JP3653926B2 - Method for producing metal oxide-supported composite - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a metal oxide-supported composite suitable for decomposing and removing reducible substances and oxidizable substances present in industrial waste liquids.
[0002]
[Prior art]
In general, metal oxides, hydroxides, peroxides, hydrated oxides, and oxyhydroxides (hereinafter collectively referred to as “metal oxides”) are industrially used as functional materials such as surface modifiers and catalysts. In the case of using for the above, it is necessary to mold or fix to the carrier.
[0003]
For example, the use as a surface modifier of a fluorine-based organic polymer cation exchange membrane for salt electrolysis is disclosed in JP-A-57-39185, JP-A-57-172927, and JP-A-57-207184. It is disclosed. This is a composite in which a metal oxide porous layer is deposited on the surface of a cation exchange membrane for electrolysis to form a metal oxide layer. The manufacturing method includes an operation of mixing a metal oxide powder with a binder in a medium, forming a cake of a porous layer on a filter, and heating and pressing the film surface. This complex is usually used as a diaphragm in electrolysis of an aqueous sodium chloride solution or the like, but the metal oxide is supported only on the surface of the ion exchange membrane and is held by physical bonding force. For this reason, the metal oxide is easily peeled off from the cation exchange membrane by stirring, heating or the like, and the temporal stability in performance is poor. In addition, the manufacturing process is long and complicated, and many devices such as a filter and a hot press machine are required, and the productivity is low.
[0004]
JP-A-6-23375 discloses an oxide of at least one metal selected from Mn, Group 1B elements of the periodic table and Group 8 elements of the periodic table (hereinafter referred to as Mn) and a fluorine-based organic polymer positive electrode. A method of using a complex with an ion exchanger as another catalyst, that is, a catalyst for decomposing and removing a reducible substance and an oxidizable substance has been proposed.
[0005]
The composite is a fluorinated organic polymer cation exchanger firmly supporting a metal oxide such as Mn, and has an excellent function of decomposing reducible substances present in the solution. In the production method, a fluorine-based organic polymer cation exchanger is brought into contact with a homogeneous solution in which a salt such as Mn is dissolved and / or a suspension of metal oxides such as Mn. In this method, a metal ion such as Mn is used, and then Mn and the like are precipitated as an oxide with an oxidizing agent and / or an alkali to form a composite with a fluorinated organic polymer cation exchanger. In this method, a high-performance composite can be produced, and the reducible substance and the oxidizable substance can be catalytically decomposed and removed. An important operation in this method is an operation of exchanging the counter ion of the ion exchanger with an ion such as Mn. For this operation, a homogeneous solution in which a salt such as Mn is usually dissolved is used. However, in this case, the ion exchange rate cannot be increased, and the utilization rate of salts such as Mn is lowered. In order to achieve a high ion exchange rate, an excess metal salt is required, which is not economical. Further, after the ion exchange, a waste liquid containing an excessive salt such as Mn is generated, and the recovery of the salt or detoxification treatment is necessary from the environmental and economic aspects, and the operation becomes complicated.
[0006]
Japanese Patent Application Laid-Open No. 6-23375 discloses that as another operation for exchanging the counter ion of the ion exchanger with an ion such as Mn, it is brought into contact with a suspension of an oxide such as Mn. In this method, although the utilization rate of oxides such as Mn can be increased, the ion exchange rate is not so high, and the amount of liquid increases due to by-produced water. The amount of water is so large that it cannot be ignored when the amount of the complex is large, so that a large-capacity apparatus is required. Further, the surface of the oxides is active, and easily reacts with carbon dioxide gas in the air, becomes inactive, and ion exchange is inhibited. At this time, problems such as consolidation may occur.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for producing a metal oxide-supported composite that can solve the various problems. That is, as a method of supporting an oxide such as Mn on a cation exchanger, the operation is simple, the utilization rate of Mn and the like is high, and there is no waste liquid containing a salt such as Mn which is an environmental problem. A highly economical industrial production method of the composite, and a metal oxide such as Mn, which has a strong bond between a cation exchanger and excellent durability, and maintains high performance for a long period of time. An object of the present invention is to provide an industrial production method for a supported composite.
[0008]
[Means for Solving the Problems]
The present invention is characterized in that an H-type cation exchanger and a metal are brought into contact with each other through water to make the counter ion of the cation exchanger a metal ion, and then contacted with an oxidizing agent and / or an alkali. The present invention provides a novel method for producing a metal oxide-supported composite.
[0009]
The gist of the present invention is that an H-type cation exchanger and a solid metal are brought into contact with each other through water, ion exchange is performed, and a counter ion of the ion exchanger is exchanged with the metal ion. is there. In conventional techniques, ion exchange is performed in a solution state in which the metal ions are dissolved. Ion exchange using metal deviates from conventional common sense. However, as a result of repeated studies, the present inventors have found ion exchange using a solid metal, and have reached production of a metal oxide-supported composite having high industrial utility value. The completion of this technology has had many unexpected and significant benefits. The industrial value of the present invention is extremely great.
[0010]
Hereinafter, the present invention will be described in detail.
[0011]
In the production of this complex, it is essential that the H-type cation exchanger and the metal are first brought into contact with each other through water. In the H-type cation exchanger, the counter ion of the exchange group is substantially H. ⁺ (Hydrogen ion) A cation exchanger capable of replacing a counter ion with an ion such as Mn by contacting with a metal such as Mn. As used herein, substantially means that 50% or more of the counter ions are H. ⁺ Indicates that Preferably it is 60% or more. H ⁺ The ratio is low, Na ⁺ If the ratio of other cations such as these is high, ion exchange with the metal becomes insufficient.
[0012]
As the cation exchanger, either an inorganic cation exchanger or an organic polymer cation exchanger can be preferably used. Specifically, the former is a zeolite, and the latter is a hydrocarbon cation exchanger and a fluorinated cation exchanger having an exchange group such as a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, and a phenolic hydroxyl group. Can do.
[0013]
Zeolite includes Zeolite contained in natural minerals, high silica-pentacil type zeolite ZSM-5, silicalite, mordenite, and faujasite X-type, Y-type, and A-type zeolite. Any of these can be used. Preferred zeolites are those with high acid resistance, i.e., high silica ratios, which are easily converted to H-type in aqueous solution. Applicable.
[0014]
Hydrocarbon cation exchangers include commercially available cation exchange resins, chelate resins, and cation exchange membranes. Fluorine cation exchangers include commercially available fluorinated organic polymer cation exchange resins and fluorinated organics. There are polymer cation exchange membranes, and any of them can be used. Among these, a fluorine-based cation exchanger is preferable from the viewpoints of heat resistance, chemical resistance, free shape selectivity, and the like.
[0015]
Hereinafter, a suitable fluorine-based cation exchanger will be described.
[0016]
Specifically described as a fluorine-based organic polymer cation exchanger, for example, Nafion (manufactured by Du Pont) in which a cation exchange group is introduced into a copolymer of tetrafluoroethylene and perfluorovinyl ether, Flemion (Asahi Glass ( A cation exchanger to which a trademark such as “made by Co., Ltd.” is attached can be suitably used. This perfluorocation exchanger has the most durability. However, what is obtained by contacting a hydrocarbon cation exchanger with a fluorine gas diluted with an inert gas such as nitrogen or argon is partially hydrogenated in the main chain. However, it has good durability and can be suitably used as the present invention. As the ion exchange group of these fluorine-based organic polymer cation exchangers, there are a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, and a phenolic hydroxyl group, and any of them can be suitably used. Among these, those having a sulfonic acid group or a carboxylic acid group are more preferable in terms of bonding strength with an oxide such as Mn. Further, the larger the ion exchange capacity of the fluorinated organic polymer cation exchanger is, the more preferable it is because the metal oxide can be strongly bonded and the amount of oxide supported can be increased. Specifically, it is preferable to select one having 0.3 milligram equivalent / (gram-dried product) or more, particularly 0.5 milligram equivalent / (gram-dried product) or more. The shape of the fluorinated organic polymer cation exchanger may be any of membrane, sphere, and fiber. Further, as the fluorine-based organic polymer cation exchanger, a used fluorine-based organic polymer cation exchange membrane used as a diaphragm for salt electrolysis with an ion exchange membrane method may be used. Just cut it off and use it.
[0017]
The counter ion of a commercially available fluorinated organic polymer cation exchanger is substantially H. ⁺ If it is (H type), it can be exchanged for ions such as Mn by bringing it into contact with a solution and / or suspension of a metal such as Mn as it is. However, in general, fluorinated organic polymer cation exchangers are difficult to deteriorate, K type (counter ion is K ⁺ ), Na type (counter ion is Na ⁺ ) Etc., and used cation exchange membranes used as a membrane for salt electrolysis are Na-type. In that case, an acid is used to form the H type. The acid to be used may be any of mineral acids such as hydrochloric acid, sulfuric acid and nitric acid, and organic acids such as acetic acid, tartaric acid and benzoic acid, but it is highly economical, easy to treat waste acid, and easy to handle. Acid is preferred. For the H type, any of batch type, continuous type and semi-batch type may be used, and any of fixed bed, fluidized bed and moving bed may be used. A more preferable method is a batch type or a fixed bed flow type. In the case of the batch type, not all of the H-type is obtained in a single process, but some ions other than the H-type may remain. Substantially H ⁺ Any type is acceptable. More preferably, the batch type is repeated to increase the H-type ratio, and the preferable H-type ratio can be easily increased to 60% or more, and more preferably 80% or more. The higher the concentration and temperature of the acid, the better the efficiency, but it is preferable. However, the range in which the fluorine-based organic polymer cation exchanger does not deteriorate and does not require a special apparatus material is more preferable. The concentration is 0.001 to 5 mol / liter, and the temperature is 5 to 100 ° C.
[0018]
The fluorine-based organic polymer cation exchanger made H-type by the above method is brought into contact with a metal such as Mn through water, and the counter ion of the fluorine-based organic polymer cation exchanger is used as a metal ion such as Mn. However, the metal such as Mn in the present invention is specifically a metal.
Mn, Fe, Co, Ni, Cu, Pd, etc. can be mentioned.
[0019]
A metal such as Mn may be used alone or different metals may be present together. Furthermore, although the reason is not clear, ions of the same element as the metal are dissolved in the form of a salt.
When ion exchange of a metal such as Mn is performed, the exchange rate can be increased. The amount of metal such as Mn added is not particularly limited, but it is preferably stoichiometric or slightly excessive with respect to the ion exchange group, and the amount of exchange of ions such as Mn can be increased. In view of economy and operability, the stoichiometric amount is preferably twice or less. Even if an excessive amount is used, the unreacted metal can be easily recovered as a solid and can be reused. This is also a major feature of the present invention. The metal such as Mn used for the ion exchange may be powdery, granular, or plate-like, but is more preferably powdery. This is because since the specific surface area is large, the ion exchange rate can be increased and the ion exchange can be performed efficiently. What is particularly important is the particle diameter, and the average particle diameter is preferably 1 mm or less, more preferably 0.1 mm or less. The suspension concentration of the metal such as Mn at this time is not limited as long as it can be stirred, but if the concentration is too low, the capacity of the apparatus increases. Conversely, if it is too high, the power required for stirring increases. From these things, a preferable range is 0.001-30 wt%, More preferably, it is 0.01-20 wt%. Ion exchange can be suitably performed within this suspension concentration range.
[0020]
The ion exchange rate and ion exchange rate do not vary greatly depending on the suspension concentration of the metal, and an almost stable rate and exchange rate can be maintained. This is also a major feature of the present invention. The reason for this is not clear, but careful observation shows that the metal powder uniformly adheres to the surface of the H-type cation exchanger and becomes smaller and smaller over time. This is probably because ion exchange progressed.
[0021]
This is not seen in the method of using the metal oxide disclosed in JP-A-6-23375 for ion exchange.
[0022]
The ion exchange with the metal of the present invention is faster and more stable than the above publication. Inferring the reason for this, in addition to the above-mentioned adhesion, the reactive metal surface reacts with water and hydrolyzes to produce intermediate active species such as a highly active hydroxide on the surface, and the hydroxide Is H ⁺ This is thought to be due to the rapid reaction with ions and ion exchange.
[0023]
The ion exchange method may be any of batch, continuous, and semi-batch, and any of fixed bed, fluidized bed, and moving bed can be selected. More preferably, it is a batch type, and ion exchange can be carried out efficiently. In addition, the counter ion of the fluorinated organic polymer cation exchanger is changed to an ion such as Mn by performing the ion exchange in this way, but the valence of the counter ion is not limited.
[0024]
The time for the ion exchange treatment is usually 2 to 100 hours. If the treatment temperature is too low, it takes time for ion exchange, and if it is too high, an expensive one is required from the viewpoint of inhibiting corrosion of the apparatus material, so 5 to 100 ° C, particularly 10 to 90 ° C is preferable.
[0025]
Thus, the fluorinated organic polymer cation exchanger is exchanged for metal ions such as Mn. The ion exchange rate is high, and it can be easily increased to 60% or more, further 90% or more, 95% or more even in a single batch operation. This high ion exchange rate is also a major feature of the present invention. In batch ion exchange using an aqueous solution of a commonly used metal salt, a high ion exchange rate cannot be obtained in a single operation due to ion exchange equilibrium. By repeating the batch operation several times or by continuous flow operation, the ion exchange rate is increased, for example, 90% or more.
[0026]
In addition, in the ion exchange of the present invention, the treatment waste liquid containing metal ions such as Mn is hardly derived. This is also a feature of the present invention. In conventional ion exchange using an aqueous solution of a metal salt, due to the ion exchange equilibrium, a treatment liquid containing a metal ion such as Mn and a counter ion of the ion exchanger is surely generated. Complicated operations such as the above measures were required.
[0027]
The fluorine-based organic polymer cation exchanger obtained by the ion exchange treatment as described above is then contacted with an oxidizing agent and / or an alkali. By this treatment, ions such as Mn in the ion exchanger are converted into the oxide, and a metal oxide-supported composite is obtained.
[0028]
The oxidizing agent is not particularly limited, but is preferably chlorine, hypochlorous acid (salt), chlorous acid (salt), chloric acid (salt), chlorinated cyanuric acid (salt); bromine, hypobromous acid (salt) ), Bromic acid (salt), bromic acid (salt); iodine, iodine oxyacid (salt); one or two of hydrogen peroxide, ozone, permanganic acid (salt), dichromic acid (salt), etc. More than seeds can be raised. Of these, chlorine and hypochlorite that are easily available and have no adverse environmental impact are desirable. By contact with this oxidizing agent, ions such as Mn are precipitated as fine high-order valence oxides bonded to the inside and the surface of the ion exchanger. In this case, the bond between the oxide such as Mn and the cation exchanger in the metal oxide-supported composite becomes stronger and more active as a catalyst as compared with the composite using only alkali described later. This is the preferred method. Although this is not certain, it is presumed that the valence of Mn or the like becomes high and is caused by an electrical action with the exchange group of the ion exchanger. Further, the treatment with an oxidizing agent preferably has a pH of 5 or more, more preferably 7 or more, and can be carried efficiently in a short time. However, even if it is higher than pH 14, the effect of shortening the time beyond that is not great, and the alkali consumption is increased. When the oxidizing agent is an aqueous solution of hypochlorite, the pH is usually 10 or more, and it can be suitably used as it is. On the other hand, when it dissolves in water like chlorine and generates an acid, it is preferable to make the pH 5 or more by using an alkali together.
[0029]
Examples of the alkali include aqueous solutions of alkali metal hydroxides, carbonates thereof, alkaline earth metal hydroxides, ammonia, amines, etc., but aqueous solutions of alkali metal hydroxides such as sodium and potassium. Such a strong alkali is preferable because the carrying efficiency can be increased. This is because the rate of the above conversion reaction can be increased. By contact with the alkali, ions such as Mn are precipitated as fine hydroxides in a form firmly bonded to the inside and the surface of the ion exchanger. The time for the conversion treatment of ions such as Mn to oxide varies depending on the kind, concentration and amount of the oxidizing agent and / or alkali, pH, temperature, etc., but is usually 3 minutes to 3 hours. If the treatment temperature is too low, the conversion takes a long time or the conversion becomes insufficient, and if it is too high, only a large amount of heat energy is consumed. Good to do. That is, it can be suitably carried out at room temperature.
[0030]
If the treatment with the oxidizing agent is performed with hypochlorous acid, the counter ion of the ion exchanger constituting the metal oxide-supported composite is H ⁺ In this case, the above ion exchange and conversion processes can be repeated as they are, and the loading amount can be increased. When sodium hypochlorite or the like is treated as an oxidizing agent, the counter ion of the ion exchanger of this complex is Na. ⁺ In this case, it is H again with a weak acid. ⁺ After forming the mold, the loading amount can be increased by repeating the above operation. Although the carrying operation may be performed once, the carrying amount can be increased when the number of repetitions is 2 or 3 times. In addition, even if it repeats 4 times or more, the load of the said oxide does not increase so much.
[0031]
The use of a composite of an oxide such as Mn obtained by the above operation and a fluorinated organic polymer cation exchanger is as follows:
(1) Decomposition of an oxidizable substance by bringing a solution of the oxidizable substance into contact with the complex in the presence of an oxidizing agent.
(2) Decomposition of the oxidizable substance by contacting the complex with an oxidant and then contacting with the solution of the oxidizable substance.
(3) It is effective as a catalyst for decomposing the reducible substance by bringing a solution of the reducible substance into contact with the complex.
[0032]
Furthermore, the composite produced by the production method of the present invention has a high binding force between the metal oxide and the fluorine-based organic polymer cation exchanger, and can be processed in a stirring system, which is impossible with conventional catalysts. . As described above, the reason why the bonding force is strong is not clear, but a resin or anion exchanger that does not have an ion exchange group does not show a strong bonding force. It is estimated that some kind of chemical traction is working.
[0033]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these Examples.
[0034]
In the examples, the amount of metal supported (wt%) relative to the H-type of the fluorine-based organic polymer cation exchanger in the metal oxide-supported composite is determined by placing an oxide such as Mn in a sample of the composite in hydrochloric acid. After dissolution, the amount of metal (Ag) was measured by inductively coupled plasma emission spectroscopy using SPS-7000 manufactured by Seiko Electronics Co., Ltd. After drying at ℃ 12 hours, weigh (Wg),
(A / W) x 100
Sought by.
[0035]
Example 1
Ion exchange membrane method 100 g (in terms of dry weight) of a fluorine-based organic polymer cation exchange membrane Nafion 954 (manufactured by Du Pont) used for salt electrolysis was thoroughly washed with water and then cut into a size of 10 mm × 10 mm (this cut) The pieces are hereinafter referred to as Nafion membrane pieces).
[0036]
Place 500 ml of N-HCl and 100 g of Nafion membrane in a 1 liter beaker and leave it for 1 hour. ⁺ From ion to H ⁺ Replaced with ions. Since not all could be replaced with the H-type by a single operation, the same operation was repeated two more times. As a result, almost all counter ions of the Nafion membrane piece ion exchange group are H. ⁺ (Hydrogen ion) (hereinafter referred to as H-type Nafion membrane piece).
[0037]
In a 1-liter separable flask, 880 ml of pure water and 3.15 g of Ni powder Type 287 manufactured by Nikko Fine Products Co., Ltd. (average particle size of 2.6 to 3.3 μm, specific surface area of 0.56 cm) ² / G), and the temperature was adjusted to 50 ° C. in a constant temperature water bath. 100 g of the H-type Nafion membrane piece was placed in a 1-liter separable flask, and ion exchange into Ni-type was started at a stirring speed of 300 rpm. After 5 hours of ion exchange treatment, the entire Nafion membrane piece was taken out and the Ni exchange amount was measured for a part of the Nafion membrane piece. As a result, 0.023 g of Ni was obtained per 1 g of Nafion membrane piece (dry weight conversion). ²⁺ Ions were exchanged (hereinafter referred to as Ni-type Nafion membrane pieces).
[0038]
Next, when the entire amount of the Ni-type Nafion membrane piece was placed in a 1 liter beaker containing 0.5 liter of a 3.1 wt% NaClO aqueous solution (pH 10) and stirred with a glass rod, the nickel ions became black oxides. It was. After the treatment for 1 hour, the ratio of Ni to the dry weight of the fluorinated organic polymer cation exchange membrane of the composite was 2.1%.
[0039]
Next, 89 g of the above complex (in terms of dry weight) was placed in a reaction vessel of a 1.5 liter separable flask with an overflow tube, and the stirring speed was 300 rpm.
A 6.1 wt% NaClO aqueous solution (pH 10) was continuously supplied at a flow rate of 0.4 liter / hr, and at the same time, the treatment liquid was discharged from the overflow pipe. It was observed that NaClO decomposed in the reaction tank and oxygen gas was generated. Three days after starting the reaction, the NaClO concentration at the outlet of the reaction vessel was 1.2 wt%, and the decomposition rate was 80.3%. When the reaction was further continued, the NaClO concentration at the outlet of the reaction vessel after 22 days was 1.3 wt%, the decomposition rate was 78.7%, and almost no change in the performance of the composite was observed. Further, there was almost no change such as peeling of nickel oxide from the composite.
[0040]
Example 2
100 g of used H-type Nafion membrane pieces were obtained by the same operation as in Example 1. In a 1 liter separable flask, 500 ml of pure water and reagent-grade NiCl manufactured by Kishida Chemical Co., Ltd. ₂ ・ 6H ₂ NiCl with O119g ₂ 4.56 g of Ni powder used in Example 1 was further added, and the temperature was adjusted to 50 ° C. in a constant temperature water bath. 100 g of the H-type Nafion membrane piece was placed in a 1-liter separable flask, and ion exchange into Ni-type was started at a stirring speed of 300 rpm. The whole amount of Nafion membrane piece was taken out in 4 hours of ion exchange treatment, and Ni exchange amount was measured for a part of the Nafion membrane piece. ²⁺ Ions were exchanged (hereinafter referred to as Ni-type Nafion membrane pieces). NiCl after ion exchange ₂ Ni in the aqueous solution ²⁺ The pH of the solution became neutral without containing cations other than ions. The NiCl ₂ The aqueous solution could be reused.
[0041]
Next, when the entire amount of the Ni-type Nafion membrane piece was placed in a 1 liter beaker containing 0.5 liter of a 3.1 wt% NaClO aqueous solution (pH 10) and stirred with a glass rod, the nickel ions became black oxides. It was. After the treatment for 1 hour, the ratio of Ni to the dry weight of the fluorinated organic polymer cation exchange membrane of the composite was 2.2%.
[0042]
Next, 88 g (in terms of dry weight) of the above composite was put into a reaction vessel of a 1.5 liter separable flask with an overflow tube, the stirring speed was 300 rpm,
A 6.2 wt% NaClO aqueous solution (pH 11) was continuously supplied at a flow rate of 0.4 liter / hr, and at the same time, the treatment liquid was discharged from the overflow pipe. It was observed that NaClO decomposed in the reaction tank and oxygen gas was generated. Three days after starting the reaction, the NaClO concentration at the outlet of the reaction vessel was 1.3 wt%, and the decomposition rate was 79.0%. When the reaction was further continued, the NaClO concentration at the outlet of the reaction vessel after 17 days was 1.4 wt%, the decomposition rate was 77.4%, and almost no change in the performance of the composite was observed. Further, there was almost no change such as peeling of nickel oxide from the composite.
[0043]
Example 3
H-type ZSM-5 (manufactured by Tosoh Corporation, SiO ₂ / Al ₂ O _Three (Molar ratio) = 70) 20 grams of powder and 2 grams of Ni powder similar to those used in Example 1 were suspended in an aqueous solution and subjected to ion exchange treatment at a temperature of 50 ° C. for 5 hours. As a result, about 0.01 gram of nickel could be ion-exchanged with respect to 1 gram of ZSM-5. This Ni-type ZSM-5 was suspended in a 3 wt% NaClO aqueous solution having a pH of 10 and subjected to an oxidation treatment for 30 minutes. As a result, the zeolite turned black and a composite of zeolite and nickel oxide could be prepared.
[0044]
Comparative Example 1
1-liter separable flask with 880 ml of pure water, reagent grade NiCl manufactured by Kishida Chemical Co., Ltd. ₂ ・ 6H ₂ 12.8 g of O was dissolved, and the temperature was adjusted to 50 ° C. in a constant temperature water bath. After thoroughly washing 100 g of the H-type Nafion membrane piece with water, NiCl ₂ Was put into a 1 liter separable flask, and ion exchange into Ni-type was started at a stirring speed of 300 rpm. The whole amount of Nafion membrane piece was taken out in one day of the ion exchange treatment, and the Ni exchange amount was measured for a part of the Nafion membrane piece. ²⁺ Ions were not exchanged (hereinafter referred to as Ni-type Nafion membrane pieces).
[0045]
Next, when the entire amount of the Ni-type Nafion membrane piece was placed in a 1 liter beaker containing 0.5 liter of a 3.0 wt% NaClO aqueous solution (pH 10) and stirred with a glass rod, nickel ions became black oxide. The ratio of Ni to the dry weight of the fluorinated organic polymer cation exchanger of the obtained composite was as low as 0.9%.
[0046]
Next, 90 g of the above composite (in terms of dry weight) was placed in a reaction vessel of a 1.5-liter separable flask with an overflow tube, and the stirring speed was 300 rpm. Ca (ClO) ₂ An aqueous solution of pH 9.5 containing 10.2 wt%, NaCl 19.8 wt% and 900 mg / liter SS is continuously supplied at a flow rate of 0.35 liter / hr, and at the same time, the processing solution flows out from the overflow pipe. I let you. Ca (ClO) in the reaction vessel ₂ Was decomposed and oxygen gas was generated. Three days after starting the reaction, Ca (ClO) at the outlet of the reaction vessel ₂ The concentration was 4.03 wt% and the decomposition rate was 60.5%, which was considerably lower than the decomposition rate (= 78.7%) in the example, for example, Example 1.
[0047]
When the reaction was further continued, Ca (ClO) at the outlet of the reaction vessel after 17 days was obtained. ₂ The concentration was 4.18 wt%, and the decomposition rate was 59.0%, further decreasing.
[0048]
【The invention's effect】
According to the method of the present invention, an oxide such as Mn can be effectively, efficiently and industrially supported on a cation exchanger, and a metal oxide-supported composite can be produced.
[0049]
The effects of the present invention are listed below.
[0050]
(1) The material of the metal oxide to be supported is a metal, is easily available, has high handleability, is inexpensive and economical.
[0051]
(2) When a metal is used and the counter ion of the cation exchanger is a metal ion, a solution containing metal ions, which is an environmentally and economically problematic matter, is not substantially derived, which is extremely useful for environmental measures.
[0052]
(3) Even if a metal equivalent to the counter ion of the cation exchanger is used, the ion exchange can be performed almost completely, and the utilization rate can be greatly increased.
[0053]
(4) Even if the metal is used excessively, after completion of the ion exchange, the liquid and the metal can be easily separated by operations such as decantation and filtration, and the recovered metal can be reused as efficiently as before.
[0054]
(5) The support strength of the obtained metal oxide-supported composite is extremely high, exhibits high resistance to mechanical action such as stirring, has high durability, and can be used as a catalyst for a long time.
[0055]
(6) The action of the metal oxide-supported complex as a catalyst is large and can be suitably used for decomposing oxidizable substances and reducible substances.

Claims (3)

A metal characterized in that an H-type cation exchanger and a metal are brought into contact with each other through water, whereby the counter ion of the cation exchanger is converted into the metal ion and then brought into contact with an oxidizing agent and / or an alkali. A method for producing an oxide-supported composite. The method for producing a metal oxide-supported composite according to claim 1, wherein the cation exchanger is a fluorine-based organic polymer cation exchanger. The method for producing a metal oxide-supported composite according to claim 1 or 2, wherein the metal is at least one metal selected from Mn, Group 1B elements of the periodic table and Group 8 elements of the periodic table.