KR20020060002A - Multifunctional oxidation catalysts for removal of chlorinated volatile organic compounds - Google Patents

Abstract

PURPOSE: Provided is a multifunctional oxidation catalysts, which can remove chlorinated volatile organic compounds at low temperatures of 20 to 220°C as well as minimize generation of another forms of chlorinated volatile organic compounds after reaction. CONSTITUTION: The present invention is characterized in that sulfated metal oxide support is impregnated with (i) as active species, 0.5-2.0 wt.% of one novel metal selected from Pt, Pd, Ir and Rh; (ii) as subsidiary active species, Cu 2.0-10.0 wt.%, Ni 0.1-1.0 wt.%. The sulfated metal oxide support is selected from zirconia, titania and ceria containing SO4 in an amount of 0.3 to 2.3 wt.%. And a porous molecular sieve material is used as support, together with the sulfated metal oxide support within the range of less than 50%. The porous molecular sieve material, such as protonic zeolite or ammonium zeolite, is selected from BEA, MFI, MOR and FAU zeolite with a Si/Al ratio within the range of 10 to 100.

Description

Multifunctional oxidation catalysts for removal of chlorinated volatile organic compounds}

The present invention relates to an oxidation catalyst for removing volatile organic chlorine compounds, and more particularly, platinum (Pt), palladium (Pd), iridium (Ir) and rhodium (Rh) on a sulfated metal oxide carrier. The precious metal selected from among them is contained as an active metal, and if necessary, transition metals such as copper (Cu) and nickel (Ni) are evenly supported in a certain content ratio together with the precious metal as auxiliary active metals, and thus used as active metals and carriers. By maximizing the function of the components and inducing synergies with each other, it not only effectively removes volatile organic chlorine compounds at low temperature of 20-220 ℃, but also minimizes the formation of another type of volatile organic chlorine compounds after the reaction. The present invention relates to an oxidation catalyst for removing volatile organochlorine compounds which simultaneously realizes energy saving.

Halogenated volatile organic compounds (hereinafter abbreviated as "HVOCs") are frequently used in the solvent process or in the manufacturing of fine chemicals. Unlike general paraffinic or aromatic volatile organic compounds, their toxicity is very high. Strong and degradable materials are urgently needed to develop efficient treatment technologies. Currently, simple incineration or regenerative incineration is carried out as a method of treating HVOCs. However, since the combustion temperature is high and the fuel consumption is high, a considerable amount of CO ₂ is emitted, and secondary air pollutants such as nitrogen oxides and dioxins are used. It is very likely to occur.

In addition to the above-described incineration method, a method of treating HVOCs using an oxidation catalyst is known, wherein the oxidation catalyst used is a noble metal (Pt, Pd, Rh, etc.) and a transition metal (V, Cr, Mn, Fe, Co, Ni, Cu). It can be divided into two types. In general, the oxidation behavior of HVOCs differs from ordinary volatile organic compounds (VOCs), which react with metal catalysts to produce volatile toxic metal oxyhalides, which not only poison the catalyst. Hardly degradable secondary pollutants are produced. In particular, noble metal catalysts may react with HVOCs to generate polyhalogenated organic compounds. According to recent reports, transition metal catalysts are known to have higher poisoning resistance to chlorine and hydrochloric acid than noble metals when oxidizing HVOCs.

On the other hand, when zeolite is used as a catalyst carrier or zeolite itself is used as a catalyst, it shows high oxidation activity against HVOCs. For example, zeolite catalysts such as Cr-Y, Cr-ZSM-5, Co-Y, and Y are completely oxidized CHCl ₃ , CCl _4, etc. at a relatively low temperature (200-300 ° C.) to produce H ₂ O, CO _2. It can be effectively converted to HCl to inhibit the production of several major byproducts, CO, COCl ₂ and polychlorolated hydrocarbons. Such catalytic activity is known that the zeolite catalyst organically combines the role of the adsorption catalyst to perform the reaction at the acidic point present in the zeolite. Catalytic total oxidation techniques of catalysts of VOCs are well known.

However, volatile organic chlorine compounds' (hereinafter abbreviated as "Cl-VOCs"), for example trichloroethylene, vinyl chloride, tetrachloroethylene, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloro Complete oxidation techniques for compounds containing chlorine atoms such as ethane, carbon tetrachloride, chloroform, chlorobenzene and the like remain technically inconvenient. Cl-VOCs, for example, not only form HCl and Cl ₂ after oxidation, but they also easily poison the catalyst. In addition, since various different types of chlorinated derivative compounds such as dioxins are formed after the oxidation reaction, it is not easy to completely oxidize and remove Cl-VOCs as a catalyst having a simple oxidation capability. In addition, in the industrial field, not only VOCs but also various kinds of Cl-VOCs are discharged together, so multi-functional catalyst materials must be designed and manufactured to remove and process them simultaneously. Actually, representative catalysts used for complete oxidation of Cl-VOCs can be separated into ① precious metal (Pt / Pd) series, ② vanadia series, ③ chromium series, and ④ single or complex oxide series (Perovskite type oxide). .

To date, techniques for oxidizing and decomposing halogenated hydrocarbons on chromium oxide or platinum-supported boehmite catalysts (US Pat. Nos. 3,972,979, 4,053,557); A technique for oxidizing and decomposing halogenated organic compounds at a temperature of at least 350 ° C. using ruthenium (Ru), ruthenium-platinum (Ru-Pt), and platinum (Pt) supported catalysts, respectively [US Pat. Nos. 4,059,675, 4,059,676] 4,059,683; Catalyst production technology in which platinum is dispersed and supported on at least one carrier selected from zirconium (Zr), manganese (Mn), cerium (Ce), cobalt (Co), and vanadium (V) oxides (US Pat. No. 5,283,041); Catalyst technology using a carrier of a different acidity (US Pat. No. 5,643,545) and the like are known. However, in the above-described prior art, various kinds of Cl-VOCs having different compositions after reaction are generated as by-products, causing secondary contamination, and thus, higher temperatures than necessary are required for complete oxidation and removal of such HVOCs. For example, when 1,1,1-trichloroethane is oxidized by a catalyst, another form of Cl-VOCs of trichloroethylene, dichloroethylene, tetrachloroethylene, monochloroethylene is produced as a by-product, which is a catalyst Since the generation of by-products can be minimized by the activation temperature, the functionality according to the active ingredients of the catalyst, and the reaction conditions, the optimum catalyst design must be preceded.

Catalysts used to remove Cl-VOCs, supported by precious metals such as platinum [J. Corella, JM Toledo and AM Padilla, Appl. Catal. B. 27 (2000) 243], catalysts supported by transition metals such as chromium [AM Padilla, J. Corella and JM Toledo, Appl. Catal. B. 22 (1999) 107 is commercially available. Platinum-based catalysts have good activity but are uneconomical, while chromium-based catalysts have good activity and are economical. There is a need to design and manufacture a catalyst that can overcome the disadvantages they have.

Accordingly, the present inventors based on the basic concept that the activity of the catalyst is determined by the active metal site (acidic site), acidic site, and the oxygen adsorption capacity of the catalyst component, effectively oxidizing Cl-VOCs at low temperatures We have tried to develop a new catalyst system that can be removed by removal and maximal inhibition of formation of another form of Cl-VOCs after oxidation. That is, the present invention develops a catalyst having a strong oxidizing power that maximizes the functions of each of the components used as the active metal and the carrier or induces synergism with each other, and is unlikely to form another form of Cl-VOCs after oxidation. It is.

Therefore, the present invention is not only removes Cl-VOCs at a temperature of about 65 to 250 ° C. lower than conventional noble metals alone as a catalyst in which an optimal active metal and a carrier are used to coexist with super acidic sites, and another form after the reaction. It is an object of the present invention to provide a multifunctional catalyst that can simultaneously realize environmental purification and energy saving by minimizing the production of Cl-VOCs.

In the present invention, a sulfated metal oxide carrier is supported by 0.5 to 2.0% by weight of a precious metal selected from platinum (Pt), palladium (Pd), iridium (Ir), and rhodium (Rh) as an active metal. It is characterized by an oxidation catalyst for removing volatile organochlorine compounds (Cl-VOCs) carrying 0.0 to 15.0% by weight of a transition metal as an active metal.

Referring to the present invention in more detail as follows.

The present invention is to support a specific active metal on a sulfated metal oxide carrier in a certain content ratio to simultaneously contain a highly dispersed metal and acidic sites to efficiently oxidize and remove Cl-VOCs even at low temperatures, during the oxidation process It relates to an oxidation catalyst for removing volatile organochlorine compounds (Cl-VOCs) that minimizes the production of another type of Cl-VOCs.

In the present invention, the sulfate type metal oxide used as a carrier includes zirconia (ZrO ₂ ), titania (TiO ₂ ) and ceria (CeO ₂ ) containing 0.1 to 3.5% by weight of sulfuric acid group (SO ₄ ), preferably 0.3 to 2.3% by weight. ) Is selected from. The present invention is characterized by using a sulfate type metal oxide as a carrier, because the acidity is much stronger than a simple metal oxide or acid type (H) metal oxide, so that hydrocarbons can be more easily cracked. to be. Therefore, if the amount of sulfuric acid groups in the metal oxide is less than 0.1% by weight, the function of the sulfuric acid group may not be sufficiently exhibited. If the content of the sulfuric acid group is more than 3.5% by weight, the sulfuric acid groups other than the chemically bonded sulfuric acid groups may be present. More sulfuric acid than necessary is generated and eliminated in the form of SOx at high temperature, thereby inhibiting Cl-VOC oxidation.

On the other hand, in the present invention, the porous metal sieve may be mixed with the above-described sulfate type metal oxide as a carrier, thereby making up for the disadvantage that the surface area of the sulfate type metal oxide is small. That is, the sulfate type metal oxide and the porous molecular sieve are chemical mixtures, not just physical mixtures, and since the sulfate type metal oxide and the active metal components are uniformly dispersed on the surface of the molecular sieve with a large cross-sectional area, the active active ingredient of the catalyst has excellent activity. Do it. The porous molecular sieve should be mixed and used in a range of less than 50% by weight with respect to the sulfate type metal oxide. If the amount of the mixture is more than 50% by weight, the active ingredient may be highly dispersed, but Cl is highly toxic. In the VOC atmosphere, porous molecular sieves are easily poisoned and have a problem of being difficult to use for a long time. The porous molecular sieve which can be mixed and used as a carrier according to the present invention is selected from zeolites having BEA, MFI, MOR and FAU structures in the range of 5 to 500, preferably 10 to 100, as proton- or ammonium-type zeolites. do.

In addition, the present invention supports a precious metal selected from platinum, palladium, iridium and rhodium as the active metal, and may optionally support the transition metal as a secondary active metal in a predetermined content range. Even if a noble metal is contained alone as an active metal, sufficient catalytic activity can be obtained. However, when supporting the transition metal together, the catalytic activity can be obtained by maximizing the function of the active metal or inducing synergy with each other. In fact, according to the experimental results of the present inventors, it was confirmed that the oxidation catalysts mixed with these in a certain content ratio had superior catalytic activity compared to the oxidation catalysts each supporting a precious metal or transition metal on a carrier having the same composition. The catalytic activity is maximized when the active metal contained in the oxidation catalyst is contained 0.5 to 2.0% by weight of the noble metal and 2.0 to 15.0% by weight of the transition metal with respect to the carrier. It is preferable to use nickel or copper as the transition metal, and especially when 0.5 to 2.0% by weight of precious metal, 2.0 to 10.0% by weight of copper and 0.1 to 1.0% by weight of nickel are simultaneously contained as an active metal with respect to the carrier. Improved results.

The oxidation catalyst of the present invention composed of the above components was pretreated by firing in an oxygen atmosphere, 500-600 ° C. for 5-15 hours before assessing the activity.

The present invention as described above will be described in more detail based on the following Examples and Experimental Examples, but the present invention is not limited thereto.

Example 1 Pd / SO ₄ -ZrO ₂ Preparation of the catalyst

1.51 g (NH ₄ ) ₂ SO ₄ was dissolved in 1 M sulfuric acid solution until it was saturated, and then dried 12.6 g Zr (OH) ₄ was charged at 110 ° C. for 4 hours and stirred overnight. Then, the mixture was dried with stirring at 80 ° C. and calcined at 550 ° C. for 4 hours to prepare SO ₄ -ZrO ₂ . After dissolving 0.0877 g PdCl ₂ in 500 ml of 16% ammonia water, 5 g SO ₄ -ZrO ₂ was added thereto, and the mixture was maintained at 80 ° C. for 8 hours, and then evaporated while stirring. The prepared catalyst was dried at 110 ° C. for 2 hours and then calcined at 500 ° C. for 6 hours.

Example 2 Pd, Cu / SO ₄ -ZrO ₂ Preparation of the catalyst

1.5 g (NH ₄ ) ₂ SO ₄ was dissolved in 1 M sulfuric acid solution until it was saturated, and then 12.6 g Zr (OH) ₄ dried at 110 ° C. for 4 hours was added to the solution and stirred overnight. Thereafter, the mixture was dried with stirring at 80 ° C. and calcined at 550 ° C. for 4 hours to prepare SO ₄ -ZrO ₂ . Using a solution of PdCl ₂ , CuCl ₂ , Cu (NO ₃ ) ₂ H ₂ O, etc., make a fixed ratio of the mixed solution, and then mix a specific ratio of the mixed solution until the carrier SO ₄ -ZrO ₂ is barely wetted. It was. At this time, Pd and Cu supported on the carrier were 1% by weight and 6.58% by weight, respectively, and the carrier was washed 2-3 times with 0.1 N HCl solution, filtered with distilled water, and then calcined at 300 ° C. for 3 hours. Thereafter, the mixture was dried at room temperature for 8 hours and calcined at 500 ° C. for 6 hours.

Example 3 Pd, Cu, Ni / SO ₄ -ZrO ₂ Preparation of the catalyst

After a certain ratio of the mixed solution was prepared using each aqueous solution such as PdCl ₂ , CuCl ₂ , CuSO ₄ · H ₂ O, NiCl ₂ · H ₂ O, and the carrier SO ₄ -ZrO ₂ prepared in Example 1 was barely A specific ratio of the mixed solution was mixed until wet. At this time, Pd, Cu, Ni supported on the carrier were 1% by weight, 6.58% by weight, 0.12% by weight, respectively, and the carrier was washed 2-3 times with 0.1 N HCl solution, filtered with distilled water, and then calcined at 300 ° C. for 3 hours. Was used. After drying at room temperature for 8 hours, it was calcined at 500 ° C. for 6 hours.

Example 4 Pd, Cu, Ni / SO ₄ -ZrO ₂ , USY-zeolite catalyst

1.51g (NH₄)₂SO₄Dissolved in 1M sulfuric acid solution until saturated, and then Zr (OH) dried at 4 ° C.₄And USY-zeolite were mixed in a weight ratio of 1: 1 to the solution and 80 Dried under stirring at 550C and 550 The mixed / acid-forming carrier was prepared by baking in an air atmosphere at 4 ° C. for 4 hours. PdCl₂, CuCl₂, Cu (NO₃)₂H₂O, NiCl₂H₂O and H₂After using O to make a mixed solution of a certain ratio, the mixed solution of a specific ratio was mixed until the barely wet with the prepared mixed / acid-forming carrier. At this time, Pd, Cu, Ni supported on the carrier were 1% by weight, 6.58% by weight, 0.12% by weight, respectively, and the carrier was washed 2-3 times with 0.1 N HCl solution, filtered with distilled water, and then calcined at 300 ° C. for 3 hours. Was used. Thereafter, the mixture was dried at room temperature for 8 hours and calcined at 500 ° C. for 6 hours.

Example 5 Pt / SO ₄ -ZrO ₂ , USY-zeolite catalyst

Dissolve 1.51 g (NH ₄ ) ₂ SO ₄ in 1 M sulfuric acid until saturated, and then mix Zr (OH) ₄ and USY (zeolite) in a weight ratio of 1: 1, which was dried at 110 ° C. for 4 hours. Then, the mixture was dried with stirring at 80 ° C. and calcined at 550 ° C. for 4 hours in an air atmosphere to prepare a mixed / acidic carrier.

500 ml of 16% ammonia was added until 0.0688 g of PtCl ₂ was completely dissolved, and 5 g of the mixed / acid-forming carrier were uniformly mixed and maintained at 80 ° C. for 15 hours with stirring, followed by evaporation to carry out the Pt-supported catalyst. Prepared. At this time, the ratio of the mixed solution and the carrier was 1 g carrier per 100 ml mixed solution, and the ratio of the final Pt supported on the carrier was 1% by weight. After evaporation, the resultant was dried at 110 ° C. for 2 hours and calcined at 500 ° C. for 6 hours.

Example 6: Pd, Ni / SO ₄ -ZrO ₂ Preparation of the catalyst

After a certain ratio of the mixed solution was prepared using each aqueous solution such as PdCl ₂ , NiCl ₂ · H ₂ O, and the like, the mixed solution of a specific ratio was mixed until the carrier SO ₄ -ZrO ₂ prepared in Example 1 was barely wetted. It was. Pd and Ni supported on the carrier were 1% by weight and 0.12% by weight, respectively, and the carrier was washed 2-3 times with 0.1 N HCl solution, filtered with distilled water, and then calcined at 300 ° C. for 3 hours. Thereafter, the mixture was dried at room temperature for 8 hours and calcined at 500 ° C. for 6 hours.

Comparative Example 1: Pd / ZrO ₂ Preparation of the catalyst

After dissolving 0.0877 g PdCl ₂ in 500 ml of 16% ammonia water, 5 g SO ₄ -ZrO ₂ was added thereto, and the mixture was maintained at 80 ° C. for 8 hours, and then evaporated while stirring. The prepared catalyst was dried at 110 ° C. for 2 hours and then calcined at 500 ° C. for 6 hours.

Comparative Example 2: SO ₄ -ZrO ₂ Preparation of the catalyst

1.51 g (NH ₄ ) ₂ SO ₄ was dissolved in 1 M sulfuric acid solution until it was saturated, and then dried 12.6 g Zr (OH) ₄ was charged at 110 ° C. for 4 hours and stirred overnight. Then, the mixture was dried with stirring at 80 ° C. and calcined at 550 ° C. for 4 hours in an air atmosphere to prepare SO ₄ -ZrO ₂ .

Comparative Example 3: SO ₄ / TiO ₂ Preparation of the catalyst

After dissolving 1.5 g of (NH ₄ ) ₂ SO ₄ in a certain amount of aqueous solution until it was saturated, 35.6 g of titanium (IV) poroxide was added to the solution and stirred for 10 hours. Thereafter, the mixture was dried with stirring at 80 ° C. and calcined at 550 ° C. for 4 hours in an air atmosphere to prepare SO ₄ / TiO ₂ .

Comparative Example 4: Pd / Al ₂ O ₃ Preparation of the catalyst

0.0877 g PdCl in 500 ml solution of 16% aqueous ammonia₂Put it in and melt it well 5g Al₂O₃80 after inserting It was kept for 8 hours at ℃ and then evaporated while stirring. 150 Dry for 1 hour at ℃ 550 It baked at 4 degreeC for 4 hours.

Comparative Example 5: Pt / Al ₂ O ₃ Preparation of the catalyst

0.0688 g PtCl ₂ was dissolved in 500 ml of 16% aqueous ammonia solution, and 5 g Al ₂ O ₃ was added thereto. The mixture was maintained at 80 ° C. for 8 hours, and evaporated while stirring. It dried at 150 degreeC for 1 hour, and baked at 550 degreeC for 4 hours.

Comparative Example 6: Preparation of Pd / USY-zeolite Catalyst

0.0877 g PdCl ₂ was dissolved in a 500 ml solution of 16% ammonia water, and 5 g USY zeolite was added thereto, followed by stirring at 80 ° C. for 8 hours. Thereafter, the mixture was slowly cooled to room temperature, filtered, and washed with excess 70 ° C water. After drying at room temperature it was calcined at 500 ℃ for 4 hours.

Comparative Example 7: Preparation of Co / Y-zeolite Catalyst

1 g of Y-zeolite was added to 100 ml of 0.1 M Co (CH ₃ COO) ₂ aqueous solution and stirred at room temperature for 10 hours. The stirred solution was filtered and washed with 40 ° C H ₂ O. It was dried at room temperature and calcined at 500 ° C. for 2 hours in an air atmosphere.

Comparative Example 8: Cr / ZSM-5 Preparation of Zeolite Catalyst

An aqueous solution of 0.777 g of Cr (NO ₃ ) ₃ .9H ₂ O was dissolved in 12 ml of water, and 10 g of ZSM-5 was dropped and uniformly wetted, and then mixed well and dried at room temperature. After drying for 2 hours at 110 ℃ and calcined at 500 ℃ 4 hours.

Comparative Example 9: Ni / NiAl ₂ O ₄ Preparation of the catalyst

NiAl ₂ O ₄ was prepared by the following method. Ni (NO ₃ ) ₂ · 6H ₂ O, Al (NO ₃ ) ₃ · 9H ₂ O Aqueous solution in which the molar ratio of Ni and Al is 1: 2 using an aqueous solution is 0.6 M NH ₄ OH using a pH of 4 The mixture was slowly mixed until it reached 8 and stirred for 8 hours. The precipitate was filtered, washed with distilled water, dried at 100 ° C. for 8 hours and calcined at 700 ° C. for 5 hours. Ni / NiAl ₂ O ₄ was prepared by infiltrating the prepared 10 g NiAl ₂ O ₄ with 10.45 g of an aqueous NiAl ₂ O ₄ .6H ₂ O solution and calcining at 350 ° C. for 30 minutes.

Comparative Example 10 NiMnO ₃ Preparation of the catalyst

A 0.5M mixed aqueous solution was prepared using 2.91 g Ni (NO ₃ ) ₂ H ₂ O, 2.56 g Mn (NO ₃ ) ₂ H ₂ O, 200 mL water, and then 8.41 in 100 mL H ₂ O. A 1 M aqueous NaHCO ₃ solution prepared by adding g of NaHCO ₃ was gradually dropped into the mixed aqueous solution to coprecipitate. The coprecipitated mixed aqueous solution was filtered, washed with water, dried at 60 ° C., and calcined at 400 ° C. for 5 hours.

Comparative Example 11: Na ₃ Fe _0.5 Zr _1.5 (PO ₄ ) ₃ Preparation of the catalyst

To 100 ml of water, 8.5 g NaNO ₃ , 13.5 g Fe (NO ₃ ) .9H ₂ O, 8.5 g ZrO (NO ₃ ) ₂ .2H ₂ O, 23 g NH ₄ H ₂ PO ₄ , respectively An aqueous solution of was made. At this time, the molar ratio of the samples per aqueous solution of NaNO ₃ , Fe (NO ₃ ) ₃ .9H ₂ O, ZrO (NO ₃ ) ₂ .2H ₂ O, and NH ₄ H ₂ PO ₄ was set to 1.5 / 0.5 / 1.5 / 3. Thereafter, each aqueous solution was slowly precipitated by dropping NaNO ₃ , Fe (NO ₃ ) ₃ · 9H ₂ O, and ZrO (NO ₃ ) ₂ · 2H ₂ O aqueous solution in order to the stirred NH ₄ H ₂ PO ₄ aqueous solution. The co-precipitated mixed aqueous solution was heated at 60 ° C. for 3 hours to gel, and then heated at 110 ° C. until it became a dry gel. It was then calcined at 750 ° C. for 1 hour.

Comparative Example 12: Pd, Cu / ZrO ₂ Preparation of the catalyst

Each solution of PdCl ₂ , CuCl ₂ , Cu (NO ₃ ) ₂ H ₂ O, etc. was used to form a constant ratio of the mixed solution, and the mixed solution of the specific ratio was mixed until the carrier ZrO ₂ became barely wet. At this time, Pd and Cu supported on the carrier were 1% by weight and 6.58% by weight, respectively, and the carrier was washed 2-3 times with 0.1 N HCl solution, filtered with distilled water, and then calcined at 300 ° C. for 3 hours. Thereafter, the mixture was dried at room temperature for 8 hours and calcined at 500 ° C. for 6 hours.

Comparative Example 13: Pd, Cu, Ni / ZrO ₂ Preparation of the catalyst

A certain ratio of mixed solution was prepared using each aqueous solution such as PdCl ₂ , CuCl ₂ , CuSO ₄ · H ₂ O, and NiCl ₂ · H ₂ O, and then the mixed solution of a specific ratio was mixed until the carrier ZrO ₂ became barely wet. . At this time, Pd, Cu, Ni supported on the carrier were 1% by weight, 6.58% by weight, 0.12% by weight, respectively, and the carrier was washed 2-3 times with 0.1N HCl solution, filtered with distilled water, and then calcined at 300 ° C for 3 hours. Was used. Then, it dried at room temperature for 8 hours, and baked at 500 degreeC for 6 hours.

Comparative Example 14 Preparation of Pd, Cu / USY Catalyst

After mixing PdCl ₂ , CuCl ₂ · H ₂ O, Cu (NO ₃ ) ₂ · H ₂ O and H ₂ O to produce a certain ratio of mixed solution, USY zeolite fired at 500 ℃ was coated with a specific ratio of mixed solution. . At this time, the amounts of Pd and Cu supported were 1% by weight and 10% by weight, respectively. Thereafter, the mixture was dried at room temperature and calcined at 500 ° C. for 5 hours.

Experimental Example: Evaluation of Catalytic Activity

The catalysts prepared in Examples and Comparative Examples were placed in a fixed bed reactor equipped with a temperature controller to perform a gas phase reaction under atmospheric pressure. Since most of Cl-VOCs have high vapor pressure, in order to supply Cl-VOCs of the desired concentration to the reactor, Cl-VOC is passed through a temperature-controlled chiller and air is mixed with the reactants to make 1000 ppm Cl-VOCs at a certain temperature. The initial concentration of was kept controlled. Cl-VOCs concentrations before and after the reaction were quantitatively analyzed by GC equipped with BP-624 column and Helium Ionization Detector (HID). The activity evaluation of the catalyst was performed at 50 ° C. intervals in the range of 100-550 ° C. The conversion rate of Cl-VOCs was calculated by Equation 1 below.

1,1,1-trichloroethane (TCA) oxidation / removal activity by catalyst division catalyst Initial TCA Concentration, ppm GHSV, h ^-1 T (50), ℃ T (90), ℃ Example 1 Pd / SO ₄ -ZrO ₂ 1,000 14,000 55 90 Example 2 Pd, Cu / SO ₄ -ZrO ₂ 1,000 14,000 60 90 Example 3 Pd, Cu, Ni / SO ₄ -ZrO ₂ 1,000 14,000 65 125 Example 6 Pd, Ni / SO ₄ -ZrO ₂ 1,000 14,000 70 120 Comparative Example 1 Pd / ZrO ₂ 1,000 6,600 120 150 Comparative Example 2 SO ₄ -ZrO ₂ 1,000 14,000 110 140 Comparative Example 9 Ni / NiAl ₂ O ₄ 1,000 6,600 175 225 Comparative Example 10 NiMnO ₃ 1,000 8,360 210 240 Comparative Example 11 Na ₃ Fe _0.5 Zr _1.5 (PO ₄ ) ₃ 1,000 6,600 270 300 Comparative Example 12 Pd, Cu / ZrO ₂ 1,000 6,600 75 135 Comparative Example 13 Pd, Cu, Ni / ZrO ₂ 1,000 6,600 85 140 T (50): 50% removal temperature of initial TCA concentration T (90): 90% removal temperature of initial TCA concentration GHSV: Gas Hourly Space Velocity

Table 1 shows a comparison of the relative 1,1,1-trichloroethane (TCA) oxidation and removal activity in several different types of catalysts. A catalyst containing only a noble metal such as Pd or the like on a carrier containing a strong acid group such as a sulfate group (Example 1), or a catalyst simultaneously containing a transition metal such as copper and nickel together with the precious metal (Example 2) , 3, and 6) are catalysts prepared by separately supporting noble metals and sulfuric acid groups under similar reaction conditions (Comparative Examples 1 and 2) or supporting precious metals and transition metals on carriers containing no sulfate groups (Comparative Example 12, 13) or the same activity at temperatures as low as 20 ~ 175 ℃ compared to other catalysts (Comparative Examples 9, 10, 11).

Oxidation / Removal Activity of Carbon Tetrachloride by Catalyst division catalyst Initial CCl ₄ Concentration, ppm GHSV, h ^-1 T (50), ℃ T (90), ℃ Example 1 Pd / SO ₄ -ZrO ₂ 1,000 20,000 140 230 Example 2 Pd, Cu / SO ₄ -ZrO ₂ 1,000 20,000 140 230 Example 3 Pd, Cu, Ni / SO ₄ -ZrO ₂ 1,000 20,000 145 235 Comparative Example 3 SO ₄ / TiO ₂ 1,000 20,000 220 265 Comparative Example 6 Pd / USY 1,000 20,000 330 400 Comparative Example 7 Co / Y 1,000 20,000 350 420 Comparative Example 14 Pd, Cu / USY 1,000 20,000 175 290 T (50): 50% removal temperature of initial carbon tetrachloride concentration T (90): 90% removal temperature of initial carbon tetrachloride concentrationGHSV: Gas Hourly Space Velocity

Table 2 shows a comparison of the oxidation / removal activity of the carbon tetrachloride relative to the different types of catalysts. A catalyst containing only a noble metal such as Pd or the like on a carrier containing a superacidic group such as sulfated (Example 1) or a catalyst simultaneously containing a transition metal such as copper, nickel, etc. (Example 2, 3) compared to the catalyst prepared by supporting the noble metal and the transition metal on a carrier which alone or each containing no noble metal or transition metal under the same reaction conditions (Comparative Examples 3, 6, 7, 14). The same activity is exhibited at temperatures as low as -185 ° C.

Oxidation / Removal Activity of Methane Dichloride (CH ₂ Cl ₂ ) by Catalyst division catalyst Initial CH ₂ Cl ₂ Concentration, ppm GHSV, h ^-1 T (50), ℃ T (90), ℃ Example 1 Pd / SO ₄ -ZrO ₂ 1,000 20,000 210 280 Example 2 Pd, Cu / SO ₄ -ZrO ₂ 1,000 20,000 210 280 Example 3 Pd, Cu, Ni / SO ₄ -ZrO ₂ 1,000 20,000 208 277 Comparative Example 4 Pd / Al ₂ O ₃ 1,000 20,000 410 500 Comparative Example 5 Pt / Al ₂ O ₃ 1,000 20,000 350 400 Comparative Example 7 Co-Y 1,000 20,000 300 360 Comparative Example 8 Cr / ZSM-5 1,000 20,000 280 350 T (50): 50% removal temperature of initial methane dichloride concentration T (90): 90% removal temperature of initial methane dichloride concentrationGHSV: Gas Hourly Space Velocity

Table 3 shows a comparison of the oxidation / removal activity of the methane dichloride relative to the different types of catalysts. A catalyst containing only a noble metal such as Pd or the like on a carrier containing a super acidic group such as sulfated (Example 1) or a catalyst simultaneously containing a transition metal such as copper, nickel, etc. (Example 2, 3) is 70 compared to the catalyst prepared by supporting the noble metal and the transition metal on the carrier which alone or each containing no noble metal or transition metal under the same reaction conditions (Comparative Examples 4, 5, 7, 8). It shows the same activity at a temperature as low as ~ 220 ℃.

Oxidation / Removal Activity of Trichloroethylene (TCE) by Catalyst division catalyst Initial TCE Concentration, ppm GHSV, h ^-1 T (50), ℃ T (90), ℃ Example 1 Pd / SO ₄ -ZrO ₂ 1,000 15,000 290 350 Example 2 Pd, Cu / SO ₄ -ZrO ₂ 1,000 15,000 285 350 Example 3 Pd, Cu, Ni / SO ₄ -ZrO ₂ 1,000 15,000 285 350 Example 4 Pd, Cu, Ni / [SO ₄ -ZrO ₂ + USY] 1,000 15,000 290 355 Example 5 Pt / [SO ₄ -ZrO ₂ + USY] 1,000 15,000 350 410 Comparative Example 4 Pd / Al ₂ O ₃ 1,000 15,000 425 520 Comparative Example 5 Pt / Al ₂ O ₃ 1,000 15,000 400 475 Comparative Example 8 Cr / ZSM-5 1,000 15,000 400 470 T (50): 50% removal temperature of initial TCE concentration T (90): 90% removal temperature of initial TCE concentrationGHSV: Gas Hourly Space Velocity

Table 4 shows a comparison of the relative TCE oxidation / removal activity in several different types of catalysts. Catalysts containing noble metals such as Pd alone (Examples 1 and 5) on carriers containing superacidic groups such as sulfated groups, or catalysts containing transition metals such as copper and nickel together with precious metals (Examples 2, 3) a catalyst which simultaneously contains a noble metal such as Pd, Pt and a transition metal such as Cu, Ni and the like on a carrier having a sulfate type metal oxide and a porous molecular sieve together within a range of 50% by weight or less ( Example 4, 5) shows the same activity at a temperature of about 50 ~ 170 ℃ lower than the catalyst (Comparative Examples 4, 5, 8) containing a noble metal or a transition metal alone under the same reaction conditions.

As described above, the oxidation catalyst of the present invention is interpreted to show activity at a lower temperature because the acid sites synergize with each other by supporting a certain amount of precious metal and transition metal on a sulfate-containing carrier. The catalysts in which the active metals are present alone do not show relatively good activity. In addition, the catalyst proposed in the present invention not only removes the volatile organic chlorine compounds at a temperature lower than about 20-220 ° C. than the conventional noble metal-supported catalysts, but also minimizes the formation of another type of volatile organic chlorine compounds after the reaction. And it provides a method for producing a multifunctional catalyst that can realize energy saving at the same time.

Claims (6)

0.5 to 2.0% by weight of a noble metal selected from platinum (Pt), palladium (Pd), iridium (Ir) and rhodium (Rh) as an active metal is supported on a sulfated metal oxide carrier, and as an auxiliary active metal Oxidation catalyst for removing volatile organochlorine compounds (Cl-VOCs), characterized in that the transition metal is supported by 0.0 to 15.0% by weight. The oxidizing catalyst for removing volatile organochlorine compounds (Cl-VOCs) according to claim 1, wherein the sulfuric acid type metal oxide carrier is selected from zirconia, titania, and ceria containing 0.3 to 2.3 wt% of sulfuric acid group (SO ₄ ). . The method of claim 1 or 2, wherein the carrier is used to remove volatile organic chlorine compounds (Cl-VOCs), characterized in that the sulfuric acid-type metal oxide and the porous molecular sieve is used together within the range of 50% by weight or less. Oxidation catalyst. The volatile organic chlorine compound according to claim 3, wherein the porous molecular sieve is selected from zeolites having BEA, MFI, MOR and FAU structures having Si / Al ratios ranging from 10 to 100 as proton- or ammonium-type zeolites. Oxidation catalyst for the removal of Cl-VOCs). The oxidation catalyst for removing volatile organic chlorine compounds (Cl-VOCs) according to claim 1, wherein the transition metal is copper, nickel or a mixed metal thereof. The volatile organic chlorine compound according to claim 1, wherein 0.5 to 2.0% by weight of the noble metal, 2.0 to 10.0% by weight of copper, and 0.1 to 1.0% by weight of nickel are supported on the sulfated metal oxide carrier. Oxidation catalyst for removing (Cl-VOCs).