化することは広く知られており、この性
質を利用したガス感知素子を実用化されている。
しかしながらこのようなガス感知素子は、特定の
ガスを選択的に検出することができない。ガス感
知素子の特性を改善するため、金属酸化物半導体
にPd、Pt等の貴金属触媒を添加した素子も知ら
れているが（特公昭47−38840号）、これはガスへ
の感度と応答速度を改善するにとどまるものであ
つて、各種ガスへの相対感度をコントロールする
ものではない。また前記特公昭47−38840号公報
には、素子の温度を変えることにより、各種ガス
への相対感度を変えうることを記載されている
が、素子の温度には耐熱性やガスへの応答速度の
立場からの制限がある。したがつて素子の場合を
変えることによつても、特定のガスを選択的に検
出することは困難である。 It is widely known that the resistance value of metal oxide semiconductors such as SnO 2 changes depending on the gas, and gas sensing elements that take advantage of this property have been put into practical use.
However, such gas sensing elements cannot selectively detect specific gases. In order to improve the characteristics of gas sensing elements, devices in which precious metal catalysts such as Pd and Pt are added to metal oxide semiconductors are also known (Japanese Patent Publication No. 38840/1983), but this is due to the sensitivity to gas and response speed. It is only intended to improve the sensitivities, and does not control the relative sensitivity to various gases. Furthermore, the above-mentioned Japanese Patent Publication No. 47-38840 states that the relative sensitivity to various gases can be changed by changing the temperature of the element, but the temperature of the element depends on heat resistance and response speed to gas. There are restrictions from the standpoint of Therefore, it is difficult to selectively detect a specific gas even by changing the case of the element.
さらに特公昭45−17038号公報は、酸化タング
ステン薄膜の表面を、単原子層程度の白金で被覆
したガス検知素子を開示している。ここでの白金
の厚さは数原子層ないし1/100原子層程度で、酸
化活性は低い。そしてこの素子では応答特性を改
善することができるが、易燃性ガスと難燃性ガス
との相対感度を変えることはできない（同公報第
２頁〜第３頁）。 Furthermore, Japanese Patent Publication No. 45-17038 discloses a gas sensing element in which the surface of a tungsten oxide thin film is coated with platinum in a monoatomic layer. The thickness of platinum here is about several atomic layers to 1/100 atomic layer, and the oxidation activity is low. Although this element can improve the response characteristics, it cannot change the relative sensitivity between flammable and flame-retardant gases (pages 2 to 3 of the same publication).
つぎに酸化触媒により易燃性ガスを除去し、難
燃性ガスへの相対感度を増すことに付いて、２つ
の先願がある。まず特願昭49−24777号は、素子
の表面を素子と同種の金属酸化物半導体からなる
触媒フイルターで被覆した発明を開示する。しか
しこの場合、フイルターと素子との区別がつか
ず、フイルターのガス感度のため相対感度が低下
あする（同明細書第６頁）。特願昭48−41427号
は、素子を酸化触媒で包囲したガス感知素子の発
明を開示する。この場合、素子と触媒との間には
すき間が置かれており、触媒は素子からの放射熱
により100℃程度に加熱される（同明細書第５
頁）。しかし素子に直接触れないように触媒で素
子を包むという構成は複雑であり、かつ触媒の加
熱温度が低いため触媒活性も低い。 Next, there are two prior applications regarding removing flammable gases using an oxidation catalyst and increasing the relative sensitivity to flame-retardant gases. First, Japanese Patent Application No. 49-24777 discloses an invention in which the surface of an element is coated with a catalyst filter made of a metal oxide semiconductor of the same type as the element. However, in this case, the filter and the element cannot be distinguished, and the relative sensitivity decreases due to the gas sensitivity of the filter (page 6 of the same specification). Japanese Patent Application No. 48-41427 discloses an invention of a gas sensing element in which the element is surrounded by an oxidation catalyst. In this case, a gap is placed between the element and the catalyst, and the catalyst is heated to about 100°C by the radiant heat from the element (Chapter 5 of the same specification).
page). However, the structure of wrapping the element with a catalyst to prevent direct contact with the element is complicated, and the heating temperature of the catalyst is low, resulting in low catalytic activity.
この発明はメタン・エタン・プロパン・ブタン
等の難燃性のガスを、CO等の易燃性ガスから区
別して検出できる素子を提供することを目的とす
る。 An object of the present invention is to provide an element that can detect flame-retardant gases such as methane, ethane, propane, and butane, distinguishing them from easily combustible gases such as CO.
さらにこの発明では、フイルターの構造を簡単
化するとともに、フイルターでのガス感度による
相対感度の低下のない、ガス感知素子を提供する
ことを目的とするものである。 Furthermore, it is an object of the present invention to provide a gas sensing element that has a simplified filter structure and that does not reduce relative sensitivity due to gas sensitivity in the filter.
この発明は、金属酸化物半導体に一対の電極を
接続すると共に、上記半導体の外部表面に、易燃
性ガスを酸化・除去し難燃性ガスを透過させる白
金族酸化触媒フイルターを直接に被覆し、かつ前
記半導体を加熱するためのヒータを設けたもので
ある。 This invention connects a pair of electrodes to a metal oxide semiconductor, and directly coats the external surface of the semiconductor with a platinum group oxidation catalyst filter that oxidizes and removes flammable gases and allows flame-retardant gases to pass through. , and a heater for heating the semiconductor.
ここに白金族触媒としては、白金黒・パラジウ
ム黒等の金属微粉末、あるいは白金やパラジウム
等の白金族元素をアルミナやシリカ等の担体に担
持させたもの等を用いることができる。 As the platinum group catalyst, a fine metal powder such as platinum black or palladium black, or a platinum group element such as platinum or palladium supported on a carrier such as alumina or silica can be used.
またこのガス感知素子の使用にあたつては周知
のガス検出回路、例えばガス感知素子に直列に負
荷抵抗と電極とを接続したもの、を用いることが
できる。 Further, when using this gas sensing element, a well-known gas sensing circuit, for example, one in which a load resistor and an electrode are connected in series with the gas sensing element can be used.
以下にこの発明の実施例を図面をもとに説明す
る。 Embodiments of the present invention will be described below with reference to the drawings.
第１図はこの発明のもつとも基本的な実施例を
示すもので、図において１はSnO2等の金属酸化
物半導体である。２，３は一対の貴金属電極で、
半導体１の内部に埋設してあり、その抵抗値を検
出するために用いられる。４は、半導体１を加熱
するための、コイル状ヒータで、半導体１を囲繞
する位置に設けてある。５は白金属酸化触媒で、
Pd黒やPt黒、あるいは白金族元素を担体に担持
させたものからなり、半導体１およびヒータ４の
双方を内部に埋設するように設けてある。 FIG. 1 shows the most basic embodiment of the present invention, in which numeral 1 represents a metal oxide semiconductor such as SnO 2 . 2 and 3 are a pair of noble metal electrodes,
It is buried inside the semiconductor 1 and is used to detect its resistance value. 4 is a coil-shaped heater for heating the semiconductor 1, and is provided at a position surrounding the semiconductor 1. 5 is a platinum metal oxidation catalyst,
It is made of Pd black, Pt black, or a carrier supporting a platinum group element, and is provided so that both the semiconductor 1 and the heater 4 are buried therein.
第２図は他の実施例を示すもので、ヒータ４を
酸化触媒５から分離したものである。すなわち半
導体１に一対の電極２，３を埋設するとともに、
その周囲を酸化触媒５でおおい、これらを囲繞す
るようにヒータ４を設けたものである。 FIG. 2 shows another embodiment, in which the heater 4 is separated from the oxidation catalyst 5. That is, while embedding a pair of electrodes 2 and 3 in the semiconductor 1,
The periphery thereof is covered with an oxidation catalyst 5, and a heater 4 is provided so as to surround them.
第３図はガラス等の絶縁基板６を用いた実施例
を示すもので、基板６の一方の面には膜状抵抗体
からなるヒータ４を設けてある。他方の面には、
半導体属１と、これに接続した一対の電極２，３
とを設けるとともに、半導体層１を酸化触媒５で
おおつてある。 FIG. 3 shows an embodiment using an insulating substrate 6 made of glass or the like, and one surface of the substrate 6 is provided with a heater 4 made of a film resistor. On the other side,
A semiconductor element 1 and a pair of electrodes 2 and 3 connected to it
In addition, the semiconductor layer 1 is covered with an oxidation catalyst 5.
上記各実施例の素子において、ガスの検出は次
のように行なわれる。 In the elements of each of the above embodiments, gas detection is performed as follows.
空気中に、メタン・エタン・プロパン・ブタン
等の難燃性ガスが発生すると、これらのガスは酸
化触媒５を通過して半導体１に吸着し、その抵抗
値を変化させる。これらのガスは着火点が高く酸
化を受けにくいため、酸化触媒５を通過させて
も、ほとんど除去されない。 When flame-retardant gases such as methane, ethane, propane, and butane are generated in the air, these gases pass through the oxidation catalyst 5 and are adsorbed on the semiconductor 1, changing its resistance value. Since these gases have high ignition points and are difficult to be oxidized, they are hardly removed even if they are passed through the oxidation catalyst 5.
これに対してCO等の易燃性ガスの場合は、酸
化触媒５によつて容易に酸化され除去されるた
め、半導体１にはほとんど到達しない。このため
CO等の易燃性ガスへの感度は大幅に低下するよ
うになる。 On the other hand, in the case of easily flammable gas such as CO, it hardly reaches the semiconductor 1 because it is easily oxidized and removed by the oxidation catalyst 5. For this reason
Sensitivity to easily flammable gases such as CO will be significantly reduced.
以上に説明したように、この発明では半導体の
外部を白金族触媒で被覆するようにしたため、
CO等の易燃性ガスを除去し、メタン・ブタン等
の難燃性ガスのみを検出することができる。また
この発明では、素子の構成が簡単で、フイルター
部の感度による相対感度の低下がない。さらにこ
の発明では、白金族触媒を用いるので、半導体と
触媒との固相反応等の悪影響がない。 As explained above, in this invention, since the outside of the semiconductor is coated with a platinum group catalyst,
It can remove flammable gases such as CO and detect only flammable gases such as methane and butane. Further, in the present invention, the element has a simple configuration, and there is no decrease in relative sensitivity due to the sensitivity of the filter section. Furthermore, in this invention, since a platinum group catalyst is used, there is no adverse effect such as solid phase reaction between the semiconductor and the catalyst.
第１図はこの発明の実施例を示す断面図、第
２，３図はそれぞれ別の実施例を示す断面図であ
る。
１……半導体、２，３……電極、４……ヒー
タ、５……白金族触媒。
FIG. 1 is a sectional view showing an embodiment of the invention, and FIGS. 2 and 3 are sectional views showing different embodiments. 1... Semiconductor, 2, 3... Electrode, 4... Heater, 5... Platinum group catalyst.
Claims (1)
共に、上記半導体の外部表面に、易燃性ガスを酸
化・除去し難燃性ガスを透過させる白金族酸化触
媒フイルターを直接に被覆し、かつ前記半導体を
加熱するためのヒータを設けたことを特徴とする
ガス感知素子。1 A pair of electrodes are connected to a metal oxide semiconductor, and the external surface of the semiconductor is directly coated with a platinum group oxidation catalyst filter that oxidizes and removes flammable gases and allows flame-retardant gases to pass through, and A gas sensing element characterized by being provided with a heater for heating a semiconductor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17762981A JPS57127839A (en) | 1981-11-04 | 1981-11-04 | Gas detecting element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17762981A JPS57127839A (en) | 1981-11-04 | 1981-11-04 | Gas detecting element |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6362374A Division JPS50155292A (en) | 1974-06-04 | 1974-06-04 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57127839A JPS57127839A (en) | 1982-08-09 |
| JPS6137577B2 true JPS6137577B2 (en) | 1986-08-25 |
Family
ID=16034339
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17762981A Granted JPS57127839A (en) | 1981-11-04 | 1981-11-04 | Gas detecting element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57127839A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01138179U (en) * | 1988-03-11 | 1989-09-21 | ||
| JPH02153496A (en) * | 1988-12-06 | 1990-06-13 | Matsushita Electric Ind Co Ltd | Coin-operated laundry machine |
| US10964341B2 (en) | 2017-05-26 | 2021-03-30 | Tdk Corporation | Magnetoresistive effect element, magnetic head, sensor, high-frequency filter, and oscillator |
| US10971679B2 (en) | 2017-03-03 | 2021-04-06 | Tdk Corporation | Magnetoresistive effect element |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4911892A (en) * | 1987-02-24 | 1990-03-27 | American Intell-Sensors Corporation | Apparatus for simultaneous detection of target gases |
| US5635628A (en) * | 1995-05-19 | 1997-06-03 | Siemens Aktiengesellschaft | Method for detecting methane in a gas mixture |
| DE10149932B4 (en) * | 2001-10-10 | 2006-12-07 | Schott Ag | Zinc oxide-containing borosilicate glass and uses of the glass |
| US10670554B2 (en) * | 2015-07-13 | 2020-06-02 | International Business Machines Corporation | Reconfigurable gas sensor architecture with a high sensitivity at low temperatures |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4921190A (en) * | 1972-06-14 | 1974-02-25 | ||
| JPS49129596A (en) * | 1973-04-13 | 1974-12-11 | ||
| JPS50120298A (en) * | 1974-03-05 | 1975-09-20 |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4899195U (en) * | 1972-02-22 | 1973-11-22 | ||
| JPS4914188U (en) * | 1972-05-10 | 1974-02-06 | ||
| JPS545674Y2 (en) * | 1973-04-13 | 1979-03-13 |
-
1981
- 1981-11-04 JP JP17762981A patent/JPS57127839A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4921190A (en) * | 1972-06-14 | 1974-02-25 | ||
| JPS49129596A (en) * | 1973-04-13 | 1974-12-11 | ||
| JPS50120298A (en) * | 1974-03-05 | 1975-09-20 |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01138179U (en) * | 1988-03-11 | 1989-09-21 | ||
| JPH02153496A (en) * | 1988-12-06 | 1990-06-13 | Matsushita Electric Ind Co Ltd | Coin-operated laundry machine |
| US10971679B2 (en) | 2017-03-03 | 2021-04-06 | Tdk Corporation | Magnetoresistive effect element |
| US10964341B2 (en) | 2017-05-26 | 2021-03-30 | Tdk Corporation | Magnetoresistive effect element, magnetic head, sensor, high-frequency filter, and oscillator |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57127839A (en) | 1982-08-09 |
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