JPS6044052A - Internal shortcircuit battery type catalyst for oxidizing or reducing organic compound - Google Patents

Abstract

PURPOSE:To provide the titled catalyst based on a new catalyst design concept, obtained by integrating a mixture comprising three kinds of powder or short fibriform ion exchange resins containing substances coated with metals available in electrolytic reduction and electrolytic oxidation. CONSTITUTION:A powdery or short fibriform ion exchange resin is coated with a metal available in the electrolytic reduction of an oxidant while the other powdery or short fibriform ion exchange resin is coated with a metal available in the electrolytic oxidation of a reductant. Two kinds of these metal coated resins are mixed with a powdery or short fibriform ion exchange resin not coated with a metal and this mixture is integrally bonded by a binder comprising a fluorine contained resin. This catalyst is prepared on the basis of a new catalyst design concept.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internally shorted cell catalyst for oxidizing or reducing organic compounds. For more details, please refer to i91 which metals are effective for electrolytically reducing oxidants! Overturned ion exchange resin powder or type 1! A mixture of ion exchange resin powder or short fibers coated with a metal that is effective for electrolytically oxidizing the cloth and the reductant and ion exchange resin powder or short fibers that are not coated with metal are combined with a binder made of fluororesin. The present invention relates to an internal short-circuit cell type catalyst for oxidizing or reducing organic compounds, which is characterized in that it binds to and acts as a catalyst for oxidizing or reducing organic compounds.

Many chemical reactions are redox reactions. That is, a reaction in which a reductant is oxidized is an oxidation reaction, and a reaction in which an oxidant is reduced is a reduction reaction.

On the other hand, the T-78 electrochemical reaction in electrochemical devices such as batteries is also a redox reaction. That is, although an electrochemical device always includes a cathode, an anode, and an electrolyte, all cathode reactions are reduction reactions, and all anode reactions are oxidation reactions.

The difference between a normal chemical reaction and an electrochemical reaction is that, in advance, no exchange of electrons takes place, at least in appearance.
In the latter case, electrons are exchanged and current flows through the external circuit. However, even in normal chemical reactions,
If you look at it microscopically, it is actually an electrochemical reaction.In many cases, the reaction mechanism can be better understood by explaining it as an electrochemical reaction.For example, when carbon dioxide is oxidized in the presence of water using activated carbon as a catalyst, If the reaction with oxygen is avoided, sulfuric acid is produced, but this reaction is a normal catalytic chemical reaction, but microscopically, activated carbon adsorbs oxygen, The following electrolytic reduction reaction of oxygen occurs, 1,, / 2Q2+21-1++2e-→l-120(
1) At the sulfur dioxide adsorption site of activated carbon, 802-L
21-120 1+SO42-+411" ■-2e-(2) An electrolytic oxidation reaction occurs, and the overall reaction is 1/202-I S
It is explained that the following reaction occurs: O21-1 (○-) L12SO4 (3). In other words, it can be assumed that an oxygen-sulfur dioxide cell is formed on the activated carbon, which is internally short-circuited by the electronically conductive activated carbon. In this case, in the early stage of the reaction, the sulfur dioxide formed by dissolving sulfur dioxide in water acts as a supporting electrolyte, and the reaction in equation (2) has progressed to some extent. You can think that there is.

In addition, for example, Japanese Patent Publication No. 50-40395 states that when an aqueous solution of sodium sulfide is made to react with air using water-repellent activated carbon as a catalyst, elemental sulfur and sodium hydroxide are produced. It is explained that Equation (6) is a combination of the following electrolytic oxidation reaction of Equation (4) and electrolytic reduction reaction of Equation (5).

52--) So 1-2e-(4) 2820+02 +1113--+ 408-(5)2
Na2 S+ 28z O+02 -) 2SO+41'JaO1-1 (6) Although not explained in the above cited example, this reaction is
At the initial stage of the reaction, Na2S is mixed with Na2S, and after the reaction of equation (5) has progressed to a certain extent, the reaction occurs when an oxygen-sulfur sulfide battery with mono-lithium hydroxide as a supporting electrolyte is internally short-circuited with activated carbon. It is possible to explain.

In this way, an example of a reaction using activated carbon, which has electron conductivity, as a heterogeneous catalyst, appears to be a simple chemical reaction, but when viewed microscopically, it is actually an electrochemical reaction. The following items are listed in February 52-38'118.

(b) Oxidation of sodium thiA sulfate to mono-lithium sulfate by air, (b) Oxidation of ferrous sulfate or ferrous ammonium sulfate by air, (c) Hydroquinone by air Oxidation of to quinhydrone, (d)
Oxidation of phenol by air, (e) Oxidation of benzaldehyde to benzoic acid by air, (f) Reduction of silver nitrate to silver by hydrogen gas.

In any case, in order for the chemical reaction to proceed through the microscopic internal short-circuit phenomenon of the battery, the catalyst must be a solid with electronic conductivity and a supporting electrolyte must coexist. It is essential that

Conventionally, as supporting electrolytes, inorganic salts, acids, or alkali hydroxides, which are starting materials before the reaction, or reaction products generated as the reaction progresses have been used, depending on each individual reaction. The idea of actively adding electrolytes is rather one of the few. On the other hand, in organic chemical reactions, neither the reaction starting material nor the reaction product generally exhibits ionic conductivity and does not function as an electrolyte, so it is necessary to separately mix an inorganic supporting electrolyte.

However, when an inorganic supporting electrolyte is added, it becomes a big challenge to separate the desired reaction product from the inorganic supporting electrolyte after the reaction is completed. In addition, the above-mentioned special public service 1974-4
In No. 0395 and Japanese Patent Publication No. 52-38982, only activated carbon is used as a catalyst, and this activated carbon has both the function of electrolytically reducing the oxidant and the function of electrolytically oxidizing the reductant. Depending on the reaction system, activated carbon alone often does not work as well.

The present invention aims to solve this problem, and consists of powder or short fibers of ion exchange resin coated with a metal effective for electrolytically reducing the oxidant and a metal coated for electrolytically oxidizing the reductant. Ion exchange resin powder or short fibers and ion exchange resin powder or short fibers that do not coat metal! This invention provides a completely new catalyst for oxidizing or reducing organic compounds characterized by the fact that any mixture is bound together with a binder made of fluororesin (7). .

In other words, in such a catalyst, the ion exchange resin has a water content U
Since the ion exchange resin functions as a solid electrolyte, it is quite easy to separate the electrolyte from the reaction product obtained by causing a chemical reaction using this catalyst. That is, this catalyst is a heterogeneous catalyst including the iJ electrolyte.

-7j, in the catalyst of the present invention, at the contact point between the metal effective for electrolytic reduction of the oxidant and the ion exchange resin coated with this metal and the ion exchange resin coated with the metal,
The electrolytic reduction reaction of the oxidant occurs, and the electrolytic oxidation of the reductant occurs at the contact point between the right-handed metal, the ion exchange resin coated with the metal, and the ion exchange resin without the metal coating). An electrolytic oxidation reaction occurs. In other words, a battery is constructed in which the metal part that is effective for electrolytically reducing the oxidant is used as the positive electrode, the metal part that is effective for electrolytically oxidizing the 3y element is used as the negative electrode, and the ion exchange resin is used as the electrolyte. A zero-circuit current flows in a portion that is in direct contact with a metal effective for electrolytically reducing an oxidant and a metal effective for electrolytically oxidizing a reductant.

Therefore, the catalyst of the present invention will be defined as a "Nibe short 118N pond type catalyst".

Such a clear concept of a catalyst membrane system has never existed before. In a normal battery, electrical energy is extracted to an external circuit, whereas in an internally shorted battery type catalyst, the target electrolytic redox reaction proceeds at the same time as the energy is converted into heat.

Ion exchange resins used as constituent materials for internally shorted battery type catalysts include cation exchange type and anion exchange type. Suitable cation exchange resins include those based on fluorine-containing polymers such as styrene-divinylbenzene polymers or perfluorocarbons, into which sulfonic acid groups, carboxylic acid groups, or both have been introduced. ,
The present invention is not limited to these. The ions that move in this cation exchange resin are hydrogen ions.

As an anion exchange resin, an ammonium salt type amine or a j-amine such as diethylene 1 to riamine is added to a polystyrene base core. +! The hydroxyl ion transfer group may be used by treating the chromium introduced as a group with an alkali.

These ion exchange resins are suitably in the form of powder or short fibers. If it is in powder form, it should have a particle size of several tens of microns or less. A cloth-like item (1) A piece with a diameter of several millimeters and a thickness of several NV or less.

Whether to use a cabone exchange resin or an anion exchange resin must be appropriately selected depending on the target reaction system.

In order to coat a metal that exhibits an effective 1 catalytic activity in electrolytically reducing an oxidant or an effective 4 metal that exhibits a 1 catalytic activity in electrolytically oxidizing a reductant, the following steps are taken:
The cation exchange resin is impregnated in advance with a reducing agent such as hydrazine or an aqueous solution of hydrogenated hydrogen, and then the catalytic metal is applied to the surface of the cation exchange resin by adding a catalytic metal salt aqueous solution to the surface of the cation exchange resin. The cation-exchange resin is brought into contact with an aqueous catalytic metal solution, and after the hydrogen ions of the cation-exchange resin and the catalytic metal ions are once avoided, the cation-exchange resin is treated with a reducing agent solution. A method is applied in which catalyst metal is deposited on the surface of the exchange resin.

In order to precipitate the catalytic metal of an anion exchange resin, it is effective to treat the resin with an aqueous solution of a complex in which the catalytic metal is in the form of an anion.

The metal that exhibits effective catalytic activity for the electrolytic reduction of the oxidant and the metal that exhibits the effective catalytic activity for the electrolytic oxidation of the reductant are, in principle, different materials, but depending on the reaction system. The same material can also serve the purpose. Therefore, the present invention is not limited to the above-mentioned metals being Tatsumi materials.

On the other hand, when an ion exchange resin is coated with a metal, an electrolytic reduction reaction occurs at the contact point between the positive electrode made of a metal that exhibits effective catalytic activity in electrolytically reducing the oxidant and the ion exchange resin coated with this metal. The negative electrode 10 is made of a metal that is effective for electrolytically oxidizing the reductant.The electrolytic oxidation reaction at the contact point with the ion exchange resin coated with any metal progresses easily, but it is difficult to connect the positive electrode with the square rod. 7 Hiroi A conduction is difficult to proceed. The ion exchanger 1fi, which has no metal coating, is responsible for this ion conduction.
It is QJ fat.

The fluororesin binder, which is another constituent material of the internally shorted battery type catalyst, has the function of binding the J powder and the ion exchange resin, which controls electron conductivity and exhibits catalytic activity. In addition, it also has the function of adding 1 ml of water to an internally shorted battery type catalyst. In other words, an internally shorted cell catalyst uses a liquid reactant and a gaseous reactant as starting materials.
However, if the internally shorted cell catalyst is completely hydrophilic, it will be coated with liquid reactants and depleted.
Whereas adsorption sites for gaseous reactants are lost, partial water repellency secures both adsorption sites for gaseous reactants and adsorption → noids for liquid reactants, thereby facilitating the reaction. I hope things will proceed more smoothly.

Fluoropolymer binders are susceptible to attack by starting reactants (
In particular, polytetrafluoroethylene is most suitable because it has good heat resistance, good heat resistance, and does not cover the other constituent materials of the battery catalyst, but it is not limited to $81 per month. do not have.

The shapes of internally shorted battery type catalysts are granular, sheet,
It is possible to have any shape such as a cylindrical shape or a honeycomb shape. Alternatively, it may be effective to increase the mechanical strength by integrally molding a mixture of constituent materials of the internally shorted battery type catalyst with a metal mesh or expanded metal.

The internally shorted battery type catalyst according to the present invention is particularly suitable for reactions in which an aqueous solution or suspension of an organic compound is oxidized with oxygen or reduced with hydrogen, since water is essential. In fact, it is thought that the applications will be expanded in the future.

Sometimes it is more suitable to supply water in the form of steam. However, since internally shorted battery-type catalysts contain ion exchange resin, if inorganic ions coexist, ion replacement will occur, and the ion exchange resin will no longer function as a conductor for hydrogen ions or hydroxide ions. Therefore, it is desirable to apply it to a reaction system that does not contain inorganic ions.

By the way, it should be noted here that there are many reactions in which the ion exchange resin itself functions as a catalyst. For example, cation exchange resins act as catalysts for reactions such as the production and hydrolysis of esters, acetals, amides, etc., and hydration to nitrile and boxy. Anion exchange resins are also used as catalysts for aldol condensation reactions and the like.

On the other hand, since the ion exchange resin of the internally shorted battery type catalyst according to the present invention is responsible for ion conductivity, the ion exchange resin itself functions as a catalyst as described above. There should be a distinction.

On the other hand, recently, it has been reported that aniline can be produced by reducing benzyl or benzoin or by reducing nitrobenzene using a catalyst in which a metal, particularly a transition metal, is supported on an ion-exchange resin. be.

However, in these conventional catalysts, the ion exchange resin itself functions as a catalyst rather than as an electrolyte through which hydrogen ions or hydroxide ions are conducted as in the present invention. It is clear that the catalyst of the present invention does not have the catalyst design concept of using a metal effective for electrolytic oxidation and a metal effective for electrolytic reduction, and optimizing the adsorption site of the reactant by the fluororesin. should be regarded as different.

An embodiment of the present invention will be described in detail below.

Example 2 g of ion exchange resin powder with an average particle size of 50μ, which is made by introducing sulfonic acid groups into perfluorocarbon, is immersed in an aqueous solution of hydrazine, and then treated with an aqueous solution of chloroplatinic acid to coat the surface of the ion exchange resin powder. Coat with platinum. On the other hand, in the same manner, on 2 g of the above-mentioned ion exchange resin powder,
Carrying rhodium.

Next, mix the ion exchange resin powder carrying platinum, the ion exchange resin powder carrying rhodium, and the ion exchange resin powder carrying no metal = 14~40% water.
1 plus polytetrafluoride having a solid content of 60%]
Add 3 ml of an aqueous suspension of Dilene, vacuum-dry the staff thoroughly, and then dry it under vacuum to a diameter of 3n+m.

Pellets with a length of 5 mm were molded by hot pressing at 100°C. In this way, an internally shorted battery type catalyst was fabricated.

A schematic structural diagram of this internally shorted battery type catalyst is shown in FIG.

(1) and (1')4 platinum (2) and rhodium (
3) is coated ion exchange resin powder, (4) is ion exchange resin powder without metal coating, and (5) is poly coated ion exchange resin powder.
It is tetrafluoroethylene.

Next, five of these internally shorted battery type catalyst pellets were placed in a mixed solution of 101 ml of methanol and 100 ml of water, and air was blown into the mixed solution at room temperature.

As a result, when formaldehyde was analyzed after 1 hour, the oxidation rate of methanol to formaldehyde was 47.
%Met.

Comparative Example When a similar experiment was carried out in the above Example using a catalyst containing no ion exchange resin, that is, pellets of platinum black bound with a fluororesin, the oxidation rate of methanol to formaldehyde was 7%.

In other words, in the conventional example, the oxidation of methanol does not progress much due to a mere catalytic reaction, whereas it is clear that the oxidation of methanol progresses more when an internally shorted battery type catalyst is used as in the present invention. .

In the above example, the electrolytic oxidation reaction of methanol mainly occurs at the contact interface between rhodium and the ion exchange resin, and the electrolytic reduction of oxygen mainly occurs at the contact interface between platinum and the ion exchange resin. Short-circuit current flows rapidly at the contact point.

As detailed above, the present invention is based on a completely new catalyst stage concept for oxidizing or reducing organic compounds.
It provides an internal short-circuit battery type catalyst, and its industrial value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural diagram of an internally shorted battery type catalyst according to an embodiment of the present invention. 1.1'...Ion exchange resin powder coated with metal, 2...Platinum, 3...Rhodium,
4...Ion exchange resin powder with no metal coating, 5...Poly 4311 Ina 1 Separate

Claims (1)

[Claims] Metal-coated ion exchange resin powder or short mH that is effective for electrolytically reducing oxidants)! A mixture of ion exchange resin powder or short fibers coated with a metal that is effective for electrolytically oxidizing the base material and ion exchange resin powder or short fibers that are not coated with metal are combined with a binder made of fluororesin. An internal short-circuit battery type catalyst for oxidizing organic compounds which are characterized by being bound together.