JP2001070794A - Solid acid catalyst containing platinum group metal component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid acid catalyst having a distribution of a platinum group metal component suitable for an acid catalytic reaction. SOLUTION: A catalyst where a platinum group metal component is concentrated on the external surface of a particle by using a specified production method is provided, and this catalyst shows an excellent catalytic activity. The solid acid catalyst containing the platinum group metal component comprises a molded carrier consisting of a metallic oxide and/or a hydrated metallic oxide, and sulfuric acid content and the platinum group metal component, which are supported on this carrier. In the catalyst used for acid catalytic reactions, the concentration of the platinum group metal component in the external surface layer of the catalyst particle is at least 1.5 times the concentration of the platinum group metal component in the core part of the catalyst particle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid acid catalyst containing a platinum group metal component which has high activity in an acid catalyzed reaction and is excellent in handleability.

[0002]

2. Description of the Related Art In the chemical industry, alkylation reactions,
Acid catalyzed reactions such as an esterification reaction and an isomerization reaction are known. Conventionally, acid catalysts such as sulfuric acid, aluminum chloride, hydrogen fluoride, phosphoric acid, and paratoluenesulfonic acid have been used in this type of reaction. However, these acid catalysts have the property of corroding metals, so that it is necessary to use expensive anticorrosion materials or perform anticorrosion treatment on the production equipment. In addition, usually, it is difficult to separate the reactants from the reactants after the reaction, and furthermore, waste acid treatment is required, and a complicated process such as alkali washing has to be performed. Furthermore, it was very difficult to reuse the catalyst.

[0003] In order to solve such a problem, a sulfate-containing solid acid catalyst which is obtained by bringing a hydroxide or hydrated oxide of a Group IV metal of the periodic table into contact with a sulfuric acid-containing solution and calcining at 350 to 800 ° C. (Japanese Patent Publication No. 59-6181). This solid acid catalyst has an acid strength stronger than that of 100% sulfuric acid (Hammet's acidity function H ₀ is −11.93). These solid acid catalysts have high catalytic performance against various acid catalyzed reactions due to their strong acid strength, are low in corrosiveness, are easily separated from reactants, and do not require waste acid treatment.
It has the advantage of being able to reuse catalysts, and is expected to replace conventional acid catalysts in various industrial reactions.

It is already known that a catalyst obtained by calcining a zirconia gel containing sulfuric acid and containing platinum in the catalyst shows good activity in isomerization of hydrocarbons (US Pat. 032,599).

[0005] As a method for producing a metal oxide catalyst containing a platinum group metal and sulfuric acid for the main purpose of isomerization of hydrocarbons, a method comprising a step of treating with a sulfuric acid-containing compound and a step of supporting the platinum group metal is carried out. A production method that eliminates firing, a production method that changes the order of treatment with a sulfuric acid-containing compound and loading of a platinum group metal,
The production method that changed the type of the sulfuric acid-containing compound is Japanese Patent Publication 5-2.
No. 9503, Japanese Patent Publication No. 5-29504, Japanese Patent Publication No. 5-29505 and Japanese Patent Publication No. 5-29506. Japanese Patent Application Laid-Open No. 9-38494 discloses a method for producing a platinum-containing zirconia sulfate molded product.

[0006]

However, with respect to the metal oxide catalyst containing a platinum group metal and a sulfuric acid component, the distribution of the platinum group metal component in the catalyst particles has not been particularly described so far, and the preferred distribution is as follows. Was not known.

An object of the present invention is to provide a catalyst carrier comprising a metal oxide and / or a hydrated metal oxide, and a catalyst particle containing a sulfuric acid component and a platinum group metal component supported on the carrier. To provide a solid acid catalyst having a distribution of a platinum group metal component.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have developed a molded carrier comprising a metal oxide and / or a hydrated metal oxide, and a catalyst particle containing a sulfuric acid component and a platinum group metal component carried on the carrier. As a result of intensive studies on the distribution of the platinum group metal component in the above, a catalyst in which the platinum group metal component is evenly distributed over almost the entire particle can be obtained by the ordinary production method, but the platinum can be obtained by using the specific production method. The inventors have found that a catalyst in which the group metal component is concentrated in the outer surface layer of the particles can be obtained, and furthermore, have found that this catalyst exhibits excellent catalytic activity, thereby completing the present invention.

The solid acid catalyst containing a platinum group metal component according to the present invention comprises a molded support comprising a metal oxide and / or a hydrated metal oxide, and a sulfuric acid component and a platinum group metal component supported on the support. In the catalyst used for the acid-catalyzed reaction, the concentration of the platinum group metal component in the outer surface layer of the catalyst particles is at least 1.5 times the concentration of the platinum group metal component in the core of the catalyst particles.

In the present invention, the concentration of the platinum group metal component in the outer surface layer of the catalyst particle is at least three times the concentration of the platinum group metal component in the core of the catalyst particle, and the platinum group metal component in the total weight of the catalyst is Component ratio is 0.01 to 10
Weight percent, that the platinum group metal component is platinum,
Further, the ratio of sulfuric acid in the catalyst is preferably from 0.7 to 7% by weight in terms of elemental sulfur. Particularly, at least a part of the metal component of the metal oxide and / or the hydrated metal oxide is zirconium, and the catalyst contains 20 to 72% by weight of zirconium as a zirconium element by weight. At least a part of the metal component of the metal oxide is aluminum,
Aluminum in the catalyst is 5 as aluminum element weight
Preferably, the acid catalyst reaction is an isomerization reaction of a hydrocarbon containing 70% by weight or more of a saturated hydrocarbon component having 4 to 6 carbon atoms.

[0011] The method for producing a solid acid catalyst according to the present invention is a method for producing a solid support comprising a metal oxide and / or a hydrated metal oxide. It carries a platinum group metal component.

[0012]

According to the present invention, in a solid acid catalyst carrying sulfuric acid, a large amount of platinum group metal is carried on the outer surface layer and a relatively small amount of platinum group metal is carried on a core portion. And exhibit high catalytic activity in acid-catalyzed reactions,
Particularly, it can exhibit excellent catalytic activity for reactions such as hydrocarbon isomerization.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION [Solid Acid Catalyst] The solid acid catalyst of the present invention comprises a molded carrier composed of a metal oxide and / or a hydrated metal oxide, a sulfuric acid component supported on the carrier, and a catalyst particle. The surface layer contains a concentrated platinum group metal component.

The catalyst of the present invention is not a powder but has a molded shape, and a catalyst having a size of 0.5 to 20 mm can be easily obtained. 20
mm, particularly preferably 0.6 to 5 mm. The mechanical strength of the catalyst is 2 kg or more, more preferably 3 kg or more, still more preferably 4 to 8 kg, as the side crushing strength of a cylindrical pellet having a diameter of 1.5 mm.

The solid acid catalyst of the present invention comprises a metal oxide and / or a metal oxide.
Or, it includes a molded carrier made of a hydrated metal oxide.
The metal component of the metal oxide and / or the hydrated metal oxide is not particularly limited. For example, boron, magnesium,
Aluminum, silicon, phosphorus, calcium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel,
Examples thereof include copper, zinc, gallium, germanium, yttrium, zirconium, niobium, molybdenum, tin, hafnium, tungsten, lanthanum, and cerium. Preferably aluminum, silicon, titanium, manganese, iron, yttrium, zirconium, molybdenum,
Tin, hafnium and tungsten, especially aluminum, titanium, iron, zirconium and tin. These metal oxides and / or hydrated metal oxides, alone,
It can be used both as a mixture and as a composite metal oxide.

At least a portion of the metal component of the metal oxide and / or hydrated metal oxide used in the carrier of the present invention is zirconium, and zirconium is contained in the catalyst in an amount of 20 to 72% by weight, particularly 30 to 30% by weight of zirconium element.
It is preferred to contain 60% by weight. Further, at least a part of the metal component of the metal oxide and / or the hydrated metal oxide used for the carrier of the present invention is aluminum, and aluminum is contained in the catalyst in an amount of 5 to 3 as aluminum element weight.
It is preferable to contain 0%, especially 8 to 25% by weight. The solid acid catalyst of the present invention particularly preferably contains zirconium and aluminum as metal components, and may further contain a halogen, if necessary, for improving the acid catalyst performance.

The sulfuric acid content (S) in the solid acid catalyst of the present invention
The proportion of O ₄ ) is 0.7 to 7% by weight, preferably 1 to 6% by weight, particularly 2 to 5% by weight, as elemental sulfur. If the sulfuric acid content is too high or too low, the catalytic activity decreases.

The solid acid catalyst of the present invention contains one or more metals selected from platinum group metals. Examples of the platinum group metal include platinum, palladium, ruthenium, rhodium, iridium, and osmium. Preferably, platinum, palladium, ruthenium, and particularly platinum are suitably used. The proportion of the platinum group metal component in the catalyst is from 0.01 to 10% by weight, preferably from 0.05 to 5% by weight, particularly from 0.1 to 2% by weight as the metal element weight.
If the content of the platinum group metal component is too small, the effect of improving the catalytic performance is unpreferably low. If the content of the platinum group metal component is too large, the specific surface area and the pore volume of the catalyst are undesirably reduced.

The concentration of the platinum group metal component in the outer surface layer of the solid acid catalyst particles of the present invention is at least 1.5 times, preferably 3 times or more, more preferably at least 1.5 times the concentration of the platinum group metal component in the core of the catalyst particles. Is 5 times or more. Here, the outer surface layer means a range from the outer surface of the catalyst particles to 50 μm, and the core portion means a portion separated from the outer surface of the catalyst particles by 200 μm or more. The concentration of the platinum group metal component in the outer surface layer and the core can be determined as the concentration distribution of the platinum group metal component in the cross section of the catalyst from X-ray intensity measurement using an EPMA measuring device.

The specific surface area of the solid acid catalyst of the present invention is 50 to 5
00 m ² / g, preferably 100 to 300 m ² / g, particularly 150 to ²⁰⁰ m ² / g. The specific surface area can be measured by a generally known BET method.

The pore structure of the solid acid catalyst of the present invention can be measured by a nitrogen adsorption method in a pore diameter range of 0.002 to 0.05 μm, and a mercury intrusion method in a pore diameter range of 0.05 to 10 μm. . The pore volume with a pore diameter of 0.002 to 10 μm is 0.2 ml / g or more, preferably 0.3 ml / g.
As mentioned above, it is especially 0.35 ml / g to 1.0 ml / g.

[Catalyst Production Method] The method for producing a solid acid catalyst of the present invention comprises a molded carrier comprising a metal oxide and / or a hydrated metal oxide, a sulfuric acid component carried on the carrier and an outer surface of the catalyst particles. There is no particular limitation as long as a solid acid catalyst containing a platinum group metal component concentrated in the layer can be obtained. As an example, a sulfur-containing compound is added to a powder that is a precursor of a hydrated metal oxide and / or a metal hydroxide, kneaded, molded, calcined, and a platinum group metal-containing compound is supported.
A firing method is used. The method will be described below in accordance with this method, but the steps of calcining the carrier, supporting the sulfuric acid component or the platinum group metal component, and treating after the support are performed in the order as long as the predetermined platinum group metal component distribution can be obtained. Can be changed as appropriate.

[Precursor Powder of Hydrous Metal Oxide and / or Metal Hydroxide] Precursor powder of hydrated metal oxide and / or metal hydroxide forms a metal oxide constituting a carrier by firing after molding. Products and / or hydrated metal oxides, which may be produced in any manner, but are generally obtained by neutralizing or hydrolyzing metal salts, organometallic compounds, etc., washing and drying. Can be. Further, the precursor powder of the hydrated metal oxide and / or metal hydroxide is
Two or more types can be used in combination. Further, as the precursor powder of the hydrated metal oxide and / or the metal hydroxide, a composite metal hydroxide and / or a composite metal hydrated oxide can also be used.

[Sulfur-containing compound] The sulfur-containing compound is a compound containing a sulfuric acid or a compound containing a sulfur that can be converted into a sulfuric acid by a subsequent treatment such as calcination. Examples of the sulfur-containing compound include sulfuric acid, ammonium sulfate, sulfurous acid, ammonium sulfite, thionyl chloride, dimethyl sulfate, and the like. Sulfuric acid-containing compounds containing sulfuric acid are preferably used, and ammonium sulfate and dimethyl sulfuric acid cause corrosion of the production equipment. It is also preferred because of its low property.
Particularly, ammonium sulfate is most preferably used.

The sulfur-containing compound may be used as it is or as a solution such as an aqueous solution. The sulfur-containing compound may be prepared in consideration of the amount of the solution necessary for kneading, and there is no particular limitation on the concentration of the solution, whether in a solid state or a liquid state. The amount of the sulfur-containing compound to be added depends on the amount of sulfuric acid (S
It is preferable that the amount of O ₄ ) is 1 to 10% by weight, preferably 2 to 9% by weight, particularly preferably 3 to 8% by weight as the elemental sulfur.

[Kneading] The method of kneading is not particularly limited.
A kneader generally used for catalyst preparation can be used. Usually, a method in which the raw materials are charged, water is added, and the mixture is mixed with a stirring blade is suitably used, but there is no particular limitation on the sequence of charging the raw materials and the additives. Water is usually added during kneading, but the liquid to be added may be an organic solvent such as ethanol, isopropanol, acetone, methyl ethyl ketone, and methyl isobutyl ketone. The temperature and kneading time at the time of kneading vary depending on the hydrated metal oxide and / or the precursor powder of the metal hydroxide and the sulfur-containing compound as raw materials, provided that a preferable pore structure is obtained.
There is no particular limitation. Similarly, as long as the catalyst properties of the present invention are maintained, an acid such as nitric acid or a base such as ammonia, an organic compound, a metal salt, a ceramic fiber, a surfactant, a zeolite, a clay and the like are added and kneaded. No problem.

[Molding] The shaping method after kneading is not particularly limited, and a shaping method generally used for catalyst preparation can be used. In particular, extrusion molding using a screw type extruder or the like is preferably used because it can be efficiently molded into an arbitrary shape such as a pellet shape or a honeycomb shape. Although the size of the molded product is not particularly limited, it is usually molded to have a cross-sectional length of 0.5 to 20 mm. For example, if it is a columnar pellet, a pellet having a diameter of about 0.5 to 10 mm and a length of about 0.5 to 15 mm can be easily obtained.

[Firing After Molding] Firing after molding is performed in a gas atmosphere such as air or nitrogen, but it is particularly preferably performed in air. The firing temperature is the firing time,
The temperature is generally 400 to 900 ° C, preferably 500 to 800 ° C, depending on other firing conditions such as the gas flow rate. The firing time varies depending on other firing conditions such as the firing temperature and the gas flow rate, but is generally 0.05 to 20 hours, preferably 0.1 to 10 hours, and more preferably 0.2 to 5 hours.

[Platinum Group Metal Component and Carrying Thereof] The metal component selected as the platinum group metal component used in the catalyst of the present invention is preferably platinum, palladium, ruthenium or the like.
In particular, platinum is preferably used. It is preferable to use those in the form of a compound as the supporting component rather than the metal itself. These metal compounds can be used both as anhydrides and hydrates. Further, these metal compounds may be used alone or as a mixture of two or more. Further, the platinum group metal component may contain a metal component of another group. It is preferable to add these metal compounds so that the total amount of the platinum group metal components in the solid acid catalyst is 0.01 to 10% by weight, particularly 0.1 to 5% by weight.

The method for supporting these metal components is not particularly limited, but an impregnation method such as spraying or immersion, or an ion exchange method is preferably used.

The method for concentrating the platinum group metal component on the outer surfaces of the catalyst particles is not particularly limited, but includes pretreatment of the carrier, a method by selecting a supported compound, a method utilizing competitive adsorption, a drying method after the loading, and the like. Is mentioned. Preferable examples include a method in which the carrier is pretreated with a nitrogen-containing compound, particularly a basic nitrogen-containing compound such as ammonia. For example, when the present inventors spray-support an aqueous solution of chloroplatinic acid on a molded carrier pellet containing a sulfuric acid component and zirconia, platinum is generally uniformly supported on the entire pellet, whereas the carrier pellet is treated with an aqueous ammonia solution. It was found that platinum was concentrated in the outer surface layer of the pellet when an aqueous solution of chloroplatinic acid was spray-supported after pretreatment with a nitrogen component to contain nitrogen.

[Treatment After Supporting Platinum Group Metal Component] The supported catalyst is stabilized by drying, calcining, reducing, or the like. Drying and calcination are performed in a gas atmosphere such as air or nitrogen, and particularly preferably performed in air. The reduction is preferably performed in a stream containing hydrogen.

The firing temperature varies depending on other firing conditions such as the firing time, but is generally 300 to 800 ° C., particularly 400 ° C.
To 800 ° C, more preferably 500 to 700 ° C. Although the firing time varies depending on other firing conditions such as temperature, it is generally 0.05 to 20 hours, preferably 0.1 to 10 hours, and more preferably 0.2 to 5 hours.

[Contact with Halogen-Containing Compound] The solid acid catalyst of the present invention may optionally contain a halogen component in order to enhance its catalytic activity. In order to contain a halogen component, it is preferable that the solid acid catalyst is brought into contact with the halogen-containing compound after firing after molding or after firing after supporting a platinum group metal component. It is particularly preferable that the solid acid catalyst is brought into contact with the halogen-containing compound after the calcination after supporting the platinum group metal component because the halogen component is likely to remain. The halogen-containing compound is not particularly limited except that it does not contain a platinum group metal component, and chlorine, an inorganic chlorine-containing compound, and an organic chlorine-containing compound are preferably used. Particularly preferred are chlorine, hydrochloric acid, aluminum chloride, zirconium chloride, ammonium chloride, carbon tetrachloride, chloroform, methylene chloride, dichloroethane, trichloroethane, and mixtures thereof. After the contact with the chlorine-containing compound, post-treatments such as calcination, decomposition, oxidation, and reduction are preferably performed as necessary in order to stably contain chlorine in the catalyst. After contact with the chlorine-containing compound,
The chlorine content in the solid acid catalyst is preferably 0.02 to 10% by weight.

[Application to Reaction] As the acid catalyst reaction to which the solid acid catalyst according to the present invention is applied, a Lewis acid catalyst represented by an aluminum chloride catalyst or a Bronsted acid catalyst represented by sulfuric acid is conventionally used. Acid catalyzed reactions that have been used. In particular, it is preferably used for various reactions such as isomerization, disproportionation, nitration, decomposition, alkylation, esterification, acylation, etherification, rearrangement, and polymerization. Specific reactions include light naphtha isomerization, wax isomerization, olefin isomerization,
Xylene isomerization reaction, toluene disproportionation reaction, aromatic compound nitration reaction, fluorocarbon decomposition reaction, cumene hydroperoxide decomposition reaction, butene and butane alkylation reaction, aromatic compound alkylation reaction , Methacrylic acid and other esterification reactions, phthalic anhydride esterification reactions, aromatic compound acylation reactions, isobutene / methanol etherification reactions, Beckmann rearrangement reactions, tetrahydrofuran ring-opening polymerization reactions, olefin polymerization reactions, methane Can be used for the oxidative coupling reaction. In particular, a saturated hydrocarbon component having 4 to 6 carbon atoms is
It is suitably used for an isomerization reaction of a hydrocarbon containing 0% by weight or more.

[Hydrocarbon for Isomerization Reaction] The hydrocarbon used as a raw material for the isomerization reaction of the present invention is not particularly limited, but is a hydrocarbon present in a petroleum fraction having a boiling point of about -20 ° C to 150 ° C. Is preferably used. Furthermore, carbon number 4 ~
6 saturated hydrocarbons account for at least 70% by weight of the total, especially 90%
It is preferably used for hydrocarbons occupying at least% by weight. A preferred reaction is a reaction in which linear paraffin is isomerized into branched paraffin, and olefins and aromatic compounds are hydrogenated to form a chain or cyclic paraffin, and further isomerized. As the reaction conditions for the isomerization of the hydrocarbon compound, a preferable reaction temperature range is 20 to 300 ° C,
In particular, it is 100 to 250 ° C., the preferable reaction pressure is in the range of 1 to 50 kgf / cm ² , the preferable LHSV is in the range of 0.2 to 10 / hr, and the preferable range of the hydrogen / feed ratio is included in the feed hydrocarbon. Unsaturated content (olefin content,
It is at least the amount of hydrogen necessary to saturate the (aromatic component), particularly 0.01 to 10 mol / mol.

The content of the sulfur compound in the hydrocarbon used as a raw material for the isomerization reaction of the present invention is 500 pp as sulfur weight.
m, particularly preferably 100 ppm or less, more preferably 1 ppm or less. The amount of water in the hydrocarbon as a raw material for the isomerization reaction of the present invention is 100 ppm or less,
It is more preferably at most 5 ppm, particularly preferably at most 1 ppm.

In the hydrocarbon isomerization reaction of the present invention, a chlorine-containing compound is introduced into the raw material hydrocarbon as necessary and supplied into the reaction system in order to maintain the catalytic activity continuously.
As chlorine-containing compounds, chlorine, inorganic chlorine-containing compounds,
Although an organic chlorine-containing compound is mentioned, an organic chlorine-containing compound is particularly preferably used. Although the organic chlorine-containing compound is not particularly limited, for example, chloroform, carbon tetrachloride, methylene chloride, dichloroethane, trichloroethane, a mixture thereof and the like are suitably used. The amount of the chlorine-containing compound introduced is 0.1 ppm to 1000 ppm, preferably 1 to 10 ppm, as the chlorine amount in the raw hydrocarbon.
It is 0 ppm.

[0039]

The present invention will be described below in detail with reference to examples. [Method of measuring average particle size of aggregated particles] MICRO, Nikkiso Co., Ltd.
It was measured by a wet measurement method using a TRAC particle size analyzer. In this method, a powder is dispersed in water, a group of agglomerated particles flowing is irradiated with a laser beam, and a particle size analysis is performed by the forward scattered light.

[Measurement Method of Pore Structure] With respect to the specific surface area and the pore structure having a pore diameter of 0.002 to 0.05 μm, ASAP2400 manufactured by Micromeritics Co., Ltd.
It was measured by a nitrogen adsorption method using a mold measuring device. For a pore diameter range of 0.05 to 10 μm, Microme
It was measured by a mercury intrusion method using an AutoPore 9200 type measuring instrument manufactured by RITICS Corporation.

[Method of measuring average crushing strength] Toyama Sangyo Co., Ltd.
The side crushing strength was measured using a sample extruded in a cylindrical shape, dried and calcined using a TH-203CP tablet breaking strength measuring instrument manufactured by Toshiba Corporation. The tip of the measuring probe is 4.5m in diameter
m was used. The operation of applying the measurement sample to the center of the side surface of the cylindrical sample and measuring was repeated 20 times, and the average value was calculated.

[Distribution Analysis of Platinum Group Metal Component by EPMA] Using an EPMA measuring apparatus, the ratio of the concentration of the platinum group metal component between the outer surface layer of the catalyst and the core of the catalyst was measured. With respect to the outer surface layer of the catalyst, in the range of 0 to 50 μm from the outer surface of the catalyst, the concentration at five points was measured every 10 μm in the depth direction from the outer surface to the core, and the average was calculated. Regarding the core part of the catalyst, an arbitrary 5 μm apart from the outer surface of the catalyst by 200 μm or more
The density of the points was measured and the average was calculated.

The concentration is calculated by measuring the X-ray intensity at the peak position of the characteristic X-ray of the platinum group metal and the background position before and after the peak position, determining the background value at the peak position, and determining the background value at the peak position. The intensity obtained by subtracting the background from the measured intensity was used as the true intensity. The strength of the metal pure substance thus determined is ref, the average strength of the outer surface layer of the catalyst is surf, and the average strength of the core of the catalyst is bu.
When lk was used, the concentration of the platinum group metal in the catalyst was calculated as follows. The value in this case is a quantitative value (first order approximation). Outer surface layer: 100 × (surf / ref), core part: 1
00 × (bulk / ref) EPMA measuring device: EPMA JXA890 manufactured by JEOL Ltd.
0R Measurement conditions Acceleration voltage: 20 kV Sample current: 0.1 μA Beam diameter: 10 μm φ Dispersion crystal: LiF Measurement energy position (in the case of platinum) PtLα (peak position): 9.441 keV Background position: 8.768 keV, 9.817
4 keV

[Carrier A] A commercially available dried zirconium hydroxide powder having an average particle diameter of 1.2 μm was used as hydrous zirconia powder. A commercially available pseudo-boehmite powder having an average particle size of 10 μm was used as a hydrated alumina powder. 1860 g of the hydrous zirconia powder and the hydrous alumina powder 112
0 g, and further 575 g of ammonium sulfate,
Kneading was carried out for 45 minutes while adding water with a kneader equipped with stirring blades. The obtained kneaded material was extruded from an extruder having a circular opening having a diameter of 1.6 mm to form a cylindrical pellet, and dried at 110 ° C. to obtain a dried pellet. Subsequently, a part of the dried pellet was heated at 725 ° C. for 1 hour (from room temperature to 7 ° C.).
The temperature was raised to 25 ° C. in one hour) and calcined to obtain a carrier A.

The molded carrier A has an average diameter of 1.5 m.
m, a columnar shape with an average length of 5 mm, and an average crushing strength of 3.8 kg. The proportion of zirconia in carrier A is 46.6% by weight as elemental zirconium, the proportion of alumina is 15.5% by weight as elemental aluminum, the proportion of sulfuric acid is 2.5% by weight as elemental sulfur,
The proportion of nitrogen was 0.01% by weight or less. The specific surface area of the carrier A is 169 m ² / g, and the pore diameter is 0.002 to 10.
The pore volume in μm was 0.47 ml / g. The average pore diameter of the carrier A in the range of 0.002 to 0.05 μm in pore diameter was 57 °.

[Catalyst A: Example] An aqueous ammonia solution was spray-supported on 150 g of the carrier A so that the amount of nitrogen in the catalyst was 2% by weight. This was dried, and calcined at 400 ° C. for 1 hour (from room temperature to 400 ° C. in 1 hour) to obtain about 151 g of the carrier B. The ratio of nitrogen contained in the carrier B was 0.18% by weight. Next, 125 g of carrier B
Then, an aqueous solution of chloroplatinic acid was spray-loaded so that the amount of platinum in the catalyst was 0.5% by weight. After drying this, 50
The mixture was calcined at 0 ° C. for 1 hour (the temperature was raised from room temperature to 500 ° C. in 1 hour) to obtain about 125 g of Catalyst A.

In the catalyst A, platinum was concentrated in the outer surface layer, the platinum concentration in the outer surface layer of the catalyst was 1.03% by weight, the platinum concentration in the core of the catalyst was 0.08% by weight, The platinum concentration was 12.6 times the platinum concentration in the core of the catalyst. Catalyst A shape, average crushing strength, zirconia ratio, alumina ratio, sulfuric acid ratio, pore diameter 0.002 to 10μ
The pore volume of m was equivalent to that of the carrier A. The proportion of nitrogen in catalyst A is 0.01% by weight or less, the specific surface area of catalyst A is 164 m ² / g, and the pore diameter is 0.002 to 0.05 μm.
The average pore diameter in the range m was 64 °.

[Catalyst B: Comparative Example] An aqueous solution of chloroplatinic acid was spray-loaded on 125 g of carrier A so that the amount of platinum in the catalyst was 0.5% by weight. This was dried, and calcined at 500 ° C. for 1 hour (the temperature was raised from room temperature to 500 ° C. in 1 hour) to obtain about 125 g of Catalyst B.

In the catalyst B, platinum was carried almost uniformly, the platinum concentration in the outer surface layer of the catalyst was 0.46% by weight, the platinum concentration in the core of the catalyst was 0.42% by weight, and the platinum concentration in the catalyst surface layer was Was 1.1 times the platinum concentration in the core of the catalyst. Catalyst B
, The average crushing strength, the ratio of zirconia, the ratio of alumina, the ratio of sulfuric acid, the ratio of nitrogen, the specific surface area, and the pore volume with a pore diameter of 0.002 to 10 μm were equivalent to those of the carrier A. Catalyst B had an average pore diameter in the range of 0.002 to 0.05 μm of pore diameter of 62 °.

[Isomerization Reaction] 4 cc of a catalyst (catalysts A and B) sized to 16 to 24 mesh was charged with a length of 50 cm and an inner diameter of 1 cm.
The mixture was packed in a fixed-bed flow-type reactor having a diameter of 1 cm, and after the pretreatment, an isomerization reaction of light naphtha was performed. Pretreatment temperature: 4
The process was performed at 00 ° C., pressure: normal pressure, and atmosphere: air for one hour. Thereafter, the isomerization reaction was started after the inside of the reactor was set to a nitrogen atmosphere and further to a hydrogen atmosphere without introducing air.

The desulfurized light naphtha used as the reaction raw material was 4.9% by weight of butane, 56.3% by weight of pentane, 32.6% by weight of hexane, 2.3% by weight of cyclopentane,
It contains 2.8% by weight of methylcyclopentane and cyclohexane, 1.1% by weight of benzene, and 0.1% of olefin.
% By weight. The concentration of water is 40 ppm by weight.
Or less, the concentration of sulfur compounds is 1 wt ppm or less in terms of sulfur, the concentration of nitrogen compounds is 0.1 wt ppm or less in terms of nitrogen, the concentration of oxygen compounds other than water is 0.1 wt ppm or less in terms of oxygen, and chlorine compounds. Was 0.1 wt ppm or less in terms of chlorine.

The hydrogen gas brought to the reaction has a purity of 9%.
At 9.99% by volume, the water content was 0.5 ppm by weight or less, and as other impurities, the concentration of sulfur compound was 1% by weight or less in terms of sulfur, and the concentration of nitrogen compound was 0.1% by weight.
m or less, the concentration of oxygen compounds other than water is 0.1
Weight ppm or less, the concentration of chlorine compound is 0.1
It was less than ppm by weight.

The light naphtha isomerization reaction is carried out at a reaction temperature of 2
00 ° C., reaction pressure (gauge pressure): 30 kg / cm ² , L
HSV = 2 / hr, hydrogen / oil ratio (H ₂ / Oil): 2
(Mol / mol). The composition of the outlet of the reaction tube 250 hours after the start of oil passage was analyzed by gas chromatography. Table 1 shows the composition of the outlet of the reaction tube as the analysis result. In the table, i-C5 / ΔC5 is the proportion (% by weight) of isopentane in the chain hydrocarbon fraction having 5 carbon atoms, and 2,2′-DMB.
/ ΔC6 is 2,2 in the chain hydrocarbon fraction having 6 carbon atoms.
It is the ratio (% by weight) of 2'-dimethylbutane. I-C5 / ΔC5 of desulfurized light naphtha as a reaction raw material is 40.
0% by weight and 2,2′-DMB / ΔC6 were 1.2% by weight.

[0054]

[Table 1]

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G069 AA03 AA08 BA01A BA01B BA05A BA05B BA45A BB04A BB04B BB05B BB08B BB10A BB10B BC16A BC51A BC51B BC75A BC75B BD06A BD06B BD08A BD08B BD12B EA41 EC02 EB41 EC02 AA05 AC27 BA09 BA10 BA23 BA25 BA26 BA30 BA68 BC10 BC11 4H029 CA00 DA00 4H039 CJ10

Claims (9)

[Claims] 1. A catalyst comprising a metal oxide and / or a hydrated metal oxide, and a catalyst used for an acid-catalyzed reaction containing a sulfuric acid component and a platinum group metal component supported on the carrier. The solid acid catalyst wherein the concentration of the platinum group metal component in the outer surface layer is at least 1.5 times the concentration of the platinum group metal component in the core of the catalyst particles. 2. The solid acid catalyst according to claim 1, wherein the concentration of the platinum group metal component in the outer surface layer of the catalyst particles is at least three times the concentration of the platinum group metal component in the core of the catalyst particles. 3. The solid acid catalyst according to claim 1, wherein the ratio of the platinum group metal component to the total weight of the catalyst is 0.01 to 10% by weight. 4. The platinum group metal component is platinum.
3. The solid acid catalyst according to 3. 5. The catalyst according to claim 1, wherein the proportion of sulfuric acid in the catalyst is 0.7 to 7% by weight in terms of elemental sulfur.
The solid acid catalyst as described above. 6. The metal component of at least a part of the metal oxide and / or the hydrated metal oxide is zirconium,
Zirconium in the catalyst is 2 in terms of zirconium element weight.
6. The solid acid catalyst according to claim 1, which is contained in an amount of 0 to 72% by weight. 7. The metal component of at least a part of the metal oxide and / or the hydrated metal oxide is aluminum,
Aluminum in the catalyst is 5 as aluminum element weight
7. The solid acid catalyst according to claim 1, which is contained in an amount of about 30% by weight. 8. The solid acid catalyst according to claim 1, wherein the acid catalyzed reaction is an isomerization reaction of a hydrocarbon containing at least 70% by weight of a saturated hydrocarbon component having 4 to 6 carbon atoms. 9. A molded carrier comprising a metal oxide and / or a hydrated metal oxide, wherein a carrier carrying a sulfuric acid component is treated with a nitrogen-containing compound, and then a solid acid carrying a platinum group metal component. Method for producing catalyst.