JPH08257403A - Catalyst for purifying exhaust gas - Google Patents
Catalyst for purifying exhaust gasInfo
- Publication number
- JPH08257403A JPH08257403A JP7066125A JP6612595A JPH08257403A JP H08257403 A JPH08257403 A JP H08257403A JP 7066125 A JP7066125 A JP 7066125A JP 6612595 A JP6612595 A JP 6612595A JP H08257403 A JPH08257403 A JP H08257403A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- exhaust gas
- active metal
- autoclave
- transition metal
- 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.)
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- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、特に高耐熱性でNO
X (窒素酸化物)浄化能力に優れた複合酸化物より成る
排ガス浄化触媒に関する。BACKGROUND OF THE INVENTION The present invention has a high heat resistance and NO.
X (Nitrogen Oxide) The present invention relates to an exhaust gas purification catalyst composed of a composite oxide having excellent purification ability.
【0002】[0002]
【従来の技術】ディーゼルや希薄燃焼エンジン排ガスな
どのような酸素過剰雰囲気下でのNOX 浄化触媒として
ゼオライト触媒、活性金属担持触媒が知られているが、
まだ実用化のレベルに達したものはない。BACKGROUND OF THE INVENTION Diesel, zeolite catalysts as NO X purification catalyst in an oxygen excess atmosphere such as lean-burn engine exhaust, but an active metal supported catalysts is known,
None have reached the level of practical use yet.
【0003】そして、従来より合成される酸化物触媒
は、アルミナ等の担体に活性金属を担持するといった手
法により作成されるのが普通である。The conventionally synthesized oxide catalyst is usually prepared by a method of supporting an active metal on a carrier such as alumina.
【0004】[0004]
【発明が解決しようとする課題】従来より合成される活
性金属担持触媒は、前述のようにアルミナ等の担体に金
属塩水溶液等を含浸して担持するのが一般的である。担
持した活性金属は、ある程度の粒径(約50〜100Å
程度)を持ち、この粒径が小さいほど触媒活性が高いこ
とが一般的に知られている。しかし、含浸後の乾燥時等
に、担持金属の粒成長や凝集が生じ、粒径を小さくする
ことはほとんど不可能である。又、この活性金属粒子
は、アルミナ上に担持されているだけなので、熱により
活性金属粒子同士が燒結してしまい、触媒性能が不可逆
的に著しく低下するという問題があった。The active metal-supported catalyst conventionally synthesized is generally carried by impregnating a carrier such as alumina with an aqueous solution of a metal salt as described above. The supported active metal has a certain particle size (about 50-100Å
It is generally known that the smaller the particle size, the higher the catalytic activity. However, it is almost impossible to reduce the particle size because the supported metal particles grow or agglomerate during drying after impregnation. Further, since the active metal particles are only supported on alumina, there is a problem that the active metal particles are sintered by heat and the catalytic performance is irreversibly deteriorated.
【0005】一方、活性金属をイオン交換して作製した
イオン交換ゼオライトは、ゼオライトのイオン交換サイ
トに活性金属がイオンの状態で存在し、非常に高いNO
X 浄化率を示すが、イオン交換サイトとイオンの結合力
が非常に弱く、わずかな熱によりイオンが動いてしま
い、NOX 浄化能が不可逆的に低下してしまう。また、
イオン交換をしたゼオライトの耐熱性が低く、高温では
ゼオライトの細孔構造が崩れてしまう欠点を持ってい
た。On the other hand, the ion-exchanged zeolite prepared by ion-exchange of the active metal has a very high NO because the active metal exists in the ion-exchange site of the zeolite in an ionic state.
Although it shows the X purification rate, the binding force between the ion exchange site and the ion is very weak, and the ions move due to slight heat, so that the NO X purification ability is irreversibly reduced. Also,
The ion-exchanged zeolite has low heat resistance and has a drawback that the pore structure of the zeolite collapses at high temperature.
【0006】この発明は、活性金属粒子が単に表面に担
持されたものやイオン交換サイトに活性金属イオンが弱
く結合しているものとは異なり、活性金属が単原子レベ
ルで触媒構造内に高分散化し、しかも、この構造内に活
性金属が強固に取り込まれた構造を有し、かつ、前記活
性金属が表面の一部を形成しており、高いNOX 浄化能
と、高い熱耐久性の両面を有した排ガス浄化触媒を提供
することを目的とする。The present invention is different from active metal particles simply supported on the surface or active metal ions weakly bound to the ion exchange site, and the active metal is highly dispersed in the catalyst structure at the single atom level. In addition, it has a structure in which the active metal is firmly incorporated in the structure, and the active metal forms a part of the surface, and has both high NO x purification ability and high thermal durability. An object of the present invention is to provide an exhaust gas purifying catalyst having the above.
【0007】さらに、この発明は、この様な構造を形成
させた触媒は、例えば、活性金属がCuのような熱的に
不安定で動きやすい金属でも、触媒構造内に活性金属が
強固に固定されるので、耐熱性が飛躍的に向上し、しか
も、活性金属がイオン交換ゼオライトに近い原子レベル
の高分散を形成しているため、従来では得られなかった
高いNOX 浄化能と、高い熱耐久性を有する触媒特性を
得ることを目的とする。Further, according to the present invention, in the catalyst having such a structure, even if the active metal is a thermally unstable and easily movable metal such as Cu, the active metal is firmly fixed in the catalyst structure. As a result, the heat resistance is dramatically improved, and since the active metal forms a high dispersion at the atomic level close to that of ion-exchanged zeolite, it has a high NO x purification capacity and high heat that have not been obtained in the past. The purpose is to obtain a durable catalytic property.
【0008】[0008]
【課題を解決するための手段】すなわち、この発明は、
遷移金属原子の少なくとも1種類と、Al,Siのうち
少なくとも1種類の元素を含む複合酸化物より成り、か
つ前記遷移金属原子が表面の一部を形成してなることを
特徴とする排ガス浄化触媒に係わり、さらに、複合酸化
物の遷移金属原子は、当該原子の周りの第二近接原子以
内に、同一の原子が存在しないことを特徴とする排ガス
浄化触媒に係わる。この場合、上記構造が含まれていれ
ば、遷移金属原子の周りの第二近接原子以内に同一の原
子が存在している構造が存在していても、同様の触媒性
能が得られるので、このような排ガス浄化触媒の提供も
含まれる。That is, the present invention provides:
An exhaust gas purifying catalyst comprising a composite oxide containing at least one kind of transition metal atom and at least one kind of element selected from Al and Si, wherein the transition metal atom forms a part of the surface. Further, the transition metal atom of the composite oxide is related to the exhaust gas purifying catalyst, wherein the same atom does not exist within the second adjacent atom around the atom. In this case, if the above structure is included, even if there is a structure in which the same atom exists within the second neighboring atom around the transition metal atom, similar catalytic performance is obtained, so The provision of such an exhaust gas purifying catalyst is also included.
【0009】そして、前記排ガス浄化触媒をオートクレ
ーブ処理することにより浄化活性を著しく向上させるこ
とを特徴とする排ガス浄化触媒に係わり、更にオートク
レーブ処理は、複合酸化物の結晶相が分離する臨界温度
以下の温度範囲で、好ましくは水またはアルコールで行
うことを特徴とする排ガス浄化触媒に係わる。Further, the present invention relates to an exhaust gas purifying catalyst characterized in that the purifying activity is remarkably improved by subjecting the exhaust gas purifying catalyst to an autoclave treatment. Further, the autoclave treatment is performed at a temperature below a critical temperature at which a crystal phase of a composite oxide is separated. The present invention relates to an exhaust gas purifying catalyst, which is carried out in a temperature range, preferably with water or alcohol.
【0010】[0010]
【作用】この発明に係る排ガス浄化触媒は、活性金属で
ある遷移金属原子のうち少なくとも一種類と、Al,S
iのうち少なくとも一種類の元素を含む複合酸化物触媒
で、活性金属が単原子レベルで触媒構造内に高分散化
し、しかも構造内に活性金属が強固に取り込まれた構造
を有し、かつ、前記活性金属が表面の一部を形成してい
るので、きわめて高いNOX 浄化能と、高い熱耐久性の
両面を有した触媒であり、活性金属粒子が単に表面に担
持されたものやイオン交換サイトに活性金属イオンが弱
く結合しているものとは基本的に異なり、前記の様な構
造を形成させた触媒は、例えば、活性金属がCuのよう
な熱的に不安定で動きやすい金属でも、触媒構造内に活
性金属が強固に固定されるので、耐熱性が飛躍的に向上
し、しかも、活性金属がイオン交換ゼオライトに近い原
子レベルの高分散を形成しているため、従来では得られ
なかった高いNOX 浄化能と、高い熱耐久性の両面を有
する触媒特性を得ることが可能となる。The exhaust gas purifying catalyst according to the present invention contains at least one kind of transition metal atom which is an active metal and Al, S.
A composite oxide catalyst containing at least one element of i, which has a structure in which an active metal is highly dispersed in a catalyst structure at the level of a single atom, and the active metal is firmly incorporated in the structure, and Since the active metal forms a part of the surface, it is a catalyst having both extremely high NO x purification capacity and high thermal durability, and the active metal particles are simply supported on the surface or ion exchange. Basically, it is different from the one in which the active metal ion is weakly bound to the site, and the catalyst having the above-mentioned structure is formed, for example, even if the active metal is a thermally unstable and mobile metal such as Cu. Since the active metal is firmly fixed in the catalyst structure, the heat resistance is dramatically improved, and the active metal forms a high dispersion at the atomic level close to that of ion-exchanged zeolite. There was no high NO x purification It is possible to obtain catalytic properties having both chemical ability and high thermal durability.
【0011】そして、更に水またはアルコールなどを用
いてオートクレーブ処理を行うと、オートクレーブ内の
特殊な環境により、適度な結晶性の向上と安定化が起こ
り、触媒活性点の更なる活性化が促され、NOX 浄化能
が極めて高くなる。When the autoclave treatment is further carried out using water or alcohol, due to the special environment inside the autoclave, the crystallinity is appropriately improved and stabilized, and further activation of the catalytically active sites is promoted. , NO x purification capacity becomes extremely high.
【0012】しかし、オートクレーブ処理温度を必要以
上に上げると、結晶化が極端に向上して結晶相の分離が
おこり、遷移金属原子が金属酸化物粒子として析出され
るため、本発明の特殊な構造が破壊され、高い触媒活性
が得られなくなるので、オートクレーブ処理温度はその
臨界温度以下の範囲内にとどめる必要がある。However, if the temperature of the autoclave treatment is raised more than necessary, the crystallization is remarkably improved, the crystal phase is separated, and the transition metal atoms are precipitated as metal oxide particles, so that the special structure of the present invention is used. Therefore, it is necessary to keep the autoclave treatment temperature within the range of the critical temperature or lower since it is destroyed and high catalytic activity cannot be obtained.
【0013】[0013]
実施例 (1)-1〔オートクレーブ未処理および水を用いた
オートクレーブ処理によるCu−Al複合酸化物合成〕 まず、酸化物換算でCuOが5重量(wt)%となるよ
うに硝酸アルミニウムと硝酸銅を混合した水溶液を作製
する。Example (1) -1 [Synthesis of Cu-Al composite oxide by unclaved autoclave and autoclave using water] First, aluminum nitrate and copper nitrate were added so that CuO was 5% by weight (wt) in terms of oxide. To prepare an aqueous solution.
【0014】この水溶液を攪拌しながら0.5〜3%に
稀釈したアンモニア水をゆっくりと滴下し、中和させて
CuとAlの共沈物を得る。この時、溶液濃度が濃すぎ
たり、アンモニア水滴下速度が速すぎると原子レベルで
の均一混合物が得られない。溶液濃度は0.4mol/
l以下、アンモニア水滴下速度は10cc/min以下
でなければならない。この共沈物を純水でろ過洗浄して
Cu−Alゲルを得る。While stirring this aqueous solution, ammonia water diluted to 0.5 to 3% is slowly added dropwise to neutralize it to obtain a coprecipitate of Cu and Al. At this time, if the solution concentration is too high or the ammonia water dropping rate is too fast, a uniform mixture at the atomic level cannot be obtained. Solution concentration is 0.4 mol /
1 or less, and the ammonia water dropping rate must be 10 cc / min or less. This coprecipitate is filtered and washed with pure water to obtain a Cu-Al gel.
【0015】これをオートクレーブを用いて200℃以
下の種々の温度条件で水熱処理した。この水熱処理した
ものを大気乾燥後、110℃で一晩乾燥し、乳鉢にて粉
砕した。この粉末を700℃で1時間焼成して、水熱処
理された求める複合酸化物触媒、すなわち排ガス浄化触
媒を合成した。This was hydrothermally treated in an autoclave under various temperature conditions of 200 ° C. or lower. The hydrothermally treated product was air-dried, then dried at 110 ° C. overnight and crushed in a mortar. This powder was calcined at 700 ° C. for 1 hour to synthesize a hydrothermally treated desired composite oxide catalyst, that is, an exhaust gas purifying catalyst.
【0016】なお、上記の方法で調製したCu−Alゲ
ルを、オートクレーブで水熱処理を行わないでそのまま
乾燥、焼成したものも合成した。A Cu-Al gel prepared by the above method was also dried and calcined without hydrothermal treatment in an autoclave to synthesize it.
【0017】なお、上記の方法で調製したCu−Alゲ
ルを水熱処理を行わないでそのまま乾燥、焼成したもの
と、比較例としてCuを含まないAl酸化物を上記方法
と同様に調製してγAl2 O3 を作製し、そのγAl2
O3 に対して酸化物換算でCuOが5重量%となるよう
に硝酸銅を混合した水溶液を作製して、その中にγAl
2 O3 を入れ、このγAl2 O3 を入れた水溶液を攪拌
しながら0.5〜3%に希釈したアンモニア水をゆっく
りと滴下し、中和させてCuをγAl2 O3 に担持させ
た触媒も調製した。The Cu-Al gel prepared by the above method was directly dried and calcined without hydrothermal treatment, and a Cu-free Al oxide as a comparative example was prepared in the same manner as in the above method. 2 O 3 was produced and its γAl 2
An aqueous solution was prepared by mixing copper nitrate such that CuO was 5% by weight in terms of oxide with respect to O 3 , and γAl was added to the aqueous solution.
2 O 3 was added, and the aqueous solution containing γAl 2 O 3 was slowly added dropwise with stirring to a 0.5 to 3% diluted ammonia water to be neutralized to support Cu on γAl 2 O 3 . A catalyst was also prepared.
【0018】具体的には、表1において示したように酸
化物換算でCuOが重量パーセント5%のCu−Al複
合酸化物であって、オートクレーブによって、水熱温度
で100℃,120℃,150℃、190℃および20
0℃で処理したものと、オートクレーブ処理しないもの
とをそれぞれNo.1〜No.6として合成した。Specifically, as shown in Table 1, CuO is a Cu-Al composite oxide containing CuO in a weight percentage of 5% as shown in Table 1, which is heated by an autoclave at hydrothermal temperatures of 100 ° C, 120 ° C, and 150 ° C. ℃, 190 ℃ and 20
The samples treated at 0 ° C. and those not subjected to autoclave were treated with No. 1 to No. 6 was synthesized.
【0019】そして、併せて従来の手法によりCuOを
保持させた酸化物触媒は、重量比で5%のCuOを備え
るCuO担持アルミナとして合成し、150℃の水熱温
度でオートクレーブ処理したものとオートクレーブで処
理しないものを比較例のNo.1bおよびNo.1aと
して合成した。In addition, an oxide catalyst which retains CuO by a conventional method is also synthesized as CuO-supporting alumina having 5% by weight of CuO and autoclaved at a hydrothermal temperature of 150 ° C. and an autoclave. Those that are not processed in No. of the comparative example. 1b and No. It was synthesized as 1a.
【0020】以上の合成された触媒のNOX 浄化活性測
定は、既存の測定機器である固定床常圧流通式反応装置
で行った。The NO x purification activity of the above synthesized catalyst was measured by a fixed bed atmospheric pressure flow reactor which is an existing measuring instrument.
【0021】反応ガスの組成はNO:1000ppm,
C3 H6 :1000ppm,CO:1200ppm,H
2 :400ppm,O2 :6%,CO2 :10%,H2
O:10%,N2 :Bal.でGHSV(空間速度)は
200,000h-1で行った。その結果を、表1に示
す。The composition of the reaction gas is NO: 1000 ppm,
C 3 H 6: 1000ppm, CO : 1200ppm, H
2 : 400 ppm, O 2 : 6%, CO 2 : 10%, H 2
O: 10%, N 2: Bal. The GHSV (space velocity) was 200,000 h −1 . The results are shown in Table 1.
【0022】本発明に係る実施品No.1からNo.5
は、すべての浄化項目で満足すべき浄化率を示し、最大
で30%のNOX 浄化能の向上が見られた。また、この
時N2 Oの生成は見られなかった。但し、水熱処理20
0℃の実施品No.6は、NOX の浄化率が10%以下
となり、些か触媒機能が低下していることが分った。The product No. according to the present invention. 1 to No. 5
Indicates all purification rate satisfactory in cleaning items, improved up to 30% of the NO X purification performance was observed. Further, at this time, generation of N 2 O was not seen. However, hydrothermal treatment 20
0 ° C. product No. In No. 6, the NO x purification rate was 10% or less, and it was found that the catalytic function was slightly deteriorated.
【0023】また、反応ガス中での800℃熱劣化テス
トを行った。その結果を表2に示す。Further, a heat deterioration test at 800 ° C. in a reaction gas was conducted. The results are shown in Table 2.
【0024】表2によれば、No.1,No.4に示す
本発明の実施品は10時間テストでもNOX について熱
劣化が殆ど生じていないことが分かるが従来型の比較例
No.1aの品物は、その熱劣化がきわめて大きいこと
が分かる。According to Table 2, No. 1, No. It can be seen that the product of the present invention shown in FIG. 4 shows almost no thermal deterioration with respect to NO x even in the 10-hour test, but the conventional comparative example No. It can be seen that the heat deterioration of the item 1a is extremely large.
【0025】このように本発明の触媒は、耐熱性に優れ
ていることが判る。Thus, it can be seen that the catalyst of the present invention has excellent heat resistance.
【0026】更に、合成した触媒のうち、本実施例のN
o.1,No.2,No.3,No.4,No.5およ
びNo.6についてXRD(粉末X線回折)を行ったと
ころ、No.3,No.4およびNo.6のみを示す図
1に示されるようにオートクレーブ処理後の触媒はアモ
ルファスに近い擬ベーマイトの結晶構造を取っている
が、オートクレーブ処理温度が上がるに従って、擬ベー
マイトの結晶性が向上している事が判る。しかし、オー
トクレーブ処理温度200℃のような高温にすると、実
施例No.6の様に、ベーマイトの結晶性が極端に向上
し、実施例No.3,No.4では構造中に取り込まれ
ていた活性金属(Cu)が、実施例No.6では析出さ
れて、ベーマイト以外にCuOの結晶相が分離存在して
いることが明確に判る。従って、実施例No.6のよう
に、オートクレーブ処理温度を上げすぎると、結晶相の
分離が起こる臨界温度以上となることが判った。Furthermore, among the synthesized catalysts, N of the present embodiment is used.
o. 1, No. 2, No. 3, No. 4, No. 5 and No. When XRD (powder X-ray diffraction) was performed on No. 6, No. 3, No. 4 and No. As shown in FIG. 1 showing only No. 6, the catalyst after the autoclave treatment has a crystal structure of pseudo-boehmite which is close to amorphous, but the crystallinity of the pseudo-boehmite is improved as the autoclave treatment temperature rises. I understand. However, when the autoclave treatment temperature was set to a high temperature such as 200 ° C., the example No. As in No. 6, the crystallinity of boehmite was extremely improved, and Example No. 3, No. In Example 4, the active metal (Cu) incorporated in the structure was the same as in Example No. 4. In No. 6, it is clearly seen that the crystal phase of CuO is separated and present in addition to boehmite. Therefore, in Example No. It was found that when the autoclave treatment temperature was raised too high as in 6, the temperature was above the critical temperature at which the separation of the crystalline phase occurred.
【0027】この、実施例No.1,No.2,No.
3,No.4およびNo.5をオートクレーブ処理をし
たものを、大気中で700℃焼成を行ったところ、γA
l2O3 に相転移していたが、活性金属は構造に取り込ま
れたままでCuOの析出は見られなかった。しかし、実
施例No.6は、γ−Al2 O3 に相転移しているが、
オートクレーブ処理の時に析出していたCuOがそのま
ま存在し、No.3,No.4およびNo.6のみを示
す図2に示されるように、本発明の構造をとることがで
きないことが判る。This example No. 1, No. 2, No.
3, No. 4 and No. When 5 was autoclaved, it was calcined at 700 ° C in the air, and γA
Although it had undergone a phase transition to l 2 O 3 , the active metal was still incorporated in the structure and no precipitation of CuO was observed. However, in Example No. 6 has a phase transition to γ-Al 2 O 3 ,
CuO that had been precipitated during the autoclave treatment was still present, and No. 3, No. 4 and No. It can be seen that the structure of the present invention cannot be taken, as shown in FIG.
【0028】このように結晶相が分離しない臨界温度以
下の温度域でオートクレーブ処理をすることが必要であ
ることが判る。Thus, it is understood that it is necessary to carry out the autoclave treatment in a temperature range below the critical temperature at which the crystal phase does not separate.
【0029】そこで、触媒活性の良かったオートクレー
ブ処理温度域の複合酸化物の、活性金属原子近傍の局所
構造解析を広域X線吸収微細構造解析(以下、EXAF
S解析と略す)で行ったところ、図3から図5に示す結
果が得られた。Therefore, the local structure analysis in the vicinity of the active metal atom of the complex oxide in the autoclave treatment temperature range where the catalytic activity was good was analyzed by the wide area X-ray absorption fine structure analysis (hereinafter, EXAF).
S analysis was abbreviated), and the results shown in FIGS. 3 to 5 were obtained.
【0030】図3から図5に示すグラフは、CuのEX
AFS信号をフーリエ変換した動径分布関数を示してい
る。グラフにはフーリエ変換の実数部と虚数部を示して
いる。グラフ中のドットは実測データを示し、線は解析
結果を示している。パラメータはMcKaleをもちい
て、R空間にて解折を行った。この結果、第一近接原子
が酸素、第二近接原子がアルミニウムであり、図5およ
び図6より第二近接原子内に活性金属であるCuが存在
しないことが判る。表3に、その解析結果を示す。The graphs shown in FIGS. 3 to 5 show the Cu EX.
The radial distribution function which Fourier-transformed the AFS signal is shown. The graph shows the real and imaginary parts of the Fourier transform. The dots in the graph represent the actual measurement data, and the line represents the analysis result. The parameter was McKale, and the analysis was performed in the R space. As a result, it is found from FIG. 5 and FIG. 6 that the first adjacent atom is oxygen and the second adjacent atom is aluminum, and that Cu, which is an active metal, does not exist in the second adjacent atom. Table 3 shows the analysis results.
【0031】このことにより、オートクレーブ処理を臨
界温度以下の190℃以下で行ったものは、活性金属が
触媒構造内に単原子レベルで高分散化し、構造内に強固
に取り込まれている事が判る。From this, it can be seen that when the autoclave treatment is carried out at 190 ° C. or lower, which is lower than the critical temperature, the active metal is highly dispersed at the level of a single atom in the catalyst structure and is firmly incorporated in the structure. .
【0032】ところで、従来より行われている手法によ
り作成したCuO担持アルミナ触媒は、すべてのCuO
が活性アルミナの表面上に存在し、しかも約50〜10
0Å程度のクラスターを形成し、一つの活性金属粒子
に、数百から数千の原子が集まっているものと言われて
いる。しかし、本発明の触媒は、活性金属が単原子レベ
ルで触媒構造内に高分散化し、しかも、この構造内に活
性金属が強固に取り込まれた構造を有し、かつ、前記活
性金属が表面の一部を形成した構造をもっている。原子
が単原子レベルで存在する場合、クラスター又はそれ以
上のバルクで存在するときとは異なった特性を示すこと
が一般に知られている。Cuが単原子程度の状態で存在
している場合がNOX 浄化にいかに有用であるかは、C
uイオンをゼオライトにイオン交換したCuイオン交換
ゼオライトのNOX 浄化能を見ても明白である。本発明
の触媒は高分散した活性金属が触媒構造内に強固に取り
込まれているため熱的に安定であり、高いNOX 浄化能
と、高い熱耐久性の両面を有した触媒であり、自動車排
ガス等のNOX 浄化触媒として適していることが判る。By the way, the CuO-supported alumina catalyst prepared by the conventional method is
Exists on the surface of activated alumina, and is about 50 to 10
It is said that clusters of about 0Å are formed, and hundreds to thousands of atoms are gathered in one active metal particle. However, the catalyst of the present invention has a structure in which the active metal is highly dispersed in the catalyst structure at the level of a single atom, and further, the active metal is firmly incorporated in this structure, and the active metal has a surface structure. It has a partly formed structure. It is generally known that when atoms are present at the monatomic level, they exhibit different properties than when they are present in the bulk of clusters or larger. How useful is the NO x purification when Cu is present in the state of a single atom is C
It is also clear by looking at the NO x purification capacity of the Cu ion-exchanged zeolite in which the u ions have been ion-exchanged. The catalyst of the present invention is thermally stable because the highly dispersed active metal is firmly incorporated in the catalyst structure, and has both high NO x purification capacity and high thermal durability. It is found that the catalyst is suitable as a NO x purification catalyst for exhaust gas and the like.
【0033】[0033]
【表1】 [Table 1]
【0034】[0034]
【表2】 [Table 2]
【0035】[0035]
【表3】 [Table 3]
【0036】実施例 (1)-2〔オートクレーブ未処理およ
び水を用いたオートクレーブ処理によるCu−Al複合
酸化物合成〕 酸化物換算でCuOが15重量(wt)%となるように
硝酸アルミニウムと硝酸銅を混合した水溶液を作成し
た。Example (1) -2 [Synthesis of Cu-Al complex oxide by unclaved autoclave and autoclave using water] Aluminum nitrate and nitric acid were added so that CuO was 15% by weight (wt) in terms of oxide. An aqueous solution containing copper was prepared.
【0037】この水溶液を攪拌しながら0.5〜3%に
稀釈したアンモニア水をゆっくりと滴下し、中和させて
CuとAlの共沈物を得る。この時、溶液濃度が濃すぎ
たり、アンモニア水滴下速度が速すぎると原子レベルで
の均一混合物が得られない。溶液濃度は0.4mol/
l以下、アンモニア水滴下速度は10cc/min以下
でなければならない。この共沈物を純水でろ過洗浄して
Cu−Alゲルを得る。Ammonia water diluted to 0.5 to 3% was slowly added dropwise to this aqueous solution with stirring to neutralize it to obtain a coprecipitate of Cu and Al. At this time, if the solution concentration is too high or the ammonia water dropping rate is too fast, a uniform mixture at the atomic level cannot be obtained. Solution concentration is 0.4 mol /
1 or less, and the ammonia water dropping rate must be 10 cc / min or less. This coprecipitate is filtered and washed with pure water to obtain a Cu-Al gel.
【0038】これをオートクレーブを用いて200℃以
下の温度条件で水熱処理した。この水熱処理したものを
大気乾燥後、110℃で一晩乾燥し、乳鉢にて粉砕し
た。この粉末を700℃で1時間焼成して、水熱処理さ
れた求める複合酸化物触媒No.8およびNo.9を合
成した。This was hydrothermally treated in an autoclave under the temperature condition of 200 ° C. or lower. The hydrothermally treated product was air-dried, then dried at 110 ° C. overnight and crushed in a mortar. This powder was calcined at 700 ° C. for 1 hour and hydrothermally treated to obtain the desired complex oxide catalyst No. 8 and No. 9 was synthesized.
【0039】なお、上記の方法で調製したCu−Alゲ
ルを水熱処理を行わないでそのまま乾燥、焼成したもの
(No.7)と、比較例としてCuを含まないAl酸化
物を上記方法と同様に調製してγAl2 O3 を作製し、
そのγAl2 O3 に対して酸化物換算でCuOが15重
量%となるように硝酸銅を混合した水溶液を作製して、
その中にγAl2 O3 を入れ、このγAl2 O3 を入れ
た水溶液を攪拌しながら0.5〜3%に希釈したアンモ
ニア水をゆっくりと滴下し、中和させてCuをγAl2
O3 に担持させた触媒(No.2a)も調製した。The Cu-Al gel prepared by the above method was dried and calcined as it is without hydrothermal treatment (No. 7) and the Cu-free Al oxide as a comparative example was the same as the above method. To prepare γAl 2 O 3 ,
An aqueous solution was prepared by mixing copper nitrate so that CuO was 15% by weight in terms of oxide with respect to γAl 2 O 3 .
Put γAl 2 O 3 therein, the γAl 2 O 3 aqueous solution was dropwise slowly ammonia water diluted to 0.5% to 3% agitation were placed, GanmaAl a Cu by neutralizing 2
A catalyst (No. 2a) supported on O 3 was also prepared.
【0040】NOX 浄化活性は固定床常圧流通式反応装
置で行った。反応ガスの組成はNO:1000ppm,
C3 H6 :1000ppm,CO:1200ppm,H
2 :400ppm,O2 :6%,CO2 :10%,H2
O:10%,N3 :Bal.でGHSVは200,00
0h-1で行った。The NO X purification activity was carried out in a fixed bed atmospheric pressure flow reactor. The composition of the reaction gas is NO: 1000 ppm,
C 3 H 6: 1000ppm, CO : 1200ppm, H
2 : 400 ppm, O 2 : 6%, CO 2 : 10%, H 2
O: 10%, N 3: Bal. And GHSV is 200,00
It was performed at 0 h -1 .
【0041】その結果を、表4に示す。この様に最大で
31%のNOX 浄化能の向上が見られた。また、この時
N2 Oの生成は見られなかった。但し、オートクレーブ
処理を200℃で行ったNo.9は複合酸化物の結晶を
分離する臨界温度以上であるのでNOX 浄化能が低下し
ているのが分る。The results are shown in Table 4. The maximum increase of 31% of the NO X purification performance as was seen. Further, at this time, generation of N 2 O was not seen. However, in No. 1 where the autoclave treatment was performed at 200 ° C. No. 9 is above the critical temperature for separating the crystals of the composite oxide, and therefore it can be seen that the NO x purification ability is lowered.
【0042】[0042]
【表4】 [Table 4]
【0043】実施例(2)〔オートクレーブ未処理およ
びアルコールを用いたオートクレーブ処理によるCu−
Al複合酸化物合成〕 エタノールと純水を1:5で混合した溶液に、酸化物換
算でCuOが5重量%となるように硝酸アルミニウムと
硝酸銅を混合した。この混合水溶液を攪拌しながら0.
5〜3%に希釈したアンモニア水をゆっくりと滴下し、
中和させてCuとAlの共沈物を得る。この共沈物をエ
タノールと純水を1:1で混合した溶液でろ過洗浄後、
エタノールのみで再度ろ過洗浄してCu−Alゲルを得
る。Example (2) [Cu-untreated autoclave and autoclaved with alcohol]
Synthesis of Al complex oxide] Aluminum nitrate and copper nitrate were mixed in a solution in which ethanol and pure water were mixed at a ratio of 1: 5 so that CuO was 5% by weight in terms of oxide. While stirring this mixed aqueous solution,
Ammonia water diluted to 5 to 3% is slowly added dropwise,
It is neutralized to obtain a coprecipitate of Cu and Al. The coprecipitate was filtered and washed with a solution of ethanol and pure water mixed at a ratio of 1: 1,
The filter is washed again with only ethanol to obtain a Cu-Al gel.
【0044】これをオートクレーブを用いて100〜2
00℃の温度で処理した。このオートクレーブ処理した
ものを大気乾燥後、110℃で一晩乾燥し、乳鉢にて粉
砕した。この粉末を700℃で1時間焼成して、オート
クレーブ処理の複合酸化物触媒を合成した。This was put in an autoclave for 100 to 2
Treated at a temperature of 00 ° C. The autoclaved product was air-dried, dried overnight at 110 ° C., and crushed in a mortar. This powder was calcined at 700 ° C. for 1 hour to synthesize an autoclave-processed composite oxide catalyst.
【0045】なお、上記の方法で調製したCu−Alゲ
ルを、オートクレーブ処理を行なわないでそのまま乾
燥、焼成したものNo.10と、Cuを含まないAl酸
化物γAl2 O3 にCuOを純水−エタノール混合溶液
中で担持させた触媒も合成した。The Cu-Al gel prepared by the above method was dried and calcined as it was without autoclaving. 10 and a catalyst in which CuO was supported on an Al oxide γAl 2 O 3 containing no Cu in a pure water-ethanol mixed solution were also synthesized.
【0046】具体的には、表5において示したように、
CuOが重量比で5%のCu−Al複合酸化物であっ
て、オートクレーブで100℃,120℃,150℃お
よび200℃で処理したものNo.11〜No.14
と、処理しないものNo.10を合成した。Specifically, as shown in Table 5,
CuO is a Cu-Al composite oxide containing 5% by weight of CuO, which was treated in an autoclave at 100 ° C, 120 ° C, 150 ° C and 200 ° C. 11-No. 14
What is not processed No. 10 was synthesized.
【0047】併せて、Cuを含まないAl酸化物を上記
方法と同様に調製してγAl2 O3を作製し、そのγA
l2 O3 に対して、酸化物換算でCuOが5重量%とな
るように硝酸銅を混合した純水とアルコールの混合溶液
を作製して、その中にγAl2 O3 を入れ、このγAl
2 O3 を入れた水溶液を攪拌しながら0.5〜3%に希
釈したアンモニア水をゆっくりと滴下し、中和させてC
uをγAl2 O3 に担持させ、ろ過、洗浄、乾燥、焼成
等も上記と同様に行ってCuO担持アルミナ触媒も調製
した。そして、150℃のオートクレーブで処理したも
のNo.3bと、処理しないものNo.3aとを合成し
た。At the same time, an Al oxide containing no Cu was prepared in the same manner as in the above method to prepare γAl 2 O 3 , and its γA
A mixed solution of pure water and alcohol was prepared by mixing copper nitrate such that CuO was 5% by weight in terms of oxide with respect to l 2 O 3 , and γAl 2 O 3 was put in the mixed solution.
While stirring the aqueous solution containing 2 O 3 , 0.5 to 3% of ammonia water diluted slowly was added dropwise to neutralize C
A CuO-supported alumina catalyst was also prepared by supporting u on γAl 2 O 3 and performing filtration, washing, drying, firing and the like in the same manner as above. And what was processed with the autoclave of 150 degreeC No. No. 3b and one not processed. 3a was synthesized.
【0048】以上の合成された触媒のNOX 浄化活性
は、既存の測定機器である固定床常圧流通式反応装置で
行なった。The NO x purification activity of the above-synthesized catalyst was measured by a fixed bed atmospheric pressure type reactor which is an existing measuring instrument.
【0049】反応ガスの組成はNO:1000ppm,
C3 H6 :1000ppm,CO:1200ppm,H
2 :400ppm,O2 :6%,CO2 :10%,H2
O:10%,N2 :Bal.でGHSVは200,00
0h-1で行った。The composition of the reaction gas is NO: 1000 ppm,
C 3 H 6: 1000ppm, CO : 1200ppm, H
2 : 400 ppm, O 2 : 6%, CO 2 : 10%, H 2
O: 10%, N 2: Bal. And GHSV is 200,00
It was performed at 0 h -1 .
【0050】表5から分かるようにCu含有量が5%の
場合、最大で29%のNOX 浄化能の向上が見られた。
また、この時N2 Oの生成は見られなかった。The amount containing Cu As can be seen from Table 5 that when the 5% maximum increase of 29% of the NO X purification performance was observed.
Further, at this time, generation of N 2 O was not seen.
【0051】なお、実施例のうち、オートクレーブ処理
が200℃のNo.14はNOX 浄化率が低下している
結果となった。Incidentally, among the examples, No. 1 whose autoclave treatment was 200 ° C. No. 14 resulted in a reduced NO x purification rate.
【0052】したがって、特にオートクレーブ処理の場
合臨界温度以下のNo.11〜No.13においてすべ
ての浄化項目で満足できる結果が認められる。Therefore, particularly in the case of autoclave treatment, No. 11-No. In No. 13, satisfactory results are recognized in all purification items.
【0053】[0053]
【表5】 [Table 5]
【0054】実施例(3)〔Co,Ni,Fe,−Al
複合酸化物合成〕 硝酸コバルト、硝酸ニッケル、硝酸鉄をそれぞれ酸化物
換算で5重量%となるように硝酸アルミニウムと混合し
た溶液を作成する。以下、実施例(1)と同様な方法で
オートクレーブ未処理のものと、オートクレーブ水熱処
理した複合酸化物触媒No.15,16,17を合成し
た。Example (3) [Co, Ni, Fe, -Al
Composite Oxide Synthesis] A solution is prepared by mixing cobalt nitrate, nickel nitrate, and iron nitrate with aluminum nitrate so as to each be 5% by weight in terms of oxide. Hereinafter, the autoclave untreated and the autoclave hydrothermally treated composite oxide catalyst No. 1 were processed in the same manner as in Example (1). 15, 16, 17 were synthesized.
【0055】これ等の複合酸化物は、前記実施例の場合
と同様にオートクレーブ未処理の場合は勿論のこと臨界
温度以下の温度範囲に相当する190℃未満のオートク
レーブ処理でも満足すべき浄化能が得られた。These composite oxides have satisfactory purifying ability not only when the autoclave is untreated as in the above-mentioned examples but also when the autoclave is treated at less than 190 ° C. which corresponds to a temperature range below the critical temperature. Was obtained.
【0056】そして、実施例(1)と同様な方法で、N
OX 浄化活性を測定した結果を、表6に示す。いづれも
きわめて安定したNOX 浄化効果を示したことが分る。Then, in the same manner as in Example (1), N
Table 6 shows the results of measuring the O X purification activity. It can be seen that in each case, the NO x purification effect was extremely stable.
【0057】[0057]
【表6】 [Table 6]
【0058】実施例(4)〔オートクレーブ未処理およ
び水を用いたオートクレーブ処理によるCu−Al−S
i複合酸化物合成〕 実施例(1)と同様な方法で、酸化物換算でCuOが5
重量%、SiO2 が10重量%となるように硝酸アルミ
ニウムと硝酸銅と水ガラスを混合した水溶液を作製し
た。Example (4) [Cu-Al-S untreated with autoclave and autoclaved with water]
Synthesis of i complex oxide] In the same manner as in Example (1), CuO was 5 in terms of oxide.
An aqueous solution was prepared by mixing aluminum nitrate, copper nitrate, and water glass so that the weight% and the SiO 2 were 10% by weight.
【0059】この水溶液を攪拌しながら0.5〜3%に
希釈したアンモニア水をゆっくりと滴下し、中和させて
CuとAlとSiの共沈物を得る。この時、溶液濃度が
濃すぎたり、アンモニア水滴下速度が速すぎると原子レ
ベルでの均一混合物が得られない。溶液濃度は0.4m
ol/l以下、アンモニア水滴下速度は10cc/mi
n以下でなければならない。この共沈物を純水でろ過洗
浄してCu−Alゲルを得る。Ammonia water diluted to 0.5 to 3% was slowly added dropwise to this aqueous solution with stirring to neutralize it to obtain a coprecipitate of Cu, Al and Si. At this time, if the solution concentration is too high or the ammonia water dropping rate is too fast, a uniform mixture at the atomic level cannot be obtained. Solution concentration is 0.4m
ol / l or less, ammonia water dropping rate is 10 cc / mi
must be n or less. This coprecipitate is filtered and washed with pure water to obtain a Cu-Al gel.
【0060】これをオートクレーブを用いて200℃以
下の温度で水熱処理した。この水熱処理したものを大気
乾燥後、110℃で一晩乾燥し、乳鉢にて粉砕した。こ
の粉末を700℃で1時間焼成して、水熱処理複合酸化
物触媒を合成した(No.19〜No.23)。This was hydrothermally treated at a temperature of 200 ° C. or lower using an autoclave. The hydrothermally treated product was air-dried, then dried at 110 ° C. overnight and crushed in a mortar. This powder was calcined at 700 ° C. for 1 hour to synthesize a hydrothermally treated composite oxide catalyst (No. 19 to No. 23).
【0061】併せて、上記の方法で調製したCu−Al
−Siゲルを水熱処理を行わないでそのまま乾燥、焼成
したもの(No.18)と、比較用としてCuを含まな
いAl−Si酸化物にCuOを担持させた触媒も合成し
た(No.4a,No.4b)。In addition, Cu-Al prepared by the above method
-Si gel was dried and calcined as it was without hydrothermal treatment (No. 18), and for comparison, a catalyst in which CuO was supported on an Al-Si oxide containing no Cu was also synthesized (No. 4a, No. 4b).
【0062】NOX 浄化活性測定は固定床常圧流通式反
応装置で行った。反応ガスの組成はNO:1000pp
m,C3 H6 :1000ppm,CO:1200pp
m,H2 :400ppm,O2 :6%,CO2 :10
%,H2 O:10%,N2 :Bal.でGHSVは20
0,000h-1で行った。その結果を、表7に示す。こ
のように最大で30%のNOX 浄化能の向上が見られ
た。また、この時N2 Oの生成は見られなかった。The NO X purification activity measurement was carried out in a fixed bed atmospheric pressure flow reactor. The composition of the reaction gas is NO: 1000 pp
m, C 3 H 6 : 1000 ppm, CO: 1200 pp
m, H 2 : 400 ppm, O 2 : 6%, CO 2 : 10
%, H 2 O: 10%, N 2 : Bal. And GHSV is 20
It was carried out at 10,000 h -1 . The results are shown in Table 7. Thus improvement of up to 30% of the NO X purification performance was observed. Further, at this time, generation of N 2 O was not seen.
【0063】この表からも分るように水熱処理が200
℃では、臨界温度を越えているので他の実施例と同じよ
うにNOX 浄化率が低下するので好ましくない。As can be seen from this table, the hydrothermal treatment is 200
Since the critical temperature is exceeded at a temperature of ° C, the NO x purification rate is lowered as in the other examples, which is not preferable.
【0064】なお、以上の実施例では専ら共沈法につい
ての複合酸化物の合成について記述したが、その他アル
コキシド法でも同様に実施でき、これらの方法を用いる
ことにより、活性遷移金属原子が、周りの第二近接原子
以内にそれと同じ遷移金属原子が存在しない状態が得ら
れ、これにより触媒機能を著しく向上できると共に耐熱
性も向上できる利点を有する。In the above-mentioned examples, the synthesis of the complex oxide by the coprecipitation method was mainly described, but the other alkoxide method can also be carried out in the same manner. It is possible to obtain a state in which the same transition metal atom does not exist within the second adjacent atom of, and this has the advantage that the catalytic function can be remarkably improved and the heat resistance can be improved.
【0065】また、オートクレーブ処理は水、アルコー
ル以外の液体を用いてもよい。Liquids other than water and alcohol may be used for the autoclave treatment.
【0066】なお、担体となるべき触媒の酸化物換算を
主としてCuOが5重量%および15重量%とした場合
について記述したが、異なる量でも同様に実施できるこ
とは勿論である。It is to be noted that although the case where the oxide conversion of the catalyst to be the carrier is mainly 5% by weight and 15% by weight of CuO has been described, it goes without saying that different amounts can be similarly used.
【0067】[0067]
【表7】 [Table 7]
【0068】[0068]
【発明の効果】この発明で得られる排ガス浄化触媒は、
活性金属である遷移金属原子のうち少なくとも一種類
と、Al,Siのうち少なくとも一種類の元素を含む複
合酸化物触媒で、活性金属が単原子レベルで触媒構造内
に高分散化し、しかも構造内に活性金属が強固に取り込
まれた構造を有し、かつ、前記活性金属が表面の一部を
形成しており、高いNOX 浄化能と、高い熱耐久性の両
面を有した触媒であり、活性金属粒子がクラスター状態
で単に表面に担持されたものやイオン交換サイトに活性
金属イオンが弱く結合しているものとは基本的に異な
り、前記の様な構造を形成させた触媒は、例えば、活性
金属がCuのような熱的に不安定で動きやすい金属で
も、触媒構造内に活性金属が強固に固定されるので、耐
熱性が飛躍的に向上し、しかも、活性金属がイオン交換
ゼオライトに近い原子レベルの高分散を形成しているた
め、従来では得られなかった高いNOX 浄化能と、高い
熱耐久性の両面を有する触媒特性を得ることが可能とな
った。The exhaust gas purifying catalyst obtained by the present invention is
A composite oxide catalyst containing at least one kind of transition metal atom which is an active metal and at least one kind of element of Al and Si, wherein the active metal is highly dispersed in the catalyst structure at the single atom level, and Has a structure in which the active metal is firmly incorporated, and the active metal forms a part of the surface, and is a catalyst having both high NO x purification capacity and high thermal durability. Basically different from those in which the active metal particles are simply supported on the surface in a cluster state or those in which the active metal ions are weakly bound to the ion exchange sites, the catalyst having the structure as described above is, for example, Even if the active metal is a thermally unstable and mobile metal such as Cu, the active metal is firmly fixed in the catalyst structure, so the heat resistance is dramatically improved, and the active metal is ion-exchanged zeolite. Close atom Since forming the high dispersion of Le, a high NO X purification performance which can not be obtained by the conventional, it becomes possible to obtain a catalytic properties with both surfaces of the high thermal durability.
【0069】そして、更にオートクレーブ処理を行う
と、オートクレーブ内の特殊な環境により、適度な結晶
性の向上と安定化が起こり、触媒活性点の更なる活性化
が促され、NOX 浄化能が極めて高くなる。When the autoclave treatment is further carried out, due to the special environment inside the autoclave, the crystallinity is appropriately improved and stabilized, the further activation of the catalytic active sites is promoted, and the NO x purification capacity is extremely high. Get higher
【0070】なお、オートクレーブ処理はNOX 浄化能
を向上できるが、好ましくは複合酸化物の結晶相が分離
する臨界温度以下での処理温度が、最良のNOX 浄化能
を有する触媒として形成できる。[0070] Incidentally, although autoclaving can improve the NO X purification performance, preferably the treatment temperature below a critical temperature at which the crystal phase of the composite oxide is separated can be formed as a catalyst having the best of the NO X purification performance.
【図1】 この発明に係る排ガス浄化触媒の水熱処理後
のXRD解析を示すグラフFIG. 1 is a graph showing an XRD analysis after hydrothermal treatment of an exhaust gas purifying catalyst according to the present invention.
【図2】 同じく同上触媒の700℃焼成後のXRD解
析グラフFIG. 2 is an XRD analysis graph of the same catalyst as above, after calcining at 700 ° C.
【図3】 同じく同上触媒の150℃の水熱処理後の排
ガス浄化触媒の解析グラフ[Fig. 3] Similarly, an analysis graph of an exhaust gas purifying catalyst after hydrothermal treatment of the same catalyst at 150 ° C.
【図4】 同じく同上触媒の150℃の水熱処理後の排
ガス浄化触媒の解析グラフFIG. 4 is an analysis graph of an exhaust gas purifying catalyst after hydrothermal treatment of the same catalyst at 150 ° C.
【図5】 同じく同上触媒の150℃の水熱処理後の排
ガス浄化触媒の解析グラフFIG. 5 is an analysis graph of an exhaust gas purifying catalyst after hydrothermal treatment of the same catalyst as above at 150 ° C.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 FI 技術表示箇所 B01J 23/08 ZAB B01J 23/20 ZABA 23/10 ZAB 23/22 ZABA 23/20 ZAB 23/26 ZABA 23/22 ZAB 23/28 ZABA 23/26 ZAB 23/30 ZABA 23/28 ZAB 23/32 ZABA 23/30 ZAB 23/34 ZABA 23/32 ZAB 23/36 ZABA 23/34 ZAB 23/42 ZABA 23/36 ZAB 23/44 ZABA 23/42 ZAB 23/46 ZAB 23/44 ZAB ZABA 23/46 ZAB 301A 23/52 ZABA 301 23/74 ZAB 23/52 ZAB 37/10 ZAB 23/74 ZAB B01D 53/36 ZAB 23/745 102Z 23/75 B01J 23/74 301A 23/755 311A 37/10 ZAB 321A ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Office reference number FI Technical display location B01J 23/08 ZAB B01J 23/20 ZABA 23/10 ZAB 23/22 ZABA 23/20 ZAB 23/26 ZABA 23/22 ZAB 23/28 ZABA 23/26 ZAB 23/30 ZABA 23/28 ZAB 23/32 ZABA 23/30 ZAB 23/34 ZABA 23/32 ZAB 23/36 ZABA 23/34 ZAB 23/42 ZABA 23 / 36 ZAB 23/44 ZAB A 23/42 ZAB 23/46 ZAB 23/44 ZAB ZABA 23/46 ZAB 301A 23/52 ZABA 301 23/74 ZAB 23/52 ZAB 37/10 ZAB 23/74 ZAB B01D 53/36 ZAB 23/745 102Z 23/75 B01J 23/74 301A 23/755 311A 37/10 ZAB 321A
Claims (5)
l,Siのうち少なくとも1種類の元素を含む複合酸化
物より成り、かつ前記遷移金属原子が表面の一部を形成
してなることを特徴とする排ガス浄化触媒。1. At least one transition metal atom and A
An exhaust gas purification catalyst comprising a complex oxide containing at least one element of l and Si, and the transition metal atom forming a part of the surface.
の周りの第二近接原子以内に、好ましくは異なる原子が
存在することを特徴とする請求項1記載の排ガス浄化触
媒。2. The exhaust gas purifying catalyst according to claim 1, wherein the transition metal atom of the composite oxide is preferably a different atom within the second adjacent atom around the atom.
浄化触媒をオートクレーブ処理して得ることを特徴とす
る排ガス浄化触媒。3. An exhaust gas purification catalyst obtained by subjecting the exhaust gas purification catalyst according to claim 1 to an autoclave treatment.
晶相が分離する臨界温度以下の温度範囲で行うことを特
徴とする請求項3記載の排ガス浄化触媒。4. The exhaust gas purifying catalyst according to claim 3, wherein the autoclave treatment is carried out in a temperature range below a critical temperature at which the crystal phase of the composite oxide separates.
ルで行うことを特徴とする請求項4記載の排ガス浄化触
媒。5. The exhaust gas purifying catalyst according to claim 4, wherein the autoclave treatment is performed with water or alcohol.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7066125A JPH08257403A (en) | 1995-03-24 | 1995-03-24 | Catalyst for purifying exhaust gas |
US08/613,284 US5834395A (en) | 1995-03-24 | 1996-03-11 | Catalyst for controlling emissions |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7066125A JPH08257403A (en) | 1995-03-24 | 1995-03-24 | Catalyst for purifying exhaust gas |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH08257403A true JPH08257403A (en) | 1996-10-08 |
Family
ID=13306849
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7066125A Pending JPH08257403A (en) | 1995-03-24 | 1995-03-24 | Catalyst for purifying exhaust gas |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH08257403A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010527877A (en) * | 2007-05-24 | 2010-08-19 | ズード−ケミー アーゲー | Metal-doped zeolite and process for producing the same |
JP2011088093A (en) * | 2009-10-23 | 2011-05-06 | Toyota Motor Corp | Catalyst for nox cleaning |
JP2013203578A (en) * | 2012-03-28 | 2013-10-07 | Osaka Gas Co Ltd | Titanium oxide structure having high crystallinity and high specific surface area |
JP2014172775A (en) * | 2013-03-07 | 2014-09-22 | Tohoku Univ | Method for producing powder |
US9084988B2 (en) | 2011-02-07 | 2015-07-21 | Toyota Jidosha Kabushiki Kaisha | NOX purification catalyst |
-
1995
- 1995-03-24 JP JP7066125A patent/JPH08257403A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010527877A (en) * | 2007-05-24 | 2010-08-19 | ズード−ケミー アーゲー | Metal-doped zeolite and process for producing the same |
JP2011088093A (en) * | 2009-10-23 | 2011-05-06 | Toyota Motor Corp | Catalyst for nox cleaning |
US9084988B2 (en) | 2011-02-07 | 2015-07-21 | Toyota Jidosha Kabushiki Kaisha | NOX purification catalyst |
JP2013203578A (en) * | 2012-03-28 | 2013-10-07 | Osaka Gas Co Ltd | Titanium oxide structure having high crystallinity and high specific surface area |
JP2014172775A (en) * | 2013-03-07 | 2014-09-22 | Tohoku Univ | Method for producing powder |
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