JPS6168314A - Production of porous silica, alumina, titania, and zirconia - Google Patents

Abstract

PURPOSE:To produce uniform, amorphous, and porous silica, alumina, titania, and zirconia by prepg. specified soln. having uniform compsn. of each oxygen- contg. org. compd. of Si, Al, Ti or Zr, transforming the soln. to sol by hydrolysis, and transforming the sol to gel, and dissipating residual compd. in the gel. CONSTITUTION:An oxygen-contg. org. compd. such as alkoxide, ketoalcohol, etc. of Si, Al, Ti, Zr, etc. is dissolved uniformly in a soln. contg. at least one kind of polar compd. having multidentate or crosslinking coordination power such as dihydric alcohol, aminoalcohol, etc. at 10-100 deg.C. The compd. is hydrolyzed at 20-80 deg.C to prepare uniform sol, and transforms further to agar-like gel. The gel is dried at low temp., crushed to appropriate size, heat-treated at 200-700 deg.C under reduced pressure to dissipate and remove residual polar compd. Thus, uniform porous silica, alumina, titania, or zirconia, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides oxygen-containing organosilicon, aluminum, titanium,
Alternatively, a zirconium compound is mixed in a solution containing a polar compound having polydentate or cross-linking coordination ability to form a homogeneous solution, and then the homogeneous sol undergoes a gelation process in which the entire sol is gelled by hydrolysis. After drying the gel at a low temperature, a heat treatment process is performed to scatter the remaining polar compounds in the gel, thereby producing polydentate or polar compounds.

The present invention relates to a method for producing silicon, asilicon, aluminum, titanium, or zirconium oxides whose crosslinking coordination ability and structure are targeted.

Amorphous silicon, aluminum, titanium, or zirconium oxides can be produced by precipitating metal oxides or metal hydroxides by adding acids or alkalis to aqueous solutions of catalysts, adsorbents, sensors, and inorganic metal salts. , dissolve the metal alcokind in ethanol, glopanol, etc.
In this method, water is added to perform hydrolysis to obtain metal oxides or metal hydroxides.

Although the former method is simple, it has the disadvantage that it is difficult to eliminate impurities contained in the raw materials, and salts used for precipitation are likely to be incorporated as impurities.

In the latter method, since the metal alkoxide can be easily purified by distillation or sublimation, it is relatively easy to eliminate impurities, but it is not easy to control the expansion of the porous surface area.

Whenever silicon, aluminum, titanium, or zirconium oxides are utilized in catalysts, adsorbents, or sensors, the surface area and pore size of the oxides is an important consideration. As a method for controlling the surface area and pore structure, i'lJ ethylene glycol,
There are methods such as adding polyvinyl alcohol, polyacrylamide, or cellulose ether, washing the gel with monohydric alcohol, acid treatment or water treatment, and baking treatment, each of which has its own advantages.

However, these methods are limited to special materials such as alumina, and it is difficult to control a wide range using only individual methods, and these treatments may introduce impurities or change the properties of the metal oxide. do. In some cases. Other controlled porosity methods include methods for producing porous glass. With this method, the pore diameter can be changed from tens of amps to several thousand amps by heat treatment and acid treatment, but at present it is limited to the production of 2 to 3 composite metal oxides including silicone and cerium dioxide. The scope of application is quite narrow.

The present inventors kept the above points in mind and conducted various studies to produce homogeneous, amorphous silica, alumina, titania, or zirconia with controlled surface area and pores, and as a result, the present invention was achieved. It has been reached.

The present invention provides a method for treating a compound of one or more oxygen-containing organosilicon, aluminum, titanium, or zirconium compounds at a temperature of 10°C to 100°C with one type of polar compound having polydentate or crosslinking coordination ability. Alternatively, it is possible to mix two or more types in a solution to make a homogeneous solution, and then go through a gelation process in which the entire sol is gelled from a homogeneous sol by hydrolysis, and the polarity remaining in the gel after drying at low temperature. By applying a heat treatment process that scatters the compound,
The polydentate or cross-linked coordination ability of polar compounds and their structure are characterized by their use in homogeneous amorphization, pore design, or surface area design of silicon, aluminum, titanium, or zirconium oxides. The present invention provides a method for producing homogeneous amorphous silica, alumina, titania, or zirconia.

That is, since the first step in preparing homogeneous silica, alumina, titania, or zirconia is to create a homogeneous solution, polydentate or crosslinking with oxygenated organosilicon, aluminum, titanium, or zirconium compounds is possible. It is important to keep in mind that the polar compound having coordination ability becomes a homogeneous solution without forming a precipitate. For this purpose, the combination of an oxygen-containing organosilicon, aluminum, titanium, or zirconium compound and a polar compound having polydentate or bridging coordination ability, and the mixing temperature are often important issues. For example, oxygen-containing organometallic compounds such as aluminum, titanium, and zirconium, especially alkoxides, produce precipitates that are insoluble in ethylene glyfur and propanediol. Amino alcohols and highly branched oxygenated compounds (dihydric alcohols,
Keto alcohol, oxycarboxylic acid). On the other hand, oxygen-containing organometallic compounds of silicon, especially these alkoxides/dos, do not contain such N, and almost all 211i alcohols, amino alcohols, keto alcohols, ketocarboxylic acids, oxycarboxylic acids, Dicarbo/@ etc. can be used. If the mixing temperature is too high, an abnormal reaction may occur between the polar compound used and the oxygen-containing organosilicon, aluminum, titanium, or zirconium compound, resulting in the formation of an insoluble precipitate, so it is necessary to avoid excessive heating. Temperature: 10℃~
100°C, preferably 20°C to 80'C. In addition, if the mixing temperature is high, hydroxyl groups are easily etherified and carboquine groups are easily esterified, and in this case, the multidentate and crosslinking coordination abilities of polar compounds are significantly reduced. is 20℃～80℃
°C is preferred.

Next, the amount of polar compounds to be used is an important issue in order to compensate for the decrease in polar compounds due to unavoidable etherification and esterification, and to ensure smooth solization and gelation. Often polydentate or bridge-coordinated. If the amount used is too large, the gel will not be uniformly gelled, and the gel will float in the solution, and also in this case, gelation will take a long time. Therefore, the amount of the compound having polydentate or crosslinking coordination ability is 0.01 molar ratio to the amount of the oxygen-containing organosilicon, aluminum, titanium, or zirconium compound used.
to 15 are preferable, and 01 to 5 are particularly preferable. The amount of water used is also important for gelation; if the amount is too small, gelation will take several days or more, and if it is too large, uniform gelation will be difficult.

For example, if an oxide precipitate is formed without gelation, the absolute amount of polydentate or crosslinking polar compounds in the metal oxide will decrease, and eventually porosity and surface area expansion will proceed smoothly. do not have. Therefore, the amount of water used during hydrolysis is 0.5 to 20 in molar ratio to the oxygen-containing organosilicon, aluminum, titanium, or zirconium compound.
and 1 to 10 are particularly suitable.

The oxygen-containing organosilicon, aluminum, titanium, or zirconium compounds used in the present invention are sometimes difficult to hydrolyze depending on the metal species and ligands.

In such a case, if a hydrolysis accelerator such as an acid or an alkali is used, hydrolysis can proceed quickly and gelation can be smoothly performed. As the hydrolysis accelerator, any ordinary inorganic acid, organic acid, inorganic alkali, or organic alkali can be used as long as it is soluble, but if you do not want the hydrolysis accelerator to remain in the final metal oxide, , organic acids (carbo/acids, ketocarboxylic acids, oxycarboxylic acids, etc.) or organic alkalis as hydrolysis accelerators.
(Amines, amino alcohols, etc.) For example, formic acid, silicic acid, tartaric acid, malonic acid, koha, etc. are ground into a jelly-like or agar-like gel to an appropriate size and heated at a temperature of 80°C to 110°C under reduced pressure for several hours to 30 minutes. Dry for an hour. After drying, heat treatment is performed to scatter the remaining polydentate or crosslinking coordination-capable polar compounds, thereby forming an amorphous metal oxide f.
The heat treatment may be performed by setting the temperature and atmosphere within the range of 200 to 700° C. depending on the intended use of the silicon, aluminum, titanium, or zirconium oxide. In this case, all usual heat treatment methods can be employed, and it is also possible to combine several heat treatment methods.

For example, heat treatment can be performed only in a hydrogen atmosphere, or in oxygen or air. Furthermore, after heat treatment in rIII element, air, or inert gas, further heat treatment can be performed in a hydrogen stream.

Silicon, aluminum, titanium, or zirconium oxide produced by the method described above is powder
Linear diffraction and electron microscopy confirmed that it was amorphous and homogeneous, and the surface area and pore size were determined by BET method and pulse adsorption method using adsorption of methylpentane, n-hexane, etc. The pore distribution was determined, and it was confirmed that the surface area and pores were controlled by the manufacturing method. That is, in silica, the surface area is 150 to 1000 ze/g depending on the polar compound used, the pore diameter is distributed below d50A, and the pore volume is
It is 0.01 to 0.4 cm/9. In addition, the surface area of alumina varies from 50 to 850 rrj/I depending on the polar compound used, and the surface area of titania varies from 0.4 to 60 rrj/11
For zirconia, control was possible between 0.4 and 15 m'7.9. Such control of surface area and pores, particularly over a wide range of silica and alumina, is extremely difficult with conventional manufacturing methods, and has been made possible for the first time by the present invention. The amorphous silicon, aluminum, titanium, or zirconium oxides obtained in this way are highly homogeneous and can be fully used as adsorbents, sensors, optical semiconductors, catalysts, etc., and are particularly useful as catalysts for oxidation, isomerization, etc. It can be effectively used for cracking, hydration, hydrogenation, etc.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 4 g of methanol containing 10% hydrogen chloride was placed in a 200 m beaker, and 50 II of ethylene glycol and 63.3. Add iil of tetraethoxylan, 65
Stir at ℃ for 3 hours. Next, add water from 11.5.9 and stir for another hour at the same temperature, then add water from 12I again and stir at the same temperature, and the entire solution solidifies into an agar-like gel. . After leaving the gel at the same temperature for 1 hour,
Further, leave it at 25°C overnight. Next, crush the gel to an appropriate size, place it in a 20 (Jml) eggplant-shaped flask, and place it under reduced pressure.
Dry on a rotary evaporator at 100°C for 24 hours. Yield 25. lJ (approximately 14 times the calculated value of Si02).

The dried gel was pulverized, spread in a quartz tube, and heated for 40 minutes in a hydrogen stream.
Heat treatment was performed at 0°C for 8 hours. Silica was obtained in exactly the same manner using a different type of diol instead of ethylene glycol. Table 1 shows the physical property values.

Example 2 Put 15 ml of tart-butanol into a 300 d beaker, add 50 g of pinacol, and heat at 45°C.
Warm until completely dissolved. Next, 9.3 I of aluminum 5ea-butoxide was added, and after warming at 65°C for 2 hours with stirring, a tart containing 5.51 of water was added.
Add 100 grams of butanol solution and heat at the same temperature for an additional 2 hours while stirring. Furthermore, ter containing 5.51 water
When 50ml of t-butanol is added and stirred at the same temperature, it solidifies into agar-like form. The subsequent operations are the same as in Example 1. In addition, various aluminas were obtained by performing similar operations using various polar compounds instead of pinacol. Table 2 shows the physical property values.

Example 3 15 d of ethanol was placed in a 50 mj beaker, 1 g of methanol containing 10 t of hydrogen chloride was added thereto, 17.4 fi of titanium 1ea-propoxide was added, and the mixture was heated at 80° C. for 20 minutes. Next, 45 m/ml of ethanol containing 1.5 g of water was added, heated at the same temperature for 2 hours, and then 1 t/t of ethanol containing 1.511 g of water was added.
rst was added and stirred at the same temperature, it gelled into a jelly-like state. The subsequent operations were performed in the same manner as in Example 1, except that the heat treatment temperature was 300'C. surface area 50
．． 2 m'/i.

Example 4゜ Pour 15 ml of ethanol into a 300 ml beaker.

Add 50.1 g of pinacol to this and dissolve by heating at 45° C. for 30 minutes. 2 g of methanol containing 50.71 parts of zirconium n-globoxoxide and 101 parts of hydrogen chloride is added to this solution, and the mixture is heated at 65 DEG C. for 3 hours with stirring. Next, ethanol solution 6 containing 5.5/l of water
When 0 ml of the solution is added and stirred at the same temperature, it becomes a gel. The subsequent operations were the same as in Example 1, except that all heat treatment was performed at 350°C.

Surface area 13°/11° Table 2 Polar compounds when preparing the surface area of amorphous alumina Surface area (V?) 1
Hexylene glycol 8232 Pinacol 6803 Diacetone alcohol 60543-Methyl-1,3-butanediol 47753-
Human tetraxy-5-methyl-2-butanone 33063
-Aminopropyl/- 62 and pore adsorption pulse number 2.2 DMB 3-MP n -C62735 or above 0 2 67 or above Procedural amendment (voluntary) 60 Kagiken No. 524 April 20, 1985 1, Incident Display 1988 Patent Application No. 188611
No. 3. Patent applicant related to the case of the person making the amendment Address: 1-3-1 Kasumigaseki, Chiyoda-ku, Tokyo Name (114) Director of the Agency of Industrial Science and Technology Todoroki Written amendment to the procedure (voluntary) 59 Kagiken Penalty 78 @ Showa December 14, 1959 1 “Director General Manabu Shiga 1, Indication of the case 1988 Patent Application No. 188611
Patent applicant related to Case No. 3゜ Address: 1-3-1 Kasumigaseki, Chiyoda-ku, Tokyo Name (114) Director of the Agency of Industrial Science and Technology Todoroki Tatsu 8,
1.Corrected contents The following amendments are made in the specification of the present application.

(1) “0.4 to 60J” on page 12, line 14
Corrected to ~120J.

(2) Correct "0.4-15m/g-J" on page 12, line 15 to "0.4-65m/1".

(3) Correct "ethanol" in the second line from the bottom of page 14 to "hexylene glycol."

(4) Page 15, lines 6 to 7, “Heat treatment temperature is set to 3000
"Except that the heat treatment was performed at 300C in air for 30 hours," should be corrected to "Except that the heat treatment was performed at 300C in air for 30 hours."

(5) “Surface area 50.2 mVPJ” on page 15, line 8.
Surface area 95.6m will be corrected in July.

(6) In the second line from the bottom of page 15, change the phrase “Example 3” to “Example 3”.
” will be corrected.

Claims (10)

[Claims] (1) At a temperature of 10°C to 100°C, an oxygen-containing organosilicon, aluminum, titanium, or zirconium compound is added in a solution containing one or more polar compounds having polydentate or crosslinking coordination ability. They are mixed to form a homogeneous solution, and then undergo a gelation process in which the entire sol is transformed from a homogeneous sol into a gel through hydrolysis. After drying the gel at a low temperature, a heat treatment process is performed to scatter the polar compounds remaining in the gel. This method is characterized by the use of the multidentate or cross-linked coordination ability and structure of polar compounds for homogeneous amorphization, pore design, or surface design of the target inorganic oxide. porous silica, alumina, titania,
and a method for producing zirconia. (2) A patent in which the oxygen-containing organosilicon, aluminum, titanium, and zirconium compound is one or a mixture of two or more of alkoxides, ketoalcohol compounds, diketone compounds, ketocarboxylic acid compounds, oxycarboxylic acid compounds, and carboxylic acid compounds The method according to claim 1. (3) A polar compound with polydentate or crosslinking coordination ability is
dihydric alcohol, amino alcohol, keto alcohol,
The method according to claim 1, wherein the method is one or a mixture of two or more of diketones, ketocarboxylic acids, oxycarboxylic acids, and dicarboxylic acids. (4) A diol whose dihydric alcohol has 14 or less carbon atoms
Claim 3 which is a species or a mixture of two or more species
Section method. (5) The molar ratio (polar compound/organometallic compound) of the polydentate or polar compound having crosslinking coordination ability and the oxygen-containing, organosilicon, aluminum, titanium, or zirconium compound is 0.01 to 15. The method of claim 1. (6) The method according to claim 1, wherein the mixing ratio is from 0.1 to 5 in terms of molar ratio. (7) The method according to claim 1, wherein the mixing and hydrolysis temperature of the raw material compounds is from 20°C to 80°C. (8) The amount of water used during hydrolysis is 0.0 molar ratio (water/oxygen-containing organometallic compound) to the oxygen-containing organosilicon, aluminum, titanium, or zirconium compound.
5 to 20. The method of claim 1. (9) The method according to claim 1, wherein the molar ratio during the hydrolysis is from 1 to 10. (10) The method according to claim 1, wherein the heat treatment temperature is from 200°C to 700°C.