JPS62269745A - Catalyst composition for oxidation reaction - Google Patents

Abstract

PURPOSE:To improve the catalytic activity and the oxidation efficiency by depositing a platinum group element as the first component, an element such as Sn as the second component, and a rare-earth element as the third component on an inorg. carrier, and specifying the ratios of the first component to the second and third components. CONSTITUTION:(a) One or more kinds of elements selected from platinum group elements, (b) >=1 kind of element selected from a group consisting of Sn, Bi, Ce, Te, and Sb, and (c) >=1 kind of element selected from rare-earth elements are deposited on an inorg. carrier to obtain the catalyst composition for oxidation reaction. In this case, the atomic ratio (b/a) of the (a) component to the (b) component is controlled to 0.001-10, and the atomic ratio (c/a) of the (a) component to the (c) component is adjusted to 0.01-5. Besides, 0.1-20wt% (a) component, 0.001-20wt% (b) component, and 0.01-20wt% (c) component are deposited. The catalyst is used when oxidized saccharides are produced by oxidizing saccharides.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a catalyst composition for an oxidation reaction used in producing a W-class oxide by oxidizing a II-class oxide.

wM acid oxides are used in many industrial fields, and the most representative example is gluconic acid, which is a monosaccharide, or its salt. These are widely used as chelating agents, cleaning agents for surfaces of metals such as iron and aluminum, glass surfaces, virgoo detergents, concrete admixtures, pharmaceuticals, and food additives.

Other oligosaccharide oxides, such as the disaccharide maltopionic acid or its salts, and oligosaccharide oxides of trisaccharides or more, are also expected to be used as chelating agents, building blocks for detergents, and raw materials for pharmaceuticals.

Furthermore, dialdehyde starch oxides, cyclic oligosaccharides such as β-cyclodextrin and methylated β-cyclodextrin oxides can be used in various ways depending on the functions derived from their structures. That is, the present invention provides a catalyst composition for oxidation reactions for producing various sugar oxides in high yield, which can be used in a variety of ways.

[Conventional technology and problems]

Currently, gluconic acid, a monosaccharide, is industrially produced by fermentation. Although this method is the easiest and economically superior method, it has many problems such as the difficulty in separating bacterial cells, controlling by-products, and treating wastewater.

On the other hand, as a method for solving these problems in the fermentation method, a method is known in which glucose and molecular oxygen are catalytically oxidized in an alkaline atmosphere in the presence of a platinum or palladium-based noble metal catalyst. For example, Tokuko Sho 60-922
No. 39 and Japanese Patent Publication No. 60-92240 describe a method of improving the yield by adding a second catalyst element such as bismuth or selenium as a second catalyst component to main catalyst elements such as platinum or palladium. has been done.

Therefore, as a result of additional tests using these two catalysts described in the publication and glucose as the oxidizable substance, the reaction yield was 95%.
Although the above was achieved, the durability of the catalyst was still unsatisfactory.

Furthermore, we performed a similar reaction by changing the oxidized product from maltose to maltotriose and higher-order oligosaccharides, but the yields were approximately 70% and 20%, respectively.As the number of glucose residues increased, the oxidation reaction increased. sex has decreased.

Thus, currently no catalyst has been developed that converts oligosaccharides of disaccharides or higher into the corresponding carboxylic acids with good yield.

On the other hand, Ws have an aldehyde group and a primary hydroxyl group as oxidized sites. The former is oxidized to the corresponding carboxyl group with good yield at a low temperature of 30 to 60°C, whereas in the latter case, in order to proceed with the oxidation reaction with good yield, it is necessary to
The reaction temperature must be set to 0°C, which is slightly higher than the former.

This indicates that aldehyde groups are easily oxidized, whereas -class hydroxyl groups are difficult to oxidize.

Conventionally, 5χB115, which is described in the aforementioned Japanese Patent Publication No. 60-92239 and Japanese Patent Publication No. 60-92240, has been used as a catalyst for oxidizing aldehyde groups of sugars with good yield.
There is χPd/C or 1χ5e15χPd/C. However, even when the primary hydroxyl groups of sugars were oxidized using the catalysts described in these publications, the yield was extremely low. Therefore, methods such as raising the reaction temperature or increasing the amount of catalyst added may be considered, but when these methods are adopted, the decomposition of the raw materials and oxidized products occurs, resulting in problems in terms of quality.

As described above, at present, no catalyst has been developed that can efficiently oxidize not only aldehyde groups of sugars but also -class hydroxyl groups at low temperatures.

[Means for solving problems]

Therefore, the present inventors conducted intensive research to find a highly active catalyst capable of oxidizing both the aldehyde group and the primary hydroxyl group of class IA, and as a result, completed the present invention.

That is, the present invention uses 1 selected from platinum group elements (palladium, platinum, ruthenium, rhodium) as the first catalyst component.
More than one element, as the second catalyst component, tin, bismuth,
One or more elements selected from the group consisting of selenium, tellurium, and antimony, and one or more elements selected from rare earth elements as the third catalyst component are supported on an inorganic carrier, and the first catalyst component The ratio R1 (second component/first component) of the second catalyst component is 0.001 to 10 in atomic ratio, and the ratio R2 (third component/first component) of the first catalyst component and the third catalyst component is 0.001 to 10. The object of the present invention is to provide a catalyst composition for an oxidation reaction used when producing a class II acid oxide by oxidizing 118M, which is characterized in that the atomic ratio of the components (component) is 0.01 to 5 in atomic ratio.

In the oxidation reaction catalyst composition of the present invention, it is important to simultaneously use one or more of the first catalyst component, one or more of the second component, and one or more of the third component.

The ratios of the second and third components to the first catalyst component, which is the main catalyst element, R1 and R2 are each 0.00 in atomic ratio.
The range is from 1 to 10.0.01 to 5, preferably from 0.005 to ? , 0.05 to 3, particularly preferably 0.01 to 4.0.1 to 1.5.

Further, the catalyst of the present invention is used as a supported catalyst supported on an inorganic carrier. Generally known inorganic carriers are used. Examples include activated carbon, asbestos, alumina, silica gel, activated clay, and diatoms, among which activated carbon is particularly preferred.

The supported amounts of the first, second and third catalyst components are usually 0.1-20% by weight, 0.001-20% by weight, and 0% by weight, respectively.
．． 01 to 20% by weight, preferably 1 to 15% by weight, 0.01 to 15% by weight, and 0.05 to 15% by weight, respectively.
15% by weight, particularly preferably 2 to 13% by weight, respectively.
The content is 0.05 to 10% by weight, and 0.1 to 5% by weight.

Furthermore, the catalyst of the present invention may contain alkaline earth elements, zinc, transition metals, etc., as necessary, in order to improve the durability of the catalyst or the hue of the reaction product when the catalyst of the present invention is used in an oxidation reaction. Compounds can be added.

Raw materials for the first catalyst component include ruthenium chloride, rhodium chloride, rhodium nitrate, palladium chloride, palladium iodide, palladium nitrate, palladium oxide, chloroplatinic acid,
Examples include platinum iodide, platinum nitrate, platinum oxide, platinum chloride, platinum cyanide, platinum iodide, intramolecular complexes such as palladium acetate and palladium acetylacetone, or pre-prepared platinum carbon catalysts and palladium carbon catalysts. However, palladium chloride and chloroplatinic acid are particularly preferred.

Raw materials for the second catalyst component include tellurium tribromide, tellurium dichloride, tellurium oxide, tellurium tetrachloride, tellurium tetrabromide, tellurium tetraiodide, telluric acid and its alkali metal salts, tellurite acid and its alkali metal salts. Metal salt, or a compound formed between the first component or the third component of the catalyst, tin tetrachloride, tin tetrabromide, tin iodide, tin oxide, selenium oxide, selenite, selenite, selenium chloride, Alkali metal salt of selenite or selenite, hydrogen selenide, or catalyst No. 1
or selenides formed between the components or the third component of the catalyst, such as palladium selenide, platinum selenide, or binary selenides or selenides, such as bismuth selenide, formed between the second component of the catalyst, and Examples include antimony oxide, antimony oxychloride, antimony pentachloride, bismuth chloride, bismuth oxychloride, bismuth oxybromide, bismuth tartrate, bismuth hydroxide, and the like.

Examples of raw materials for the third catalyst component include chlorides, nitrates, acetates, and sulfates of rare earth elements, such as lanthanum chloride, lanthanum nitrate, cerium chloride, cerium nitrate, praseodymium chloride, praseodymium nitrate, neodymium chloride, neodymium nitrate, etc. Cerium chloride and lanthanum chloride are particularly good.

The catalyst of the present invention is prepared by known methods. In preparing the catalyst, an aqueous solution of the first, second and third components of the catalyst is prepared and adsorbed onto, for example, activated carbon in ion-exchanged water. At this time, if an aqueous solution of the catalyst component cannot be prepared, it is solubilized with hydrochloric acid or the like and adsorbed. After adsorption, the catalyst components are reduced using a reducing agent such as formalin, hydrogen, hydrazine, or sodium borohydride. After reduction, the catalyst of the present invention is obtained by washing the catalyst with water and separating it by filtration. Although the catalyst usually has a water content of 50 to 60%, it can be used in the oxidation reaction without drying. Other catalysts of the invention can be prepared in a similar manner. Although the catalysts of the present invention are reusable, some may be re-reduced to maintain high levels of activity.

Examples of ills to be oxidized in carrying out the present invention include the following.

Monosaccharides having an aldehyde group include glucose and derivatives thereof; monosaccharides without an aldehyde group include methyl glucoside, gluconic acid, and salts thereof.

Oligosaccharides having aldehyde groups include maltose, maltotriose, maltotetraose, and lower oligosaccharide mixtures.

Furthermore, as a cyclic oligosaccharide without an aldehyde group,
β-cyclodextrin and its methylated products.

Alternatively, dialdehyde starch and the like may be mentioned.

-a, the reaction is carried out in an aqueous solution system. At that time, a 10 to 70% aqueous solution of the sugar to be oxidized, preferably 20 to 40%
% aqueous solution is used. The amount of catalyst added is the oxidized material wI
0.1 to 20%, preferably 0.5 to 15% of @
It is.

As the oxidizing agent, oxygen or an oxygen-containing gas such as air is used.

The reaction temperature is 20-90°C, preferably 25-80°C. The pressure is preferably 10 atm or less, particularly normal pressure. Also, as the pH of the reaction system decreases as the oxidation reaction progresses, the pressure is continuously or intermittently maintained so that the pH of the reaction system is 7.5 to 11. It is better to add an aqueous caustic alkali solution.

The catalyst of the present invention is characterized in that the phenomenon of self-poisoning of the catalyst by oxygen, which is characteristic of noble metal catalysts, is greatly suppressed, and therefore the oxidation yield is high.

Another feature is that the catalytic activity is extremely high due to the addition of rare earth elements.
40°C) is possible.

〔Example〕

The present invention will be explained in detail by giving examples below.

Example 1 (Preparation of 2χCe/3χB115χPd/C catalyst)9.
0g of activated carbon is soaked in 1OO- of ion-exchanged water. As a raw material for the first catalyst component, 0.83 g of palladium chloride is dissolved in 22 m of a 5% aqueous hydrochloric acid solution. As a raw material for the second catalyst component, 0.45g of bismuth chloride was mixed with 6% hydrochloric acid 3
6-Dissolve in. 0.53 as a raw material for the third component of the catalyst
Dissolve g of cerium chloride in ion exchange water.

A solution of these three types of catalyst components is added to the previously prepared activated carbon for adsorption treatment. Then 48% caustic soda 17
g, 12n7 of 37% formalin aqueous solution was added, 8
Catalyst reduction is carried out at 0°C.

The reduced catalyst is washed with ion-exchanged water, and the catalyst is filtered off.

The resulting catalyst was a 2XCe/3χ containing about 50% water.
B115χPd/C catalyst. The catalyst can be used for oxidation reactions without drying.

Examples 2 to 6 Other catalysts of the present invention were prepared in the same manner (Table 1).

(Conversion of glucose) 500 g of a 30% aqueous solution of commercially available glucose and the catalyst of the invention were placed in 11 round-bottomed flasks equipped with a thermometer, a stirrer, a pH meter, an oxygen inlet tube, a caustic soda aqueous solution inlet tube and a waste gas outlet. Add 4.5 g (moisture content = 50%, equivalent to 2.3 g dry product).

While stirring, the temperature was raised to 40° C., and oxygen gas was introduced by bubbling at a rate of 3 Q 1 /hr. On the other hand, as the oxidation reaction progresses, the pEI of the reaction system decreases, so a caustic soda aqueous solution is continuously introduced to maintain the pH of the reaction system at about 10. During the reaction, a large amount of heat is generated, so cooling is required. The reaction was completed in 45 minutes. The results are shown in Table 1.

In addition, under similar conditions, the catalysts described in Japanese Patent Publication No. 60-92239 and Japanese Patent Publication No. 60-92240 (5χ old 15χPd/C, 1χ5s15χPd, respectively)
/C), and the activity was compared with the catalyst of the present invention.

The results are shown in Table 1. This shows that the catalyst of the present invention has higher catalytic activity.

Table 1 Example 7 2χCe/3χBt15χPd/C which is a catalyst of the present invention
Using a catalyst, a 20% aqueous solution of the compounds shown in Table 2 was
Oxygen oxidation was performed at rto, temperature of 60° C., and normal pressure. The results are shown in Table 2.

Table 2

Claims (1)

[Scope of Claims] 1 The first catalyst component is one or more elements selected from platinum group elements (palladium, platinum, ruthenium, rhodium), and the second catalyst component is tin, bismuth, selenium, tellurium, and antimony. One or more elements selected from the group consisting of: and one or more elements selected from rare earth elements as the third catalyst component are supported on an inorganic carrier; The ratio R1 (second component/first component) is 0.001 to 10 in atomic ratio, and the ratio R2 (third component/first component) of the catalyst first component and the catalyst third component is in atomic ratio. A catalyst composition for an oxidation reaction used in producing a saccharide oxide by oxidizing a saccharide, characterized in that the oxidation ratio is 0.01 to 5. 2. The catalyst composition for oxidation reactions according to claim 1, wherein the first catalyst component is platinum and/or palladium. 3 Content of the first catalyst component in the catalyst composition is 0.1 to 2
The catalyst composition for oxidation reactions according to claim 1, wherein the content is 0% by weight. 4 Content of the second catalyst component in the catalyst composition is 0.001
The catalyst composition for oxidation reactions according to claim 1, wherein the content is 20% by weight. 5 Content of the third catalyst component in the catalyst composition is from 0.01 to
The catalyst composition for oxidation reactions according to claim 1, wherein the content is 20% by weight.