JP5333373B2 - NOVEL STRUCTURE CONTAINING SILICA ALUMINA AND METHOD FOR PRODUCING THE SAME - Google Patents

Description

  The present invention relates to a novel structure containing silica alumina and a method for producing the same. More specifically, the present invention relates to a structure composed of a carrier component in which silica alumina is present in the structure surface layer portion and the structure body excluding the surface layer portion is substantially free of silica alumina, and a method for producing the structure.

  Since silica alumina is a material having solid acidity, it is used in many reactions as a catalyst for chemically converting a substance (see Non-Patent Document 1). For example, it is used as a catalyst for cracking, alkylation reaction, esterification reaction, isomerization reaction and the like, which are chemical conversion reactions of hydrocarbons.

  For the reaction using an acid catalyst, aluminum chloride, phosphoric acid, sulfuric acid, hydrofluoric acid, paratoluenesulfonic acid, or the like is used. However, since these acid catalysts are extremely corrosive substances, they corrode the metals used in the reaction apparatus. For this reason, there is a problem that an expensive corrosion-resistant material for preventing corrosion must be used or a corrosion prevention treatment has to be performed.

  In addition, a homogeneous catalyst such as sulfuric acid requires a separation step such as distillation separation of the catalyst, so that it is not economical in terms of equipment and separation energy, and when separation of the catalyst is difficult, complicated washing such as alkali washing is required. In addition to the need for operation, wastewater treatment is required, which has also caused problems in terms of environmental conservation. For this purpose, a solid catalyst in which aluminum chloride is supported on an alumina carrier is used, but aluminum chloride is an extremely unstable substance, which is easily decomposed by water to lower the catalytic activity and generate hydrochloric acid. Therefore, it is necessary to completely remove water from the reaction raw material. Further, since it is difficult to restore the activity of the catalyst once lost, there is a problem that a chlorine-containing compound such as hydrochloric acid has to be supplied in order not to deactivate the catalyst.

  As a method for overcoming these drawbacks, a method using a solid acid as a catalyst has been proposed. For example, a method for producing 4-methoxyphenol by continuously supplying hydroquinone and methanol to a solid acid catalyst layer such as silica alumina has been proposed. (See Patent Document 1). Further, a method for producing P-butenylphenols by reacting phenols with 1,3-butadiene in the presence of a solid acid has been proposed (see Patent Document 2).

  As a method for producing silica alumina used as a solid acid catalyst in many reactions in this way, for example, silica and alumina hydrogel are kneaded to prepare a crude silica alumina hydrogel, which is purified and then baked to obtain solid acidity. The method of giving is used. Moreover, when using a solid catalyst with an industrial reactor, since it is desired to shape | mold to the magnitude | size of about 1 mm-6 mm, the method of shape | molding a silica alumina is devised. For example, a silica alumina sol prepared by reacting a sodium silicate aqueous solution and an aluminum sulfate aqueous solution is pulverized through a grooved cone and precipitated into heated mineral oil to form a sphere (non-contained). (See Patent Document 2).

  As a method for defining the form and structure of silica alumina, for example, a method of preparing amorphous silica alumina having high acidity, a large specific surface area, and a large pore volume has been proposed (see Patent Document 3). In this method, a solution of aluminum salt and a precipitating agent are added to the reactor in parallel flow, and then the pH and temperature are controlled to form an alumina colloid, and then a silicon compound is added to have large pores. Silica alumina can be prepared. In addition, a method for producing a silica alumina thin film by impregnating a solution containing a silica alumina compound into a multilayer bilayer film of an amphiphile prepared on a substrate and then removing the amphiphile is proposed. (See Patent Document 4). In this method, it has been shown that a silica-alumina thin film having a multilayer structure composed of an ultra-thin film at a nanometer level can be produced.

  Further, a method has been proposed in which the surface of alumina is modified with a silicon-containing compound and the alumina surface is modified to silica alumina by firing the compound (see Patent Document 5 and Patent Document 6). In this method, the properties of the catalyst such as acidity are controlled by modifying alumina with silica, and the skeletal isomerization reaction of alkenes proceeds efficiently.

Acid-base catalyst, 179 pages, industrial books (1963) Catalyst preparation, page 346, Kodansha (1964)

JP-A-9-151151 JP-A-6-40982 Japanese Patent Laid-Open No. 11-157828 Japanese Patent No. 3137379 US Pat. No. 4,038,337 Japanese Examined Patent Publication No. 4-72809 Japanese Patent No. 3553878

  In the reaction using the solid catalyst, the reaction raw material and the reaction product enter the inside of the structure through the pores of the entire structure including the forming agent or the support. Therefore, the structure of the structure, that is, the pore distribution and the surface area are important factors that influence the reaction activity. In the methods of Patent Document 1 and Patent Document 2, the structures of these structures are not defined, and it is necessary to mold the silica alumina so as to have an appropriate structure.

  Patent Document 3 and Patent Document 4 propose controlling the structure of the structure by forming it into a thin film or controlling the pore structure. Moreover, in patent document 4 and patent document 5, a catalyst can be prepared, maintaining the pore structure of an alumina by modifying the shape | molded alumina. However, the distribution of silica alumina in the molded structure is not controlled, and silica alumina having catalytic activity exists in the entire structure including the inside.

  In a reaction using a solid catalyst, if the product produced when the reaction raw material comes into contact with the catalyst active site is detached from the catalyst without coming into contact with the catalyst active site again, the desired product can be generated without causing successive reactions. A thing is obtained. However, since the reaction raw materials and reaction products that have penetrated into the structure including the support stay in the structure for a long time, the sequential reaction proceeds at the catalytic activity point inside the structure, The product is further changed to another substance and the selectivity is lowered. In addition, high-boiling substances and coke produced by the sequential reaction of the target product precipitate on the active sites and pores of the catalyst, causing poisoning of the active sites and blockage of the pores, resulting in a decrease in catalytic activity. In addition, problems such as a reduction in catalyst life occur.

  In addition, when a side reaction proceeds at a catalytic active point inside the structure and carbonaceous matter such as coke is deposited, a problem occurs when the catalyst is regenerated. In other words, when regenerating a catalyst whose catalytic activity has decreased due to the deposition of carbonaceous matter, it is necessary to perform heat treatment in an oxidizing atmosphere to burn and remove the deposited carbonaceous matter, but it is generated inside the catalyst structure including the support. The carbonaceous material is difficult to burn, and if the carbonaceous material is rapidly oxidized, there is a problem that the catalytic activity is lowered due to the destruction of the structure generated by the gas generated by the combustion or the high temperature or the decomposition of the catalytic activity point. Therefore, for example, as disclosed in Patent Document 7, it is necessary to perform the regeneration process in an atmosphere in which the oxygen concentration is reduced to 0.2 to 5% by volume, which is extremely lower than the oxygen concentration in the air, and the operation of the regeneration process is complicated. As a result, a problem arises that a long time is required.

  In order to solve these problems, the reaction product is a catalyst active point, that is, a catalyst structure in which the silica alumina having catalytic activity is immediately released from the place where it is present, and coke generation inside the structure including the support, etc. It is necessary that the side reaction does not proceed.

  The present invention has been made in view of the above problems, and its purpose is that silica alumina having catalytic activity exists only in the surface layer portion of the structure effective as a catalyst, and the inside of the structure has substantially a catalytic activity point. The object is to provide a structure which is a non-existent carrier and a method for producing the structure.

  As a result of intensive studies to solve the above-described problems, the present inventors have found a novel structure containing silica alumina and have completed the present invention.

  That is, the present invention relates to a structure that is a carrier in which silica alumina is present only in the surface layer portion of the structure and silica alumina having substantially catalytic activity is not present inside the structure surface layer portion, and a manufacturing method thereof. is there.

  The novel structure containing silica alumina of the present invention is a carrier in which silica alumina is present in the surface layer portion of the structure, and the inner layers other than the structure surface layer portion are substantially free of silica alumina having catalytic activity. It has a structure.

  Here, the structure in the present invention refers to an object formed so as to resist a load such as its own weight or external force.

  In the structure of the present invention, the thickness of the layer where silica alumina is present in the surface layer of the structure is preferably 1 to 1000 μm, more preferably 1 to 500 μm from the outer surface of the structure. Further, the inside excluding the surface layer of the structure is a carrier containing substantially no silica alumina having catalytic activity.

  The shape of the structure of the present invention is not particularly limited, and for example, a spherical shape, a cylindrical shape, a hollow cylindrical shape, a plate shape, an elliptical shape, a sheet shape, a honeycomb shape and the like as shown in FIGS. Preferably, it is spherical, elliptical, cylindrical, hollow cylindrical, more preferably spherical, because it has sufficient reaction activity and can suppress side reactions and coking.

  Further, the size of the structure of the present invention is not particularly limited. For example, since side reactions and coking can be suppressed, it is preferably in the range of 10 μm to 10 cm, more preferably in the range of 100 μm to 5 cm. The structure of this is mentioned.

  In the structure of the present invention, the presence or absence of a binder is not particularly limited.

  The method for producing the structure of the present invention is not particularly limited. For example, (1) a method in which a hydroxide and / or oxide of silicon and aluminum is supported on the surface layer portion of the support and fired at 200 to 800 ° C., (2) After supporting a raw material salt of silica and alumina on a carrier, hydrolysis is carried out to precipitate silicon and aluminum hydroxide and / or oxide on the surface layer of the carrier, and firing at 200 to 800 ° C. (3) A solution containing silica and alumina raw material salt is sprayed on the surface layer of the carrier, and the raw material salt is supported on the surface layer portion of the structure and then hydrolyzed, thereby hydrolyzing silicon and aluminum hydroxide and / or Alternatively, after the oxide is supported on the surface layer of the support, firing is performed at 200 to 800 ° C., (4) silicon that is a raw material for silica and alumina on the outer surface of the support that is the inside of the structure, and Hydroxides and / or oxides coated of aluminum, it is possible to produce a structure by a method of baking at 200 to 800 ° C.. The method (1) is preferably used because the silica alumina supported on the surface layer portion of the structure is difficult to diffuse inside and the silica alumina having catalytic activity present on the surface layer does not peel off.

  In the present invention, the method (1) will be described in detail. First, a basic substance and / or water is impregnated and supported on a carrier. By immersing this carrier in a solution in which the raw material salt of silica and alumina is dissolved, the raw material salt in the solution comes into contact with the basic substance and / or water impregnated in the carrier, and a hydroxide is obtained by hydrolysis reaction or the like. Or it becomes an oxide and precipitates on the surface layer of the carrier. Thereafter, drying and baking at 200 to 800 ° C. in the air can be performed to produce a structure which is a carrier in which silica alumina is present in the surface layer portion and silica alumina having catalytic activity is not present inside the surface layer.

  In the method (1), a case where silica or alumina is used as a carrier will be described. When silica is used as a support, first, a basic substance and / or water is impregnated and supported on the silica support. By immersing this silica support in a solution in which the alumina raw material salt is dissolved, the alumina raw material salt in the solution comes into contact with the basic substance and / or water impregnated in the silica support and is hydrolyzed by a hydrolysis reaction or the like. It becomes a product or an oxide and precipitates on the surface layer of the silica support. At this time, a raw material salt of silica is not necessary. Thereafter, drying and calcination in air at 200 to 800 ° C. can produce a structure which is a silica carrier in which silica alumina is present in the surface layer portion and silica alumina having catalytic activity is not present in the inside other than the surface layer.

  In the case of using alumina as a carrier, first, a basic substance and / or water is impregnated and supported on the alumina carrier. By immersing the alumina support in a solution in which the silica raw material salt is dissolved, the silica raw material salt in the solution comes into contact with the basic substance and / or water impregnated in the alumina support, and is hydroxylated by a hydrolysis reaction or the like. It becomes a product or an oxide and precipitates on the surface layer of the alumina support. At this time, a raw material salt of alumina is not necessary. Thereafter, drying and calcination at 200 to 800 ° C. in the air can be performed to produce a structure which is an alumina carrier in which silica alumina is present in the surface layer portion and silica alumina having catalytic activity is not present inside the surface layer.

  The basic substance used in the method of the present invention is not particularly limited and can be used regardless of inorganic substance or organic substance. For example, alkali metals such as lithium, sodium and potassium cesium, magnesium, calcium, strontium, strontium, Alkalinity metals such as barium, ammonia, methylamine, ethylamine, propylamine, butylamine, dibutylamine, cyclobutylamine, phenylamine, benzylamine, butylbenzylamine, phenyleneamine, dicyclohexylamine, decylamine, ethanolamine, propanolamine, Amines such as phenylethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide Pyridines such as pyridine, methylpyridine, dimethylpyridine, ethylpyridine, diethylpyridine, phenylpyridine, aminopyridine, nitropyrine, bromopyridine, chloropyridine, quinoline, methylquinoline, dimethylquinoline, hydroxymethylquinoline, Quinolines such as vinylquinoline, phenylquinoline, hydroxyquinoline, tetrahydroquinoline, aminoquinoline, chloroquinoline, bromoquinoline, nitroquinoline and methoxyquinoline can be used. Since the silica alumina raw material supported on the surface layer of the structure is difficult to diffuse inside, ammonium compounds such as alkali metals, alkalinity metals, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, Pyridines and quinolines are preferred. Furthermore, ammonium compounds such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, pyridines, and quinolines are preferred because no basic substance remains after firing.

  The raw material salt of silica that can be used in the present invention is not particularly limited as long as it is a compound containing silicon. For example, tetraethoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, aminopropyltriethoxy Silane, triethoxyvinylsilane, methyltriethoxysilane, diethoxydimethylsilane, methyltrimethoxysilane, aminopropyltrimethoxysilane, ethoxytrimethylsilane, dihydroxydiphenylsilane, aminopropyldimethylmethoxysilane, carbomethoxyethyldimethoxymethylsilane, dimethoxymethyl -N-octadecylsilane, dimethylmethoxy-n-propylsilane, dimethylmethoxy-n-octylsilane, octyltriethoxysilane, ethyltriethoxysilane, Silane compounds such as limethoxy (7-octen-1-yl) silane, ammonium hexafluorosilicate, ammonium fluoride, hexafluorosilicic acid, hydrofluoric acid, silicic acid, silicon tetrachloride, sodium silicate, Silicon-containing compounds such as water glass can be used, preferably tetraethoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, aminopropyltriethoxysilane, triethoxyvinylsilane, methyltriethoxysilane, di- Ethoxydimethylsilane can be used.

  The raw material salt of alumina that can be used in the present invention is not particularly limited as long as it is a compound containing aluminum. For example, aluminum salts such as aluminum chloride, aluminum nitrate, aluminum sulfate, and aluminum carbonate; lithium aluminate, Aluminates such as sodium aluminate, potassium aluminate, rubidium aluminate, cesium aluminate; aluminum alkoxides such as aluminum methoxide, aluminum ethoxide, aluminum propoxide, aluminum butoxide, etc. can be used, preferably Aluminum salts such as aluminum chloride, aluminum nitrate, aluminum sulfate, and aluminum carbonate can be used.

  In the method of the present invention, the carrier to be used is not particularly limited, and is a carrier having substantially no catalytic activity for the catalytic reaction to be used. For example, silica, alumina, titania, activated carbon, acetylene black, oxidation Zinc, calcium carbonate, barium sulfate, silicon carbide, carbon nanotubes, carbon nanohorns, hydrotalcite, montmorillonite, saponite, magnesia and the like may be used, but silica and alumina are preferred.

  The temperature of the baking performed by the method of the present invention may be 200 to 800 ° C. Since the basic organic substance used when the silica alumina having catalytic activity is supported on the surface layer portion does not remain, the temperature is preferably 250 to 700 ° C. The firing time may be 0.5 to 20 hours.

  The structure of the present invention can be used as a solid acid catalyst. For example, catalytic cracking reaction of light oil and heavy oil; hydrocracking reaction of heavy oil; cyclohexane dehydrogenation, cyclopentene isomerization dehydrogenation, paraffin cyclization dehydrogenation, paraffin isomerization, paraffin hydrogenation Catalytic reforming reaction of heavy fraction of petroleum naphtha such as cracking; Alkane such as butane, pentane, hexane, butene, pentene, hexene, xylene, skeletal isomerization reaction of alkene and hydroisomerization reaction of alkene; benzene, alkylbenzene , Naphthalene, phenol, thiophene, pyridine and the like, ethylene, propylene, butene, pentene, hexene, methanol, ethanol, propanol, butanol, ethyl chloride, propyl prolide, butyl chloride and other olefins, and alcohols such as alkyl halides. Alkylation reaction; Isomerization, disproportionation, transalkylation of alkyl aromatics such as benzene, ethylbenzene, propylbenzene, butylbenzene, xylene, diethylbenzene, dipropylbenzene, dibutylbenzene, trimethylbenzene, triethylbenzene, tripropylbenzene, tributylbenzene, It can be used for dealkylation reaction, dehydrogenation reaction; polymerization of olefins such as ethylene, propylene, butene, pentene and hexene; ring-opening polymerization reaction of cyclic ethers such as tetrahydrofuran; and reduction reaction of NOX.

  The structure of the present invention can also be used as a catalyst support, for example, one group element such as lithium, sodium, potassium, rubidium and cesium; two groups such as beryllium, magnesium, calcium, strontium and barium. Elements; 3 group elements such as scandium, yttrium, lanthanoid and actinoid; 4 group elements such as titanium and zirconium; 5 group elements such as vanadium, niobium and tantalum; 6 group elements such as chromium, molybdenum and tungsten; manganese, rhenium and the like 7 group elements; 8 group elements such as iron, ruthenium and osmium; 9 group elements such as cobalt, rhodium and iridium; 10 group elements such as nickel, palladium and platinum; 11 group elements such as copper, silver and gold; , Cadmium and other 12 group elements; boron, aluminum, gallium, indigo Supports one or more kinds of elements such as 13 group elements such as sulfur and thallium; 14 group elements such as germanium, tin and lead; 15 group elements such as antimony and bismuth, and 16 group elements such as sulfur and tellurium. Can be used.

  The structure of the present invention is a support in which silica alumina is present in the surface layer portion of the structure, and silica alumina having substantially catalytic activity is not present inside other than the surface layer portion. Therefore, since the reaction raw materials and reaction products do not come into contact with the catalyst inside the structure where side reactions are likely to occur, the selectivity of the target product is high, and poisoning of active sites and pore clogging occur. Since it is difficult to reduce the catalytic activity, it has the effect that the catalyst life is long. In addition, since there is no catalytic active site inside the structure, carbonaceous matter does not precipitate inside the structural body, so that the catalyst can be easily regenerated by burning carbonaceous matter.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

The measurement methods used in the following examples are shown.
(Line analysis to determine the distribution of silica alumina in the depth direction)
A sample obtained by embedding the obtained structure in a resin and cutting with an ultramicrotome was subjected to an electron beam probe microanalyzer (EPMA) (trade name EPM-810, manufactured by Shimadzu Corporation) with a voltage of 20 kV and a current of 10 nA. Was used to perform a line analysis in the depth direction of the particle cross section, and the distribution of silicon and aluminum was measured.
(Measurement of ammonia temperature-programmed desorption spectrum for analyzing acid properties)
Using a temperature-programmed desorption spectrometer (trade name TPD-1-AT, manufactured by Bell Japan), pretreatment was performed at 500 ° C. for 1 hour in a helium stream, and then ammonia was adsorbed at 100 ° C. The measurement was performed at a measurement temperature at a rate of temperature increase of 10 ° C./min.

Example 1
16.5 g of 1.0 mol / liter tetra-n-propylammonium hydroxide aqueous solution was added to silica beads ("Caract Q-50" manufactured by Fuji Silysia Chemical Ltd., particle shape: spherical, particle diameter: 1.7-4. 10 g (0 mm, surface area: 80 m ² / g, average pore diameter 50 nm) was added, and silica beads were impregnated with an aqueous solution, and then dried under reduced pressure at 50 ° C. for 2 hours at 20 hPa.

  Next, 1.02 g of aluminum nitrate nonahydrate was dissolved in 10 ml of ethanol, and the silica beads impregnated and supported with tetrapropylammonium hydroxide were added and stirred for 30 minutes. After stirring, it was dried under reduced pressure at 50 ° C. and 20 hPa for 2 hours, and then calcined at 600 ° C. for 3 hours in an air stream.

  FIG. 5 shows the results of line analysis of aluminum and silicon of the obtained silica-alumina structure. It was found that the supported aluminum was present within 400 μm from the outer surface of the silica beads. The results of measuring the ammonia temperature programmed desorption spectrum are shown in FIG. It was found that an ammonia desorption peak appeared around 200 ° C., and solid acid sites appeared due to the formation of silica alumina.

Comparative Example 1
1.02 g of aluminum nitrate nonahydrate was dissolved in 10 ml of ethanol. In the resulting solution, silica beads ("Cartict Q-50" manufactured by Fuji Silysia Chemical Co., Ltd., particle shape: spherical, particle diameter: 1.7 to 4.0 mm, surface area: 80 m ² / g, average pore diameter of 50 nm) 10 g was added and stirred for 30 minutes. After stirring, it was dried under reduced pressure at 50 ° C. and 20 hPa for 2 hours, and then calcined at 600 ° C. for 3 hours in an air stream.

  FIG. 7 shows the results of line analysis of aluminum and silicon of the obtained silica-alumina structure. The supported aluminum was also present inside the silica beads.

Example 2
Alumina beads (“KHD-24” manufactured by Sumitomo Chemical Co., Ltd., particle shape: spherical, particle diameter: 2.4-4.0 mm, surface area: 270 m ² / g, pore volume 0.38 ml / g) at 200 ° C. for 3 hours Heat-dried. 10 ml of water was added to 20.0 g of the alumina beads and stirred for 30 minutes. After stirring, it was dried under reduced pressure at 50 ° C. and 20 hPa for 30 minutes. From the weight increase before the addition of water, 3.15 g of the added water remained.

  Next, 2.14 g of tetraethoxysilane was dissolved in 7.5 ml of hexane, added to the previously obtained water-impregnated alumina beads, and stirred for 30 minutes. After stirring, it was dried under reduced pressure at 50 ° C. and 20 hPa for 2 hours, and then calcined at 600 ° C. for 3 hours in an air stream.

  FIG. 8 shows the results of line analysis of aluminum and silicon of the obtained silica-alumina structure. It was found that the supported silicon was present within 500 μm from the outer surface of the alumina beads.

Example 3
A silica alumina structure was prepared in the same manner as in Example 2 except that 7.5 ml of ethanol was used instead of 7.5 ml of hexane.

  FIG. 9 shows the results of line analysis of aluminum and silicon of the obtained silica-alumina structure. It was found that the supported aluminum was present within 500 μm from the outer surface of the silica beads.

Comparative Example 2
Alumina beads (“KHD-24” manufactured by Sumitomo Chemical Co., Ltd., particle shape: spherical, particle diameter: 2.4-4.0 mm, surface area: 270 m ² / g, pore volume 0.38 ml / g) at 200 ° C. for 3 hours Heat-dried.

Next, 2.14 g of tetraethoxysilane was dissolved in 7.5 ml of hexane, added to the previously obtained dry alumina beads, and stirred for 30 minutes. After stirring, it was dried under reduced pressure at 50 ° C. and 20 hPa for 2 hours, and then calcined at 600 ° C. for 3 hours in an air stream.

  FIG. 10 shows the results of line analysis of aluminum and silicon of the obtained silica-alumina structure. The supported silicon was present almost uniformly up to the inside of the alumina beads.

Comparative Example 3
A silica-alumina structure was prepared in the same manner as in Comparative Example 2 except that 7.5 ml of ethanol was used instead of 7.5 ml of hexane.

  FIG. 11 shows the results of line analysis of aluminum and silicon of the obtained silica-alumina structure. The supported silicon was present almost uniformly up to the inside of the alumina beads.

  The present invention provides a structure in which silica alumina having catalytic activity exists only in the surface layer portion of the structure effective as a catalyst, and a structure that is a carrier having substantially no catalytic active site inside the structure, and a method for producing the structure. In particular, the resulting structure is expected to develop as a catalyst for various reactions.

Sectional view of the spherical structure of the present invention Sectional view of the cylindrical structure of the present invention Sectional view of the hollow cylindrical structure of the present invention Sectional view of the plate-like structure of the present invention Results of silicon and aluminum line analysis of the structure of Example 1 Measurement result of ammonia temperature programmed desorption spectrum of the structure of Example 1 Results of line analysis of silicon and aluminum of the structure of Comparative Example 1 Results of silicon and aluminum line analysis of the structure of Example 2 Results of silicon and aluminum line analysis of the structure of Example 3 Results of line analysis of silicon and aluminum of the structure of Comparative Example 2 Results of line analysis of silicon and aluminum of the structure of Comparative Example 3

1 Silica Alumina 2 Support

Claims (3)

After impregnating and supporting water on an alumina carrier, tetraethoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, aminopropyltriethoxysilane, triethoxyvinylsilane, methyltriethoxysilane, diethoxydimethylsilane A method for producing a structure comprising impregnating a raw material salt of silica selected and supporting a hydroxide and / or oxide of silicon on a surface layer of an alumina support, followed by firing at 200 ° C. to 800 ° C. . 2. The structure according to claim 1, wherein silica alumina is present in the surface layer of the structure, and the inside of the structure excluding the surface layer is an alumina support substantially free of silica alumina. Production method. The method for producing a structure according to claim 1 or 2, wherein silica alumina is produced in a surface portion from the outer surface of the structure to a depth of 1 to 1000 µm.

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