JPH0687976B2 - Gold catalyst for removing nitrogen oxides and method for removing nitrogen oxides - Google Patents
Gold catalyst for removing nitrogen oxides and method for removing nitrogen oxidesInfo
- Publication number
- JPH0687976B2 JPH0687976B2 JP3072355A JP7235591A JPH0687976B2 JP H0687976 B2 JPH0687976 B2 JP H0687976B2 JP 3072355 A JP3072355 A JP 3072355A JP 7235591 A JP7235591 A JP 7235591A JP H0687976 B2 JPH0687976 B2 JP H0687976B2
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- Prior art keywords
- catalyst
- oxide
- gold
- nitrogen
- nitrogen oxides
- Prior art date
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、各種内燃機関、燃焼機
器等より排出される排気ガス中に含まれる窒素酸化物を
還元し、除去するための窒素酸化物除去用金触媒と窒素
酸化物の除去方法に関する。FIELD OF THE INVENTION The present invention relates to a nitrogen oxide removing gold catalyst and a nitrogen oxide for reducing and removing nitrogen oxide contained in exhaust gas discharged from various internal combustion engines, combustion equipment and the like. Regarding removal method.
【０００２】[0002]
【従来技術とその問題点】各種内燃機関、燃焼機器等よ
り排出される排気ガスの中には、窒素酸化物（Ｎ
ＯX ）、不完全燃焼成分（一酸化炭素、水素、炭化水素
等）及び水分が含まれている。これらＮＯX 等は、人体
に有害なものであり、環境汚染を引き起こす酸性雨等の
原因となっており、現在その対策が切望されている。2. Description of the Related Art Exhaust gas discharged from various internal combustion engines, combustion equipment, etc. contains nitrogen oxides (N
O X), incomplete combustion components (carbon monoxide, hydrogen, contains hydrocarbons or the like) and moisture. These NO x and the like are harmful to the human body and cause acid rain and the like that cause environmental pollution, and countermeasures against them are currently desired.
【０００３】これら内燃機関、燃焼機器等より排出され
る排気ガスのうち触媒を用いて窒素酸化物を除去する方
法として自動車のガソリンエンジン用触媒（いわゆる三
元触媒）が知られており実用化されるに至っている。上
記三元触媒は、排気ガス中に含まれている一酸化炭素、
炭化水素等を還元剤として、窒素酸化物を窒素に還元す
るための触媒であり、このような反応を促進する活性物
質としてＰｔ、Ｒｕ、Ｒｈ等の貴金属とペロブスカイト
型構造を有する複合金属酸化物が知られている。 しか
しながら、上記のような触媒は、中温域（４００〜８０
０℃付近）でのＮＯX の還元に対しては有効であるが、
排気ガスの温度は室温付近（始動時）から高温（８００
〜１０００℃以上）まで大きく変化するので、中温域以
外の温度範囲、例えば機関の始動時あるいはコ・ジェネ
レーションシステムの熱を回収した後の排気ガスのよう
な低温域（室温〜４００℃付近）において有効に作用せ
ず使用できないという問題点がある。A catalyst for automobile gasoline engines (so-called three-way catalyst) is known and put into practical use as a method for removing nitrogen oxides from the exhaust gas discharged from these internal combustion engines, combustion equipment and the like by using a catalyst. Has reached the end. The three-way catalyst, carbon monoxide contained in the exhaust gas,
A composite metal oxide having a perovskite structure with a noble metal such as Pt, Ru, or Rh, which is a catalyst for reducing nitrogen oxides to nitrogen using a hydrocarbon or the like as a reducing agent and as an active substance that promotes such a reaction. It has been known. However, the above-mentioned catalyst is used in the medium temperature range (400 to 80
It is effective for the reduction of NO x at around 0 ° C),
The temperature of exhaust gas ranges from near room temperature (at the time of starting) to high temperature (800
Temperature range other than the middle temperature range, for example, in the low temperature range (room temperature to around 400 ° C) such as exhaust gas after starting the engine or after recovering the heat of the cogeneration system. There is a problem that it does not work effectively and cannot be used.
【０００４】[0004]
【問題点を解決するための手段】本発明者は、上記の問
題点に鑑み、鋭意研究を重ね、先に可燃性ガスの接触用
触媒として金超微粒子を金属酸化物に固定化した触媒
（特開昭６０−２３８１４８号）を開発し、上記触媒が
酸化触媒又は還元触媒として有効であるとの知見に基づ
き特開昭６３−２５２９０８号に係る発明を開発した。In view of the above-mentioned problems, the present inventor has conducted extensive studies, and firstly, a catalyst in which ultrafine gold particles are immobilized on a metal oxide as a catalyst for contact with combustible gas ( JP-A-60-238148) was developed, and the invention according to JP-A-63-252908 was developed based on the finding that the above catalyst is effective as an oxidation catalyst or a reduction catalyst.
【０００５】本発明者らは、より有効な触媒を得るため
に種々検討を重ねた結果、金を特定金属の酸化物複合体
に固定化する時はＮＯX の還元反応に対して極めて高い
活性をもつことを見出し、本発明を完成した。As a result of various investigations to obtain a more effective catalyst, the present inventors have found that when gold is immobilized on an oxide complex of a specific metal, it has an extremely high activity for reducing NO x. The present invention has been completed and the present invention has been completed.
【０００６】即ち、本発明は、Ｚｎ、Ｍｇ、Ｍｎ、Ｎ
ｉ、Ｃｏ及びＣｕからなる群より選ばれた少なくとも１
種の金属とＦｅからなる複合金属酸化物に金が固定化さ
れていることを特徴とする窒素酸化物除去用金触媒、及
び該触媒を用いる窒素酸化物除去方法に係るものであ
る。That is, according to the present invention, Zn, Mg, Mn, N
at least 1 selected from the group consisting of i, Co and Cu
The present invention relates to a gold catalyst for nitrogen oxide removal, characterized in that gold is immobilized on a composite metal oxide composed of a seed metal and Fe, and a nitrogen oxide removal method using the catalyst.
【０００７】以下、本発明について詳細に説明する。The present invention will be described in detail below.
【０００８】本発明の触媒は、本発明者らにより発明さ
れ開示された製法、即ち１）共沈法（特開昭６０−２３
８１４８号）、２）均一析出沈殿法（特開昭６２−１５
５９３７号）、３）滴下中和沈殿法（特開昭６３−２５
２９０８号）、４）還元剤添加法（特開昭６３−２５２
９０８号）、５）ｐＨ制御中和沈殿法（特開昭６３−２
５２９０８号）、６）カルボン酸金属塩添加法（特開平
２−２５２６１０号）等の公知の各種方法により製造す
ることができ、同様に出発物質は、金化合物としては塩
化金塩等の水溶性金塩を使用し、複合金属酸化物原料と
してはＺｎ、Ｍｇ、Ｍｎ、Ｎｉ、Ｃｏ及びＣｕの少なく
とも１種の金属並びに鉄の硝酸塩、硫酸塩、塩化物等が
使用できる。The catalyst of the present invention is manufactured by the present inventors and has been disclosed, that is, 1) a coprecipitation method (JP-A-60-23).
8148), 2) uniform precipitation-precipitation method (JP-A-62-15).
5937), 3) drop neutralization precipitation method (JP-A-63-25)
2908), 4) Method for adding a reducing agent (Japanese Patent Laid-Open No. 63-252).
908), 5) pH control neutralization precipitation method (JP-A-63-2).
No. 52908), 6) metal carboxylic acid salt addition method (JP-A-2-252610), and other known methods. Similarly, the starting material is a water-soluble gold salt such as gold chloride. A gold salt is used, and as the composite metal oxide raw material, at least one metal selected from Zn, Mg, Mn, Ni, Co, and Cu, and iron nitrate, sulfate, chloride, and the like can be used.
【０００９】本発明における複合金属酸化物の構造は、
Ｚｎ、Ｍｇ、Ｍｎ、Ｎｉ、Ｃｏ及びＣｕからなる群より
選ばれた少なくとも１種の金属をＭとするスピネル構造
（ＭＦｅ2 Ｏ4 ）を有し、この構造を保つ範囲内でＦｅ
とＭの割合を変えることができる。一般にその割合は、
ＭX ＦｅY Ｏ4 で表すと、Ｘ＝０．７〜１．３、Ｙ＝
２．３〜１．７の範囲とするのが好ましい。The structure of the composite metal oxide in the present invention is
It has a spinel structure (MFe 2 O 4 ) in which M is at least one metal selected from the group consisting of Zn, Mg, Mn, Ni, Co and Cu, and Fe within the range of maintaining this structure.
And the ratio of M can be changed. Generally, the ratio is
In terms of M X Fe Y O 4 , X = 0.7 to 1.3, Y =
It is preferably in the range of 2.3 to 1.7.
【００１０】前記の共沈法等により得られるものを乾燥
し、焼成することにより上記複合金属酸化物に金が固定
化された窒素酸化物除去用金触媒を得る。上記焼成温度
は、使用温度により異なるが通常２００〜６００℃程度
である。また、金と上記複合金属酸化物の割合は、金固
定化触媒中の金の含有量が０．１〜２０重量％程度とす
るのが好ましい。The catalyst obtained by the above coprecipitation method or the like is dried and calcined to obtain a nitrogen oxide removing gold catalyst in which gold is immobilized on the composite metal oxide. The firing temperature is usually about 200 to 600 ° C., though it depends on the use temperature. Further, the ratio of gold to the composite metal oxide is preferably such that the gold content in the gold-immobilized catalyst is about 0.1 to 20% by weight.
【００１１】また、より実用的な形態で使用することを
目的として各種金属酸化物系担体及び金属系担体に上記
触媒を担持させることもできる。上記各担体としては、
アルミナ、シリカ、アルミナ−シリカ、ゼオライト、酸
化チタン等の金属酸化物系担体、あるいはステンレスス
チール、鉄、銅、アルミニウム等の金属系担体を例示す
ることができる。担持させるにあたっては、各種方法を
採ることができ、例えば本発明者ら先に発明した特開平
１−９４９４５号に開示された方法に従って行なえばよ
い。より具体的には、アルミナビーズ等の担体を鉄塩及
び上記Ｚｎ等の塩を含む水溶液に浸漬した後に焼成し、
ついで金塩の水溶液に浸漬して熟成させた後に再び焼成
することにより上記触媒は担持される。The catalyst may be supported on various metal oxide-based carriers and metal-based carriers for the purpose of using it in a more practical form. As each of the above carriers,
Examples thereof include metal oxide type carriers such as alumina, silica, alumina-silica, zeolite and titanium oxide, and metal type carriers such as stainless steel, iron, copper and aluminum. Various methods can be adopted for supporting, for example, the method disclosed in Japanese Patent Laid-Open No. 1-94945 previously invented by the present inventors. More specifically, the carrier such as alumina beads is immersed in an aqueous solution containing an iron salt and the above-mentioned salt such as Zn, and then baked,
Then, the catalyst is supported by immersing it in an aqueous solution of a gold salt for aging and then firing it again.
【００１２】本発明の触媒は、各種内燃機関、燃焼機器
等の排気ガスのように窒素酸化物ＮＯX （一酸化窒素Ｎ
Ｏ、二酸化窒素ＮＯ2 、亜酸化窒素Ｎ2 Ｏ等）を含有す
るガスを処理して、窒素酸化物を還元し低減させるとい
う顕著な効果を発揮する。上記処理は、還元剤の存在下
に行なわれ、還元剤としては排気ガス中の不完全燃焼成
分（一酸化炭素ＣＯ、水素Ｈ2 、炭化水素等）を利用す
るか、あるいは積極的に還元剤を添加して０〜５００℃
の反応温度下で行なう。[0012] The catalyst of the present invention, various internal combustion engine, nitrogen oxides as the exhaust gas such as a combustion equipment NO X (nitrogen monoxide N
O, nitrogen dioxide NO 2 , nitrous oxide N 2 O, etc.) is treated to exert a remarkable effect of reducing and reducing nitrogen oxides. The above treatment is carried out in the presence of a reducing agent, and an incomplete combustion component (carbon monoxide CO, hydrogen H 2 , hydrocarbon, etc.) in the exhaust gas is used as the reducing agent, or the reducing agent is positively used. Add 0 to 500 ℃
At the reaction temperature of.
【００１３】[0013]
【発明の効果】本発明の窒素酸化物除去用金触媒によれ
ば、中温域（４００〜８００℃）はもとより、従来の触
媒では不可能であった低温域（室温〜５００℃）から高
温域（８００〜１０００℃）においても非常に優れた触
媒作用を発現することができる。しかも水分の存在下で
も触媒の活性は低下することなく、むしろ促進されてお
り、従来の触媒よりも悪条件での使用が可能となり、実
質的に窒素酸化物の排出を阻止することができる。EFFECTS OF THE INVENTION According to the gold catalyst for removing nitrogen oxides of the present invention, not only the medium temperature range (400 to 800 ° C.) but also the low temperature range (room temperature to 500 ° C.) to the high temperature range not possible with conventional catalysts. Even at (800 to 1000 ° C.), a very excellent catalytic action can be exhibited. Moreover, even in the presence of water, the activity of the catalyst is not lowered, but rather promoted, and it is possible to use it under adverse conditions as compared with the conventional catalyst, and it is possible to substantially prevent the emission of nitrogen oxides.
【００１４】また、窒素酸化物還元と同時に排気ガス中
に存在する一酸化炭素等の不完全燃焼成分を還元剤とし
て利用することができるので、機関の外部に有害物質を
放出することがなく、結果として環境の保護に極めて大
きな役割を果たすことができる。Further, since incomplete combustion components such as carbon monoxide existing in the exhaust gas can be utilized as a reducing agent at the same time as the reduction of nitrogen oxides, no harmful substances are released to the outside of the engine, As a result, it can play a very important role in protecting the environment.
【００１５】[0015]
【実施例】以下、実施例を示し、本発明の特徴とすると
ころをより一層明瞭にする。EXAMPLES Examples will be shown below to further clarify the features of the present invention.
【００１６】[0016]
【実施例１】塩化金酸［ＨＡｕＣｌ4 ・４Ｈ2 Ｏ］０．
６６ｇ［０．００１６モル］、硝酸塩［Ｆｅ（ＮＯ3 ）
3 ・９Ｈ2 Ｏ］８．０８ｇ［０．０２０モル］及び硝酸
ニッケル［Ｎｉ（ＮＯ3 ）2 ・６Ｈ2 Ｏ］２．９１ｇ
［０．０１０モル］を３００ｍｌの蒸留水に溶解させた
（Ａ液）。次いで、炭酸ナトリウム［Ｎａ2 ＣＯ3 ］
５．３９ｇ［０．０５１モル］を２００ｍｌの蒸留水に
溶解させた（Ｂ液）。Example 1 Chloroauric acid [HAuCl 4 .4H 2 O]
66 g [0.0016 mol], nitrate [Fe (NO 3 )]
3 · 9H 2 O] 8.08g [ 0.020 mol] and nickel nitrate [Ni (NO 3) 2 · 6H 2 O] 2.91g
[0.010 mol] was dissolved in 300 ml of distilled water (solution A). Then sodium carbonate [Na 2 CO 3 ]
5.39 g [0.051 mol] was dissolved in 200 ml of distilled water (solution B).
【００１７】次に、Ｂ液の中にＡ液を滴下し、１時間攪
拌した。得られた共沈物を充分に水洗した後、乾燥し、
空気中４００℃で５時間焼成することにより、金固定化
ニッケル鉄酸化物触媒（ＮＯ．１）［Ａｕ／ＮｉＦｅ2
Ｏ4 、原子比Ａｕ／（Ｆｅ＋Ｎｉ）＝１／１９］を得
た。Next, the solution A was dropped into the solution B and stirred for 1 hour. The resulting coprecipitate is thoroughly washed with water and then dried,
By calcining in air at 400 ° C. for 5 hours, a gold-immobilized nickel iron oxide catalyst (NO. 1) [Au / NiFe 2
O 4 , atomic ratio Au / (Fe + Ni) = 1/19] was obtained.
【００１８】また、上記と同様にして各種金属塩を用い
て本発明触媒ＮＯ．２〜ＮＯ．６を得た。Further, in the same manner as described above, the catalyst NO. 2 to NO. Got 6.
【００１９】続いて、上記各触媒を用いて、一酸化窒素
の除去性能を以下の方法で調べた。上記触媒を７０〜１
２０メッシュにふるい分けしたものを０．１５ｇ用い、
一酸化窒素と一酸化炭素を共に１０００ｐｐｍ含むヘリ
ウム混合ガスを５０ｍｌ／分の流量で流通させ、生成し
た窒素の濃度を測定した。その結果を表１に示す。尚、
表１には比較のためにＡｕ／α−Ｆｅ2 Ｏ3 及びＺｎＦ
ｅ2 Ｏ4 （比較例１及び２）を用いた場合の結果を併記
する。Subsequently, the removal performance of nitric oxide was examined by the following method using each of the above catalysts. 70 to 1 of the above catalyst
Using 0.15 g of that which has been sieved to 20 mesh,
A helium mixed gas containing both 1000 ppm of nitric oxide and carbon monoxide was passed at a flow rate of 50 ml / min, and the concentration of generated nitrogen was measured. The results are shown in Table 1. still,
Table 1 shows Au / α-Fe 2 O 3 and ZnF for comparison.
The results when using e 2 O 4 (Comparative Examples 1 and 2) are also shown.
【００２０】 表 １ 触 媒 窒素転化率（％） 100℃ 150℃ 200℃ No1 Ａｕ／ＮｉＦｅ2 Ｏ4 (Au:Ni:Fe=1:6.3:12.7) 86.4 94.0 100 No2 Ａｕ／ＺｎＦｅ2 Ｏ4 (Au:Zn:Fe=1:6.3:12.7) 83.8 100 No3 Ａｕ／ＭｇＦｅ2 Ｏ4 (Au:Mg:Fe=1:6.3:12.7) 35.4 80.2 No4 Ａｕ／ＭｎＦｅ2 Ｏ4 (Au:Mn:Fe=1:6.3:12.7) 81.1 96.5 100 No5 Ａｕ／ＣｏＦｅ2 Ｏ4 (Au:Co:Fe=1:6.3:12.7) 75.3 94.3 100 No6 Ａｕ／ＣｕＦｅ2 Ｏ4 (Au:Cu:Fe=1:6.3:12.7) 73.2 88.3 100 比較例1 Ａｕ／α−Ｆｅ2 Ｏ3 (Au:Fe=1:19) 22.6 78.0 100 比較例2 ＺｎＦｅ2 Ｏ4 29.2 87.2 反応ガス：ＮＯ（０．１％）＋ＣＯ（０．１％）／Ｈｅ この結果により、一酸化窒素の除去性能を一酸化窒素が
窒素に変化した割合で評価すると、試験温度１００℃の
場合、金固定化酸化鉄（比較例１）ではＮＯX 除去率は
２２．６％と低いが、酸化鉄をフェライト化し、亜鉛、
マグネシウム、マンガン、コバルト又は銅の酸化物との
複合体に固定化した本発明触媒（ＮＯ．１〜６）ではい
ずれの場合でも、高い除去性能を示した。尚、低い転化
率の場合には一酸化窒素の一部が亜酸化窒素に転化する
が、試験温度が上昇するにつれてその生成量は減少す
る。即ち、本発明の金触媒は、亜酸化窒素の還元に対し
ても有効であることがわかる。Table 1 Nitrogen conversion of catalyst (%)100 ℃ 150 ℃ 200 ℃ No1 Au / NiFe2OFour(Au: Ni: Fe = 1: 6.3: 12.7) 86.4 94.0 100 No2 Au / ZnFe2OFour(Au: Zn: Fe = 1: 6.3: 12.7) 83.8 100 No3 Au / MgFe2OFour(Au: Mg: Fe = 1: 6.3: 12.7) 35.4 80.2 No4 Au / MnFe2OFour(Au: Mn: Fe = 1: 6.3: 12.7) 81.1 96.5 100 No5 Au / CoFe2OFour(Au: Co: Fe = 1: 6.3: 12.7) 75.3 94.3 100 No6 Au / CuFe2OFour(Au: Cu: Fe = 1: 6.3: 12.7) 73.2 88.3 100 Comparative Example 1 Au / α-Fe2O3(Au: Fe = 1: 19) 22.6 78.0 100 Comparative Example 2 ZnFe2OFour29.2 87.2 Reaction gas: NO (0.1%) + CO (0.1%) / He This result shows that the removal performance of nitric oxide depends on nitric oxide.
When evaluated by the rate of conversion to nitrogen, the test temperature of 100 ° C
In case of gold fixed iron oxide (Comparative Example 1), NOXThe removal rate is
Although low as 22.6%, iron oxide is ferriticized and zinc,
With oxides of magnesium, manganese, cobalt or copper
The catalyst of the present invention (NO. 1 to 6) immobilized on the complex
Even in the case of deviation, high removal performance was exhibited. Low conversion
Rate, some of the nitric oxide is converted to nitrous oxide
However, its production amount decreases as the test temperature increases.
It That is, the gold catalyst of the present invention is suitable for the reduction of nitrous oxide.
However, it turns out that it is effective.
【００２１】このようにＺｎ、Ｍｇ、Ｍｎ、Ｎｉ、Ｃ
ｏ、Ｃｕからなる群の少なくとも１種の金属とＦｅとの
複合酸化物に金を固定化することにより、高活性化でき
ることが明らかである。Thus, Zn, Mg, Mn, Ni, C
It is apparent that high activation can be achieved by immobilizing gold on a composite oxide of Fe and at least one metal of the group consisting of o and Cu.
【００２２】[0022]
【実施例２】実施例１で得た金固定化コバルト鉄酸化物
触媒（ＮＯ．５）を用いて、湿分による影響を調べた。Example 2 Using the gold-immobilized cobalt iron oxide catalyst (NO. 5) obtained in Example 1, the effect of moisture was investigated.
【００２３】上記触媒を７０〜１２０メッシュにふるい
分けしたものを０．１５ｇ用い、一酸化窒素１０００ｐ
ｐｍ、一酸化炭素１０００ｐｐｍ及び水１．８体積％を
含むヘリウム混合ガスを５０ｍｌ／分の流量で流通さ
せ、生成した窒素の濃度を測定した。その測定結果を表
２に示す。0.15 g of the above-mentioned catalyst which was sieved to 70-120 mesh was used, and 1000 p of nitric oxide was used.
Helium mixed gas containing pm, 1000 ppm of carbon monoxide and 1.8 vol% of water was passed at a flow rate of 50 ml / min, and the concentration of generated nitrogen was measured. The measurement results are shown in Table 2.
【００２４】 表 ２ 測定条件 窒素転化率（％） 100℃ 150℃ 200℃ 湿分あり 75.3 94.3 100 湿分なし 93.0 100 触媒Ａｕ／ＣｏＦｅ2 Ｏ4 (Au:Co:Fe=1:6.3:12.7) 反応ガス： ＮＯ（０．１％）＋ＣＯ（０．１％）／Ｈｅ（湿分な
し） ＮＯ（０．１％）＋ＣＯ（０．１％）＋Ｈ2 Ｏ（１．８
％）／Ｈｅ（湿分あり） 上記結果より、水分が共存していてもその除去性能の低
下は認められず、必然的に水分が含有されている燃焼排
気ガス等に対して本発明の触媒は実用上極めて有利であ
ることがわかる。Table 2 Measurement conditions Nitrogen conversion (%)100 ℃ 150 ℃ 200 ℃ With moisture 75.3 94.3 100No moisture 93.0 100 Catalyst Au / CoFe2OFour(Au: Co: Fe = 1: 6.3: 12.7) Reaction gas: NO (0.1%) + CO (0.1%) / He (no moisture
)) NO (0.1%) + CO (0.1%) + H2O (1.8
%) / He (with moisture) From the above results, the removal performance is low even when water is present.
The lower part is not recognized, and the combustion exhaust gas containing water is inevitable.
The catalyst of the present invention is extremely advantageous in practical use against gas and the like.
I understand that
【００２５】[0025]
【実施例３】化学量論から外れた不定比のフェライト酸
化物に金を固定化した触媒（ＮＯ．７〜９）を実施例１
と同様の方法で調製した。これらの触媒を用いて一酸化
窒素の除去性能を実施例１と同様の方法で測定した。そ
の結果を表３に示す。Example 3 A catalyst (NO. 7-9) in which gold was immobilized on a non-stoichiometric non-stoichiometric ferrite oxide was used in Example 1.
Prepared in a similar manner to. Using these catalysts, the removal performance of nitric oxide was measured by the same method as in Example 1. The results are shown in Table 3.
【００２６】 表 ３ 触 媒 窒素転化率（％） 100℃ 150℃ 200℃ Ａｕ／Ｚｎ0.8 Ｆｅ2.2 Ｏ4 (Au:Zn:Fe=1:5.1:13.9) 91.2 100 Ａｕ／Ｍｎ0.8 Ｆｅ2.2 Ｏ4 (Au:Mn:Fe=1:5.1:13.9) 84.5 100 Ａｕ／Ｃｏ0.8 Ｆｅ2.2 Ｏ4 (Au:Co:Fe=1:5.1:13.9) 82.3 100 反応ガス：ＮＯ（０．１％）＋ＣＯ（０．１％）／Ｈ
ｅ この結果より、亜鉛、マンガン、コバルトを含むフェラ
イト酸化物のすべてが化学量論比の触媒体よりも性能が
向上した。鉄の２価イオンが導入され得るような不定比
にすることで、一酸化窒素の除去性能が向上することは
明らかである。Table 3 Nitrogen conversion of catalyst (%)100 ℃ 150 ℃ 200 ℃ Au / Zn0.8Fe2.2OFour(Au: Zn: Fe = 1: 5.1: 13.9) 91.2 100 Au / Mn0.8Fe2.2OFour(Au: Mn: Fe = 1: 5.1: 13.9) 84.5 100 Au / Co0.8Fe2.2OFour(Au: Co: Fe = 1: 5.1: 13.9) 82.3 100 Reactive gas: NO (0.1%) + CO (0.1%) / H
e From this result, it is confirmed that the blower containing zinc, manganese, and cobalt.
All of the ito oxides outperform the stoichiometric catalysts.
Improved. Nonstoichiometric ratio so that divalent iron ions can be introduced
The removal performance of nitric oxide can be improved by
it is obvious.
【００２７】[0027]
【実施例４】実施例１で調製したＮＯ．２及びＮＯ．５
の触媒を用い、二酸化窒素の除去性能を以下の方法で調
べた。Example 4 The NO. 2 and NO. 5
Using the above catalyst, the removal performance of nitrogen dioxide was examined by the following method.
【００２８】上記触媒を７０〜１２０メッシュにふるい
分けしたものを０．１５ｇ用い、二酸化窒素５００ｐｐ
ｍと一酸化炭素１０００ｐｐｍを含むヘリウム混合ガス
を５０ｍｌ／分の流量で流通させ、生成した窒素の濃度
を測定した。その測定結果を表４に示す。尚、比較のた
めにＡｕ／α−Ｆｅ2 Ｏ3を用いた場合の結果も併記す
る。0.15 g of the above-mentioned catalyst sieved to 70-120 mesh was used, and 500 pp of nitrogen dioxide was used.
A helium mixed gas containing m and 1000 ppm of carbon monoxide was caused to flow at a flow rate of 50 ml / min, and the concentration of generated nitrogen was measured. The measurement results are shown in Table 4. For comparison, the results when Au / α-Fe 2 O 3 is used are also shown.
【００２９】 表 ４ 触 媒 窒素転化率（％） 100℃ 150℃ 200℃ 比較例1 Ａｕ／α−Ｆｅ2 Ｏ3 (Au:Fe=1:19) 25.8 80.2 100 No2 Ａｕ／ＺｎＦｅ2 Ｏ4 (Au:Mg:Fe=1:6.3:12.7) 85.4 100 No5 Ａｕ／ＣｏＦｅ2 Ｏ4 (Au:Co:Fe=1:6.3:12.7) 78.5 94.6 100 反応ガス：ＮＯ2 （０．０５％）＋ＣＯ（０．１％）／Ｈｅ この結果より、これらの触媒は一酸化窒素の場合と同様
に、二酸化窒素の還元に対して極めて高い活性を示すこ
とがわかる。Table 4 Catalyst Nitrogen conversion (%)100 ℃ 150 ℃ 200 ℃ Comparative Example 1 Au / α-Fe2O3(Au: Fe = 1: 19) 25.8 80.2 100 No2 Au / ZnFe2OFour(Au: Mg: Fe = 1: 6.3: 12.7) 85.4 100 No5 Au / CoFe2OFour(Au: Co: Fe = 1: 6.3: 12.7) 78.5 94.6 100 Reaction gas: NO2(0.05%) + CO (0.1%) / He From these results, these catalysts are similar to the case of nitric oxide.
Has extremely high activity for reducing nitrogen dioxide.
I understand.
【００３０】[0030]
【実施例５】実施例１で調製した金固定化亜鉛フェライ
ト触媒（ＮＯ．２）を用いて一酸化炭素以外の還元剤に
よる一酸化窒素の除去性能を調べた。Example 5 Using the gold-immobilized zinc ferrite catalyst (NO. 2) prepared in Example 1, the removal performance of nitric oxide with a reducing agent other than carbon monoxide was examined.
【００３１】上記各触媒を７０〜１２０メッシュにふる
い分けしたものを０．１５ｇ用い、一酸化窒素と還元性
ガス［水素、メタン（ＣＨ4 ）、プロパン（Ｃ
3 Ｈ8 ）、プロピレン（Ｃ3 Ｈ6）］を共に１０００ｐ
ｐｍ含むヘリウム混合ガスを５０ｍｌ／分の流量で流通
させ、生成した窒素の濃度を測定した。その測定結果を
図１に示す。Using 0.15 g of each of the above catalysts sieved to 70 to 120 mesh, nitric oxide and a reducing gas [hydrogen, methane (CH 4 ), propane (C
3 H 8 ), propylene (C 3 H 6 )] both at 1000 p
A helium mixed gas containing pm was passed at a flow rate of 50 ml / min, and the concentration of generated nitrogen was measured. The measurement result is shown in FIG.
【００３２】[0032]
【図１】この結果、作用温度域の序列は、水素・一酸化
炭素（５０〜１００℃）＜プロパン・プロピレン（３０
０〜３５０℃）＜メタン（４５０℃）の結果となった。
これより、還元剤として一酸化炭素のみならず、水素、
各種炭化水素を用いても優れた効果を発揮できることが
わかる。また、排気ガスの温度は、燃焼機器の機種、運
転条件等により大きく変化するが、本発明の触媒は適当
な還元剤の組み合わせにより広い条件のもとで対処する
ことができる。[Fig. 1] As a result, the order of operating temperature ranges is as follows: hydrogen / carbon monoxide (50 to 100 ° C) <propane / propylene (30
The result was 0-350 ° C) <methane (450 ° C).
From this, not only carbon monoxide but also hydrogen,
It can be seen that excellent effects can be exhibited even if various hydrocarbons are used. Further, the temperature of the exhaust gas varies greatly depending on the type of combustion equipment, operating conditions, etc., but the catalyst of the present invention can be dealt with under a wide range of conditions by combining appropriate reducing agents.
【００３３】[0033]
【実施例６】より実用的な形態で使用することを想定し
て、次の方法により触媒をアルミナビーズに担持させた
触媒を調製した。Example 6 Assuming that the catalyst was used in a more practical form, a catalyst in which the catalyst was supported on alumina beads was prepared by the following method.
【００３４】本発明者らがすでに発明した方法（特開平
１−９４９４５号）に従い、３２６ｍ2 ／ｇの表面積を
もつ直径２ｍｍのγ−アルミナのアルミナビーズに硝酸
第二鉄と硝酸コバルトを溶解させた水溶液を含浸させ、
４００℃で４時間焼成し、ＣｏＦｅ2 Ｏ4 担持アルミナ
ビーズ３０ｇを６００ｍｌの水中に投入し、炭酸ソーダ
の１モル水溶液を用いてｐＨ８と調整した後、１５ｇの
塩化金を含む０．０１モル水溶液を加え、７０℃で１時
間熟成した。According to the method already invented by the present inventors (JP-A-1-94945), ferric nitrate and cobalt nitrate were dissolved in alumina beads of γ-alumina having a surface area of 326 m 2 / g and a diameter of 2 mm. Impregnated with
After being calcined at 400 ° C. for 4 hours, 30 g of CoFe 2 O 4 -supporting alumina beads was put into 600 ml of water, and the pH was adjusted to 8 using a 1 mol aqueous solution of sodium carbonate, and then a 0.01 mol aqueous solution containing 15 g of gold chloride. Was added and the mixture was aged at 70 ° C. for 1 hour.
【００３５】得られた触媒前駆体を水で洗浄後、４００
℃で５時間焼成して、金固定化コバルトフェライト酸化
物担持アルミナビーズ触媒（Ａｕ／ＣｏＦｅ2 Ｏ4 ／ア
ルミナビーズ、金固定量５ｇ／ｌ）を得た。After washing the obtained catalyst precursor with water, 400
The mixture was calcined at 5 ° C. for 5 hours to obtain a gold-immobilized cobalt ferrite oxide-supported alumina bead catalyst (Au / CoFe 2 O 4 / alumina beads, gold immobilization amount: 5 g / l).
【００３６】上記触媒を用いて実施例１及び２と同様の
方法で一酸化窒素の除去性能を調べた。その結果を表５
に示す。Using the above catalyst, the removal performance of nitric oxide was examined in the same manner as in Examples 1 and 2. The results are shown in Table 5.
Shown in.
【００３７】 表 ５ 測定条件 窒素転化率（％） 100℃ 150℃ 200℃ 湿分あり 3.1 8.3 60.2 湿分なし 15.5 62.3 95.3 触媒Ａｕ／ＣｏＦｅ2 Ｏ4 (Au:Co:Fe=1:6.3:12.7) 反応ガス： ＮＯ（０．１％）＋ＣＯ（０．１％）／Ｈｅ（湿分な
し） ＮＯ（０．１％）＋ＣＯ（０．１％）＋Ｈ2 Ｏ（０．６
％）／Ｈｅ（湿分あり） 上記の結果より、固定化する金の量を５ｇ／ｌに減らし
ても、実用上充分な活性を示した。また、水分により大
きな促進効果も認められた。Table 5 Measurement conditions Nitrogen conversion (%)100 ℃ 150 ℃ 200 ℃ With moisture 3.1 8.3 60.2No moisture 15.5 62.3 95.3 Catalyst Au / CoFe2OFour(Au: Co: Fe = 1: 6.3: 12.7) Reaction gas: NO (0.1%) + CO (0.1%) / He (no moisture
)) NO (0.1%) + CO (0.1%) + H2O (0.6
%) / He (with moisture) From the above results, the amount of immobilized gold was reduced to 5 g / l
However, it showed practically sufficient activity. Also, due to moisture
A kinako promoting effect was also observed.
【００３８】以上の各実施例の結果より、本発明の触媒
が排気ガス等に含まれる窒素酸化物を還元除去するのに
極めて有効であることがわかる。From the results of the above examples, it is understood that the catalyst of the present invention is extremely effective in reducing and removing nitrogen oxides contained in exhaust gas and the like.
【図１】各還元剤における反応温度と窒素転化率との関
係を示すグラフである。FIG. 1 is a graph showing a relationship between a reaction temperature and a nitrogen conversion rate in each reducing agent.
Claims (5)
らなる群より選ばれた少なくとも１種の金属とＦｅから
なる複合金属酸化物に金が固定化されていることを特徴
とする窒素酸化物除去用金触媒。1. Nitrogen in which gold is immobilized on a composite metal oxide consisting of Fe and at least one metal selected from the group consisting of Zn, Mg, Mn, Ni, Co and Cu. Gold catalyst for oxide removal.
ことを特徴とする請求項１記載の窒素酸化物除去用金触
媒2. A gold catalyst for removing nitrogen oxides according to claim 1, wherein the catalyst according to claim 1 is supported on a carrier.
シリカ、ゼオライト及び酸化チタンの中から選ばれた少
なくとも１種の金属酸化物系担体、又はステンレススチ
ール、鉄、銅及びアルミニウムの中から選ばれた少なく
とも１種の金属系担体を用いることを特徴とする請求項
２記載の窒素酸化物除去用金触媒。3. Alumina, silica, alumina-as a carrier
At least one metal oxide-based carrier selected from silica, zeolite and titanium oxide, or at least one metal-based carrier selected from stainless steel, iron, copper and aluminum is used. The gold catalyst for removing nitrogen oxides according to claim 2.
理して窒素酸化物を還元するにあたり、請求項１乃至３
のいずれかに記載の触媒の存在下に処理を行なうことを
特徴とする窒素酸化物除去方法。4. A method of treating a nitrogen oxide-containing gas in the presence of a reducing agent to reduce the nitrogen oxide, wherein:
A method for removing nitrogen oxides, which comprises performing the treatment in the presence of the catalyst according to any one of 1.
炭化水素又は低級不飽和炭化水素を用い、触媒として請
求項４記載の窒素酸化物除去用金触媒を用いることを特
徴とする窒素酸化物除去方法。5. Nitrogen oxidation, characterized in that hydrogen, carbon monoxide, lower saturated hydrocarbon or lower unsaturated hydrocarbon is used as the reducing agent, and the gold catalyst for nitrogen oxide removal according to claim 4 is used as the catalyst. How to remove things.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3072355A JPH0687976B2 (en) | 1991-03-11 | 1991-03-11 | Gold catalyst for removing nitrogen oxides and method for removing nitrogen oxides |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3072355A JPH0687976B2 (en) | 1991-03-11 | 1991-03-11 | Gold catalyst for removing nitrogen oxides and method for removing nitrogen oxides |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04281846A JPH04281846A (en) | 1992-10-07 |
| JPH0687976B2 true JPH0687976B2 (en) | 1994-11-09 |
Family
ID=13486925
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3072355A Expired - Lifetime JPH0687976B2 (en) | 1991-03-11 | 1991-03-11 | Gold catalyst for removing nitrogen oxides and method for removing nitrogen oxides |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0687976B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2535763B2 (en) * | 1993-09-28 | 1996-09-18 | 工業技術院長 | Catalyst for removing nitrogen oxides and method for removing nitrogen oxides |
| TW200838607A (en) * | 2007-03-30 | 2008-10-01 | Tatung Co | Preparation of mangania-iron-supported nano-gold catalysts and using the same |
| JP4901938B2 (en) * | 2009-10-23 | 2012-03-21 | トヨタ自動車株式会社 | NOx purification catalyst |
| US9084988B2 (en) | 2011-02-07 | 2015-07-21 | Toyota Jidosha Kabushiki Kaisha | NOX purification catalyst |
| JP6264639B2 (en) * | 2013-10-29 | 2018-01-24 | 株式会社豊田中央研究所 | N2O decomposition catalyst and N2O-containing gas decomposition method using the same |
| CN105238172B (en) * | 2015-11-13 | 2017-11-21 | 中瑞电气有限公司 | A kind of insulator of saline-alkaline corrosion-resistant |
| CN105255276B (en) * | 2015-11-13 | 2017-12-26 | 重庆市木越机械制造有限公司 | A kind of power industry special coating of saline-alkaline corrosion-resistant |
-
1991
- 1991-03-11 JP JP3072355A patent/JPH0687976B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04281846A (en) | 1992-10-07 |
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