WO2005089939A1 - Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas - Google Patents

Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas Download PDF

Info

Publication number
WO2005089939A1
WO2005089939A1 PCT/JP2004/003795 JP2004003795W WO2005089939A1 WO 2005089939 A1 WO2005089939 A1 WO 2005089939A1 JP 2004003795 W JP2004003795 W JP 2004003795W WO 2005089939 A1 WO2005089939 A1 WO 2005089939A1
Authority
WO
WIPO (PCT)
Prior art keywords
catalyst
nitrogen oxides
exhaust gas
producing
firing
Prior art date
Application number
PCT/JP2004/003795
Other languages
French (fr)
Japanese (ja)
Inventor
Hideo Kameyama
Yu Kaku
Original Assignee
Tokyo University Of Agriculture And Technology Tlo Co., Ltd.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tokyo University Of Agriculture And Technology Tlo Co., Ltd. filed Critical Tokyo University Of Agriculture And Technology Tlo Co., Ltd.
Priority to JP2006511099A priority Critical patent/JPWO2005089939A1/en
Priority to PCT/JP2004/003795 priority patent/WO2005089939A1/en
Priority to TW093108490A priority patent/TW200531740A/en
Publication of WO2005089939A1 publication Critical patent/WO2005089939A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • B01D53/9413—Processes characterised by a specific catalyst
    • B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0215—Coating
    • B01J37/0225—Coating of metal substrates
    • B01J37/0226—Oxidation of the substrate, e.g. anodisation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B01D2255/2065—Cerium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20761—Copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/209—Other metals
    • B01D2255/2092—Aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • B01J37/0248—Coatings comprising impregnated particles

Definitions

  • the present invention relates to a catalyst for reducing nitrogen oxides, a catalyst using the same, and a method for reducing nitrogen oxides in exhaust gas.
  • the present invention relates to a catalyst suitable for reduction and removal of nitrogen oxides and a catalyst body carrying the same, and more particularly, to a catalyst suitable for reduction and removal of nitrogen oxides in exhaust gas discharged from a diesel engine.
  • 11-6 catalyst a catalyst body having the catalyst supported on a substrate surface, and its production
  • the present invention relates to a method and a method for removing nitrogen oxides, which is effective under a high-concentration oxygen atmosphere and in the presence of sulfur oxides and steam, using the catalyst.
  • Nitrogen oxides emitted from various types of combustion equipment are air pollutants that are harmful to humans and the environment, and their reduction is desired.
  • the three-way catalytic method and selective catalytic reduction using NH 3 have been used to reduce nitrogen oxides (NO x) contained in exhaust gas from diesel engines, which is a major source of air pollution.
  • NO x nitrogen oxides
  • the actual exhaust gas contains a high concentration of oxygen or coexists with a large amount of steam sulfuric acid and yellow oxide. Did not.
  • the use of a noble metal as a denitration catalyst is often disadvantageous in that the catalyst is expensive.
  • Yoshinari et al. (Tomohiro Yoshinari, Application of Alumina Catalyst to NOx Removal of Diesel Engine Exhaust Gas, Catalyst, 39, 222-22-27 (19997)) used anoremina catalyst.
  • the effect of the presence of sulfur on the removal of nitric oxide using methanol as a reducing agent was examined.If the sulfur content in the exhaust gas was 100 ppm or more, the initial removal rate was 70% in 5 to 10 hours. Reported a decrease to 40% (see especially Figure 3).
  • the present inventors have intensively studied a reduction catalyst for nitrogen oxides in order to solve the conventional drawbacks.
  • the catalyst activity is only maintained for a long period of time. It was found that the reduction rate of nitrogen oxides was improved when sulfur compounds and steam coexisted, and the present invention was reached.
  • a first object of the present invention is to efficiently reduce nitrogen oxides (NO x) to nitrogen even in a high-concentration oxygen atmosphere, and to have high-concentration sulfur oxides and water vapor in exhaust gas. Even in such a case, it is an object of the present invention to provide a nitrogen oxide reduction catalyst that does not decrease the reduction reaction efficiency for a long period of time.
  • a second object of the present invention is to efficiently reduce nitrogen oxides (NO 2) to nitrogen even in a high-concentration oxygen atmosphere, and to have high-concentration sulfur oxides and water vapor in exhaust gas.
  • Another object of the present invention is to provide a nitrogen oxide reduction catalyst which is effective for a long period of time and is effective for making the temperature distribution in the reactor uniform.
  • a third object of the present invention is to provide a method for efficiently reducing nitrogen oxides in exhaust gas discharged from a diesel engine.
  • a fourth object of the present invention is to provide an apparatus suitable for efficiently reducing nitrogen oxides in exhaust gas discharged from a diesel engine. Disclosure of the invention
  • the present invention provides a selective reduction catalyst for nitrogen oxides comprising two metals, Cu—Ce, and a selective reduction of nitrogen oxides having this catalyst supported on an anodized metal surface.
  • the weight ratio of Cu to Ce in the catalyst is preferably 90: 1 to 14: 3. Moreover, the catalyst body 2 per apparent lm, the amount of supported Cu is 7. 0 ⁇ 9. O g of is preferably carried amount of C e is 0. 1 to 1. 5 g, catalyst-carrying
  • the surface is preferably a porous surface formed by subjecting an aluminum surface formed by anodization to a hydration treatment and then firing the aluminum surface.
  • Such a catalyst body is obtained by anodizing the surface of a substrate having an anodizable metal surface, hydrating the anodized surface formed thereby, and then firing, followed by Cu and C
  • the substrate is immersed in an aqueous solution containing e, dried, and fired to produce the substrate.
  • a nitrogen-containing high-concentration exhaust gas containing nitrogen oxides is introduced into a reaction chamber having such a catalyst body therein, and the nitrogen oxides are reduced at 350 to 500 ° C. while appropriately adding hydrocarbons. Nitrogen oxides in exhaust gas can be reduced and removed. According to this method, the removal rate of nitrogen oxides does not decrease even when the exhaust gas contains a high concentration of sulfur compounds or water vapor.
  • Figure 2 is a graph showing the Cu_C eZA 1 2 0 3 alumite catalysts of the present invention, by supplying 'stop of sulfur dioxide 1-5% water vapor and 500 ppm, the through time changes dependent reduction rate of nitric oxide It is.
  • Copper and cerium used in the catalyst of the present invention are appropriately selected from water-soluble metal salts.
  • Can be used Te in particular, copper nitrate trihydrate (C u (N 0 3) 2 - 3 H 2 0), cerium nitrate hexahydrate (C e (N 0 3) 3 - 6 ⁇ 2 ⁇ ) are preferred.
  • the catalyst of the present invention is preferably used by being supported on a metal substrate having an anodized alumite surface.
  • the above substrate is not particularly limited as long as it has an aluminum-layer or aluminum alloy layer of 40 m or more whose surface can be anodized, but in particular, the whole substrate is made of aluminum or aluminum alloy. Is preferred.
  • the length and shape of the substrate are not particularly limited as long as it is linear or plate-like (including ribbon-like), but it should be a plate-like, mesh-like, or honeycomb-like substrate. It is particularly preferable that these substrates are formed integrally with the reactor.
  • the anodic oxidation of the substrate surface of the catalyst body may be performed by dipping in an acidic solution such as an aqueous oxalic acid solution and according to a known method.
  • the reaction chamber may be formed by using the catalyst body after forming the catalyst body, but it is preferable to form the reaction chamber in advance and then anodize the inside. In order to increase the specific surface area of the anodized surface thus obtained, it is preferred in the present invention that the surface is further hydrated and then fired.
  • the hydration treatment may be performed with hot water or steam at 50 to 350 ° C, but is preferably performed at 60 to 85 ° C from the viewpoint of workability and treatment effect.
  • the treatment time of the hydration treatment depends on the temperature of the treated water. In the present invention, at 60 to 85 ° C
  • the hydration treatment it is preferable to perform the hydration treatment for 1 hour or more, and even if it is 2 hours or more, the surface area will not increase substantially further. After the hydration treatment, it is preferable to air dry at room temperature for 4 hours or more.
  • the firing temperature is preferably from 400 ° C. to 550 ° C. 1S In the present invention, the firing is preferably performed at about 500 ° C. for about 3 hours.
  • the Cu-Ce catalyst of the present invention can be easily supported on the substrate surface by a known impregnation method or the like.
  • the loading of copper and cerium may be simultaneous loading or individual loading. In any case, than to calcination treatment after them supported, C u _ C e / A 1 2 0.
  • Loading amount of copper in the nitrogen oxide selective reduction catalyst of the present invention is 7.5 to 8.5 preferably g is Roh m 2 (apparent area), cerium 0. 1 ⁇ 1. 5 g Zm 2 ( (Visible area).
  • the alumite catalyst body obtained in this way is appropriately installed in, for example, an exhaust gas passage of a diesel engine, the installed location becomes a reaction chamber, and unburned hydrocarbons present in the exhaust gas and replenishment from the outside. Nitrogen oxides in the exhaust gas can be reduced to harmless nitrogen by using the hydrocarbons added as a reducing agent.
  • the reaction temperature is preferably around 450 ° C., but can be appropriately adjusted depending on other reaction conditions.
  • a reaction chamber having the catalyst body therein may be manufactured and installed in the exhaust gas passage, or the exhaust gas may be introduced into the reaction chamber.
  • the above-mentioned hydrocarbon as a reducing agent to be supplementarily added can be appropriately selected from known saturated or unsaturated hydrocarbons which are gaseous at 400 ° C. These hydrocarbons may be used alone or as a mixture of two or more, and may be mineral hydrocarbon oils such as gasoline, kerosene, gas oil, and heavy oil.
  • the ratio of oxygen and hydrocarbons contained in normal exhaust gas deviates from 1 far from 1. Essentially, all exhaust gas is converted into nitrogen gas, carbon dioxide gas, and water by complete combustion. However, it is essentially necessary to add hydrocarbons. In the present invention, it is preferable to adjust the amount of hydrocarbon to be added so that the rate of reduction of nitrogen oxide is maximized around 450 ° C. As a result, the nitrogen oxide reduction rate Can be reduced to about 40%.
  • an oxidation reaction chamber having an oxidation catalyst is provided at the latter stage of the reduction reaction so as not to exhaust the carbonization as it is.
  • the particulate matter contained in the exhaust gas of the diesel engine was removed before the reduction reaction chamber. It is preferable to provide a filter for performing the operation.
  • the present invention can be made suitable for treating exhaust gas from a diesel engine.
  • Example 1 the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.
  • Example 1
  • a commercially available aluminum plate (JIS A1050) having a thickness of 0.5 mm is degreased with a 20% aqueous sodium hydroxide solution at room temperature for 3 minutes, and then immersed in a 30% nitric acid aqueous solution for 1 minute to perform surface treatment. I went. Next, using a 4% aqueous oxalic acid solution, anodic oxidation was performed at a liquid temperature of 20 ° C. and a voltage density of 50. OAZm 2 for 16 hours. Thereafter, in order to remove oxalic acid remaining in the anodized acid film, the film was baked at 350 ° C. for 1 hour.
  • the alumite catalyst body having an apparent surface area of 2 ⁇ 2 cm 2 was finely cut into 80 pieces (0.5 mm3 ⁇ 4), diluted with quartz sand, and filled in a reaction tube having an inner diameter of 15 mm.
  • a reaction tube having an inner diameter of 15 mm. Contains 15% oxygen, 0.5% propylene and 1 000 ppm nitric oxide Helium gas was flowed through the reaction tube at a space velocity of 10,000 / hour to a gas flow rate of 150 ml.
  • the temperature range of 200 ° C ⁇ 500 ° C the result of examining the C uC e / A l 2 O 3 anodized catalytic denitration activity of the present invention shown in FIG. As is evident from Fig.
  • the nitric oxide reduction rate did not reach 20% at temperatures below 300 ° C, but within a wide temperature range from 350 ° C to 450 ° C, a 30% reduction rate was observed. Obtained. In particular, a nitric oxide reduction rate of about 40% was obtained in the temperature range of 400 to 450 ° C. In addition, a reaction selectivity to nitrogen of more than 90% was obtained over the entire temperature range.
  • NOx nitrogen oxides

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Catalysts (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

A catalyst for the selective reduction of nitrogen oxides, characterized in that it comprises two metals of Cu-Ce; a catalytic article which comprises a metal having an anodically oxidized surface and the above catalyst carried on the anodically oxidized surface; a method for manufacturing the catalytic article; and a method and a device for reducing nitrogen oxides in an exhaust gas by using the catalytic article. The surface of the catalytic article for carrying the catalyst is preferably a porous surface formed by subjecting an aluminum surface to anodic oxidation and then to a hydration treatment, and firing the resultant surface. A method comprising introducing an exhaust gas containing nitrogen oxides and having a high oxygen content into a reaction chamber having the catalytic article placed inside it, and reducing the nitrogen oxides at 350 to 500˚C, while adding a hydrocarbon suitably, allows the reduction and removal of the nitrogen oxides in the exhaust gas with good efficiency, even in the case of an exhaust gas containing a sulfur compound and steam in high concentrations.

Description

窒素酸化物の還元触媒、 それを用いた触媒体及び排ガス中の窒素酸化物低減方法 技術分野 TECHNICAL FIELD The present invention relates to a catalyst for reducing nitrogen oxides, a catalyst using the same, and a method for reducing nitrogen oxides in exhaust gas.
本発明は窒素酸化物の還元除去に適した触媒及びそれを担持した触媒体に関 し、 特に、 ディーゼルエンジンから排出される排ガス中の窒素酸化物の低減'除 去に適した、 。11ーじ6触媒、 該触媒を基体表面に担持させた触媒体、 その製造 明  The present invention relates to a catalyst suitable for reduction and removal of nitrogen oxides and a catalyst body carrying the same, and more particularly, to a catalyst suitable for reduction and removal of nitrogen oxides in exhaust gas discharged from a diesel engine. 11-6 catalyst, a catalyst body having the catalyst supported on a substrate surface, and its production
方法及び該触媒体を用いた、 高濃度酸素雰囲気下で、 硫黄酸化物及び水蒸気が共 存する条件下でも有効な、 窒素酸化物の除去方法に関する。 The present invention relates to a method and a method for removing nitrogen oxides, which is effective under a high-concentration oxygen atmosphere and in the presence of sulfur oxides and steam, using the catalyst.
書 背景技術  Background art
種々の燃焼機器から排出される窒素酸化物は、 人体や環境に有害な大気汚染物 質であり、 その低減が望まれている。 なかでも、 主な大気汚染源となっているデ イーゼルエンジンの排ガス中に含まれる窒素酸ィ匕物 (NO x ) に対しては、 これ まで、 三元触媒法、 NH3を用いる選択的接触還元法、 種々の金属を担持したゼ ォライト及ぴ白金や銅などを担持したアルミナ触媒法などが知られている。 しか しながら、 実際の排ガス中には高濃度の酸素が含まれていたり大量の水蒸気ゃ硫 黄酸化物が共存するために、 これらの従来法においては触媒の劣化が起こり実用 上満足できるものではなかった。 また、 脱硝触媒として貴金属を使用することが 多いために触媒体が高価となるという欠点があつた。 Nitrogen oxides emitted from various types of combustion equipment are air pollutants that are harmful to humans and the environment, and their reduction is desired. In particular, the three-way catalytic method and selective catalytic reduction using NH 3 have been used to reduce nitrogen oxides (NO x) contained in exhaust gas from diesel engines, which is a major source of air pollution. There are known a zeolite supporting various metals and an alumina catalyst method supporting platinum, copper and the like. However, the actual exhaust gas contains a high concentration of oxygen or coexists with a large amount of steam sulfuric acid and yellow oxide. Did not. In addition, the use of a noble metal as a denitration catalyst is often disadvantageous in that the catalyst is expensive.
かかる欠点は、 アル力リ金属またはアル力リ土類金属の一方または双方の含有 量が 0 . 5 w t %以下で、 一定の細孔半径と細孔容積を有するアルミナ触媒を用 いる事によって改善された （特開平 0 6— 2 0 5 9 4 1号公報、 同 0 7— 1 3 6 4 6 6号公報） 1 これらの触媒の調製に際する製造条件の制御が容易であると 言えるものではない上、 粒状触媒体であるため、 これを反応器に充填すると反応 器内の温度分布を均一にすることが困難であるという公知の欠点が生じる。 そこ で、 これをゼオライトなどの担体に担持させると、 触媒体の製造が煩雑となる上 反応させる排ガスの ¾ ^を 5 0 0 °C以下に制御する必要が生じるという欠点があ つた （特開平 1 0— 1 1 3 5 5 8号公報)。 また、 この場合の実施例では、硫黄濃 度が数十 p m程度に過ぎない軽油が使用されており、 硫黄が 1 0 0 p p m以上 含有される場合に付いては全く検討されていない （【0 0 1 3】 参照）。 These disadvantages are alleviated by using an alumina catalyst having a fixed pore radius and a fixed pore volume in which the content of one or both of alkali metal and alkaline earth metal is 0.5 wt% or less. (Japanese Unexamined Patent Publication Nos. H06-2055941 and 07-1366466) 1 It can be said that the production conditions for preparing these catalysts can be easily controlled. In addition, since it is a granular catalyst body, if it is filled in a reactor, it has a known disadvantage that it is difficult to make the temperature distribution in the reactor uniform. Therefore, if this is supported on a carrier such as zeolite, the production of the catalyst body becomes complicated, and the 排 ガ ス ^ of the exhaust gas to be reacted needs to be controlled to 500 ° C. or less. Tsuta (Japanese Patent Application Laid-Open No. H10-113558). Further, in the example in this case, light oil having a sulfur concentration of only about several tens of pm is used, and the case where sulfur is contained at 100 ppm or more is not studied at all ([0 0 1 3]).
更に、 吉成ら （吉成 知博、 アルミナ触媒の定量式ディーゼルエンジン排ガス N O X除去への適用、触媒、 3 9 , 2 2 2 - 2 2 7 ( 1 9 9 7 ) ) は、 ァノレミナ触 媒を用い、 メタノールを還元剤とする酸化窒素の除去における硫黄の存在の影響 を検討し、 排ガス中の硫黄含有量が 1 0 0 p p m以上であると、 5〜 1 0時間で 初期除去率 7 0 %であったものが 4 0 %に減少することを報告している （特に第 3図参照）。  Furthermore, Yoshinari et al. (Tomohiro Yoshinari, Application of Alumina Catalyst to NOx Removal of Diesel Engine Exhaust Gas, Catalyst, 39, 222-22-27 (19997)) used anoremina catalyst. The effect of the presence of sulfur on the removal of nitric oxide using methanol as a reducing agent was examined.If the sulfur content in the exhaust gas was 100 ppm or more, the initial removal rate was 70% in 5 to 10 hours. Reported a decrease to 40% (see especially Figure 3).
このように、 従来技術ではディーゼルエンジン排ガスのような、 高濃度酸素雰 囲気下で、 しかも硫黄や水蒸気が ^存する排ガス中から窒素酸化物を除去する実 用化技術は未だ知られていない。  As described above, in the prior art, a practical technology for removing nitrogen oxides from an exhaust gas containing sulfur or water vapor in a high-concentration oxygen atmosphere such as diesel engine exhaust gas has not yet been known.
そこで、 本発明者らは係る従来の欠点を解決すべく窒素酸化物の還元触媒体に ついて鋭意検討した結果、 C u— C e触媒の場合には、 触媒活性が長期間維持さ れるだけでなく、 硫黄化合物や水蒸気が共存する場合の方が窒素酸化物の低減率 が向上する事を見いだし、 本発明に到達した。  Thus, the present inventors have intensively studied a reduction catalyst for nitrogen oxides in order to solve the conventional drawbacks. As a result, in the case of a Cu—Ce catalyst, the catalyst activity is only maintained for a long period of time. It was found that the reduction rate of nitrogen oxides was improved when sulfur compounds and steam coexisted, and the present invention was reached.
従って本発明の第 1の目的は、 高濃度の酸素雰囲気下でも効率良く窒素酸化物 (N O x ) を窒素に還元することができると共に、 排ガス中に高濃度の硫黄酸化 物や水蒸気が存在する場合であっても、 長期間にわたり、 前記還元反応効率が低 下する事のない窒素酸化物の還元触媒を提供することにある。  Therefore, a first object of the present invention is to efficiently reduce nitrogen oxides (NO x) to nitrogen even in a high-concentration oxygen atmosphere, and to have high-concentration sulfur oxides and water vapor in exhaust gas. Even in such a case, it is an object of the present invention to provide a nitrogen oxide reduction catalyst that does not decrease the reduction reaction efficiency for a long period of time.
本発明の第 2の目的は、 高濃度の酸素雰囲気下でも効率良く窒素酸化物 （N O χ ) を窒素に還元することができると共に、 排ガス中に高濃度の硫黄酸化物や水 蒸気が存在しても長期間にわたって有効で、 反応装置内の温度分布の均一化に有 効な、 窒素酸化物の還元触媒体を提供することにある。  A second object of the present invention is to efficiently reduce nitrogen oxides (NO 2) to nitrogen even in a high-concentration oxygen atmosphere, and to have high-concentration sulfur oxides and water vapor in exhaust gas. Another object of the present invention is to provide a nitrogen oxide reduction catalyst which is effective for a long period of time and is effective for making the temperature distribution in the reactor uniform.
本発明の第 3の目的は、 ディーゼルエンジンから排出される排ガス中の窒素酸 化物の効率的な低減方法を提供する事にある。  A third object of the present invention is to provide a method for efficiently reducing nitrogen oxides in exhaust gas discharged from a diesel engine.
更に本発明の第 4の目的は、 ディーゼルエンジンから排出される排ガス中の窒 素酸化物を効率的に低減するに適した装置を提供する事にある。 発明の開示 Further, a fourth object of the present invention is to provide an apparatus suitable for efficiently reducing nitrogen oxides in exhaust gas discharged from a diesel engine. Disclosure of the invention
本発明は、 Cu— C eの 2金属からなることを特徴とする窒素酸化物の選択的 還元触媒、 この触媒体を陽極酸化された金属表面に担持してなる窒素酸化物の選 択的還元触媒体、 その製造方法、 前記触媒体を用いた排ガス中の窒素酸化物の低 減方法、 及びその為の装置である。  The present invention provides a selective reduction catalyst for nitrogen oxides comprising two metals, Cu—Ce, and a selective reduction of nitrogen oxides having this catalyst supported on an anodized metal surface. A catalyst, a method for producing the same, a method for reducing nitrogen oxides in exhaust gas using the catalyst, and an apparatus therefor.
前記触媒における C uと C eの重量比は 90 ： 1〜14： 3であることが好ま しい。 また、 前記触媒体は、 見かけの lm2あたり、 前記 Cuの担持量が 7. 0 〜9. O g、 C eの担持量が 0. 1〜1. 5 gであることが好ましく、 触媒担持 表面は陽極酸化によつて形成されたアルミニゥム表面を水和処理し、 次レ、で焼成 する事によって形成された多孔質表面であることが好ましい。 The weight ratio of Cu to Ce in the catalyst is preferably 90: 1 to 14: 3. Moreover, the catalyst body 2 per apparent lm, the amount of supported Cu is 7. 0 ~9. O g of is preferably carried amount of C e is 0. 1 to 1. 5 g, catalyst-carrying The surface is preferably a porous surface formed by subjecting an aluminum surface formed by anodization to a hydration treatment and then firing the aluminum surface.
また、 このような触媒体は、 陽極酸化可能な金属表面を有する基体の前記表面 を陽極酸化し、 これによつて形成した陽極酸化表面を水和処理した後焼成し、 次 いで、 Cuと C eを含有する水溶液中に前記基体を浸漬し、 乾燥後焼成する事に よって製造する事が好ましい。  In addition, such a catalyst body is obtained by anodizing the surface of a substrate having an anodizable metal surface, hydrating the anodized surface formed thereby, and then firing, followed by Cu and C Preferably, the substrate is immersed in an aqueous solution containing e, dried, and fired to produce the substrate.
このような触媒体を内部に有する反応室に窒素酸化物を含有する酸素濃度の高 ぃ排ガスを導入し、 適宜炭化水素を添加しながら 350〜 500 °Cで前記窒素酸 化物を還元すれば、 排ガス中の窒素酸化物を低減.除去することができ、 この方 法によれば、 排ガス中に高濃度の硫黄化合物や水蒸気が含有される場合でも窒素 酸化物の除去率が低下する事はない。 図面の簡単な説明  A nitrogen-containing high-concentration exhaust gas containing nitrogen oxides is introduced into a reaction chamber having such a catalyst body therein, and the nitrogen oxides are reduced at 350 to 500 ° C. while appropriately adding hydrocarbons. Nitrogen oxides in exhaust gas can be reduced and removed. According to this method, the removal rate of nitrogen oxides does not decrease even when the exhaust gas contains a high concentration of sulfur compounds or water vapor. Brief Description of Drawings
図 1は、 本発明の Cu— C eZA l 203アルマイト触媒を用いた場合における、 一酸化窒素の低減率と温度の関係を表す。 1, in the case of using the Cu- C eZA l 2 0 3 alumite catalysts of the present invention, representing a relationship between the reduction rate and the temperature of the nitric oxide.
図 2は、 本発明の Cu_C eZA 1203アルマイト触媒における、 1 5%の水 蒸気と 500 p p mの二酸化硫黄の供給 '停止による、 一酸化窒素の低減率の経 時変化依存性を表すグラフである。 発明を実施するための最良の形態 Figure 2 is a graph showing the Cu_C eZA 1 2 0 3 alumite catalysts of the present invention, by supplying 'stop of sulfur dioxide 1-5% water vapor and 500 ppm, the through time changes dependent reduction rate of nitric oxide It is. BEST MODE FOR CARRYING OUT THE INVENTION
本発明の触媒に使用する銅とセリウムは、 水溶性の金属塩の中から適宜選択し て使用することができるが、特に、硝酸銅三水化物 (C u (N 03) 2 - 3 H 20)、 硝酸セリウム六水化物 （C e (N 0 3) 3 - 6 Η 2 θ) 等の硝酸塩が好ましい。 本 発明の触媒は、 陽極酸化アルマイト表面を有する金属基体に担持して使用する事 が好ましい。 Copper and cerium used in the catalyst of the present invention are appropriately selected from water-soluble metal salts. Can be used Te, in particular, copper nitrate trihydrate (C u (N 0 3) 2 - 3 H 2 0), cerium nitrate hexahydrate (C e (N 0 3) 3 - 6 Η 2 θ ) Are preferred. The catalyst of the present invention is preferably used by being supported on a metal substrate having an anodized alumite surface.
上記基体は、 表面が陽極酸化可能な 4 0 m以上のアルミ -ゥム層又はアルミ ニゥム合金層を有する限り特に限定されるものではないが、 特に、 基体全体がァ ルミニゥム又はアルミニウム合金であることが好ましい。 又、 基体の形状は、 線 状又は板状 （リボン状も含む） であれば、 その長さや形状が特に限定されるもの ではないが、 プレート状、 メッシュ状またはハエカム状等の基体であることが好 ましく、 特にこれらの基体が反応器と一体的に形成されている事が好ましい。 触媒体の基体表面の陽極酸化は、 例えばシュゥ酸水溶液などの酸性溶液に浸漬 し、 公知の方法に従って行えば良い。 触媒体とした後にこれを用いて反応室を形 成しても良いが、 予め反応室を形成した後に、 その内部を陽極酸化することが好 ましい。 このようにして得た陽極酸化表面の比表面積を増大させるために、 本発 明では更に水和処理し次いで焼成することが好ましい。  The above substrate is not particularly limited as long as it has an aluminum-layer or aluminum alloy layer of 40 m or more whose surface can be anodized, but in particular, the whole substrate is made of aluminum or aluminum alloy. Is preferred. The length and shape of the substrate are not particularly limited as long as it is linear or plate-like (including ribbon-like), but it should be a plate-like, mesh-like, or honeycomb-like substrate. It is particularly preferable that these substrates are formed integrally with the reactor. The anodic oxidation of the substrate surface of the catalyst body may be performed by dipping in an acidic solution such as an aqueous oxalic acid solution and according to a known method. The reaction chamber may be formed by using the catalyst body after forming the catalyst body, but it is preferable to form the reaction chamber in advance and then anodize the inside. In order to increase the specific surface area of the anodized surface thus obtained, it is preferred in the present invention that the surface is further hydrated and then fired.
上記水和処理は、 5 0〜3 5 0 °Cの熱水或いは水蒸気によって行えばよいが、 作業性や処理効果などの観点から、 特に 6 0〜8 5 °Cで行うことが好ましい。 水 和処理の処理時間は処理水の温度によつて異なる。 本発明では、 6 0〜 8 5 °Cで The hydration treatment may be performed with hot water or steam at 50 to 350 ° C, but is preferably performed at 60 to 85 ° C from the viewpoint of workability and treatment effect. The treatment time of the hydration treatment depends on the temperature of the treated water. In the present invention, at 60 to 85 ° C
1時間以上水和処理することが好ましく、 2時間以上にしても、 ほぼ表面積はそ れ以上増大しなくなる。 又、 水和処理の後には、 室温で 4時間以上自然乾燥する ことが好ましい。 It is preferable to perform the hydration treatment for 1 hour or more, and even if it is 2 hours or more, the surface area will not increase substantially further. After the hydration treatment, it is preferable to air dry at room temperature for 4 hours or more.
本発明においては、 上記の水和処理された陽極酸化皮膜の少なくとも表面を τ/ 一アルミナに変化させ、 それによつてその比表面積をさらに増大させるために焼 成することが好ましい。 焼成温度は、 4 0 0 °C〜 5 5 0 °Cであることが好ましレヽ 1S 本発明では特に 5 0 0 °C程度で 3時間程度行うことが好ましレ、。  In the present invention, it is preferable that at least the surface of the anodized film subjected to the hydration treatment is changed to τ / monoalumina, and the anodic oxide film is calcined to further increase its specific surface area. The firing temperature is preferably from 400 ° C. to 550 ° C. 1S In the present invention, the firing is preferably performed at about 500 ° C. for about 3 hours.
本発明の C u - C e触媒の基体表面への担持は公知の含浸法等によつて容易に 行うことができる。 銅とセリウムの担持は同時担持であっても個別担持であって も良い。 いずれにしても、 これらを担持させた後焼成処理することより、 C u _ C e /A 1 2 0。触媒体からなる本発明の窒素酸化物選択還元触媒体を得ること ができる。 The Cu-Ce catalyst of the present invention can be easily supported on the substrate surface by a known impregnation method or the like. The loading of copper and cerium may be simultaneous loading or individual loading. In any case, than to calcination treatment after them supported, C u _ C e / A 1 2 0. Obtaining a nitrogen oxide selective reduction catalyst of the present invention comprising a catalyst Can do.
本発明の窒素酸化物選択還元触媒体における銅の担持量は 7 . 5〜 8 . 5 gノ m 2 (見かけ面積）であることが好ましく、セリウムは 0 . 1〜1 . 5 g Zm 2 (見 力け面積） であることが好ましい。 触媒金属の粒子径を小さくして触媒体の比表 面積を増大させるために、 本発明においては、 数回に分けて担持操作を行うこと が好ましい。 例えば、 含浸法による場合の担持操作の回数は、 担持溶液中の触媒 金属のイオン濃度によって異なるが、 本発明では、 2 5 °Cで、 銅イオン 0 . 0 3 3モル/ L〜0 . 5モル/ L、 セリウムイオン 0 . 5モル/ L〜l . 0モノレ/ L の水溶液を用い、 1時間当たり、 2回〜 5回同時担持 （銅ィオンとセリウムィォ ンを同時に含有する水溶液を用いる） することが好ましレ、。 毎回の担持後には、 焼成処理することが好ましい。 焼成は、 4 5 0 °C〜 5 5 0でで 3時間程度行うこ とが好ましい。 Loading amount of copper in the nitrogen oxide selective reduction catalyst of the present invention is 7.5 to 8.5 preferably g is Roh m 2 (apparent area), cerium 0. 1~1. 5 g Zm 2 ( (Visible area). In order to increase the specific surface area of the catalyst body by reducing the particle size of the catalyst metal, it is preferable in the present invention to carry out the loading operation several times. For example, the number of loading operations in the case of the impregnation method differs depending on the ion concentration of the catalyst metal in the loading solution. Molar / L, cerium ion 0.5 mol / L to 1.0 monole / L aqueous solution, 2 to 5 times per hour (using an aqueous solution containing copper ion and cerium ion simultaneously) That's good ,. After each loading, it is preferable to perform a baking treatment. The calcination is preferably performed at 450 ° C. to 550 for about 3 hours.
このようにして得られたアルマイト触媒体を、 例えば、 ディーゼルエンジンの 排ガス路中に適宜設置すれば、 その設置した箇所が反応室となり、 排ガス中に存 在する未燃焼の炭化水素や外部から補充的に添加した炭化水素を還元剤として、 排ガス中の窒素酸化物を無害の窒素に還元することができる。 反応温度は 4 5 0 °C近辺とすることが好ましいが、 その他の反応条件によって適宜調整する事が できる。  If the alumite catalyst body obtained in this way is appropriately installed in, for example, an exhaust gas passage of a diesel engine, the installed location becomes a reaction chamber, and unburned hydrocarbons present in the exhaust gas and replenishment from the outside. Nitrogen oxides in the exhaust gas can be reduced to harmless nitrogen by using the hydrocarbons added as a reducing agent. The reaction temperature is preferably around 450 ° C., but can be appropriately adjusted depending on other reaction conditions.
また、 前記触媒体を内部に有する反応室を製造し、 これを排ガス流路中に設置 したり、 排ガスをその反応室に導入するようにしても良い事は当然である。 上記した、 補充的に添加する還元剤としての炭化水素は、 4 0 0 °Cでガス状で ある飽和又は不飽和の公知の炭化水素の中から適宜選択する事ができる。 これら の炭化水素は単独で用いても 2種以上を混合して用いても良く、ガソリン、灯油、 軽油、 重油などの鉱油系炭化水素油であっても良い。  Further, it is natural that a reaction chamber having the catalyst body therein may be manufactured and installed in the exhaust gas passage, or the exhaust gas may be introduced into the reaction chamber. The above-mentioned hydrocarbon as a reducing agent to be supplementarily added can be appropriately selected from known saturated or unsaturated hydrocarbons which are gaseous at 400 ° C. These hydrocarbons may be used alone or as a mixture of two or more, and may be mineral hydrocarbon oils such as gasoline, kerosene, gas oil, and heavy oil.
通常の排ガスに含有される酸素と炭化水素の比率は 1から遥かにずれる力 理 想的には完全燃焼させて全ての排ガスを窒素ガス、 炭酸ガス及び水にすることで あるから、 反応に際しては、 事実上炭化水素を添加することが不可欠となる。 本 発明においては、 4 5 0 °C近辺で酸化窒素の低減率が最大となるように、 添加す る炭化水素の量を調整すること力好ましい。 これによつて、 窒素酸化物の低減率 を 40 %程度にする事ができる。 The ratio of oxygen and hydrocarbons contained in normal exhaust gas deviates from 1 far from 1.Essentially, all exhaust gas is converted into nitrogen gas, carbon dioxide gas, and water by complete combustion. However, it is essentially necessary to add hydrocarbons. In the present invention, it is preferable to adjust the amount of hydrocarbon to be added so that the rate of reduction of nitrogen oxide is maximized around 450 ° C. As a result, the nitrogen oxide reduction rate Can be reduced to about 40%.
本発明においては、 窒素酸化物の還元反応を行わせる際に一食化炭素が生じる ので、 これをそのまま排気しないように、 上記還元反応の後段に酸化触媒を有す る酸化反応室を配して、一酸化炭素を安全な炭酸ガスに酸化することが好ましい。 また、 ディーゼルエンジンの排ガス中に含有される粒状物質が前記還元反応のた めの触媒体表面に付着してその活性を下げる事を防止するために、 還元反応室の 前段に、 粒状物質を除去するためのフィルターを設置する事が好ましい。  In the present invention, carbon monoxide is generated when the reduction reaction of nitrogen oxides is performed. Therefore, an oxidation reaction chamber having an oxidation catalyst is provided at the latter stage of the reduction reaction so as not to exhaust the carbonization as it is. Thus, it is preferable to oxidize carbon monoxide to safe carbon dioxide gas. In order to prevent the particulate matter contained in the exhaust gas of the diesel engine from adhering to the surface of the catalyst for the above-mentioned reduction reaction and lowering its activity, the particulate matter was removed before the reduction reaction chamber. It is preferable to provide a filter for performing the operation.
このようにする事によって、 本発明を、 ディーゼルエンジンからの排ガス処理 に好適なものとする事ができる。 実施例  By doing so, the present invention can be made suitable for treating exhaust gas from a diesel engine. Example
以下、 本宪明を実施例によって更に詳述するが、 本発明はこれによって限定さ れるものではない。 実施例 1.  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Example 1.
厚さ 0. 5 mmの巿販アルミニウム板 （J I S A1050) を、 20%の水 酸化ナトリウム水溶液を用い、 室温で 3分間脱脂処理し、 次いで 30%の硝酸水 溶液に 1分間浸して表面処理を行つた。 次に、 4 %のシュゥ酸水溶液を用いて、 液温 20°C、 電圧密度 50. OAZm2で 16時間陽極酸化を行った。 その後、 陽極酸ィヒ膜に残留するシユウ酸を除去するために、 350°Cで 1時間焼成した。 更に 80°Cで 1時間、 イオン交換水を用いて水和処理を行った。 得られた基体を 室温で 4時間自然乾燥し、 500 で 3時間焼成した。 次いで、 0. 03 3モル /Lの Cu (N03) 2■ 3H20と 0. 1モノレ/ Lの C e (N03) 3 ' 6 H20を 含有するィオン交換水中で、 合計 5回含浸操作を行つて本発明の C u— C e ZA 1203アルマイト触媒体を作製した。 尚、 各触媒担持操作の後には、 500°Cで 3時間焼成した。 A commercially available aluminum plate (JIS A1050) having a thickness of 0.5 mm is degreased with a 20% aqueous sodium hydroxide solution at room temperature for 3 minutes, and then immersed in a 30% nitric acid aqueous solution for 1 minute to perform surface treatment. I went. Next, using a 4% aqueous oxalic acid solution, anodic oxidation was performed at a liquid temperature of 20 ° C. and a voltage density of 50. OAZm 2 for 16 hours. Thereafter, in order to remove oxalic acid remaining in the anodized acid film, the film was baked at 350 ° C. for 1 hour. Further, hydration treatment was performed at 80 ° C for 1 hour using ion-exchanged water. The obtained substrate was naturally dried at room temperature for 4 hours and fired at 500 for 3 hours. Then, in Ion exchange water containing C e (N0 3) 3 ' 6 H 2 0 of 0.03 3 mol / L of Cu (N0 3) 2 ■ 3H 2 0 and 0.1 Monore / L, total 5 the times impregnation to produce a C u- C e ZA 1 2 0 3 alumite catalyst of paragraph shall present invention. After each catalyst loading operation, baking was performed at 500 ° C. for 3 hours.
次に、 見かけ表面積が 2 X 2 c m2の上記アルマイト触媒体を 80枚に （ 0. 5mm ¾) 細かく切り、 石英砂で希釈して、 内径 1 5 mmの反応管に充填し た。 1 5 %の酸素、 0. 5 %のプロピレン及び 1 000 p p mの一酸化窒素を含 有するヘリゥムガスを、 空間速度が 10000/時間で 1 50ml 分のガス流 量となるように反応管に流した。 200 °C〜 500 °Cの温度範囲で、 本発明の C u-C e/A l 2 O 3アルマイト触媒の脱硝活性を検討した結果を図 1に示した。 図 1から明らかなように、 300 °C以下の温度では一酸化窒素の低減率が 20 % に達しなかったが、 350°C〜450°Cの幅広い温度範囲内で、 30%の低減率 が得られた。 特に、 400°C〜450°Cの温度範囲内では約 40%の一酸化窒素 の低減率が得られた。 さらに、 全温度範囲内で、 ほぼ 90%以上の窒素への反応 選択率が得られた。 Next, the alumite catalyst body having an apparent surface area of 2 × 2 cm 2 was finely cut into 80 pieces (0.5 mm¾), diluted with quartz sand, and filled in a reaction tube having an inner diameter of 15 mm. Contains 15% oxygen, 0.5% propylene and 1 000 ppm nitric oxide Helium gas was flowed through the reaction tube at a space velocity of 10,000 / hour to a gas flow rate of 150 ml. In the temperature range of 200 ° C~ 500 ° C, the result of examining the C uC e / A l 2 O 3 anodized catalytic denitration activity of the present invention shown in FIG. As is evident from Fig. 1, the nitric oxide reduction rate did not reach 20% at temperatures below 300 ° C, but within a wide temperature range from 350 ° C to 450 ° C, a 30% reduction rate was observed. Obtained. In particular, a nitric oxide reduction rate of about 40% was obtained in the temperature range of 400 to 450 ° C. In addition, a reaction selectivity to nitrogen of more than 90% was obtained over the entire temperature range.
次に、 450°C及び 400°Cで 1 5 %の水蒸気及ぴ 500 p p mの二酸化硫黄 を添加し、 これらの場合における本発明の Cu— C eZA 1 203アルマイト触媒 の脱硝活性への経時依存性を検討した（図 2参照)。図 2から明らかなように、 1 5%の水蒸気を入り口ガスに導入すると脱硝活性が低下したが、 水蒸気を停止す ると脱硝活性が殆ど元に戻った。 Was then added 1-5% water vapor及Pi 500 ppm of sulfur dioxide at 450 ° C and 400 ° C, time to Cu- C eZA 1 2 0 3 alumite catalytic denitration activity of the present invention in these cases Dependencies were examined (see Figure 2). As is clear from FIG. 2, the introduction of 15% steam into the inlet gas reduced the denitration activity, but when the steam was stopped, the denitration activity almost recovered.
本発明の C u— C e/A 12O3アルマイト触媒の、 炭化水素を還元剤とする従 来の酸化窒素の選択還元触媒と異なるところは、 500 p p mの二酸化硫黄を入 り口ガスに入れても一酸化窒素の低減率が低下せず、 逆に 50 %に向上し、 また それが長時間維持できたことである。 二酸化硫黄の導入を停止すると一酸化窒素 の低減率が元の水準に戻り、 触媒の経時劣化は全く見られなかった。 Of C u- C e / A 1 2 O 3 anodized catalyst of the present invention, where the hydrocarbon different from the selective reduction catalyst in nitric oxide traditional to reducing agent is 500 ppm of sulfur dioxide inlet Rikuchi gas The nitric oxide reduction rate did not decrease with the addition, but increased to 50%, and it was maintained for a long time. When the introduction of sulfur dioxide was stopped, the nitric oxide reduction rate returned to the original level, and no deterioration of the catalyst with time was observed.
又、 1 5%の水蒸気と 500 p pmの二酸化硫黄を同時に導入した場合 （ディ ーゼルエンジン実排ガスをシミュレーションするモデルガス） では、 一酸化窒素 の低減率が約 60 %まで向上するという、 従来の技術からは予想することのでき ない結果が得られた。  When 15% steam and 500 ppm sulfur dioxide are introduced simultaneously (a model gas that simulates actual diesel engine exhaust gas), the reduction rate of nitric oxide is improved to about 60%. Gave unexpected results.
450 °Cで 6 5時間経ても、 触媒の水蒸気又は Z及び二酸化硫黄による劣化は 観測されず、 無硫無水の状態に戻ると殆ど初期の活性水準に戻った。 更に、 40 0 °Cまで温度を下げても高レ、活性が得られた。 産業上の利用性  Even after 65 hours at 450 ° C, no deterioration of the catalyst due to water vapor or Z and sulfur dioxide was observed, and the activity returned to almost the initial level when it returned to the anhydrous state. Further, even if the temperature was lowered to 400 ° C., high activity and activity were obtained. Industrial applicability
本発明に依れば、 酸素の過剰雰囲気下で、 効率良く窒素酸化物 （NOx) を低 減■除去することができるだけでなく、 排ガス中に高濃度の硫黄酸化物及び水蒸 気が共存する場合には、 従来とは全く異なり、 返って窒素酸化物の低減率が向上 するので産業上極めて有意義である。 According to the present invention, not only can nitrogen oxides (NOx) be efficiently reduced and removed under an oxygen excess atmosphere, but also high concentrations of sulfur oxides and water vapor in exhaust gas can be obtained. In the presence of energy, it is quite significant from an industrial point of view, since the rate of reduction of nitrogen oxides is greatly improved.

Claims

請求の範囲 The scope of the claims
1. Cu-C eの 2金属からなることを特徴とする窒素酸化物の選択的還元触媒。 1. A selective reduction catalyst for nitrogen oxides, comprising two metals, Cu-Ce.
2. 前記 Cuと C eの重量比が 90 ： 1-14 : 3である、 請求項 1に記載され 5 た窒素酸化物の選択的還元触媒。  2. The catalyst for selective reduction of nitrogen oxides according to claim 1, wherein the weight ratio of Cu to Ce is 90: 1-14: 3.
3. 陽極酸化された金属表面に、 Cu— C eの 2金属からなる触媒を担持してな ることを特徴とする、 窒素酸化物の選択的還元触媒体。  3. A selective catalyst for the reduction of nitrogen oxides, characterized in that an anodized metal surface carries a catalyst composed of two metals, Cu—Ce.
4、 前記 Cuの担持量が 7. 0〜9. 0
Figure imgf000011_0001
〇 6の担持量が0. 1〜； L. 4.The supported amount of Cu is 7.0-9.0
Figure imgf000011_0001
〇 6 is 0.1 ~; L.
5 g 2である、 請求項 3に記載された窒素酸化物の選択的還元触媒体。 10 5. 前記金属表面がアルミニウム表面であると共に、 触媒担持表面が、 前記陽極 酸化によって形成されたアルマイト表面を水和処理し、 次いで焼成する事によつ て形成された多孔質表面である、 請求項 3または 4に記載された窒素酸化物の選 択的還元触媒体。 5 is a g 2, selective reduction catalyst of the nitrogen oxides according to claim 3. 10 5. The metal surface is an aluminum surface, and the catalyst-carrying surface is a porous surface formed by subjecting the alumite surface formed by the anodic oxidation to a hydration treatment and then firing. 5. The selective reduction catalyst for nitrogen oxide according to claim 3 or 4.
6. 陽極酸化可能な金属表面を有する基体の前記表面を陽極酸ィヒし、 これによつ 15 て形成された陽極酸化皮膜表面を水和処理した後焼成し、 次いで、 〇11と〇6を 含有する水溶液中に前記基体を浸漬し、 乾燥後焼成する事を特徴とする触媒体の 製造方法。  6. Anodizing the surface of the substrate having a metal surface capable of being anodized, hydrating the surface of the anodic oxide film formed thereby, followed by firing; A method for producing a catalyst, comprising immersing the substrate in an aqueous solution containing, drying and firing.
7.前記水溶液が硝酸塩水溶液である、請求項 6に記載された触媒体の製造方法。  7. The method for producing a catalyst according to claim 6, wherein the aqueous solution is a nitrate aqueous solution.
8. 前記水溶液中の Cuイオン濃度が 0. 033モル// 、 C eイオン濃度が 0. 20 1〜0. 5モル ZLである、 請求項 6又は 7に記載された触媒体の製造方法。 8. Cu ion concentration in the aqueous solution is 0.033 mol / /, C e ion concentration is 0.20 1 to 0.5 mol ZL, method for producing a catalyst body according to claim 6 or 7.
9. 触媒担持後の焼成が 450〜 550 °Cでなされる、 請求項 6に記載された触 媒体の製造方法。  9. The method for producing a contact medium according to claim 6, wherein the firing after supporting the catalyst is performed at 450 to 550 ° C.
1 0. 触媒担持とその後の焼成をそれぞれ 2度以上繰り返す、 請求項 9に記載さ れた触媒体の製造方法。  10. The method for producing a catalyst body according to claim 9, wherein the catalyst loading and the subsequent calcination are each repeated twice or more.
-25 1 1. 前記金属表面がアルミニウム表面である、 請求項 6に記載された触媒体の 製造方法。 -25 1 1. The method for producing a catalyst according to claim 6, wherein the metal surface is an aluminum surface.
12. アルマイト表面に Cu— C e触媒を担持してなる Cu— C r/A 1203触 媒体を内部に有する反応室に窒素酸化物を含有する酸素濃度の高い排ガスを導入 し、 適宜炭化水素を添加しながら 350-500°Cで前記窒素酸化物を還元して 除去する事を特徴とする窒素酸化物の除去方法。 12. introducing a high oxygen concentration exhaust gas containing nitrogen oxides into the reaction chamber having a Cu- C e catalyst formed by carrying a Cu- C r / A 1 2 0 3 catalyst medium anodized surface therein, suitably Reduce the nitrogen oxides at 350-500 ° C while adding hydrocarbons A method for removing nitrogen oxides, which comprises removing.
13. 前記排ガスが硫黄化合物を含有する排ガスである、 請求項 12に記載され た窒素酸化物の除去方法。  13. The method for removing nitrogen oxides according to claim 12, wherein the exhaust gas is an exhaust gas containing a sulfur compound.
14. 前記排ガスが水蒸気を含有する請求項 12又は 13に記載された窒素酸化 物の除去方法。  14. The method for removing nitrogen oxide according to claim 12, wherein the exhaust gas contains water vapor.
15. 排ガス中の粒状物質を除去するためのフィルター、 アルマイト表面に Cu — C e触媒を担持してなる Cu— C r/A 1203触媒体を内部に有する反応室、 及び、酸化反応室を順次上流側から下流側に向けて配してなることを特徴とする、 排ガス中の窒素酸化物の低減装置。 15. filter for removing particulate matter in the exhaust gas, Cu alumite surface - C e catalyst formed by carrying a Cu- C r / A 1 2 0 3 reaction chamber having catalyst body therein, and the oxidation reaction A device for reducing nitrogen oxides in exhaust gas, wherein the chambers are sequentially arranged from upstream to downstream.
PCT/JP2004/003795 2004-03-19 2004-03-19 Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas WO2005089939A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2006511099A JPWO2005089939A1 (en) 2004-03-19 2004-03-19 Nitrogen oxide reduction catalyst body, method for producing the same, method for reducing nitrogen oxide in exhaust gas using the same, and apparatus therefor
PCT/JP2004/003795 WO2005089939A1 (en) 2004-03-19 2004-03-19 Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas
TW093108490A TW200531740A (en) 2004-03-19 2004-03-29 Nitrogen oxide selective reduction catalyst, catalyst body using the same, method of manufacturing catalyst body, method of eliminating nitrogen oxides and device for decreasing nitrogen oxides in exhaust gas

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2004/003795 WO2005089939A1 (en) 2004-03-19 2004-03-19 Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas

Publications (1)

Publication Number Publication Date
WO2005089939A1 true WO2005089939A1 (en) 2005-09-29

Family

ID=34993490

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2004/003795 WO2005089939A1 (en) 2004-03-19 2004-03-19 Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas

Country Status (3)

Country Link
JP (1) JPWO2005089939A1 (en)
TW (1) TW200531740A (en)
WO (1) WO2005089939A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012055855A (en) * 2010-09-10 2012-03-22 Tokyo Univ Of Agriculture & Technology Catalyst carrier, catalyst body, and method for manufacturing the same
WO2018150823A1 (en) * 2017-02-17 2018-08-23 住友精化株式会社 Method for producing structured catalyst and method for producing hydrogen using structured catalyst
CN113816470A (en) * 2021-10-18 2021-12-21 重庆工商大学 Cu/amorphous Al2O3Catalyst, preparation method and application thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6097047A (en) * 1983-11-01 1985-05-30 Toyota Central Res & Dev Lab Inc Oxidizing catalyst
JPH05200255A (en) * 1992-01-28 1993-08-10 Riken Corp Exhaust gas cleaning method
JPH05285387A (en) * 1992-04-13 1993-11-02 Hitachi Ltd Catalyst for purification of exhaust gas and purification method
JP2002119856A (en) * 2000-10-13 2002-04-23 Hideo Kameyama Anodized aluminum catalyst carrier having increased bet specific surface area and its manufacturing method
JP2003206733A (en) * 2002-01-16 2003-07-25 Hitachi Ltd Exhaust emission control device for internal combustion engine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6097047A (en) * 1983-11-01 1985-05-30 Toyota Central Res & Dev Lab Inc Oxidizing catalyst
JPH05200255A (en) * 1992-01-28 1993-08-10 Riken Corp Exhaust gas cleaning method
JPH05285387A (en) * 1992-04-13 1993-11-02 Hitachi Ltd Catalyst for purification of exhaust gas and purification method
JP2002119856A (en) * 2000-10-13 2002-04-23 Hideo Kameyama Anodized aluminum catalyst carrier having increased bet specific surface area and its manufacturing method
JP2003206733A (en) * 2002-01-16 2003-07-25 Hitachi Ltd Exhaust emission control device for internal combustion engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012055855A (en) * 2010-09-10 2012-03-22 Tokyo Univ Of Agriculture & Technology Catalyst carrier, catalyst body, and method for manufacturing the same
WO2018150823A1 (en) * 2017-02-17 2018-08-23 住友精化株式会社 Method for producing structured catalyst and method for producing hydrogen using structured catalyst
JPWO2018150823A1 (en) * 2017-02-17 2019-12-12 住友精化株式会社 Method for producing structure catalyst, and method for producing hydrogen using structure catalyst
CN113816470A (en) * 2021-10-18 2021-12-21 重庆工商大学 Cu/amorphous Al2O3Catalyst, preparation method and application thereof

Also Published As

Publication number Publication date
TW200531740A (en) 2005-10-01
JPWO2005089939A1 (en) 2008-01-31

Similar Documents

Publication Publication Date Title
ES2542510T3 (en) CHA copper zeolite catalysts
US7005116B2 (en) Process for reducing nitrogen oxides
JP5354903B2 (en) Catalyst and nitrogen oxide reduction method
ES2633320T5 (en) Method and system for purifying exhaust gases from an internal combustion engine
JP2008002451A (en) Exhaust emission control device for diesel engine and exhaust emission control method for diesel engine
EP1994982A1 (en) Catalyst body which uses an anodized layer
RU2515727C2 (en) Method of obtaining nanostructured catalytic coatings on ceramic carriers for neutralisation of waste gasses of internal combustion engines
JP2017140614A (en) Catalyst and method for producing catalyst
JP4189337B2 (en) Exhaust gas purification system
JP2006320893A (en) Selective reduction catalyst for nitrogen oxide
WO2005089939A1 (en) Catalyst for reducing nitrogen oxides, catalytic article using the same and method for reducing nitrogen oxides in exhaust gas
JP2021155276A (en) Porous ceramic structure and manufacturing method of porous ceramic structure
JP4537392B2 (en) Nitrogen oxide treatment method
JP2023026798A (en) Waste gas processing system of ammonia engine and waste gas processing method of ammonia engine
Karthikeyan Research on Metal Doped Zeolite as Catalyst to Reduce NO X Emission from Lean Burn Gasoline Engines
JP3970093B2 (en) Ammonia decomposition removal method
JP4822374B2 (en) Method for producing exhaust gas purification catalyst
JP2849133B2 (en) Method for catalytic decomposition of nitrogen oxides
JP2004068717A (en) Method for removing nitrogen oxide in contacting manner and its device
JP3623255B2 (en) Catalyst and method for removing nitrogen oxides from engine exhaust gas
RU2005138180A (en) METHOD FOR PRODUCING ICE EXHAUST GAS CATALYST CATALYST
KR100506717B1 (en) Catalytic systems for reduction of pressure drop for automobile and method for manufacturing the same
JPS631449A (en) Catalyst for purifying exhaust gas
JP2003117353A (en) Method for catalytically reducing nitrogen oxide and catalyst therefor
JP2023518579A (en) Zeolite containing platinum and zinc

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2006511099

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Country of ref document: DE

122 Ep: pct application non-entry in european phase