JP3707503B2 - Decomposition catalyst for volatile organochlorine compounds - Google Patents

Description

【００２５】
実施例９〜１１：
（１）担体の調製
実施例１で用いたオルトリン酸溶液に変えてオルトホウ酸２６．５ｇ（Ｂ_２Ｏ_３として１５ｇ）を用いた以外は実施例１と同じ組成で、かつ同一手順で得られた捏和物を、製丸機にて直径２ｍｍφのビードに造粒し、１００℃の温度で１５時間乾燥した後、５００℃で２時間焼成して、ホウ素をＢ_２Ｏ_３として３重量％、ジルコニア（ＺｒＯ_２）を３５重量％含み、残部が実質的にチタニア（ＴｉＯ_２）からなるホウ素ージルコニアーチタニア担体ＢＡを得た。
一方、上記のメタチタン酸ケーキ１９６７ｇに対する水酸化ジルコニウム粉体をオルトホウ酸の加入量の組み合わせを、それぞれ３０４ｇと２２．８ｇ、９３０ｇと３４．０ｇと変化させたことを以外は上記手順と同様の手順を用いて、上記担体ＢＡとジルコニアの含有量の異なる（ホウ素の含有量は同一で、チタニアの含有量が異なる）担体ＢＢ、ＢＣを得た。担体ＢＡ、ＢＢ、ＢＣの組成をそれぞれ表２に示す。
（２）触媒の調製
塩化白金酸２．０ｇを水３０ミリリットルに溶解し、担体の吸水量に見合う液量に水で液量調節を行った含浸溶液を、担体ＢＡ、ＢＢ、ＢＣそれぞれ１５０ｇに含浸させ、１１０℃で１５時間乾燥し、次いで５００℃で２時間焼成して触媒ＬＫ、ＬＬ、ＬＭを得た。触媒ＬＫ、ＬＬ、ＬＭともに白金の担持量は０．５重量％である。
（３）触媒の評価
実施例１と同様な試験を行った結果、表２に示すように触媒ＬＫ、ＬＬ、ＬＭは、用いたホウ素ージルコニアーチタニア担体のホウ素の含有量が３つともＢ_２Ｏ_３として３重量％であって、またジルコニアの含有量もそれぞれ３５重量％、２５重量％、５０重量％と本発明の組成範囲内であり、低濃度から高濃度までトリクロロエチレンを９９．９％以上の分解率で、長時間にわたり効率良く分解し無害化できた。
【００２６】
比較例６と７：
（１）担体の調製
メタチタン酸ケーキ１９６７ｇに加える、水酸化ジルコニウム粉体とオルトホウ酸の加入量の組み合わせを、それぞれ１０１ｇと１８．９ｇ、１４１７ｇと４４．２ｇと変化させたこと以外は実施例９に示す方法と同様の手順でホウ素ージルコニアーチタニア担体ＢＧ、ＢＨを得た。担体ＢＧ、ＢＨの組成をそれぞれ表２に示す。
（２）触媒の調製
実施例９に示す方法と同様の方法により上記担体ＢＧ、ＢＨに白金を担持し、触媒ＬＱ、ＬＲを作製した。白金の担持量は０．５重量％である。
（３）触媒の評価
触媒ＬＱ、ＬＲを用いて実施例１と同様の試験を行った結果を表２に示す。触媒ＬＱ、ＬＲは、用いたホウ素ージルコニアーチタニア担体のジルコニアの含有量がそれぞれ１０重量％、６０重量％と本発明の範囲外であり、トリクロロエチレンの分解率は低濃度でも高濃度でも９９．９％を下回っている。
【００２７】
実施例１２と１３：
（１）担体の調製
メタチタン酸ケーキ１９６７ｇに加える、水酸化ジルコニウム粉体とオルトホウ酸の加入量の組み合わせを、それぞれ４８５ｇと１７．４ｇ、５１０ｇと４５．７ｇと変化させたこと以外は実施例９に示す方法と同様の手順でホウ素ージルコニアーチタニア担体ＢＤ、ＢＥを得た。担体ＢＤ、ＢＥの組成をそれぞれ表２に示す。
（２）触媒の調製
実施例９に示す方法と同様の方法により上記担体ＢＤ、ＢＥに白金を担持し、触媒ＬＮ、ＬＯを作製した。白金の担持量は０．５重量％である。
（３）触媒の評価
触媒ＬＮ、ＬＯを用いて実施例１と同様の試験を行った結果を表２に示す。触媒ＬＮ、ＬＯは、用いたホウ素ージルコニアーチタニア担体のホウ素の含有量がＢ_２Ｏ_３換算でそれぞれ２重量％、５重量％であり、またジルコニア含水量が３５重量％と本発明の範囲内であり、低濃度から高濃度までトリクロロエチレンを９９．９％以上の分解率で、長時間にわたり効率良く分解し無害化できた。
【００２８】
比較例８と９：
（１）担体の調製
メタチタン酸ケーキ１９６７ｇに加える、水酸化ジルコニウム粉体とオルトホウ酸の加入量の組み合わせを、それぞれ４７０ｇと８．６ｇ、５２７ｇと６６．２ｇと変化させたこと以外は実施例９に示す方法と同様の手順で、ホウ素−ジルコニアーチタニア担体ＢＩ、ＢＪを得た。担体ＢＩ、ＢＪの組成をそれぞれ表２に示す。
（２）触媒の調製
実施例９に示す方法と同様の方法により上記担体ＢＩ、ＢＪに白金を担持し、触媒ＬＳ、ＬＴを作製した。白金の担持量は０．５重量％である。
（３）触媒の評価
触媒ＬＳ、ＬＴを用いて実施例１と同様の試験を行った結果を表２に示す。触媒ＬＳ、ＬＴは、用いたホウ素ージルコニアーチタニア担体のホウ素の含有量がＢ_２Ｏ_３換算でそれぞれ１重量％、７重量％と本発明の範囲外であり、表２に示すように、トリクロロエチレンの分解率は低濃度でも高濃度でも９９．９％を下回っている。
【００２９】
実施例１４〜１６：
（１）担体の調製
担体としては、実施例９に示す担体ＢＡと同じものを用意した。
（２）触媒の調製
塩化白金酸１．０ｇ、４．０ｇ、１２．０ｇをそれぞれ水３０ミリリットルに溶解し、担体の吸水量に見合う液量に水で液量調節を行った含浸溶液を実施例９で得たホウ素ージルコニアーチタニア担体ＢＡの各々１５０ｇにそれぞれ含浸させ、１１０℃で１５時間乾燥し、次いで５００℃で２時間焼成して触媒ＬＵ、ＬＶ、ＬＷを得た。
（３）触媒の評価
触媒ＬＵ、ＬＶ、ＬＷを用いて実施例１と同様の試験を行った結果を表２に示す。触媒ＬＵ、ＬＶ、ＬＷは、本発明の組成範囲内のホウ素ージルコニアーチタニア担体に白金をＰｔとしてそれぞれ０．２５重量％、１．０重量％、３．０重量％相当量担持した触媒であり、低濃度から高濃度までトリクロロエチレンを９９．９％以上の分解率で、長時間にわたり効率良く分解し無害化できた。
【００３０】
【表２】

【００３１】
【発明の効果】
以上述べた通り、本発明の触媒を揮発性有機塩素化合物と水蒸気および空気共存下で接触させることにより、低濃度から高濃度までの揮発性有機塩素化合物を効率良く処理することができ、触媒の活性が長時間安定しており実用的である。したがって、本発明の触媒は金属の脱脂工程やドライクリーニング等から排出される排ガス、廃液中の揮発性有機塩素化合物の無害化に使用でき、環境汚染防止策上きわめて有効である。[0001]
[Industrial application fields]
The present invention relates to a catalyst for decomposing volatile organic chlorine compounds, and more particularly to a catalyst used for catalytically decomposing volatile organic chlorine compounds.
[0002]
[Prior art]
Examples of volatile organic chlorine compounds include methylene chloride, dichloroethylene, trichloroethylene, and tetrachloroethylene. Methylene chloride and trichlorethylene are widely used in degreasing processes and dry cleaning of electronic parts and metal products.
When the volatile organic chlorine compound is discharged into the atmosphere, it reaches the ozone layer and destroys the ozone layer by chlorine atoms generated by being decomposed by strong ultraviolet rays from the sun. When the ozone layer is destroyed, the amount of ultraviolet rays reaching the surface of the earth increases, causing skin cancer, cataract damage, growth inhibition of animals and plants, and so on, which is a serious problem from the viewpoint of protecting the global environment. In addition, volatile organochlorine compounds have a carcinogenic effect, and soil contamination and groundwater contamination due to illegal dumping have become a problem.
In recent years, from the viewpoint of environmental hygiene, laws and regulations have been implemented in various countries around the world, and strict management is required for volatile organic chlorine compounds and waste liquids containing them. It is desired.
Conventionally, as a method for treating volatile organic chlorine compounds such as methylene chloride, trichlorethylene, tetrachloroethylene, etc., a method of adsorbing and recovering with activated carbon, zeolite, etc. is known, but the recovered volatile organic chlorine compounds are rendered harmless. No consideration has been given to the processing method.
[0003]
Recently, thermal decomposition methods, photodecomposition methods, catalytic decomposition methods, and the like have been proposed as methods for decomposing and detoxifying volatile organic chlorine compounds. Among them, the catalytic cracking method is a simple method, while the thermal cracking method requires a large apparatus and has a high processing cost. In particular, it is attracting attention because it is effective for a gas containing selenium.
In this catalytic cracking method, a catalyst obtained by supporting copper, chromium, iron, platinum, palladium or the like as a catalyst component on a carrier made of an inorganic oxide such as alumina, silica, zeolite, titania, zirconia alone or in combination. And a volatile organic chlorine compound such as trichlorethylene are brought into contact with each other at 400 to 500 ° C. in the presence of water and oxygen or air. This method is disclosed in JP-A-50-2669. JP-A-3-12221, JP-A-3-47516 and the like.
[0004]
[Problems to be solved by the invention]
In general, in a catalytic reaction of a gas using a catalyst, it is required to perform the reaction under conditions such as high space velocity SV (gas flow rate per unit time / volume of catalyst) and fast LV (linear velocity). For this purpose, it is desirable that the catalyst used in the reaction has a high solid acidity and a large number of active sites, and that the catalyst that catalytically decomposes volatile organic chlorine compounds has excellent acid resistance against hydrogen chloride. It is important.
Considering the catalyst introduced above from these points, considering the acid resistance of the catalyst, zirconia, titania and titania-zirconia binary oxide supports are promising. In the catalyst carrying the components, the initial activity is high, but the activity cannot be maintained for a long time. On the other hand, no investigation has yet been made on a catalyst carrier to which a component having excellent acid resistance and solid acidity is added.
[0005]
The present invention has been made in consideration of the above situation, and its purpose is to decompose volatile organochlorine compounds efficiently in the presence of air and water regardless of the concentration, and for a long time. It is to provide a catalyst that can maintain activity for a period of time.
[0006]
[Means for Solving the Problems]
In order to solve the above problems and achieve the above object, the present inventors have developed a titania-zirconia binary oxide support having acid resistance against hydrogen chloride generated by decomposing volatile organic chlorine compounds. As a result of earnest research focusing on the third component capable of increasing the acidity of the solid and maintaining acid resistance, three components obtained by adding phosphorus or boron as the third component to the titania-zirconia binary oxide composition By supporting a noble metal conventionally proposed as a catalyst component on a system oxide support, the obtained catalyst was found to decompose volatile organochlorine compounds very efficiently, and the present invention was completed. It was.
That is, a catalyst for decomposing volatile organic chlorine compounds according to the present invention for solving the above-2-5 wt% of Li down the PO ₄ conversion or boron terms _{of B} 2 _{O 3,} zirconia 25-50 wt% In addition, at least one selected from the group consisting of platinum, palladium and ruthenium as a catalyst component is supported in an equivalent amount of 0.1 to 5% by weight in terms of metal on the ternary oxide carrier that is substantially composed of titania. It is characterized by having made it.
[0007]
[Action]
The gist of the present invention is that a binary oxide composition composed of zirconia (ZrO ₂ ) and titania (TiO ₂ ) having a specific composition ratio is further incorporated with phosphorus or boron as a third component. A catalyst component is added to a carrier, more specifically, a ternary oxide carrier containing 2 to 5% by weight of phosphorus as PO ₄ or boron as B ₂ O ₃ and 25 to 50% by weight of zirconia, with the balance being substantially titania. As a result, when carrying at least one selected from the group consisting of platinum, palladium and ruthenium, it was found that the effect of efficiently decomposing volatile organochlorine compounds from low to high concentration was most excellent. is there.
The details of the present invention and the operation thereof will be described more specifically as follows.
[0008]
In the present invention, a ternary oxide support composed of phosphorus, zirconia and titania (hereinafter abbreviated as “phosphorus-zirconia titania support”) can be manufactured by a general catalyst support manufacturing method such as a mixing method. Is. That is, zirconium hydroxide powder so that the content of zirconia is 25 to 50% by weight and the content of phosphorus is 2 to 5% by weight as PO ₄ when used as a catalyst carrier in a metatitanic acid hydrate cake. Then, an orthophosphoric acid solution and a molding aid are added and kneaded, followed by molding, drying, and further firing, whereby a lin-zirconia titania carrier can be produced. On the other hand, a ternary oxide support composed of boron, zirconia and titania (hereinafter abbreviated as “boron-zirconia titania support”) can also be manufactured by a general catalyst support manufacturing method such as a mixing method. is there. That is, zirconium hydroxide so that the content of zirconia is 25 to 50% by weight and the content of boron is ₂ to 5% by weight as B ₂ O ₃ when used as a catalyst carrier in the metatitanic acid hydrate cake. Boron-zirconia titania by adding powder, boric acid such as orthoboric acid, metaboric acid, tetraboric acid or the like and an aqueous boric acid solution and a molding aid, kneading, drying, and further firing. A carrier can be produced.
[0009]
The metatitanic acid hydrate cake used in the present invention is obtained by filtering and washing a metatitanic acid hydrate slurry, which is an intermediate in the production of titania by the sulfuric acid method, which is widely known as a method for producing titanium oxide. It is done.
[0010]
In the carrier of the present invention, the phosphorus content is PO ₄ or the boron content B ₂ O ₃ is 2 to 5 wt%, the zirconia content is 25 to 50 wt%, and the balance is substantially titania. This is because, outside this range, volatile organochlorine compounds from low to high concentrations cannot maintain stable decomposition activity for a long time.
[0011]
As a molding aid, the fracture strength of the molded carrier can be increased by adding titania sol, zirconium nitrate solution, ammonium zirconium carbonate solution, etc., and the moldability can be improved by adding a cellulose-based organic substance. it can. The molding aid used in the present invention may be a customary one used for producing a catalyst carrier, and is not particularly limited, but it may be one in which inorganic substances other than the composition of the present invention do not remain after firing. desirable.
[0012]
The shape of the ternary oxide support of the present invention may be a powder, a sphere, a cylinder, a three-leaf, a four-leaf, a honeycomb, a spiral, etc., which are generally used as a catalyst support, and is suitable for a catalytic reaction. Can be appropriately selected.
[0013]
Moreover, when the molded body is fired to obtain a carrier, the firing temperature of the molded body is preferably in the range of 400 to 600 ° C. If the firing temperature is too high, titania undergoes a thermal transition from the anatase structure to the rutile structure, and zirconia undergoes a thermal transition from the metastable tetragonal system to the monoclinic system, thereby reducing the specific surface area of the resulting support. .
The catalyst of the present invention carries a catalyst component such as platinum, palladium, ruthenium, etc. on the phosphorus-zirconia titania ternary oxide support or boron-zirconia titania ternary oxide support thus obtained, Next, it is dried at a temperature of 80 to 110 ° C. and fired at 400 to 600 ° C. for production.
[0014]
In order to support the catalyst component on the carrier, a salt solution of the catalyst component, that is, a platinum salt, palladium salt, or ruthenium salt aqueous solution is prepared, and the concentration of the catalyst salt aqueous solution is adjusted so that a desired amount of the catalyst component can be supported. The catalyst can be supported by impregnating the carrier therein to absorb the catalyst component, or by adsorbing the entire amount of the aqueous solution in which the desired amount of the catalyst component is dissolved.
[0015]
In the catalyst of the present invention, the supported amount of catalyst component such as platinum, palladium, ruthenium, etc. supported for obtaining a catalyst having high decomposition activity is 0.1 to 5% by weight in terms of metal. If the amount is less than 0.1% by weight, sufficient decomposition activity cannot be obtained. On the other hand, if the amount exceeds 5% by weight, there is no difference in the effect for improving the activity. This is because there is no need to carry it.
The catalyst of the present invention can decompose volatile organochlorine compounds from low to high concentration very efficiently because water molecules are adsorbed on the acid point of the solid acid, exhibiting Bronsted acid type activity, and volatile This is because the ability to extract and decompose chlorine from organochlorine compounds is improved. For this reason, it is considered that the degradation activity could be improved because the number of active sites increased due to the synergistic effect of the three components constituting the carrier.
[0016]
【Example】
Examples of the present invention will be described below together with comparative examples.
[0017]
Examples 1-3:
(1) Preparation of carrier First, 40% by weight titania, metatitanic acid slurry (manufactured by Titan Kogyo) containing 5.7% by weight as SO ₄ to 1.5 kg, in order to remove the SO ₄ concentration of 7% After adding 50 liters of ammonia water and sufficiently stirring, the operation of filtering was repeated 3 times to obtain a metatitanate cake containing 15% by weight as titania and 0.5% by weight as SO ₄ .
Next, 1967 g of this metatitanic acid cake (295 g as titania), 493 g of zirconium hydroxide powder (made by Nippon Light Metal Co., Ltd.) containing 35.5 wt% as zirconia (175 g as zirconia), and ortholine having a concentration of 85 wt% 18.2 g of acid solution (15 g as PO ₄ ) was kneaded in a kneader with a warming jacket, and then this kneaded product was titania sol containing 6% by weight of titania as a molding aid (manufactured by Taki Chemical Co., Ltd.). 250 g (15 g as titania), 15 g of Avicel (trade name, manufactured by Asahi Kasei Co., Ltd.), and 7 g of metrose (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) were added and further kneaded until sufficiently plasticized. The ignition loss of the kneaded product at 500 ° C. was 62%.
Next, the kneaded product is granulated into a bead having a diameter of 2 mmφ using a round machine, dried at a temperature of 100 ° C. for 15 hours, and then calcined at 500 ° C. for 2 hours to obtain 3 wt% phosphorus as PO _4. A zirconia (ZrO ₂ ) -containing zirconia (ZrO ₂ ) 35 wt% was obtained, and the remainder was substantially composed of titania (TiO ₂ ).
On the other hand, the same procedure as described above, except that the addition amount of the orthophosphoric acid solution of zirconium hydroxide powder to 1967 g of the above metatitanate cake was changed to 304 g and 15.7 g, and 930 g and 24.0 g, respectively. Using the procedure, carriers AB and AC having different contents of the carrier AA and zirconia (phosphorus contents are the same and titania contents are different) were obtained. The compositions of carriers AA, AB and AC are shown in Table 1, respectively.
[0018]
(2) Preparation of catalyst An impregnating solution prepared by dissolving 2.0 g of chloroplatinic acid in 30 ml of water and adjusting the amount of water with the amount of water corresponding to the amount of water absorbed by the carrier was 150 g for each of carriers AA, AB and AC. And dried at 110 ° C. for 15 hours and then calcined at 500 ° C. for 2 hours to obtain catalysts KK, KL, and KM. The supported amount of platinum for each of the catalysts KK, KL, and KM is 0.5% by weight.
[0019]
(3) Evaluation of catalyst The obtained catalyst KK, KL, and KM are filled in a fixed bed flow reactor with a catalyst loading amount of 50 ml, and 10% by volume of water is added to air containing 2000 ppm, 5000 ppm, and 10000 ppm of trichlorethylene. While the reaction temperature was 350 ° C. and the space velocity was SV = 5000 hr ⁻¹ , the decomposition reaction of trichlorethylene was performed by passing through the catalyst layer.
Since the above reaction is an exothermic reaction, heat of oxidation is generated when the concentration of trichlorethylene is increased even when the reaction temperature is set at 350 ° C., and the temperature of the catalyst when the concentration of trichlorethylene is 5000 ppm is 400 ° C. and 10000 ppm. The temperature rose to 500 ° C.
Table 1 shows the performance evaluation results of each catalyst after 100 hours had elapsed after starting the reaction with respect to each trichlorethylene concentration. In addition, the analysis of the processing gas was analyzed by the gas tomato method using a gas chromatograph manufactured by Shimadzu Corporation.
As shown in Table 1, in the catalysts KK, KL, and KM, the phosphorus content of the used phosphorus-zirconia titania carrier is 3% by weight as PO ₄ and the content of zirconia is 35% by weight and 25%, respectively. Within the composition range of the present invention, such as 50% by weight and 50% by weight, trichlorethylene was efficiently decomposed and made harmless over a long period of time at a decomposition rate of 99.9% or higher from low to high concentrations. In addition, when it does not have a decomposition rate of 99.9% or more, it cannot fully satisfy the management concentration of the working environment standard.
[0020]
Comparative Examples 1 and 2:
(1) Preparation of support Example 1 except that the addition amount of zirconium hydroxide powder and orthophosphoric acid solution added to 1967 g of metatitanate cake was changed to 101 g and 13 g, and 1417 g and 30.5 g, respectively. AG and AH of the linzirconia titania carrier were obtained by the same procedure as shown. The compositions of carriers AG and AH are shown in Table 1, respectively.
(2) Catalyst preparation Platinum was supported on the carriers AG and AH by the same method as shown in Example 1 to prepare catalysts KQ and KR. The supported amount of platinum is 0.5% by weight.
(3) Evaluation of catalyst Table 1 shows the results of tests similar to Example 1 using catalysts KQ and KR. The catalysts KQ and KR have a zirconia content of 10% by weight and 60% by weight, respectively, of the phosphorus-zirconia titania carrier used, which is outside the scope of the present invention. The decomposition rate of trichlorethylene is 99. It is below 9%.
[0021]
Examples 4 and 5:
(1) Preparation of carrier Example 1 except that the combination of addition amount of zirconium hydroxide powder and orthophosphoric acid solution added to 1967 g of metatitanic acid cake was changed to 485 g and 11.9 g, 510 g and 31.3 g, respectively. In the same manner as in the method shown in Fig. 1, Linzirconia arcania carriers AD and AE were obtained. The compositions of the carriers AD and AE are shown in Table 1, respectively.
(2) Catalyst preparation Platinum was supported on the carriers AD and AE by the same method as shown in Example 1 to prepare catalysts KN and KO. The supported amount of platinum is 0.5% by weight.
(3) Evaluation of catalyst Table 1 shows the results of tests similar to Example 1 using catalysts KN and KO. In the catalysts KN and KO, the phosphorus content of the used phosphorus-zirconia titania carrier is 2% by weight and 5% by weight, respectively, in terms of PO _{4 and} the content of zirconia is 35% by weight, which is within the scope of the present invention. From a low concentration to a high concentration, trichlorethylene was efficiently decomposed and made harmless over a long period of time with a decomposition rate of 99.9% or more.
[0022]
Comparative Examples 3-5:
(1) Preparation of support Examples except that the combination of the addition amount of zirconium hydroxide powder and orthophosphoric acid solution added to 1967 g of metatitanate cake was changed to 479 g, 5.9 g, 527 g and 45.4 g, respectively. Phosphorus-zirconia-titania carriers AI and AJ were obtained by the same procedure as in Example 1.
Further, as a carrier containing no phosphorus, 1967 g of the metatitanic acid cake was added with 470 g of zirconium hydroxide powder without adding the orthophosphoric acid solution, and the same procedure as shown in Example 1 was followed. An oxide carrier AF was obtained. The compositions of carriers AI, AJ, and AF are shown in Table 1, respectively.
(2) Preparation of catalyst Platinum was supported on the carriers AI, AJ, and AF by the same method as shown in Example 1 to prepare catalysts KS, KT, and KP. The supported amount of platinum is 0.5% by weight.
(3) Evaluation of catalyst Table 1 shows the results of tests similar to Example 1 using catalysts KS, KT, and KP. Catalysts KS and KT are out of the scope of the present invention, in which the phosphorus content of the used linzirconia titania support is 1% by weight and 7% by weight in terms of PO ₄ respectively, and the catalyst KP does not contain any phosphorus. There is no catalyst using a two-component oxide support of zirconia architectania. As shown in Table 1, the decomposition rate of trichlorethylene is below 99.9% at both low and high concentrations.
[0023]
Examples 6-8:
(1) Preparation of carrier The same carrier as AA shown in Example 1 was prepared.
(2) Preparation of catalyst 1.0 g, 4.0 g and 12.0 g of chloroplatinic acid were dissolved in 30 ml of water, respectively, and an impregnation solution was prepared by adjusting the amount of water with water to match the amount of water absorbed by the carrier. 150 g of each lin-zirconia titania support AA obtained in Example 1 was impregnated, dried at 110 ° C. for 15 hours, and then calcined at 500 ° C. for 2 hours to obtain catalysts KU, KV and KW.
(3) Evaluation of catalyst Table 1 shows the results of tests similar to Example 1 using catalysts KU, KV, and KW. Catalysts KU, KV, and KW are catalysts having platinum, platinum, and platinum corresponding to 0.25 wt%, 1.0 wt%, and 3.0 wt%, respectively, supported on a phosphorus-zirconia architectania support within the scope of the present invention. Trichlorethylene was efficiently decomposed and made harmless over a long period of time with a decomposition rate of 99.9% or more from low to high concentrations.
[0024]
[Table 1]

[0025]
Examples 9-11:
(1) Preparation of support The same composition as in Example 1 and the same procedure except that orthoboric acid 26.5 g (15 g as B ₂ O ₃ ) was used instead of the orthophosphoric acid solution used in Example 1. The kneaded product is granulated into a bead with a diameter of 2 mmφ by a round machine, dried at a temperature of 100 ° C. for 15 hours, and then calcined at 500 ° C. for 2 hours, so that boron is 3% by weight as B ₂ O _3. Boron-zirconia arcutania carrier BA containing 35% by weight of zirconia (ZrO ₂ ) and the balance substantially consisting of titania (TiO ₂ ) was obtained.
On the other hand, the procedure similar to the above procedure except that the addition amount of orthoboric acid in the zirconium hydroxide powder to 1967 g of the above metatitanate cake was changed to 304 g and 22.8 g, and 930 g and 34.0 g, respectively. Were used to obtain the carriers BB and BC having different contents of the carrier BA and zirconia (the same boron content and different titania contents). The compositions of the carriers BA, BB, and BC are shown in Table 2, respectively.
(2) Preparation of catalyst An impregnating solution obtained by dissolving 2.0 g of chloroplatinic acid in 30 ml of water and adjusting the amount of water with water to the amount of water absorbed by the carrier was added to 150 g of each of the carriers BA, BB and BC. It was impregnated, dried at 110 ° C. for 15 hours, and then calcined at 500 ° C. for 2 hours to obtain catalysts LK, LL and LM. The supported amount of platinum in each of the catalysts LK, LL and LM is 0.5% by weight.
(3) Evaluation of catalyst As a result of conducting the same test as in Example 1, as shown in Table 2, the catalysts LK, LL, and LM had a boron content of 3 in the boron-zirconia arctania carrier used. ₂ O ₃ is 3% by weight, and the content of zirconia is 35% by weight, 25% by weight, and 50% by weight, respectively, within the composition range of the present invention. With a decomposition rate of at least%, it was able to decompose efficiently and be rendered harmless over a long period of time.
[0026]
Comparative Examples 6 and 7:
(1) Preparation of carrier Example 9 except that the addition amount of zirconium hydroxide powder and orthoboric acid added to 1967 g of metatitanate cake was changed to 101 g and 18.9 g, and 1417 g and 44.2 g, respectively. Boron-zirconia arcutania carriers BG and BH were obtained by the same procedure as described above. The compositions of the carriers BG and BH are shown in Table 2, respectively.
(2) Catalyst preparation Platinum was supported on the carriers BG and BH by the same method as shown in Example 9 to prepare catalysts LQ and LR. The supported amount of platinum is 0.5% by weight.
(3) Evaluation of catalyst Table 2 shows the results of tests similar to Example 1 using catalysts LQ and LR. The catalysts LQ and LR have a zirconia content of 10% by weight and 60% by weight, respectively, in the boron-zirconia titania support used, which are outside the scope of the present invention, and the decomposition rate of trichlorethylene is 99. It is below 9%.
[0027]
Examples 12 and 13:
(1) Preparation of carrier Example 9 except that the addition amount of zirconium hydroxide powder and orthoboric acid added to 1967 g of metatitanic acid cake was changed to 485 g and 17.4 g, 510 g and 45.7 g, respectively. Boron-zirconia arcutania carriers BD and BE were obtained in the same procedure as shown in FIG. The compositions of the carriers BD and BE are shown in Table 2, respectively.
(2) Catalyst Preparation Platinum was supported on the carriers BD and BE by the same method as shown in Example 9 to prepare catalysts LN and LO. The supported amount of platinum is 0.5% by weight.
(3) Evaluation of catalyst Table 2 shows the results of tests similar to Example 1 using catalysts LN and LO. In the catalysts LN and LO, the boron content of the used boron-zirconia titania support is 2% by weight and 5% by weight in terms of B ₂ O ₃ , respectively, and the water content of zirconia is 35% by weight. From the low concentration to the high concentration, trichlorethylene was efficiently decomposed and made harmless over a long period of time with a decomposition rate of 99.9% or more.
[0028]
Comparative Examples 8 and 9:
(1) Preparation of support Example 9 except that the addition amount of zirconium hydroxide powder and orthoboric acid added to 1967 g of metatitanate cake was changed to 470 g, 8.6 g, 527 g and 66.2 g, respectively. Boron-zirconia titania carriers BI and BJ were obtained by the same procedure as shown in FIG. The compositions of the carriers BI and BJ are shown in Table 2, respectively.
(2) Catalyst preparation Platinum was supported on the carriers BI and BJ by the same method as shown in Example 9 to prepare catalysts LS and LT. The supported amount of platinum is 0.5% by weight.
(3) Evaluation of catalyst Table 2 shows the results of tests similar to Example 1 using catalysts LS and LT. In the catalysts LS and LT, the boron content of the used boron-zirconia titania support is 1% by weight and 7% by weight in terms of B ₂ O ₃ , respectively, and is outside the scope of the present invention. The decomposition rate of trichlorethylene is below 99.9% at both low and high concentrations.
[0029]
Examples 14-16:
(1) Preparation of carrier The same carrier as the carrier BA shown in Example 9 was prepared.
(2) Preparation of catalyst 1.0 g, 4.0 g and 12.0 g of chloroplatinic acid were dissolved in 30 ml of water, respectively, and an impregnation solution was prepared by adjusting the amount of water with water to match the amount of water absorbed by the carrier. 150 g of each of the boron-zirconia titania support BA obtained in Example 9 was impregnated, dried at 110 ° C. for 15 hours, and then calcined at 500 ° C. for 2 hours to obtain catalysts LU, LV, and LW.
(3) Evaluation of catalyst Table 2 shows the results of tests similar to Example 1 using catalysts LU, LV, and LW. Catalysts LU, LV, and LW are catalysts in which platinum corresponding to 0.25 wt%, 1.0 wt%, and 3.0 wt% is supported on a boron-zirconia titania support within the composition range of the present invention, respectively. Yes, trichlorethylene was decomposed efficiently from a low concentration to a high concentration with a decomposition rate of 99.9% or more over a long period of time, making it harmless.
[0030]
[Table 2]

[0031]
【The invention's effect】
As described above, by bringing the catalyst of the present invention into contact with a volatile organic chlorine compound in the presence of water vapor and air, a volatile organic chlorine compound from a low concentration to a high concentration can be efficiently treated. The activity is stable for a long time and practical. Therefore, the catalyst of the present invention can be used for detoxification of exhaust gas discharged from a metal degreasing process, dry cleaning, etc., and volatile organic chlorine compounds in waste liquid, and is extremely effective in preventing environmental pollution.

Claims (1)

Phosphorus to PO ₄ In conversion or boron to B ₂ O ₃ At least 1 selected from the group consisting of platinum, palladium, and ruthenium as a catalyst component on a ternary oxide carrier comprising 2 to 5% by weight in terms of conversion, 25 to 50% by weight of zirconia, and the balance being substantially composed of titania. A decomposition catalyst for volatile organochlorine compounds, wherein a seed is supported in an amount corresponding to 0.1 to 5% by weight in terms of metal.