JPH04313347A - Production of catalyst supporting metal or metal oxide - Google Patents

Abstract

PURPOSE:To provide the method of producing a highly active catalyst compris ing a water-repellent carrier such as org. polymers on which metal or metal oxide is suspported. CONSTITUTION:The above catalyst carrying metal or metal oxide can be obtd. by supporting an org. metal compd. on a water-repellent carrier and then converting the supported org. metal compd. into metal or metal oxide corresponding the org. metal compd.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a catalyst that can be used for various purposes by supporting a metal or metal oxide on a water-repellent carrier such as an organic polymer.

0002

[Prior Art and its Problems] A catalyst comprising catalyst particles supported on a water-repellent carrier has unique properties in organic synthesis reactions and the like. For example, Porapak Q is widely used as a column packing material for gas chromatography.
It has been reported that a catalyst in which platinum is supported on (trade name, styrene-divinylbenzene copolymer) exhibits unique activity at low temperatures in the D-H exchange reaction of D2-H2O. When producing a catalyst using this water-repellent material as a carrier, attempts have been made to, for example, immerse Polapack Q in an acetone solution of chloroplatinic acid, remove the solvent, and then perform hydrogen reduction to produce the catalyst. Inorganic salts such as chloroplatinic acid and the like have poor lipophilicity and therefore have a weak affinity for Polapac Q, and when the solvent is distilled off, they precipitate on the surface of the carrier as microcrystals. Since the precipitated chloroplatinic acid crystals are then reduced with hydrogen,
There is a drawback that the degree of dispersion of the supported metal is low and a highly active catalyst cannot be obtained.

0003

[Object of the Invention] In order to effectively utilize the unique catalytic properties produced by the above-mentioned water-repellent carrier, the present invention involves producing a highly active catalyst by highly dispersing metals and metal oxides in the water-repellent carrier. The purpose is to provide a method.

0004

[Means for Solving the Problems] The present invention provides a metal or metal compound characterized in that an organometallic compound is supported on a water-repellent carrier and the supported organometallic compound is converted into a corresponding metal or metal oxide. This is a method for producing an oxide-supported catalyst.

The present invention will be explained in detail below. In the catalyst production method according to the present invention, when supporting a non-lipophilic metal or metal oxide on a water-repellent carrier, that is, a lipophilic carrier, instead of using an inorganic compound that has poor lipophilicity like the metal, etc. , it is intended that a highly dispersed metal or metal oxide be supported on the water-repellent carrier by using an organometallic compound that is highly lipophilic.

[0006] Therefore, the organometallic compound used is not particularly limited as long as it contains the catalyst metal to be supported, but if the compound contains a halogen atom or a nitrogen atom, gas or Compounds such as halogen gas, nitrogen oxides, ammonia, etc. tend to remain as catalyst poisons on the carrier and generate harmful gases during catalyst production, so organic compounds that do not contain these atoms or contain only a small amount of these atoms, etc. It is desirable that Such compounds include, for example, metal salts of organic acids, acetylacetone compounds, π-allyl compounds, etc., but it is desirable to use metal salts of organic acids because of cost and availability. Examples of the organic acid include octylic acid, decanoic acid, neodecanoic acid, stearic acid, etc., and the organic acid has 2 carbon atoms.
In the above, it is preferable that the material consists of only carbon, hydrogen, and oxygen. However, for example, in the case of mono-substituted stearic acid in which one hydrogen is replaced with chlorine, the chlorine content in the whole is very small, and it is not as high as the chlorine content in the case of chloroplatinic acid. Even if catalyst poisoning occurs, the catalyst activity is not significantly affected and can be used in the method of the present invention. In addition to the above-mentioned monovalent organic acids, polyvalent organic acids such as glutaric acid may also be used.

Metals include noble metals such as platinum, palladium, iridium, rhodium, ruthenium, gold, and silver, as well as base metals such as iron, nickel, and cobalt, and are not particularly limited as long as they have the desired catalytic activity.

[0008] The water-repellent carrier to be used may be selected depending on the required catalytic properties, and generally, organic polymers molded into beads are used as the water-repellent carrier.

In the present invention, a water-repellent carrier such as the above-mentioned Polapack Q is immersed in a solution of the above-mentioned organometallic compound dissolved in an organic solvent such as an alcohol, a ketone, or an ether, and the organometallic compound is impregnated with the water-repellent carrier. is converted into the corresponding metal oxide by thermal decomposition etc. to produce a metal oxide supported catalyst (in the case of platinum, a platinum supported catalyst), and if a metal supported catalyst is required, hydrogen reduction is performed as necessary. A predetermined catalyst is produced. Thermal decomposition itself may be carried out according to conventional thermal decomposition conditions. Furthermore, it is not preferable to use a solvent with too high a viscosity because it becomes difficult for the organometallic compound to penetrate when the carrier is immersed. Further, if the solvent contains halogen or nitrogen, harmful gases or catalyst poisons may be generated from the solvent, so it is preferable that the solvent used does not contain the above-mentioned nitrogen or halogen.

As described above, in the method of the present invention, when supporting a hydrophilic catalyst metal or a metal oxide on a water-repellent carrier that is difficult to support, an organometallic compound containing the metal is transferred to the water-repellent carrier. After being supported in a highly dispersed state,
It is converted into the corresponding metal or metal oxide by appropriate means such as thermal decomposition. Therefore, according to the method of the present invention, it is possible to support a catalytic metal or metal oxide in a highly dispersed state on a water-repellent carrier having unique properties as a catalyst carrier, and it is possible to produce a catalyst with high activity and unique catalytic properties. It becomes possible.

Next, an example of the production of a catalyst according to the present invention will be described, but the present invention is not limited to this example.

0012

[Example] Polapack Q was immersed in an acetone solution of octylic acid platinum salt, the acetone was distilled off by vacuum drying, and then reduction was performed at 250 °C for 3 hours in a hydrogen stream, and then 1
After vacuum drying for 2 hours, a 5% platinum/Porapack Q catalyst was obtained. When the particle size of the supported platinum particles was measured by powder X-ray diffraction, it was found to be 30 Å or less, indicating that the platinum particles were highly dispersed.

[0013]

[Comparative Example] A 5% platinum/Polapack Q catalyst was obtained under the same conditions as in the example except that an acetone solution of chloroplatinic acid was used instead of platinum octylate salt. The particle size of the supported platinum particles was measured by powder X-ray diffraction and was 70 Å.

[0014]

Effects of the Invention The present invention provides a catalyst supported on a metal or metal oxide, which is characterized in that an organic metal compound is supported on a water-repellent carrier, and the supported organic metal compound is converted into a corresponding metal or metal oxide. A manufacturing method (claim 1). Although metal catalysts that use water-repellent carriers exhibit unique reaction activity, they have poor affinity for inorganic compounds, and even if they are produced using conventional thermal decomposition methods that use inorganic compounds, highly active catalysts with high dispersion can be produced. The drawback is that it cannot be done. However, in the method of the present invention, an organometallic compound having an affinity for the water-repellent carrier is used instead of the inorganic compound, the catalyst metal is supported on the carrier in a highly dispersed state, and then the corresponding metal or metal oxide is This allows the production of catalysts with high activity and unique reaction characteristics. When a compound consisting only of the metal, carbon, hydrogen and oxygen is used as the organometallic compound (Claim 2)
Since the compound does not contain halogen or nitrogen, which tend to generate harmful gases or poison the catalyst, it may generate harmful gases during the production process that would impede the production process, or reduce the activity of the catalyst being produced. It is possible to produce a highly active catalyst in a safe manner without producing catalyst poisons that would significantly reduce the performance of the catalyst. The conversion of the organometallic compound into the corresponding metal or metal oxide is preferably carried out by a normal thermal decomposition method (claim 3), and by this method, it can be efficiently and easily converted into the corresponding metal, etc. . Although it is possible to use acetylacetone, a π-allyl compound, etc. as the organometallic compound, it is preferable to use a metal salt of an organic acid which is inexpensive and easily available (claim 4).

Claims (4)

[Claims] 1. A method for producing a metal or metal oxide-supported catalyst, which comprises supporting an organometallic compound on a water-repellent carrier and converting the supported organometallic compound into a corresponding metal or metal oxide. 2. The method according to claim 1, wherein the organometallic compound consists only of metal, carbon, hydrogen and oxygen. 3. The method according to claim 1, wherein the organometallic compound is converted by a pyrolysis method. 4. The method according to claim 1, wherein the organometallic compound is a metal salt of an organic acid.