JP2002293538A - Porous calcium fluoride, its producing method, catalyst for hydrogenation reaction and method for producing trihydrofluorocarbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce porous calcium fluoride having a larger surface area than that of conventional one, to provide its producing method, to produce a carried catalyst (in particular, a catalyst for a hydrogenation reaction) of which the carrier is porous calcium fluoride and superior in activity, selectivity and durability, and to provide a method for producing trihydrofluorocarbon using the catalyst. SOLUTION: Porous calcium fluoride having BET surface area of 20-200 m<2> /g is produced by a reaction of soda lime with hydrogen fluoride. The carried catalyst (catalyst for hydrogenation reaction) comprises a metal or a metal compound on porous calcium fluoride carrier. Trihydrofluorocarbon (2) is produced by contacting fluoroalkene (1) with hydrogen in the presence of the catalyst. (In the formula, X denotes a halogen atom, Rf1 and Rf2 denote fluorine or a parafluoroalkyl group, Rf1 and Rf2 may be connected and form a ring.).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a porous calcium fluoride, a method for producing the same, a supported catalyst such as a hydrogenation catalyst using the calcium fluoride as a carrier, and a trihydrofluorocarbon using the hydrogenation catalyst. And a method for producing the same.

[0002]

_2. Description of the Related Art Calcium fluoride (CaF ₂ ) is inactive against various reactions using hydrogen gas or oxygen gas, and thus has conventionally been used as a supported catalyst (“metal or metal compound supported on a carrier”). It is known to be useful as a carrier for "catalyst". For example, Table 2001-5
In JP-A-00051, an alkaline earth metal-containing compound such as calcium fluoride or calcium molybdate is used as a carrier for a silver catalyst that oxidizes propylene to propylene oxide in a gas phase. JP-A-6-1451
No. 14 describes that an alcohol and carbon monoxide are reacted in the presence of a solid catalyst using a metal halide such as calcium fluoride as a carrier to obtain a carbonic acid diester.

[0003] JP-A-7-69943 discloses that
1,3,3,3-pentafluoropropene is reacted with hydrogen by a gas phase method in the presence of a metal oxide catalyst, and
A method for producing 1,1,3,3,3-pentafluoropropane, which is hydrogen-reduced in a temperature range of ° C., is described. Calcium fluoride, alumina, aluminum fluoride, and the like are used as carriers for supporting metal oxides. JP-A-7-112944 describes a process for producing hexafluorocyclobutene in which 1,2-dichlorohexafluorocyclobutane is dechlorinated with hydrogen in the presence of a metal oxide and / or silicon oxide catalyst. I have. Calcium fluoride, activated carbon, alumina or the like is used as a carrier for the metal oxide catalyst used in this reaction.

[0004] Calcium fluoride is naturally found as fluorspar (pure form) or fluospar (ore). In addition, it can also be artificially produced. As a conventional production method, for example, a method of reacting a soluble calcium salt with sodium fluoride, or dissolving calcium carbonate or calcium hydroxide in hydrofluoric acid, There are known methods for evaporating water.

By the way, in order to increase the amount of a supported substance (metal or metal compound) in order to improve the catalytic activity of the supported catalyst, the support needs to have a larger surface area. However, the surface area of the conventional natural product or the calcium fluoride artificially produced as described above has a certain limit, and the amount of the supported metal or metal compound also has a certain limit.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has a surface area of 20 m ² / g to ² m ² / g.
Porous calcium fluoride of 00 m ² / g, a method for producing porous calcium fluoride, a supported catalyst using the porous calcium fluoride as a carrier (particularly, a hydrogenation reaction catalyst), and the hydrogenation reaction catalyst It is an object of the present invention to provide a method for producing trihydrofluorocarbon using the same.

[0007]

The present inventors have found that porous calcium fluoride can be obtained by bringing soda lime (also referred to as "soda lime") into contact with hydrogen fluoride at a predetermined temperature. The porous calcium fluoride obtained as described above has an extremely large surface area as compared with conventional calcium fluoride, and exhibits excellent catalytic activity by supporting a noble metal or a noble metal compound on the obtained porous calcium fluoride. A hydrogenation catalyst having excellent durability can be obtained, and further, by using the obtained hydrogenation reaction catalyst, fluoroalkenes can be hydrogenated with high selectivity and high yield. They have found that they can do this and have completed the present invention.

That is, the present invention relates to the following: (1) The surface area measured by the BET method is 20 m²/ G
~ 200m²/ G, characterized in that
Calcium; (2) contacting soda lime with hydrogen fluoride
(3) a carrier comprising the porous calcium fluoride,
A supported catalyst supporting a metal or a metal compound; (4) a support comprising the porous calcium fluoride;
Catalyst for hydrogenation reaction supporting metal or noble metal compound
Medium; and (5) Formula (1): Rf₁-CF = CX-Rf₂(Where
X represents a halogen atom;₁And Rf₂Each
Independently represent a fluorine atom or a perfluoroalkyl group.
Then Rf₁And Rf₂Are bonded to each other to form a ring
Good. )), The hydrogenation reaction
Formula for contacting hydrogen in the presence of a catalytic catalyst
(2): Rf₁-CHF-CH₂-Rf₂(Where Rf
₁And Rf ₂Has the same meaning as described above. )
A method for producing rehydrofluorocarbon;
It is.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention of (1) to (5) will be described in detail. (1) Porous calcium fluoride Calcium fluoride used in the present invention is porous.
The term “porous” generally refers to a state having a large number of small cell-like voids inside or on the surface of a solid. Porous calcium fluoride of the present invention, surface area measured by the BET method is ^{20m 2} / ^g~200m 2 / g, preferably ^{30 m} 2 /
g to 150 m ² / g, more preferably 40 m ² / g to 1
00m ² / g, more preferably ^60m 2 / ^g~80m
2 / g. When the surface area measured by the BET method is less than 20 m ² / g, the amount of the metal or metal compound catalyst carried becomes insufficient, and the catalytic activity may be insufficient. On the other hand, if it exceeds 200 m ² / g, the catalyst activity may increase but the catalyst strength may decrease.

The surface area of calcium fluoride can be measured by the BET method using gas adsorption. That is,
Various gases (nitrogen, oxygen, argon, etc.) are adsorbed to the calcium fluoride near its boiling point to obtain an adsorption isotherm, and the point at which the linear part of the curve starts is point B, and the amount of gas adsorption ν _m (standard state), the surface area S is given by the formula:
S = 0.41ν _m (M / D) ^2/3 (where M represents the molecular weight of the adsorbed molecule, and D represents the density of the adsorbate at the adsorption temperature, respectively).

When the point B is not clear, the surface area S is determined by using a BET equation (Brunauer-Emmett-Taylor equation) using a horizontal axis of p / p ₀ and a vertical axis of p / ν (p ₀
-P) actually plotting the measured values as × 10 ^3,
And tilt _{(c-1) / ν m} c of the obtained straight line, gradient 1 /
seeking [nu _m from _{ν m c, S = (ν} m / 22400) × N
× a (N represents Avogadro's number, and a represents the surface area occupied by one adsorbed molecule). Here, p is the adsorption equilibrium pressure, p ₀ is the saturated vapor pressure of the adsorbed molecule at the measurement temperature, c is a constant relating to the heat of adsorption, and ν is the adsorption amount at pressure p (converted to a standard state).

The pore volume of the porous calcium fluoride of the present invention
The product (pore volume) Vs is usually 0.05 cm³/ G ~ 0.
5cm³/ G, preferably 0.06 cm³/G-0.4
cm ³/ G, more preferably 0.08 cm³/ G ~ 0.
2cm³/ G range. Method for determining pore volume Vs
For example, the total volume of calcium fluoride is V1
And calcium fluoride at a constant volume and pressure
Into the system and determine the true volume V2 from the increase in pressure.
Vs = V1−V2
The space volume filled with helium containing calcium iodide
And then exhaust the helium and then fill with mercury
A method of measuring the volume of space that is calculated and calculating from the difference, or
Absorb saturated vapor or liquid into a fixed weight of calcium fluoride
And remove the adhering liquid on the surface to increase the weight.
The method is generally used.

The average pore size of the porous calcium fluoride of the present invention is usually 20 to 200 °, preferably 30 to 200 °.
180 °, more preferably in the range of 50 to 150 °. The average pore diameter can be determined from the formula: 4 × Vs / S. Here, Vs represents the pore volume, and S represents the surface area. In addition, the average pore diameter is measured by an automatic pore diameter measuring device (for example, NOVA1000, manufactured by Yuashionix).
Can be measured.

The porous calcium fluoride of the present invention can be produced by contacting soda lime and hydrogen fluoride at a predetermined temperature. Soda lime is a white granular solid substance obtained by immersing quick lime in a concentrated solution of sodium hydroxide and heating, has a strong basicity, is used as an absorbent for carbon dioxide and water, and is generally commercially available. ing. There is no particular limitation on the shape of soda lime used in the present invention, for example, powder or pellets,
It is preferably in the form of a pellet.

The method of contacting soda lime and hydrogen fluoride at a predetermined temperature is not particularly limited. For example, (a) a method of bringing hydrogen fluoride gas into contact with soda lime in a solid state such as powder or pellets of soda lime at a predetermined temperature, or (b) adding a predetermined amount of hydrofluoric acid to a solution of soda lime. And a method of evaporating and removing the solvent. Among these, in the present invention, the method (a) is preferred from the viewpoint of having a predetermined surface area and efficiently obtaining anhydrous porous calcium fluoride.

The temperature at which soda lime is brought into contact with hydrogen fluoride is usually 0 ° C. to 400 ° C., preferably 20 ° C. to 400 ° C.
° C, more preferably in the range of 30 ° C to 280 ° C. The amount of hydrogen fluoride used is not particularly limited as long as it is sufficient to react with soda lime to generate calcium fluoride.

In the production method of the present invention, it is preferable that the soda lime is heated at 150 ° C. to 250 ° C. for 1 to 10 hours in a nitrogen gas atmosphere, dried sufficiently, and then brought into contact with hydrogen fluoride gas. In this case, it is more preferable to use anhydrous hydrogen fluoride, and it is also possible to use hydrogen fluoride diluted with a diluent gas such as nitrogen gas or argon gas. The dilution ratio of the diluent gas is not particularly limited, but usually, the inert gas: hydrogen fluoride = 1 by volume ratio.
The range is from 0: 1 to 1:10, preferably from 5: 1 to 1: 5. According to this manufacturing method, it is possible to surface area measured by the BET method to obtain a porous calcium fluoride is ^{20m 2} / ^g~200m 2 / g.

(2) Supported Catalyst The porous calcium fluoride of the present invention is useful as a carrier for various metals or metal compounds. Examples of the metal that can be supported include chromium, iron, cobalt, copper, nickel, manganese, palladium, rhodium, ruthenium, rhenium, platinum, iridium, and osmium. Examples of the metal compound include acetates, sulfates, nitrates, halides, oxides and hydroxides of these metals.

The supported catalyst of the present invention exhibits more activity than before in various catalytic reactions based on these metals or metal compounds. Particularly, a supported catalyst supporting a noble metal or a noble metal compound is useful as a catalyst for a hydrogenation reaction. When used as a catalyst for hydrogenation reaction, the supported noble metal or noble metal compound includes noble metals such as palladium, rhodium, ruthenium, rhenium, platinum, iridium, osmium, and palladium acetate, palladium sulfate, palladium nitrate, palladium chloride, and platinum oxide. And noble metal compounds. Among these, palladium or a palladium compound is particularly preferred.

These catalysts may be those composed of a single metal, or bimetallic catalysts, alloy catalysts and the like. When the supported catalyst of the present invention is used as a catalyst for a hydrogenation reaction, a catalyst containing palladium as a main component is preferable.

Further, the hydrogenation catalyst may contain a metal component (added metal component) other than the above-mentioned noble metal. Examples of the added metal component include silver, copper, gold, tellurium, zinc, chromium, molybdenum, thallium, tin, bismuth, and lead. The amount of the added metal component is preferably from 0.01 to 500 parts by weight, and more preferably from 0.1 to 300 parts by weight, based on 100 parts by weight of the metal described above, from the viewpoint of utilizing the properties of the metal. In general, when two or more kinds of metals or metal compounds are used, the characteristics of the component elements can be made to appear or the catalytic activity can be varied according to the composition.

When a metal or a metal compound is supported on porous calcium fluoride, the shape of the calcium fluoride as a carrier may be a powder or a granular material such as a sphere or a pellet. Further, the granular material may be a processed molded product or a crushed product. The amount of the metal or metal compound supported on the carrier is usually 0.05 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight.
% By weight.

Generally, the catalytic activity can be increased by increasing the amount of the metal or metal compound carried in the catalyst. The porous calcium fluoride obtained in the present invention,
Surface area as measured by the BET method is ^{20m 2} / ^g~200m 2 / g
Therefore, the amount of metal or metal compound supported can be dramatically increased.

As a method of supporting a metal or a metal compound on the porous calcium fluoride of the present invention, a conventionally known method such as an ion exchange method and an impregnation method can be adopted. For example, after mixing a porous calcium fluoride carrier and an aqueous solution of a metal compound at a predetermined ratio, the mixture is dried, and then further dried.
A method of carrying by carrying out treatment at a high temperature of 0 ° C. to 600 ° C. can be mentioned. When a metal compound is used, the aqueous solution of the metal compound can be used alone, or the aqueous solution of the metal compound and, if necessary, the added metal can be used at a desired ratio and concentration.

After the metal compound is supported on the porous calcium fluoride, it can be activated by reduction by a wet reduction method or a gas phase reduction method. In the wet reduction method, an appropriate reducing agent is added to a carrier after the metal compound of the catalyst component is carried on the carrier, and reduction is performed at room temperature. As the reducing agent, for example, formalin, hydrazine, formic acid, sodium borohydride and the like can be used. Further, in the gas phase reduction method, after the metal compound is supported, 100 ° C. to 600 ° C.
Is reduced by treating with a hydrogen stream.

(3) Production of trihydrofluorocarbon
Concrete hydrogenation reaction catalyst of the present invention have the formula _(1): Rf 1 -CF
= And the fluoroalkene represented by CX-Rf ₂ is contacted with hydrogen, the formula _{(2): Rf 1 -CHF-} CH 2 -Rf 2
Can be suitably used as a catalyst for a hydrogenation reaction for producing a trihydrofluorocarbon represented by

In the above formula (1), X represents a halogen atom such as fluorine, chlorine, bromine and iodine. In the present invention, X is preferably a fluorine atom or a chlorine atom.
Rf ₁ and Rf ₂ each independently represent a fluorine atom or a fluoroalkyl group in which some or all of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms. As such a fluoroalkyl group, a fluoroalkyl group having 1 to 20 carbon atoms is preferable, for example, a trifluoromethyl group,
1,1,1-trifluoroethyl group, pentafluoroethyl group, heptafluoro-n-propyl group, heptafluoro-isopropyl group, nonafluoro-n-butyl group,
Nonafluoro-sec-butyl group, nonafluoro-te
rt-butyl group, undecafluoro-n-pentyl group,
Examples include an undecafluoroneopentyl group, a perfluorohexyl group, a perfluoroheptyl group, a perfluorooctyl group, a perfluorononyl group, a perfluorodecyl group, and the like.

The fluoroalkene represented by the formula (1) may be _{one in} which Rf ₁ and Rf ₂ are bonded to form a ring having 4 to 8 carbon atoms. Examples of the compound having such a ring formed therein include a cyclobutene compound, a cyclopentene compound, a cyclohexene compound, a cycloheptene compound, and a cyclooctene compound.

Specific examples of the compound represented by the formula (1) include 1-chloro-1,2,3,3,4,4,4-heptafluorobutene-1,2-chloro-1,1 , 3,
3,4,4,4-heptafluorobutene-1, 2-chloro-1,1,1,3,4,4,4-heptafluorobutene-2, 1-chloro-1,2,3,3, 4,4,5
5,5-nonafluoropentene-1, 2-chloro-1,
1,3,3,4,4,5,5,5-nonafluoropentene-1, 2-chloro-1,1,1,3,4,4,5
5,5-nonafluoropentene-2,3-chloro-1,
1,1,2,4,4,5,5,5-nonafluoropentene-2,1,1,2,3,3,4,4,5,5,5-decafluoropentene-1,1,1 1,1,2,3,4
4,5,5,5-decafluoropentene-2,1-chloro-1,2,3,3,4,4,5,5,6,6,6-undecafluorohexene-1,2-chloro -1,1,
3,3,4,4,5,5,6,6,6-undecafluorohexene-1, 2-chloro-1,1,1,3,4
4,5,5,6,6,6-undecafluorohexene-
2,3-chloro-1,1,1,2,4,4,5,5
Chain fluoro such as 6,6,6-undecafluorohexene-2, 3-chloro-1,1,1,2,2,4,5,5,6,6,6-undecafluorohexene-3 Alkenes; 1-chloro-2,3,3,4,4-pentafluorocyclopentene-1, 1-chloro-2,3,3,4
4,5,5-heptafluorocyclopentene-1,1,1
2,3,3,4,4-hexafluorocyclopentene-
1,1,2,3,3,4,4,5,5-octafluorocyclopentene-1,1-chloro-2,3,3,4
4,5,5,6,6-nonafluorocyclohexene-1
Cyclic fluoroalkenes; and the like.

The hydrogen used in the hydrogenation reaction is advantageously used in an excess amount with respect to the compound represented by the formula (1). For example, 2 mol or more, preferably 2 mol to 50 mol of hydrogen may be used per 1 mol of the compound represented by the above (1).

As a method of the hydrogenation reaction, a liquid phase reaction or a gas phase reaction is possible. In the liquid phase reaction, a solvent can be used. In the gas phase reaction, a diluent can be used if desired. Further, in the gas phase reaction, a system such as a fixed bed type gas phase reaction and a fluidized bed type gas phase reaction can be employed.

The solvent used in the liquid phase reaction is not particularly limited.
Aliphatic hydrocarbons, aromatic hydrocarbons, hydrofluorocarbons, alcohols, ethers, ketones, esters, water and the like can be used. Examples of the aliphatic hydrocarbon include a chain or cyclic hydrocarbon having 4 to 15 carbon atoms such as n-butane, n-pentane, methylpentane, n-hexane, cyclopentane, and cyclohexane. Examples of the aromatic hydrocarbon include trifluoromethylbenzene. Examples of the hydrofluorocarbons include pentafluoroethane, pentafluoropropane, hexafluorobutane, decafluoropentane, and the like. Examples of the alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, cyclopentanol and the like. Examples of the ethers include diethyl ether, diisopropyl ether, ethylene glycol dimethyl ether and the like. Ketones include, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and the like. Examples of the esters include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, and the like. These solvents may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, but is usually in the range of 0 to 80 parts by weight, preferably 0 to 50 parts by weight, per 100 parts by weight of the fluoroalkene represented by the formula (1).

In the case of a gas phase reaction, the hydrogen gas used may be hydrogen gas alone or hydrogen gas diluted with a diluent gas. As a diluent that can be used, any gas may be used as long as it is an inert gas in the present hydrogenation reaction. For example, a nitrogen gas, a rare gas, a hydrocarbon gas, a hydrofluorocarbon gas, or the like can be used. These diluents can be used alone or in combination of two or more. The amount of the diluent used is not particularly limited. The amount used is generally 0 to 500 parts by weight, preferably 0 to 200 parts by weight, per 100 parts by weight of the compound represented by the formula (1).
It is in the range of parts by weight.

The pressure of the reaction system of the present hydrogenation reaction is usually from normal pressure to about 50 kgf / cm ² , preferably from normal pressure to 20 kf / cm ^2.
gf / cm ² . The reaction temperature is usually from room temperature to 3
The temperature is in the range of about 50 ° C., preferably in the range of room temperature to about 200 ° C. In the present hydrogenation reaction, it is preferable to stir or shake the inside of the reaction system as necessary.

The hydrogenation reaction of the present invention can be preferably a batch reaction or a continuous reaction in which raw materials are continuously supplied to a reaction vessel and a reaction product is continuously withdrawn from a reaction vessel (reaction tube). The reaction vessel used is a pressure vessel in the case of a batch reaction and one or more reaction vessels connected in series, for example a cascade reaction vessel, can be used in a continuous reaction. Suitable materials for the reaction vessel include, for example, stainless steel and Inconel. It is also preferable that these reaction vessels are conditioned before use, for example, by treating with nitric acid.

In this reaction, acidic components such as hydrogen chloride are produced as by-products. This acidic component is preferably absorbed or neutralized and removed during the reaction. What is necessary is just to add an additive to a system as a removal method. Examples of the additives include hydroxides, oxides, weak acid salts, and organic acid salts of alkali metals or alkaline earth metals, and specifically, soda lime,
Quick lime, alkali carbonate, alkali acetate and the like can be used.

After completion of the reaction, the desired component can be isolated by an ordinary purification method such as distillation after absorbing or neutralizing the acidic component with an additive, if necessary.

The above formula (2) obtained by the production method of the present invention
Are chain or alicyclic compounds having 4 or more carbon atoms and having a —CH ₂ —CHF— group in the molecule. In particular, the method of the present invention can be suitably applied to the synthesis of alicyclic compounds. The number of carbon atoms in the basic skeleton of the compound containing a —CH ₂ —CHF— group is usually 4 to 10, preferably 4 to 6, and particularly preferably 5.

Specific examples of the chain compound containing a —CH ₂ —CHF— group include 1,1,1,2,5,5,5
5, -heptafluoro-n-pentane, 1,1,1,
2,2,3,5,5,5-nonafluoro-n-pentane, 1,1,1,2,2,4,5,5,5-nonafluoro-n-pentane, 1,1,1,2,2 2,3,3,4
6,6,6-undecafluoro-n-hexane, 1,
1,1,2,2,3,3,5,6,6,6-undecafluoro-n-hexane and the like.

The alicyclic compound represented by the formula (2) includes a compound represented by the formula (3).

[0041]

Embedded image

In the formula (3), Rf ₃ and Rf ₄ each independently represent a fluoroalkylene group having 1 to 3 carbon atoms. Examples of the fluoroalkylene group having 1 to 3 carbon atoms include a fluoromethylene group, a difluoromethylene group, a fluoroethylene group, a difluoroethylene group, a trifluoroethylene group, a tetrafluoroethylene group, a fluorotrimethylene group, a difluorotrimethylene group, Examples include a trifluorotrimethylene group, a tetrafluorotrimethylene group, a pentafluorotrimethylene group, and a hexafluorotrimethylene group.

Specific examples of the compound represented by the above formula (3) include 1,1,2,2,3-pentafluorocyclobutane, 1,1,2,2,3,3,4-heptafluorocyclo Pentane, 1,1,2,2,3,3,4,4,5-
Alicyclic compounds such as nonafluorocyclohexane; Of these compounds, 1,1,1,2,2,2
3,5,5,5-nonafluoro-n-pentane, 1,
1,2,2,3,3,4-heptafluorocyclopentane is preferred, and 1,1,2,2,3,3,4-heptafluorocyclopentane is particularly preferred.

[0044]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

(Examples 1 to 4) Production of Porous Calcium Fluoride An appropriate amount of commercially available pellet-like soda lime was placed in a reaction tube (4 mm inside diameter × 200 mm length) made of Inconel, and dry nitrogen gas was added. The soda lime was dried by flowing at 200 ° C. for 3 hours. Thereafter, the inside of the reaction tube was replaced with a mixed gas of nitrogen gas and anhydrous hydrogen fluoride (volume ratio; 3: 1), and the mixture was heated and circulated at 40 ° C. for 3 hours. Next, after replacing the inside of the reaction tube with anhydrous hydrogen fluoride, the reaction temperature was raised to 250 ° C. over 2 hours, and the mixture was further heated at the same temperature for 10 hours. After the completion of the reaction, dry nitrogen gas was flowed into the reaction tube (10 hours), and the inside of the reaction tube was completely replaced with nitrogen gas (nitrogen washing) to obtain a desired porous calcium fluoride. Surface area (m ² / g) of the obtained porous calcium fluoride by BET method, pore volume Vs
(Cm ³ / g), the average pore size (Å), and the source (maker) of the commercially available soda lime used as the raw material are shown in Table 1. In Table 1, a indicates that the product is manufactured by Kanto Chemical Co., Ltd., b indicates that manufactured by Merck, c indicates that manufactured by Wako Pure Chemical Industries, Ltd., and d indicates that the product is soda lime manufactured by Hanoi Chemical Co., Ltd. Vs indicates the pore volume.

[0046]

[Table 1]

Example 5 Preparation of Hydrogenation Reaction Catalyst A In a 100 ml eggplant-shaped flask, 10 g of the porous calcium fluoride obtained in Example 1 was weighed, and 35%
10 ml of an aqueous hydrochloric acid solution and distilled water were added until the porous calcium fluoride was completely below the liquid level, and the mixture was allowed to stand for 8 hours. Thereafter, the solution was removed by suction filtration, and the filtrate was distilled water 2
Washed three times with 0 ml. On the other hand, palladium (II) chloride 5
Was dissolved in 3 ml of a 35% hydrochloric acid aqueous solution, and this solution was added to an eggplant flask containing porous calcium fluoride treated with the hydrochloric acid aqueous solution, and allowed to stand for 12 hours in a well-mixed state. Palladium was impregnated into the porous calcium fluoride. The obtained mixture (porous calcium fluoride impregnated with palladium chloride) was dried by heating to 60 ° C. under reduced pressure (20 mmHg), and then a reaction tube made of Inconel (inner diameter 4 mm × length 200 m)
m), and subjected to nitrogen replacement at 150 ° C. for 3 hours (nitrogen flow rate = 40 ml / min). Thereafter, the replacement gas was switched from nitrogen to hydrogen gas, and hydrogen gas was flowed at 150 ° C. for 5 hours (hydrogen flow rate = 40 ml / min). Thus, the hydrogenation reaction catalyst A of Example 5 was prepared. The amount of palladium carried on this hydrogenation catalyst was 3% by weight.

(Example 6) Production of heptafluorocyclopentane 0.41 g of the catalyst A for hydrogenation reaction prepared in Example 5 was placed in a reaction tube made of Inconel (inner diameter 4 mm x length 200 mm).
And heated at 150 ° C. under a nitrogen atmosphere for 2 minutes and then under a hydrogen atmosphere for 10 minutes to activate the catalyst. Next, the inside of the reaction tube was set to 150 ° C., and 1-chloro-2,3,3,4,4,5,5-heptafluorocyclopentene-1 (hereinafter abbreviated as “MCL”) from one inlet of the reaction tube. ) At a flow rate of 0.21 g / min and hydrogen gas at a flow rate of 200 ml / min (the time for the gas to contact the catalyst is 0.1 second). The gas flowing out from one outlet of the reaction tube after a predetermined time has elapsed from the start of the reaction is collected by a liquid nitrogen trap,
The analysis was performed by gas chromatography (hereinafter, abbreviated as “GC”). The analysis results are shown in Table 2 together with the reaction temperature and reaction time.

(Comparative Example 1) Production of heptafluorocyclopentane In Example 6, instead of using the hydrogenation catalyst obtained in Example 5, commercially available palladium on activated carbon (palladium supported amount 5% by weight; catalyst B) A hydrogenation reaction of MCL was carried out in the same manner as in Example 6 except that 0.25 g was used. Table 2 shows the results of the GC analysis of the reaction product, the reaction temperature and the reaction time. In Table 2, abbreviations represent the following meanings. F7A: 1,1,2,2,3,3,4-heptafluorocyclopentane F7E: 1,3,3,4,4,5,5-heptafluorocyclopentene F6A: 1,1,2,2,3 , 3-hexafluorocyclopentane

[0050]

[Table 2]

As is apparent from Table 2, according to the hydrogenation reaction catalyst (catalyst A) supported on the porous calcium fluoride of the present invention, the hydrogenation reaction catalyst (catalyst B) of the comparative example was used.
It was found that the desired 1,1,2,2,3,3,4-heptafluorocyclopentane can be obtained in a shorter time and with a higher selectivity as compared with. In addition, the hydrogenation catalyst A of the present example is different from the hydrogenation reaction catalyst B of the comparative example in that:
It was also found that the catalyst had an excellent catalyst life even at a high temperature of 150 ° C.

[0052]

As described above, according to the present invention,
BET surface area porous calcium fluoride is ^{20m 2} / ^g~200m 2 / g, the supported catalyst for the preparation and the porous calcium fluoride porous calcium fluoride and carrier. Further, when the supported catalyst of the present invention is a catalyst for hydrogenation reaction, the catalyst of the present invention has excellent durability, higher yield and higher selectivity than conventional catalysts for hydrogenation reaction. Hydrofluorocarbons can be produced.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C07C 19/08 C07C 19/08 23/08 23/08 // C07B 61/00 300 C07B 61/00 300 (72) Invention Person Masanori Tamura 1-1, Higashi, Tsukuba, Ibaraki Pref. Ministry of Economy, Trade and Industry, National Institute of Advanced Industrial Science and Technology (72) Inventor Toshiro Yamada 1-2-1, Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Zeon Corporation F-term in the development center (reference) 4G069 AA01 AA03 AA08 AA11 AA12 BB08A BB08B BC09A BC09B BC09C BC72A BC72B BD15A BD15B CB02 EA02Y EC02Y EC03X EC06Y EC14Y EC15Y FA02 FB13 FB29 BA44 4G076 AABA02AC03 BA25 BA26 BA32 BA34 BA36 BA37 BE20 4H039 CA40 CB10 CD20 CE40

Claims (5)

[Claims] 1. The surface area measured by the BET method is 20 m
Porous calcium fluoride, which is a ² / ^{g~200m 2} / g. 2. A method for producing porous calcium fluoride, comprising contacting soda lime with hydrogen fluoride. 3. A supported catalyst comprising a support comprising the porous calcium fluoride according to claim 1 and a metal or a metal compound supported thereon. 4. A hydrogenation catalyst comprising a support comprising the porous calcium fluoride according to claim 1 and a noble metal or a noble metal compound supported thereon. 5. The formula (1): Rf ₁ -CF = CX-Rf
₂ (wherein X represents a halogen atom, and Rf ₁ and Rf ₂
Each independently represents a fluorine atom or a fluoroalkyl group, and Rf ₁ and Rf ₂ may combine with each other to form a ring. A hydrogen atom is brought into contact with the fluoroalkene represented by the formula (2), wherein Rf ₁ —CHF—CH ₂ —Rf ₂ (X, Rf ₁ and Rf ₂ represent the same meaning as described above.)
A method for producing a trihydrofluorocarbon represented by the formula: