JPH0975718A - Material for occuluding nox and device for treating nox with same - Google Patents
Material for occuluding nox and device for treating nox with sameInfo
- Publication number
- JPH0975718A JPH0975718A JP7240281A JP24028195A JPH0975718A JP H0975718 A JPH0975718 A JP H0975718A JP 7240281 A JP7240281 A JP 7240281A JP 24028195 A JP24028195 A JP 24028195A JP H0975718 A JPH0975718 A JP H0975718A
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- JP
- Japan
- Prior art keywords
- nox
- nitrogen oxide
- exhaust gas
- storage material
- metal element
- Prior art date
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- Treating Waste Gases (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、窒素酸化物を吸蔵
することのできる新規な窒素酸化物吸蔵用材料、及びそ
の材料を用いた窒素酸化物処理装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel nitrogen oxide storage material capable of storing nitrogen oxide, and a nitrogen oxide processing apparatus using the material.
【０００２】[0002]
【従来の技術】近年問題となっている環境問題の中で、
自動車の排気ガス中の窒素酸化物等の有害物質を分解、
除去する方法の開発が急務となっている。排気ガス浄化
用触媒としては、一酸化炭素、炭化水素、窒素酸化物の
除去を同時に行う三元触媒が実用化されている。このよ
うな三元触媒としては、γ−アルミナをコートしたコー
ジェライト等の耐熱性担体にＰｄ、Ｐｔ、Ｒｈ等の貴金
属を担持させたものが一般に用いられている。2. Description of the Related Art Among the environmental problems that have become a problem in recent years,
Decomposes harmful substances such as nitrogen oxides in automobile exhaust gas,
There is an urgent need to develop a method for removal. As an exhaust gas purification catalyst, a three-way catalyst that simultaneously removes carbon monoxide, hydrocarbons, and nitrogen oxides has been put into practical use. As such a three-way catalyst, a one in which a noble metal such as Pd, Pt, or Rh is supported on a heat-resistant carrier such as cordierite coated with γ-alumina is generally used.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、酸素過
剰雰囲気で燃焼を行うリーンバーンエンジンやディーゼ
ルエンジンでは、貴金属の酸素被毒のために、この三元
触媒は有効に機能しないという問題がある。また、酸素
過剰雰囲気下で機能する触媒としてゼオライトの研究が
進んでいるが、耐熱性、耐水性の点で十分ではない。こ
れに対し、耐熱性などに優れる酸化物触媒の研究もされ
ているが、活性度の点で未だ不十分で実用化に至ってい
ないのが現状である。However, in a lean burn engine or a diesel engine that burns in an oxygen excess atmosphere, there is a problem that this three-way catalyst does not function effectively due to oxygen poisoning of noble metals. Further, although research on zeolite has been advanced as a catalyst that functions in an oxygen excess atmosphere, it is not sufficient in terms of heat resistance and water resistance. On the other hand, although studies have been made on oxide catalysts having excellent heat resistance and the like, the present situation is that they have not yet been put into practical use because of insufficient activity.
【０００４】これとは別に、火力発電所等の固定式の燃
焼装置においては、アンモニアを還元剤として酸素濃度
の高い排気ガス中の窒素酸化物の還元を行うことが実用
化されているが、この方法を、自動車等の移動式燃焼装
置や都市部での固定式燃焼装置に応用することは、アン
モニアに毒性があるため安全性の面で問題がある。Apart from this, in fixed type combustion devices such as thermal power plants, it has been put to practical use to reduce nitrogen oxides in exhaust gas having a high oxygen concentration by using ammonia as a reducing agent. Applying this method to a mobile combustion device such as an automobile or a fixed combustion device in an urban area poses a safety problem because ammonia is toxic.
【０００５】また、近年では、酸素過剰雰囲気での窒素
酸化物除去法として、燃料希薄（リーン）即ち酸素過剰
で燃焼が行われる領域では窒素酸化物を吸蔵物質に吸蔵
しておき、燃料過剰（リッチ）や理論空燃比（ストイ
キ）近傍での燃焼の際に窒素酸化物を放出し、三元触媒
を用いて還元除去する方法が考え出されている。Further, in recent years, as a method for removing nitrogen oxides in an oxygen-rich atmosphere, nitrogen oxides are stored in a storage substance in a region where fuel is lean, that is, in a region where combustion is performed in an oxygen-rich state, and an excess amount of fuel is stored. A method has been devised in which nitrogen oxides are released during combustion in the vicinity of (rich) or the stoichiometric air-fuel ratio (stoichiometric ratio), and reduction and removal are performed using a three-way catalyst.
【０００６】この窒素酸化物を吸蔵する物質としては、
Ｂａ−Ｃｕ−Ｏ系やＭｎ−Ｚｒ−Ｏ系複合酸化物などが
知られているが、より吸蔵量が多く、且つ、より高温で
も安定に吸蔵特性を示す物質が求められている。本発明
は、前記課題を解決するためになされたものであり、デ
ィーゼルエンジンなどの高酸素排気ガス中の窒素酸化物
を一時的に吸蔵、又は大気中に放出された窒素酸化物を
吸蔵除去することができる窒素酸化物吸蔵用材料、及び
その材料を用いた窒素酸化物処理装置を提供することを
目的とするものである。As a substance that occludes this nitrogen oxide,
Although Ba-Cu-O-based and Mn-Zr-O-based composite oxides are known, a substance having a larger storage amount and exhibiting stable storage characteristics even at higher temperatures is required. The present invention has been made to solve the above problems, and temporarily occludes nitrogen oxides in a high oxygen exhaust gas such as a diesel engine, or occludes and removes nitrogen oxides released into the atmosphere. It is an object of the present invention to provide a nitrogen oxide storage material that can be used, and a nitrogen oxide processing apparatus using the material.
【０００７】[0007]
【課題を解決するための手段】前記課題を解決するため
に、請求項１の発明は、少なくともＡｌ及びＳｎを主金
属元素として含むホランダイト型構造の複合酸化物から
なる窒素酸化物吸蔵用材料を要旨とする。In order to solve the above-mentioned problems, the invention of claim 1 provides a nitrogen oxide storage material comprising a composite oxide of a hollandite type structure containing at least Al and Sn as main metal elements. Use as a summary.
【０００８】請求項２の発明は、前記複合酸化物が、Ａ
YＡｌXＳｎ8-XＯ16（但し、Ａ＝アルカリ金属元素又は
アルカリ土類金属元素）で表される前記請求項１記載の
窒素酸化物吸蔵用材料を要旨とする。According to a second aspect of the invention, the composite oxide is A
The gist of the nitrogen oxide storage material according to claim 1 represented by Y Al X Sn 8-X O 16 (where A = an alkali metal element or an alkaline earth metal element).
【０００９】具体的には、Ａの金属元素として、リチウ
ム（Ｌｉ），ナトリウム（Ｎａ）、カリウム（Ｋ）、ル
ビジウム（Ｒｂ）、セシウム（Ｃｓ）、カルシウム（Ｃ
ａ）、ストロンチウム（Ｓｒ）、バリウム（Ｂａ）が挙
げられる。特に、金属元素が、Ｋ、Ｒｂ、Ｃｓ、Ｃａ、
Ｓｒ、Ｂａの場合には、ホランダイト型の結晶構造が安
定であるので好適である。Specifically, as the metal element of A, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), calcium (C)
a), strontium (Sr) and barium (Ba). In particular, if the metal element is K, Rb, Cs, Ca,
Sr and Ba are preferable because the hollandite type crystal structure is stable.
【００１０】請求項３の発明は、前記請求項１又は２記
載の窒素酸化物吸蔵用材料を、その一部又は全体に用い
て構成された窒素酸化物処理装置を要旨とする。具体的
には、窒素酸化物吸蔵用材料が、粉体の状態、又は粒状
やペレット状等に加工された状態、又はハニカム状等に
成形された状態で使用される各種の自動車等の排気ガス
浄化装置が挙げられる。A third aspect of the present invention provides a nitrogen oxide treating apparatus, which is configured by using the nitrogen oxide storage material according to the first or second aspect as a part or the whole. Specifically, exhaust gas of various automobiles, etc. used in a state where the nitrogen oxide storage material is in a powder state, a state processed into a granular shape or a pellet shape, or a state formed into a honeycomb shape or the like. Examples include a purification device.
【００１１】請求項４の発明は、自動車の排気ガスの処
理に用いる前記請求項３記載の窒素酸化物処理装置を要
旨とする。A fourth aspect of the present invention provides a nitrogen oxide treatment apparatus according to the third aspect, which is used for treating exhaust gas of an automobile.
【００１２】[0012]
（請求項１，２の発明） 本発明者らは、前記課題に対して鋭意研究を進めた結
果、アルミニウム（Ａｌ）と錫（Ｓｎ）を含み、且つホ
ランダイト型結晶構造からなる複合酸化物が高酸素濃度
下でも高い窒素酸化物吸蔵作用を有することを見出し、
本発明に至ったものである。(Inventions of Claims 1 and 2) As a result of intensive studies on the above problems, the present inventors have found that a composite oxide containing aluminum (Al) and tin (Sn) and having a hollandite type crystal structure is obtained. It was found that it has a high nitrogen oxide storage action even under high oxygen concentration
The present invention has been achieved.
【００１３】ホランダイト型複合酸化物は、一般式、Ａ
YＢXＣ8-XＯ16（但し、Ａ＝アルカリ金属元素又はアル
カリ土類金属元素、Ｂ＝２価又は３価の金属元素、Ｃ＝
４価の金属元素）で表される。金属元素Ｂは、金属元素
Ｃの一部を置換しており、この金属元素ＢとＣ及び酸素
で１次元のトンネル構造を形成し、金属元素Ａは、この
トンネル中に存在する。The hollandite type complex oxide has the general formula A
Y B X C 8-X O 16 (A = alkali metal element or alkaline earth metal element, B = divalent or trivalent metal element, C =
It is represented by a tetravalent metal element). The metal element B replaces a part of the metal element C, and the metal elements B and C and oxygen form a one-dimensional tunnel structure, and the metal element A exists in this tunnel.
【００１４】本発明の窒素酸化物吸蔵用材料は、少なく
ともＡｌとＳｎとをＢ及びＣサイトに主金属元素として
含むホランダイトである。このうち、主金属元素がＡｌ
とＳｎのみで構成される場合、その一般式は、ＡYＡｌX
Ｓｎ8-XＯ16で表される。ここで、Ａはアルカリ金属元
素又はアルカリ土類金属元素である。Ｘ及びＹの範囲
は、特に限定されないが、ホランダイト構造の安定性の
観点から０．５から２．５程度であることが望ましい。
つまり、どちらかの範囲を超えると、その原子の大きさ
の違いから構造上安定性が悪くなるからである。The nitrogen oxide storage material of the present invention is a hollandite containing at least Al and Sn at the B and C sites as main metal elements. Of these, the main metal element is Al
And Sn only, the general formula is A Y Al X
It is represented by Sn 8-X O 16 . Here, A is an alkali metal element or an alkaline earth metal element. The range of X and Y is not particularly limited, but is preferably about 0.5 to 2.5 from the viewpoint of stability of the hollandite structure.
That is, when either of the ranges is exceeded, structural stability deteriorates due to the difference in the size of the atom.
【００１５】尚、図１に、本発明の例として、Ａ＝Ｋ
（カリウム）且つＸ＝Ｙ＝１．８の場合の粉末Ｘ線回折
パターンを示した。 上述した構成の複合酸化物は、窒素酸化物を含有する
例えば排気ガスと接触させることにより、排気ガス中に
含まれる窒素酸化物（ＮＯX）を吸蔵することができ
る。つまり、ＡｌとＳｎとを主構成金属元素として含む
ホランダイト型複合酸化物を、窒素酸化物を含有する例
えば排気ガスと接触させることにより、窒素酸化物を吸
蔵させることができる。In FIG. 1, as an example of the present invention, A = K
The powder X-ray diffraction pattern in the case of (potassium) and X = Y = 1.8 is shown. The composite oxide having the above-described configuration can store nitrogen oxides (NO x ) contained in the exhaust gas by contacting with the exhaust gas containing the nitrogen oxides. That is, the nitrogen oxide can be occluded by bringing the hollandite-type composite oxide containing Al and Sn as main constituent metal elements into contact with, for example, exhaust gas containing nitrogen oxide.
【００１６】この吸蔵のメカニズムは、未だ十分には明
らかにされていないが、本発明の複合酸化物表面上で、
ＮＯがＮＯ2を経由して硝酸根あるいは亜硝酸根まで酸
化され、バルク中に取り込まれるためと考えられる。 本発明の窒素酸化物吸蔵用材料を製造する方法として
は、例えば、アルカリ金属元素又はアルカリ土類金属元
素、主金属元素（ＡｌやＳｎ）のアルコキシド等の有機
金属化合物、且つ／又は主金属元素（ＡｌやＳｎ）の硝
酸塩等の無機金属化合物を、アルコール等の溶媒に溶解
し、加水分解後に蒸発乾固又はそのまま蒸発乾固して得
られた残渣を６００℃以上で熱処理する方法が挙げられ
る。ここで、最も好ましい熱処理温度は、８００〜１２
００℃であり、それによって、ホランダイトの結晶が十
分生成し、分解もなく、且つ、比表面積も大きいものが
得られる。The mechanism of this occlusion has not been fully clarified yet, but on the surface of the composite oxide of the present invention,
It is considered that NO is oxidized to nitrate radicals or nitrite radicals via NO 2 and taken into the bulk. Examples of the method for producing the nitrogen oxide storage material of the present invention include, for example, an alkali metal element or an alkaline earth metal element, an organic metal compound such as an alkoxide of a main metal element (Al or Sn), and / or a main metal element. A method of dissolving an inorganic metal compound such as nitrate of (Al or Sn) in a solvent such as alcohol and evaporating it to dryness after hydrolysis or evaporating it to dryness as it is to heat-treat the residue at 600 ° C. or higher can be mentioned. . Here, the most preferable heat treatment temperature is 800 to 12
The temperature is 00 ° C., whereby a crystal of hollandite is sufficiently generated, decomposition is not caused, and a large specific surface area is obtained.
【００１７】尚、前記の製造方法の他に、微細な錫の酸
化物ＳｎＯ2をアルコール中に均質に懸濁させ、この懸
濁液にＡｌとＫのアルコキシドを溶解して加水分解し、
熱処理して合成する方法等があるが、本発明は、何等こ
れらの製造方法に限定されるものではない。In addition to the above manufacturing method, fine tin oxide SnO 2 is uniformly suspended in alcohol, and alkoxides of Al and K are dissolved and hydrolyzed in this suspension.
There are methods such as heat treatment and synthesis, but the present invention is not limited to these production methods.
【００１８】但し、成分元素の酸化物や炭酸塩などから
の固相反応により本発明の複合酸化物を合成することは
困難である。これは、ＡｌとＳｎのイオン半径が大きく
異なる（Ａｌ3+／Ｓｎ4+＝０．７７）ためである。 （請求項３の発明）請求項３の発明では、窒素酸化物を
吸蔵する機能を有する上述した窒素酸化物吸蔵用材料
を、その一部又は全体に用いて窒素酸化物処理装置を構
成し、例えば自動車の排気ガス等をこの窒素酸化物処理
装置に導いて、排気ガス中の窒素酸化物をこの窒素酸化
物吸蔵用材料に吸蔵させることによって、排気ガスの浄
化を効果的に行なうことが可能となる。However, it is difficult to synthesize the composite oxide of the present invention by a solid-phase reaction from oxides or carbonates of component elements. This is because the ionic radii of Al and Sn are greatly different (Al 3+ / Sn 4+ = 0.77). (Invention of Claim 3) In the invention of Claim 3, the above-mentioned nitrogen oxide storage material having a function of storing nitrogen oxides is used as a part or the whole thereof to constitute a nitrogen oxide treatment apparatus, For example, it is possible to effectively purify the exhaust gas by guiding the exhaust gas of an automobile to the nitrogen oxide treatment device and causing the nitrogen oxide in the exhaust gas to be stored in the nitrogen oxide storage material. Becomes
【００１９】具体的には、例えば、燃料希薄（リーン）
即ち酸素過剰で燃焼が行われる領域では窒素酸化物を、
前記窒素酸化物吸蔵用材料に吸蔵しておき、燃料過剰
（リッチ）や理論空燃比（ストイキ）近傍での燃焼の際
に窒素酸化物を放出し、三元触媒を用いて還元除去する
装置が挙げられる。 （請求項４の発明）特に、本発明に用いる窒素酸化物吸
蔵用材料は、高温における窒素酸化物の吸蔵能力に優れ
ているので、自動車等の高温の排気ガスを排出するとこ
ろに用いる装置として好適である。Specifically, for example, the fuel is lean.
In other words, in the region where combustion occurs with excess oxygen, nitrogen oxides,
A device for storing nitrogen oxides in the above-mentioned nitrogen oxides storage material, releasing nitrogen oxides when burning in the vicinity of fuel excess (rich) or stoichiometric air-fuel ratio (stoichiometric), and reducing and removing using a three-way catalyst Can be mentioned. (Invention of Claim 4) In particular, since the nitrogen oxide storage material used in the present invention has an excellent ability to store nitrogen oxides at high temperatures, it is used as an apparatus used for discharging high temperature exhaust gas from automobiles and the like. It is suitable.
【００２０】[0020]
【実施例】以下、本発明の実施例について、その製造方
法とともに説明する。本実施例の窒素酸化物吸蔵用材料
は、アルカリ金属としてＫを用い、Ａｌ及びＳｎを主金
属元素とし、Ｘ＝Ｙ＝１．８とするＫ1.8Ａｌ1.8Ｓｎ
6.2Ｏ16のホランダイト型の複合酸化物である。EXAMPLES Examples of the present invention will be described below together with their manufacturing methods. The nitrogen oxide storage material of this example uses K as an alkali metal, Al and Sn as main metal elements, and X = Y = 1.8. K 1.8 Al 1.8 Sn
6.2 O 16 is a hollandite type complex oxide.
【００２１】＜製造方法＞まず、本実施例の窒素酸化物
吸蔵用材料である複合酸化物の製造方法について説明す
る。テトラ−ｉｓｏ−プロポキシ錫（Ｓｎ（ｉ−ＯＰ
ｒ）4）をイソプロパノールに、また、硝酸アルミニウ
ム（Ａｌ（ＮＯ3）3・９Ｈ2Ｏ）と硝酸力リウム（ＫＮ
Ｏ3）とを蒸留水に、金属元素比、Ｋ：Ａｌ：Ｓｎが
１．８：１．８：６．２になるように溶解した。<Manufacturing Method> First, the manufacturing method of the composite oxide which is the nitrogen oxide storage material of this embodiment will be described. Tetra-iso-propoxy tin (Sn (i-OP
r) 4) to isopropanol, and aluminum nitrate (Al (NO 3) 3 · 9H 2 O) and nitric acid strength potassium (KN
O 3 ) was dissolved in distilled water so that the metal element ratio, K: Al: Sn, was 1.8: 1.8: 6.2.
【００２２】次に、テトラ−ｉｓｏ−プロポキシ錫のイ
ソプロパノール溶液に、硝酸アルミニウム＋硝酸カリウ
ムの水溶液を徐々に滴下し、テトラ−ｉｓｏ−プロポキ
シ錫を加水分解した。尚、この段階では、沈澱物として
Ｓｎ（ＯＨ）4が発生するが、Ａｌ，Ｋの硝酸塩は溶解
したままである。Next, an aqueous solution of aluminum nitrate + potassium nitrate was gradually added dropwise to an isopropanol solution of tetra-iso-propoxytin to hydrolyze tetra-iso-propoxytin. At this stage, Sn (OH) 4 is generated as a precipitate, but the nitrates of Al and K remain dissolved.
【００２３】次に、この沈澱物を含む溶液を、１００℃
で蒸発乾固し、アルミナ乳鉢で粉砕して原料組成物とし
た。これを、大気中、８００℃で６時間熱処理し、本実
施例のＫ1.8Ａｌ1.8Ｓｎ6. 2Ｏ16のホランダイト型の複
合酸化物を得た。尚、得られた合成粉末の比表面積をＢ
ＥＴ法で測定したところ３２．７ｍ2／ｇと、非常に大
きな値であった。Next, the solution containing the precipitate is treated at 100 ° C.
It was evaporated to dryness in (1) and pulverized in an alumina mortar to obtain a raw material composition. This, in the air, and heat treated 6 hours at 800 ° C., to obtain a composite oxide of hollandite type K 1.8 Al 1.8 Sn 6. 2 O 16 of the present embodiment. The specific surface area of the obtained synthetic powder is B
When measured by the ET method, it was a very large value of 32.7 m 2 / g.
【００２４】そして、この様にして得られた物質に対
し、粉末Ｘ線回折を行なうことによりホランダイト相単
相であることを確認した。このＸ線回折チャートを図１
に示す。尚、このホランダイト相単相であることは、顕
微鏡等で確認することは不可能であるので、ＪＣＰＤＳ
カード（４１−１０９７）に示されるＫＴｉ8Ｏ16のピ
ークパターンと同じであることを利用して確認した。The thus obtained substance was confirmed to be a hollandite phase single phase by performing powder X-ray diffraction. This X-ray diffraction chart is shown in FIG.
Shown in It should be noted that it is impossible to confirm with a microscope that the hollandite phase is a single phase.
It was confirmed using the same peak pattern of KTi 8 O 16 shown in the card (41-1097).
【００２５】＜実験例＞次に、本実施例の窒素酸化物吸
蔵用材料の効果を確認するために行った実験例について
説明する。上述した製造方法によって得られた粉末を、
２００ｋｇ／ｃｍ2の圧力で成形後、その成形体を粉砕
し、２８〜４８メッシュに整粒した。整粒した粉末２ｇ
をパイレックス製の反応管に詰め、この反応管に、５０
０℃で、ＮＯ＝１０００ｐｐｍ、ＣＨ4＝１０００ｐｐ
ｍ、Ｏ2＝５％、Ｈｅ＝残部の混合ガスを、排気ガスの
モデルガスとして、５０ｍｌ／ｍｉｎで流通させた。<Experimental Example> Next, an experimental example conducted for confirming the effect of the nitrogen oxide storage material of the present embodiment will be described. The powder obtained by the above-mentioned manufacturing method,
After molding at a pressure of 200 kg / cm 2 , the molded body was crushed and sized to 28 to 48 mesh. 2g of sized powder
In a reaction tube made of Pyrex, and in this reaction tube,
At 0 ℃, NO = 1000ppm, CH 4 = 1000pp
A mixed gas of m, O 2 = 5% and He = the rest was circulated at 50 ml / min as a model gas of exhaust gas.
【００２６】そして、反応管から出てきたガスに対し、
化学発光式窒素酸化物分析計及びガスクロマトグラフを
用いて、窒素酸化物吸蔵特性を評価した。具体的には、
反応管から排出されるガス中のＮＯXの濃度を窒素酸化
物分析計で、また、Ｎ2、Ｎ2Ｏ濃度をガスクロマトグラ
フで、３０分毎に測定した。ＮＯXの濃度の測定結果を
図２に示す。And for the gas coming out of the reaction tube,
The nitrogen oxide storage characteristics were evaluated using a chemiluminescent nitrogen oxide analyzer and a gas chromatograph. In particular,
The concentration of NO x in the gas discharged from the reaction tube was measured with a nitrogen oxide analyzer, and the concentrations of N 2 and N 2 O were measured with a gas chromatograph every 30 minutes. The measurement result of the concentration of NO x is shown in FIG.
【００２７】図２に示す様に、５００℃において実験を
行なった２時間に渡って、ＮＯXは全く検出されておら
ず、また、ガスクロマトグラフでＮ2及びＮ2Ｏの生成も
検出されなかったことから、導入したＮＯガスは、高温
にもかかわらず本実施例の複合酸化物に完全に吸蔵され
ていたことは明らかである。As shown in FIG. 2, NO X was not detected at all and the production of N 2 and N 2 O was not detected in the gas chromatograph for 2 hours when the experiment was conducted at 500 ° C. From this, it is clear that the introduced NO gas was completely occluded in the composite oxide of this example despite the high temperature.
【００２８】この様に、本実施例の窒素酸化物吸蔵用材
料は、比表面積が大きいので吸蔵量が大きく、しかも高
温においてもＮＯXを効果的に吸蔵するので、自動車等
の内燃機関の高温の排気ガスの浄化処理に好適である。
従って、例えば、本実施例の窒素酸化物吸蔵用材料を、
粉体のまま、又は粒状やペレット状等に加工して、又は
ハニカム状等に成形して、排気ガスの通路に設けられた
排気ガス浄化装置に充填することにより、効果的に自動
車などの排気ガス中より窒素酸化物を吸蔵して除去する
ことができる。As described above, the nitrogen oxide storage material of this embodiment has a large specific surface area and therefore a large storage amount, and also effectively stores NO X even at high temperatures, so that the high temperature of an internal combustion engine such as an automobile is high. It is suitable for purifying exhaust gas.
Therefore, for example, the nitrogen oxide storage material of the present embodiment,
Exhaust gas from automobiles, etc. can be effectively obtained by filling the exhaust gas purification device provided in the exhaust gas passage with the powder as it is, or processing it into granules or pellets, or forming it into a honeycomb shape, etc. Nitrogen oxides can be occluded and removed from the gas.
【００２９】尚、本発明は前記実施例に限定されるもの
ではなく、本実施例の要旨を逸脱しない範囲内で各種の
態様で実施できることは勿論である。The present invention is not limited to the above-mentioned embodiment, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention.
【００３０】[0030]
【発明の効果】以上、詳述した通り、本発明の複合酸化
物からなる窒素酸化物吸蔵用材料は、例えば高酸素濃度
雰囲気下において窒素酸化物（ＮＯX）の高い吸蔵特性
を高温まで有するので、ディーゼルエンジンやリーンバ
ーンエンジン等の燃焼機関の排気ガス浄化処理に有用な
ものであり、また、大気中に放出された窒素酸化物の吸
蔵除去に有用なものである。As described above in detail, the nitrogen oxide storage material comprising the composite oxide of the present invention has a high storage characteristic of nitrogen oxide (NO x ) up to a high temperature, for example, in a high oxygen concentration atmosphere. Therefore, it is useful for exhaust gas purification treatment of combustion engines such as diesel engines and lean-burn engines, and also useful for occlusion and removal of nitrogen oxides released into the atmosphere.
【００３１】従って、この複合酸化物を用いた装置に
て、効果的に自動車などの排気ガス等の浄化を行なうこ
とができる。Therefore, with the device using this composite oxide, it is possible to effectively purify exhaust gas from automobiles and the like.
【図１】 実施例における複合酸化物（Ａ＝Ｋ（カリウ
ム）、Ｘ＝Ｙ＝１．８）の粉末Ｘ線回折パターンであ
る。FIG. 1 is a powder X-ray diffraction pattern of a composite oxide (A = K (potassium), X = Y = 1.8) in an example.
【図２】 実施例の実験における複合酸化物の窒素酸化
物吸蔵特性を示したグラフである。FIG. 2 is a graph showing nitrogen oxide storage characteristics of composite oxides in experiments of Examples.
Claims (4)
して含むホランダイト型構造の複合酸化物からなる窒素
酸化物吸蔵用材料。1. A nitrogen oxide storage material comprising a composite oxide having a hollandite structure containing at least Al and Sn as main metal elements.
16（但し、Ａ＝アルカリ金属元素又はアルカリ土類金属
元素）で表される前記請求項１記載の窒素酸化物吸蔵用
材料。2. The composite oxide is A Y Al X Sn 8-X O
16. The nitrogen oxide storage material according to claim 1, which is represented by 16 (where A = alkali metal element or alkaline earth metal element).
蔵用材料を、その一部又は全体に用いて構成された窒素
酸化物処理装置。3. A nitrogen oxide processing apparatus, which is configured by using the nitrogen oxide storage material according to claim 1 or 2 as a part or the whole thereof.
求項３記載の窒素酸化物処理装置。4. The nitrogen oxide treatment device according to claim 3, which is used for treating exhaust gas of an automobile.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24028195A JP3266471B2 (en) | 1995-09-19 | 1995-09-19 | Nitrogen oxide storage material and nitrogen oxide treatment apparatus using the material |
| US08/707,488 US5898015A (en) | 1995-09-19 | 1996-09-19 | Material for absorbing nitrogen oxides comprising hollandite-type complex oxide |
| US08/821,642 US6001319A (en) | 1995-09-19 | 1997-03-20 | Method of removing nitrogen oxides using material for absorbing nitrogen oxides |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24028195A JP3266471B2 (en) | 1995-09-19 | 1995-09-19 | Nitrogen oxide storage material and nitrogen oxide treatment apparatus using the material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0975718A true JPH0975718A (en) | 1997-03-25 |
| JP3266471B2 JP3266471B2 (en) | 2002-03-18 |
Family
ID=17057161
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24028195A Expired - Fee Related JP3266471B2 (en) | 1995-09-19 | 1995-09-19 | Nitrogen oxide storage material and nitrogen oxide treatment apparatus using the material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3266471B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001198440A (en) * | 1999-11-10 | 2001-07-24 | Inst Fr Petrole | Nitrogen oxide removal method |
| DE102010049604A1 (en) | 2009-10-27 | 2011-04-28 | Kabushiki Kaisha Toyota Chuo Kenkyusho, Nagakute | Nitrogen oxide adsorption material, useful to clean exhaust gas, and remove harmful nitrogen oxide contained in diesel engine, comprises metal oxide containing metal element-A forming mono- or bivalent cation in oxide, and metal element-M |
-
1995
- 1995-09-19 JP JP24028195A patent/JP3266471B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001198440A (en) * | 1999-11-10 | 2001-07-24 | Inst Fr Petrole | Nitrogen oxide removal method |
| DE102010049604A1 (en) | 2009-10-27 | 2011-04-28 | Kabushiki Kaisha Toyota Chuo Kenkyusho, Nagakute | Nitrogen oxide adsorption material, useful to clean exhaust gas, and remove harmful nitrogen oxide contained in diesel engine, comprises metal oxide containing metal element-A forming mono- or bivalent cation in oxide, and metal element-M |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3266471B2 (en) | 2002-03-18 |
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