JPS6138627A - Catalyst stable at high temperature, process for preparing the catalyst, and process for carrying out chemical reaction using the catalyst - Google Patents

Abstract

PURPOSE:To obtain a catalyst having improved heat resistance by allowing a catalyst composition to be carried on a carrier comprised of a mixture of precursor consisting of a compound oxide of aluminium with one kind among La, Nd, and Pr, which is transformed to rare earth element beta-alumina by heating. CONSTITUTION:Alkali is added to a solution contg. a mixture of aluminum salt and at least one kind of salt of elements selected from La, Nd, and Pr to cause coprecipitation from the mixture. The coprecipitate is separated and molded to several shapes. The coprecipitate consists of a compound oxide of Al and said rare earth element(s). The compound oxide is calcined to a pecursor or a mixture of the precursor which can be transformed to rare earth element beta-alumina by heating at 1,000 deg.C for <=2hr, having at least >=10m<2>/g specific surface area. By using the calcined product as carrier, a catalyst stable at high temp. is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a catalyst stable at high temperatures, a method for preparing the same, and a catalytic reaction process using the catalyst. The catalyst used in the present invention can be used over a wide temperature range, and can maintain stability and high activity particularly at temperatures of 50° C. or higher.

[Background of the invention]

Examples of reactions that use catalysts to carry out reactions at high temperatures include oxidative removal of organic solvents, odor treatment, automobile exhaust gas purification, high-temperature steam reforming, and high-temperature denitrification. Recently, there has been a movement to apply catalytic combustion technology to large-capacity boilers, gas turbines, gas turbines for aircraft, etc.

In these methods, the reaction temperature is approximately 6,000°C or higher, and depending on the conditions, it can reach 1,400 to 1,500°C. Therefore, there is a need for a catalyst that exhibits little decrease in catalytic activity even in such a high temperature range and has high thermal stability.

Conventionally, catalysts used as high-temperature catalysts include alumina, silica alumina, etc. as carriers on which precious metals or base metal components are supported, zirconia,
Aluminum titanate, cordierite.

Ceramic materials such as silicon nitride are used as carriers, and the surface thereof is coated with activated alumina to support precious metal components.

However, when these catalysts are heated to 50°C or higher, the crystal structure of the support changes (for example, in the case of alumina, it changes from r-type to α
However, the specific surface area decreases due to crystal growth (phase transition to a type) and crystal growth, resulting in a decrease in the number of active sites due to aggregation of active ingredients, resulting in a loss of catalytic activity. Catalysts using the above-mentioned ceramic materials have a drawback that, although the ceramic itself has high heat resistance, the coating material has low heat resistance, so that the catalytic active components are not effectively utilized.

Heretofore, the following patents have been known regarding catalysts using carriers made of alumina and rare earth elements.

(1) U.S. Patent No. 3,993,572 “Catalyst component consisting of rare earth elements and platinum group” (2) U.S. Patent No. 3,966.391 “Combustion method using high temperature stable catalyst” (3) U.S. Patent No. 3,956,188 "Composition and preparation method of high temperature stable catalyst" (4) U.S. Patent No. 3,899,444 "Catalyst for exhaust gas treatment" (5) U.S. Patent No. 3,867.312 "Catalyst for exhaust gas treatment" (6) U.S. Patent 3 , 714,071'''Low density alumina particles with high strength at high temperatures'' (7) U.S. Patent 4,056,489'High temperature stable catalyst composition and method for preparing the same'' (8) U.S. Patent 4,021,185'' Composition and preparation method of catalyst stable at high temperature” (9) U.S. Patent 4,220,559 “High temperature stable catalyst”
Ql U.S. Pat. No. 4,061,594'"Alumina-based carrier stable at high temperatures" and other prior art U.S. Pat.
98,183.

3.894,140,3.88 turtle445,3,880
, 775.

λ867.309, 3,819,536, 4,374,
819゜4.369,130, 4,318,894
, 423 turtle 180° 4206.087 , 4,177.
163, 4,153,580.

4.170,573, 4,054,642, etc.

Among these, U.S. Pat. No. 3,966.391, 4,17
0,573°4.061,594 is believed to be relevant to the present invention.

In U.S. Patent 3,966.391, L a (NOs)
s, C, r Os.

Alumina powder was added to a solution containing 5r(NOx)a and these components were supported by an impregnation method, and after drying at 110C, 12
Baked at 00C for 2 hours. This catalyst is used for combustion of carbonized oil.

In US Pat. No. 4,170,573, I, a(NOx)s is impregnated into alumina powder, and after drying at 160°C for 16 hours,
After baking at 250C for 1 hour, it was impregnated with Ce(NO3)s solution and dried at 160C for 16 hours. Then 'Pt℃,
, impregnated with solution and fired at 427-649℃ to obtain Pt-L
An a-Ce-AlxOs catalyst is obtained.

U.S. Patent No. 4,061,594f discloses that alumina autoclaved at 6ooc is calcined at 5ooc, and La (N
After impregnating with Ox)s, La*Oa-AtxOs is prepared, and this is impregnated with a platinum group metal at 1000-1200C.
It is fired in

On the other hand, Journal of Solid State Chemistry
Chemistry) 1 and 193-204 (19
76) conducted research on lanthanum/β-alumina crystals, but there is no description regarding catalysts for these crystals.

[Purpose of the invention]

An object of the present invention is to provide a highly heat-resistant catalyst and a catalytic reaction process using the same.

[Summary of the invention]

Alumina such as γ- or η- has a high specific surface area and is currently widely used as a carrier coating agent.
At temperatures above 000C and especially above 900C, the phase transition to α-alumina and the growth of crystal particles result in a sintered body with a marked decrease in specific surface area, and as a result, particles of noble metals, base metals, etc., which are catalytically active components, agglomerate. However, the catalytic activity decreases. The present inventors have conducted extensive research in order to improve such thermal instability of alumina and to prevent agglomeration of catalytically active components. As a result, lanthanum β-alumina (Law
03 ・11~14At*Os) + praseodymium β-alumina (Pr*Os・11~14 kls
Os).

It was discovered that a catalyst made of neodymium β-alumina (Nd203+111-14 for 120s) (hereinafter referred to as L-β-alumina) supporting catalytically active components such as noble metals and base metals is very effective. Ta.

The present invention is a heat-resistant catalyst in which an active ingredient is supported on a carrier made of a composite oxide of aluminum and lanthanum.

The composite oxide of aluminum and lanthanum is composed of a mixture of lanthanum β-alumina and its precursor, and the precursor is
It can be converted to lanthanum β-alumina when heated at 00C for 2 hours. Further, the above composite oxide may essentially consist of a precursor of lanthanum β-alumina.

The high-temperature stable catalyst of the present invention has a catalytically active component supported on a composite oxide containing aluminum and at least one rare earth element selected from lanthanum, neodymium, and praseodymium, and the composite oxide has a specific surface area of At least 10 m”/g or more.

and chromium, strontium, cerium in an amount of less than 1% by weight, L-β-alumina and ioo.

It consists of a precursor or a mixture of precursors that are essentially L-β-alumina that can be converted to L-β-alumina when heated at C for up to 10 hours.

The details of the present invention will be described below. In the present invention, L-β-alumina is, as mentioned above, La2O3+111~14A
7!40s, Prg o3 e 11~14At2
It is a complex oxide represented by the chemical formula of On, Nd*Os・11-14AtzOa. These composite oxides are A
It is obtained by heat-treating a mixture of hydroxides and oxides of t, L a , and N dapr at a temperature of 5 ooc or more. The catalyst in which the catalytically active component was supported on this carrier was 10
Even when used at temperatures above 1,000 ℃, the catalytically active components are not aggregated by heat and can maintain high activity. This is due to the strong interaction between the composite oxide of aluminum and lanthanum, neodymium, or praseodymium and the catalytic active component.

The composite oxide consists of a mixture of L-β-alumina and a sheep precursor or the precursor. The composite oxide has excellent heat resistance and a high specific surface area. From X-ray diffraction and electron microscopy observations, it was found that this composite oxide suppresses the phase transition of alumina and is resistant to crystal growth. Further, the specific surface area of the carrier of the present invention determined from the amount of nitrogen adsorption shows very little decrease even at high temperatures. When palladium or platinum is supported as an active ingredient on the above carrier, the dispersion state (crystal particle size) of these active ingredients can be observed using an electron microscope and CO2.
As a result of investigating the chemical adsorption amount, it was found that even when fired at 1200C, the particle size was small and highly dispersed.

A composite oxide of At and La, Nb or pr may be coated on a ceramic molded body, or powders of both may be mixed to form a carrier. For example, heat-resistant materials α-alumina, titania, zirconia, magnesia, cordierite, and mullite.

It is possible to use a mixture of an oxide such as aluminum titanate and the above composite oxide. It can also be used in combination with non-oxide heat-resistant materials such as silicon nitride and silicon carbide. Further, a molded article made of the above-mentioned heat-resistant material can be coated with the composite oxide of the present invention.

In this case, it is desirable that the composite oxide consisting of At and La, Hb, or pr accounts for at least 501 or more of the total carriers.

The present inventors have revealed the following facts (hereinafter, to simplify the explanation, only La will be described).

(1) La has a similar effect on stabilizing the alumina carrier when heated at high temperature, but Ce has no stabilizing effect even though it is the same rare earth. Further Cr.

When Zr, Sr, Ca, Na, etc. are added to alumina,
Firing at 1200 C or higher promotes crystal growth.

When this phenomenon occurs, the specific surface area of the carrier decreases significantly.

(2) This composite oxide has a specific surface area of at least 10 m''/g and is in an amorphous or near-crystalline state, or can be converted into L-β-alumina when heated at 1400°C for 2 hours. The chemical form of alumina in the composite oxide is other than α-2r-, θ-2η-, κ-2, --, and δ-, and the specific surface area is desirable. is 20~100m”/g
has.

(3) The content of L-β-alumina in the composite oxide is 15 to 95% by weight. The molar ratio of La and Os to At20s in the starting material (before firing) (La2O3/
Atz O3) is 1/99 and the content of L-β-alumina is 15% by weight. Lag Os /At20s=
When the molar ratio is 20/80, the content of L-β-A12oz is 95% by weight. Similarly, La2O3/Atz03
= 10/90, L-β-alumina is 90% by weight,
La20s / At2'03 = 5/95 with u64 weight t%, La20s / Atz 03 = 2/9
8, it is 27% by weight.

The main component of the composite oxide is a mixture or precursor of L-β-alumina and its precursor, and is at least 50% by weight.
Including the above.

In powder X-ray diffraction, L-β-alumina has a Cu-Ka
When using a line, the Bragg angle 2θ is 18.9°■, 20
．． 1°■, 32.3°■, 34.0'■.

36.2°■, 39.4°■, 40.9°■, 42. ．．
8°■.

There are peaks at positions of 45.1°■, 58.0°■, and 67.4°■ (the numbers in circles indicate the order of relative intensity). In the case of composite oxide fired at 1200t:", 3rd b
1 & 9° as shown in Figure 3C.

20.1°, 323°, 34.0°, 36.2°, 4L
8'.

It has peaks at 45.1°, 58.0°, and 67.4°. This indicates that the composite oxide contains L-β-alumina. Figure 3b.

In the X-ray diffraction diagram shown in Figure 3C, the peaks are weaker and broader than in Figures 3a and 3b, so this composite oxide is composed of L-β-alumina and α-9γ-2θ-2η.
L-β having a form other than -1L-1δ-1χ-9ρ-
- Contains a precursor of alumina, which is found to be amorphous. In Figures 3b and 3C, the peaks indicated by black circles are 323°, 36.2°, 42.8',
They are 45.1° and 67.4°.

(4) Lanthanum on an alumina support with forms such as α-, γ-6θ-1δ-1η-, and κ-1ρ-.

Impregnated with a solution of praseodymium and neodymium salts, 100
When calcined at 0 to 1200 C for 2 hours, a sufficient amount of L-β-alumina is not produced.

According to the present invention, in the catalyst that is stable at high temperatures, the carrier is made of a compound containing multiple oxides. The high temperature stable catalyst of the present invention can have a honeycomb structure. The high temperature stable catalyst of the present invention can also be comprised of a carrier carrying a catalytically active component and a support for supporting the carrier. In this case, the support can be selected from metal plates, wire mesh and spongy metal. Further, a composite oxide containing an active ingredient can also be used by coating the surface of the carrier.

A preferred method for preparing the high-temperature stable catalyst of the present invention is to add an alkali to a mixed solution of an aluminum salt and a lanthanum, praseodymium or neodymium salt, separate the resulting coprecipitate by filtration, and mold the resulting product at a temperature higher than 100oC. Bake at a temperature of This firing produces a composite oxide of At and at least one of the rare earth elements La, Nb, and pr. That is, the composite oxide has a specific surface area of at least 10 m"/g or more, and the composite oxide has α-1γ-, θ-
It has an alumina structure other than 1η-1, 2χ-1ρ-1δ-, and is a precursor or L-β-alumina that can be converted to L-β-alumina when heated at 100 oc or more for less than 2 hours. This is a mixture of precursors.

Furthermore, the catalyst carrier of the present invention can be obtained by uniformly mixing fine powders of aluminum and lanthanum, neodymium, or praseodymium oxides or salts by a dry or wet method, and calcining the mixture at a temperature of 8,000 C or more, preferably 1,000 C or more, to obtain L-β- Precursors of alumina or L-β-alumina can be prepared.

When the firing temperature is 800C or less, no L-β-alumina precursor is observed to be produced.

The carrier of the present invention is prepared by the following method.

(a) Starting materials for complex oxides, namely At and L a r N
The homogeneous mixture of d+Pr salts is fired at a temperature of, for example, 800C or less. Next, it is fired at a temperature of 900C or higher, and 10
Heating above 00C for up to 10 hours produces a mixture of L-β-alumina and its precursors.

(b) The starting material for the composite oxide is fired in advance at a temperature of 800C or less. Next, the precursor of the composite oxide is impregnated with a solution containing the active ingredient, or the carrier is coated with a carrier containing the composite oxide and the active ingredient. This was fired at 900 to 1500 C for a certain period of time to produce L-β-
Precursors of alumina and mixtures thereof are formed.

The firing temperature for forming a composite oxide of At and La is preferably 9,000 or higher, preferably 10,000 or higher. If the firing temperature is below 900C, the desired composite oxide will not be formed.

The crystals of the composite oxide of the present invention are nearly amorphous, or L-
It has a structure similar to β-alumina. For this structure,
It is determined by the firing temperature and firing time.

As the temperature increases, the proportion of L-β-alumina in the composite oxide increases.

If the composite oxide precursor is heated at 15001:l' for 1 hour or more, the crystal growth of the composite oxide will be significant and the specific surface area will decrease. Even when heated at 900C, the desired composite oxide can be obtained by heating for 100 hours or more. Firing conditions should be selected from a practical standpoint. Desirable firing conditions are 1000C for at least 1 hour to 1 hour.
0.5 hours or less at 400°C is preferable. Pressure during firing is not a very important factor. The most desirable firing conditions are 1100 C for 10 hours to 13000 C for 0.5 to 2 hours and a pressure of 100 Kf/cd or less.

The powder made of the composite oxide is used in various shapes, such as spherical, one cylinder, one cylinder, ring shape, and honeycomb shape. Powders containing composite oxides can also be used on metal plates with various shapes, wire mesh, spongy metal, or inorganic heat-resistant substrates such as mullite, cordierite, α-alumina, zirconia, aluminum-1 mutitanate, and silicone carbon. Part-Time Job,
It can be used by coating silicon nitride, etc. In this case, the coating amount of the composite oxide is at least 5% by weight, preferably 5 to 5% by weight based on the total carrier.
30% by weight is good. Composite oxides of aluminum and lanthanum can be produced using conventional precipitation and deposition methods.

It can be prepared by mixing wire method, impregnation method, etc. Among these methods, the coprecipitation method is the most suitable because it can produce a homogeneous composite oxide. Furthermore, the coprecipitation method is the most effective method for producing L-β-alumina and its precursors.

The composite oxide can be obtained by a coprecipitation method or by firing a homogeneous mixture of alumina or alumina sol and lanthanum oxide or lanthanum hydroxide, or by impregnating alumina with an aqueous solution of lanthanum and heating it. It is desirable to add an alkali to a mixed solution of aluminum and lanthanum to prepare a uniform co-precipitate. According to this method, the desired composite oxide of aluminum and lanthanum can be obtained even at a relatively low temperature.

In the present invention, organic salts such as nitrates, sulfates, chlorides, alkoxides, hydroxides, oxides, etc. are used as starting materials for aluminum.

As starting materials for lanthanum, neodymium, and praseodymium, water-soluble salts such as nitrates, chlorides, and bromates, hydroxides, and oxides are used. Also, a mixed clay containing lanthanum, neodymium, and praseodymium but not containing cerium may be used.

The catalytically active component is supported on a metal or metal oxide carrier. In this case, the active ingredient is supported on the carrier by conventional methods such as impregnation and kneading. Starting materials for active ingredients include inorganic salts and complex salts.

The catalyst of the present invention is hydrogen, carbon monoxide, or hydrocarbon.

It is used in combustion reactions of fuels such as alcohol, odor removal, denitrification reactions, automobile exhaust gas treatment, etc. When the catalyst of the present invention is used for a reaction with a gas containing at least one of water, carbon monoxide, alcohol, and hydrocarbons as a combustion component, the catalytic active components include manganese, chromium, manganese, and chromium. It is desirable to use zirconium, rare earths, tin, zinc, copper dimagnesium, barium, strontium, calcium, and the like. Fuels used in such combustion reactions include methane, ethane, and propane.

These include butane, kerosene, diesel oil, light oil, liquefied natural gas, and petroleum gas. Although the reaction temperature varies depending on the type of gas, a wide range from room temperature to 15,000 liters can usually be applied. When performing a combustion reaction, the gas is brought into contact with a catalyst in the presence of a gas containing oxygen. When the fuel is methane, the reaction temperature is 400-1500
C is particularly preferred, and platinum group elements are preferred as active ingredients.

When the catalyst of the present invention is used to purify exhaust gas from an internal combustion engine, such as automobile exhaust gas, the catalyst active components include manganese and chromium from group Ⅰ of the periodic table.

It contains at least one selected from zirconium, rare earth elements, tin, zinc, copper, magnesium, barium, strontium, and calcium, and brings exhaust gas and oxygen into contact at a temperature of 150 to 1500 C in the presence of a catalyst. Group (I) elements are particularly desirable as active ingredients. In this case, carbon monoxide, hydrocarbons are oxidized, and nitrogen oxides are converted to harmless nitrogen and water.

When the catalyst of the present invention is used to reduce nitrogen oxides contained in exhaust gas from boilers, gas turbines, etc., it is carried out at 400 to 1500 tT using ammonia as a reducing agent. In this case, the active ingredient is at least one selected from group Ⅰ of the periodic table, alkaline earth metals, titanium, zirconium, vanadium, rare earth metals in group vaⅠa of the periodic table, manganese, zinc, aluminum, and tin. The above elements are desirable.

These elements are supported on the carrier in the form of oxides,
Tungsten as the most desirable element.

It contains at least one of vanadium, titanium, tin, cerium, iron, nickel, and cobalt.

When the catalyst of the present invention is used as a methanation catalyst, the active ingredients include an element from group 1 of the periodic table, zinc, and lithium.

4L of molybdenum, tin, vanadium, and cerium.

carbon monoxide or carbon dioxide and hydrogen at 250~8
Contact at 00C. The most desirable is the periodic table ■
Nickel is a group element.

When the catalyst of the present invention is used for a hydrocarbon dehydrogenation reaction, chromium, zinc, and vanadium are used as active ingredients.

It contains at least one selected from copper, silver, iron, nickel, and cobalt, and the hydrocarbon is brought into contact with the catalyst at a temperature ranging from room temperature to 1500C. In this case, it contains at least one of copper and zinc as an active ingredient, and the temperature is 300-100℃.
It is desirable to set it to 0oc.

Preparation method of Lag Os At203 support L”zOs
The method for preparing At203-based carriers is shown in FIG. Lm(N
Aqueous ammonia is added dropwise to a mixed solution of O3)s and At(NOx)s, and the precipitate is washed with water and dried.

After preliminarily firing at 500C, 1 weight of graphite is added and molded into a cylinder with a diameter of 3++m and a length of 3wx. It is then prefired at 700c for 2 hours. A40 for comparison
3 or only 20 g of La were prepared in the same manner. Lag's 5 molti, A/40s 9
Lag Ox ・kt40s (5/
95) will be described hereafter. La2 in 700℃ firing
The 0s -ALz Os (5/95) carrier has a specific surface area of 130 n2/g and a pore volume (measured from water content).
was 0.4 ml/g.

Preparation method of Pd catalyst A palladium nitrate solution was supported on the above carrier by an impregnation method. P
The d content is 1% by weight. Carrying Pd.

After that, pre-baking at 500℃ for 30 minutes, then 12
It was fired at 0.00C for 2 hours.

Experimental Equipment The activity of the catalyst was examined for methane oxidation activity using a normal flow system using a quartz tube with an inner diameter of 18 m.

Air containing 0.1 g of methane was introduced into the catalyst layer, and the methane reaction rate was measured under isothermal conditions. In addition, in order to examine the durability of the catalyst, air containing 30% of methane was preheated to 500C.
It was introduced into the catalyst layer and maintained at about 11500C (the adiabatic temperature is 1200C or higher). The amount of catalyst is 8 mt and the space velocity is 30
,000h-1. The concentration of methane was determined by gas chromatography.

The crystal structure of the carrier was investigated by X-ray diffraction and transmission electron microscopy. The dispersion state of PD supported on the carrier was determined by the amount of chemical adsorption of CO, and the specific surface area was determined by adsorption of N2.

Specific surface area and crystal structure La of La2O3A740x-based carrier
0,2,5,10,20,50,75゜100 mol%
Prepare a La20g/kt20a-based carrier containing 7
It was fired at 00C. 10000 of these (curve 11),
1zooc (curve 12), 1400t:” (curve 13)
It was baked for 2 hours. Figure 2 shows the measurement results of specific surface area. It can be seen that the specific surface area shows a maximum value when 2 to 5 mol of La is included.

When fired at 1200 C, L town 03・A4α, (2
/98) was 33 m2/g, and (5/95) was 37-7 g. On the other hand, A/403 alone has a distance of 5.6 m.
It was 2/g. As the La content increases from 10 to 100 molt, the specific surface area gradually decreases.

This result shows that adding a small amount of Lavas to kk Os significantly increases the thermal stability.

The crystal structure of the Lag Os A40s-based carrier was investigated by X-ray diffraction. . Figures 3a to 3d show 2 at 1200 C.
This figure shows an X-ray diffraction pattern of a carrier heated for a certain period of time. A
When LzOs is used alone, a peak belonging to α-kHzOs is observed, and a peak belonging to LawOs・AtzOx (5/
95), lanthanum β-Atz Os (La20m
・11A/40m) Four peaks were observed. In La2o3At20s (50/50), La A to a was generated.

It can be seen that the peak belonging to lanthanum β-At203 is weak and broad, and the crystal growth is slight. Therefore, the obtained composite oxide is considered to be a precursor of lanthanum βA1203 or a form similar to lanthanum β-kLzos.

When heated at 1000 C for 2 hours, this composite oxide showed no clear peak and was amorphous, but this is considered to be a precursor of lanthanum β-alumina. When this precursor is calcined at 1400C for 2 hours, it becomes lanthanum β-12
Convert to 0s. Lanthanum aluminate (LaAtOs) with a perovskite structure shows a strong peak. In the case of Lag Ox /Atz Os (10/90), a mixture of lanthanum β-At203 and LaklOs is produced.

Figure 4 shows La2o3・A fired at 800-1400℃.
The results of an investigation using X-ray diffraction regarding the conditions for the formation of tz Ox-based oxides are shown. It can be seen that when lanthanum β-alumina and its analogues are fired at 1400 G, La is produced in an amount of 2 to 30 mol.

LaAtOs is easily produced at low temperatures.

When klzos alone is fired at 1200C, α-A/!
Although a very strong peak of 40a is observed, Lag 0
3At20s (2/98), then -At at θ-9
A very weak peak belonging to 20s is observed. These results show that the growth of α-A120g is suppressed by adding a small amount of La20s to kl*Os.

R, C,:topp etc. are for lanthanum β-), tzOs, Lag O3'At20a (8,3/91
．． 7) f) When the mixture is heated above 1400 C, L
reported that it is generated via aAtOs (J
-Am, Cer, Soc,.

And, 416 (1980)).

In the present invention, the production of lanthanum β-At20s is observed even when calcined at a low temperature such as 100OC for 2 hours because of the difference in production method A, that is, in the present invention, the coprecipitation method is used.
This is probably because Ropp et al. prepared it from a mixture of oxides. The coprecipitation method ensures sufficient mixing of both oxides. The particle size of the Lag's At20a carrier was examined using an electron microscope. As a typical example, it was fired at 1200C (
4) ktz Os alone.

(B) Laz Oa ・ktz Os (5/95)
fc connection to tW4 is 1k, α-At203 is 500 to 15
00A, while La20a ・kHz03
(5/95), there were 100-300 Fi. L
az Os ・Atz Os (50150) i.e.
For aAAOa, it was about 100OA. 5chaper
reported that La20a prevents the sintering of rAlzOs, which is caused by the formation of LaklOs on the surface layer of the support (H, 5chaper et al.
al.

Applied Catalysis, 7,211 (
1983)). However, in the present invention, prevention of sintering is due to the generation of lanthanum-βA120s, and LaAt
It is not for the generation of 0a. This difference seems to be due to the preparation method. That is, 5chaper et al.
Molded r -Atz Os K La (NO3)
This is because a method of impregnating with S solution is adopted. This is because in the impregnation method, the concentration of La2O5 becomes high in the surface layer of the carrier, so that LaAt0a is easily generated.

P d La2o, @Activity Pd of At203 catalyst
To investigate the CH4 oxidation activity of the catalyst, CH4 was added at 0.1%.
The oxidation rate was measured at a temperature of 250 to 700C using air containing air. These measurements were performed under isothermal conditions. “Figure 5 shows pd on carriers with various composition ratios of L a / A l.
This figure shows the results of investigating the activity of a catalyst supported on . The catalyst with p d -Lag Oa·A 140 g (5/95) shows the highest activity (curve 24).

p d-Atz 03 #! The medium (song #J21) has the lowest activity. P d Law Os ・At20g
(2/98) is (10/98) as shown by curve 25.
90) (curve 23). Pd-LagOaAlzOs (501
50) has a relatively high activity as shown by curve 22, although the specific surface area is low as shown in FIG.

In order to investigate the dispersion state of Pd supported on the carrier, CO
Pd surface area was determined by adsorption. After treatment with l(e) at 250C, the amount of CO adsorption was measured at 200t:''. Figure 6 shows the results of determining the surface area of Pd supported on supports with different La contents.The Pd surface area is I, a is 5
It increases up to 10 mol and decreases to 0 at 50 mol. The particle size of the Pd catalyst was observed using an electron microscope. As a result, the particle size of Pd supported on At203 alone was 1,500 to 2,000 particles, and Laz Os ・Alz
The Pd particle size supported on Os(5/95) is 300~
There were 800 people. As the crystal particles of the carrier grow, the Pd particles also aggregate. The so-called "one-earthquake effect" is occurring.

Durability of Pd catalyst supported on lanthanum-β-kHz Oa To investigate the durability of Pd combustion catalyst, methane 3vo1%
Air containing methane was introduced into the catalyst layer at 5,000 °C, and methane was
It was burned at 150C. p d -La2O5・At2
A continuous test for 100 hours was conducted on two types of catalysts: 03 (5/95) and p d -A 120g catalyst.

In this case, the P d At20m catalyst is 10001:
I used the one fired in '. This is because when fired at 1200 C, no ignition occurs even if the gas temperature is increased to 5000 C. The durability test is shown in Figure 7.

P d -Lag Os ・klx Os (5/95
) Te shows a methane conversion rate of 99.5% or more as shown by curve 32, but in P d -klzOs it decreases from 99.5% to 98% or less as shown by curve 31.

After the durability test, the catalyst was examined using various methods. The measurement results of BET specific surface area and Pd surface area are shown in Table 1.

Table 1 For P d -A,ls Os catalysts, these surface areas are significantly reduced, whereas for P d -Law Os ”
It is relatively small for the A/40a (5/95) catalyst. Regarding the activity of both catalysts after the durability test, the reaction rate was investigated under isothermal conditions of 300 to 700C using 0.1% methane.
95), the rate constant decreased by 15 to 20 degrees, while that of P d -ktz Os decreased by 50 to 80%.

Furthermore, from observation with an electron microscope, the pd-ktz after the durability test
In the Os catalyst, the pd particle size on the carrier is 3000-500
The number had reached 0.

Examples of the present invention will be specifically described below, but the present invention is not limited to these Examples in any way.

[Embodiments of the invention]

Example 1 375.1g of aluminum nitrate and 228g of lanthanum nitrate
is dissolved in 1 t of distilled water (La/At=5/95).

While stirring this solution, 3N ammonia water was added dropwise, and p
Neutralize to H7.5. The resulting co-precipitate of aluminum and lanthanum was thoroughly washed with water, dried, and crushed to give 100%
It was baked at 0C for 5 hours. The obtained powder was formed into a cylindrical shape with a diameter of 3 m and a length of 3 m using a press molding machine to form a carrier.

On the other hand, a comparative example carrier consisting only of alumina was obtained by preparing in the same manner as described above except that lanthanum nitrate was not added.

The two types of carriers described above were impregnated with 1 weight of palladium nitrate solution as Pd, dried at 120G for 5 hours, and then calcined at 1200C for 3 hours to obtain catalysts of Example 1 and Comparative Example 1. The methane oxidation activity of this catalyst was investigated.

A continuous test was conducted for 1000 hours by flowing a gas having the following composition at a space velocity of 25,000 h''.

Gas composition 2 methane 3 air The remainder In this experiment, the reaction gas was preheated to 50°C. When the reaction rate of methane reaches 90°C or higher, the temperature of the catalyst layer increases to about 120°C.
00, the durability of the catalyst at high temperatures can be evaluated. Table 2 shows the results.

It can be seen that the catalyst obtained in Example 1 in Table 2 has excellent high-temperature durability. When the specific surface areas of the catalysts of Example 1 and Comparative Example 1 were measured after a 10°O hour test, they were 23.5, respectively.
m"/g and 5.6 m"/g. Also, the surface area of Pd is 37W in Example 1? /g-Pd.

It was 13.6 m'/g-Pd. As described above, it can be seen that the example catalyst has a better specific surface area and a better dispersion state of Pd than the comparative example catalyst, and is superior as a heat-resistant catalyst.

Example 2 3750 g of aluminum nitrate and 480 g of lanthanum nitrate are dissolved in 10 t of distilled water. Thereafter, distilled water ZSt was added to the 5ooc calcined powder IKf obtained in the same manner as in Example 1, and the powder was pulverized with a vibration mill until the average particle diameter of the powder was approximately 1 μm to prepare a slurry-like immersion liquid. A honeycomb structure (diameter 90 mm) made of a commercially available cordierite base material was added to this immersion liquid.
m, length 75 m) was immersed, then removed from the immersion liquid,
Remove excess liquid by blowing compressed air and
After drying at ', heat treatment was performed at 500C for 1 hour. This operation was repeated and finally fired at 1000C for 2 hours. The honeycomb structure thus obtained had a layer of composite oxide weighing 18.7% by weight.The specific surface area of the 2-comb carrier was ρ
, sm'/g. Next, the obtained honeycomb structure was immersed in an aqueous solution of a mixture of chloroplatinic acid and rhodium chloride, dried at 120C, and then reduced in a hydrogen stream at 600C. The catalyst contained 1.5 wt. platinum and 0.4 wt. rhodium.

This catalyst was used for oxidizing automobile exhaust gas. It was used as a catalytic converter in a regular car engine (1800cc class), and as a result of 10-day driving tests, COl, Og/Km in 10 modes.

HCO, 19g/a. These results show that the catalyst using the heat-resistant carrier of the present invention can be used for exhaust gas treatment of internal combustion engines and maintains stable performance in high-temperature reactions.

Example 3 This example describes an example in which the heat-resistant carrier of the present invention is used as a catalyst for high-temperature denitrification reaction.

500 g of metatitanic acid slurry (T
j (150 g as h) was sufficiently kneaded using a mixer.

Thereafter, it is dried at 150C, crushed and fired at 400C for 4 hours. The obtained powder is molded into a diameter of 3 m using a press molding machine.
After molding into a cylindrical shape with a thickness of 3 m, it is immersed in an aqueous hydrogen peroxide solution of ammonium tungstate. Thereafter, it is calcined at 600C for 2 hours to obtain a catalyst. The catalyst thus obtained contains 5% by weight of tungsten oxide.

The reaction uses a gas with the following composition, and the space velocity is 500031-
1. The reaction was carried out for 100 hours at a reaction temperature of 600C.

Reaction gas composition NOx 200ppm NHs 200ppm 02 3% HzO10chiN2 The removal rate of the remaining NOx was 94.8% at the initial stage and 94% after 100 hours.
．． It was 4%. As can be seen from the above results, the catalyst using the carrier of the present invention exhibits excellent performance even in high-temperature denitrification reactions.

Example 4 In this example, an example in which the catalyst was used as a catalyst for CO methanation reaction will be described.

The molded supports obtained in Example 1 and Comparative Example 1 were impregnated with nickel nitrate and fired at 500°C. After impregnating the carrier with ruthenium chloride, the carrier was fired at 100°C to obtain a completed catalyst. This catalyst is Ni
030% and Ru3%. This catalyst was packed into a reaction tube, and a gas of 8% CO, 17% H2, and 8% N2 was added.
The methanation reaction was carried out at a reaction temperature of 350C. the result,
It was found that the CO methanation yield of the catalyst of this example was about 15 times that of the catalyst of this comparative example. It can thus be seen that the catalyst of the present invention is very effective not only in reactions at high temperatures but also in reactions at relatively low temperatures.

Example 5 In this example, a methanol dehydrogenation catalyst was investigated.

The molded carrier described in Example 1 is impregnated with a solution of copper nitrate and zinc nitrate, dried and then fired at 1000°C.

Cu and 7. The content of n is 20% by weight and 10% by weight, respectively. After filling the reaction tube with the catalyst and bringing it to a temperature of 5 ooc, methanol was introduced and a dehydrogenation reaction was performed to produce formalin, and the conversion rate of methanol was 98.
The selectivity to formalin is also about 5% higher than that of conventional methods.
It was double that.

Example 6 500 g of aluminum nitrate and 30.7 g of neodymium nitrate
was dissolved in 5 tons of distilled water. 3N while stirring this solution.
Aqueous ammonia was added dropwise to neutralize to pH 8. The resulting coprecipitate of aluminum and neodymium was thoroughly washed by decantation with distilled water, filtered, and dried at 150C for one day and night. Grind to 60 mesh or less, 500℃
After firing for 2 hours, 0.5% by weight of graphite was added, and the mixture was molded into a cylindrical shape with a diameter of 3 m and a thickness of 3 m using a press molding machine. The composition of this carrier is 5 moles of NdzOs and 95 moles of AtOs. This carrier is 1
After baking at 200 C for 2 hours, the specific surface area was measured by the B, E, T method using N2 gas adsorption. Further, the crystal structure of the carrier was investigated by powder X-ray diffraction. The results are shown in Table 3.

Example 7 A carrier [F]) was prepared in the same manner as in Example 6 except that the proportions of aluminum nitrate and neodymium nitrate were changed.

0, (c) was obtained. The obtained carriers each have the following composition. (6): Nd2032 morti, At2039
8 molti, (C'): Nd2O510 molti, A
k Oa 90molti, (c): Nd20s 2
0 molti, Ak Os 80 molti. The specific surface area of these carriers and the morphology of the products were measured in the same manner as in Example 6. The results are shown in Table 3.

Example 8 500 g of aluminum nitrate and 30.5 g of praseodymium nitrate
g as a raw material, prepared in the same manner as in Example 6, and prx
oss mol%, Al40. A carrier (2) consisting of 95 molti was obtained. Further, the ratio of aluminum nitrate and praseodymium nitrate was changed, and carrier [F], f3. I got u. The obtained carriers each have the following composition.

(P'l: pr2 o3 2 moni'lb, A
k Os 98 mol%, season: PrxOslO mol!
J, Ala Os 90molti, ■: Pr20
s 20-el%, At20g 80 mol%. Table 4 shows the results of examining the specific surface area and product morphology of these carriers.

Table 4 Example 9 Using 500 g of aluminum nitrate, 1 and 6 g of neodymium nitrate, and 18.5 g of praseodymium nitrate as raw materials, 3 mortar of Nd2O was prepared in the same manner as in Example 6.

A carrier α) containing 1033 mol % of Pr and 94 mol of Al 40 g was prepared. The specific surface area of this carrier is 23, Orp? /g. Further, when the crystal structure was examined, it was confirmed that it mainly consists of neodymium-β alumina and praseodymium-β alumina. As can be seen from this result, these β-alumina-containing carriers have a high specific surface area even at high temperatures.

Example 10 500 g of alumina sol (alumina content 9.8%) and 12.3 g of neodymium carbonate were kneaded in a Laikai machine for 2 hours, and then dried at 150p for 1 day and night. After crushing to a mesh size of 6° or less and firing at 500°C for 2 hours, the graphite is reduced to 0.
．． 5% by weight was added and molded into a cylindrical shape with a diameter of 3 cm and a thickness of 3 m+ using a press molding machine. The composition of the carrier is Nd20
a 4 molti.

Ak Oa is 96 morti. This carrier was
When baked at OC or 1200C for 2 hours and measured the specific surface area, each was 96.5W? /g, 21.6
m2/g.

When the PD catalyst using the supports prepared in Examples 6 to 10 was tested for durability, it showed excellent performance at 800 to 1400C.

As described above, it can be seen that the catalyst of the present invention has a large specific surface area even at high temperatures, and can be applied to chemical reactions not only at low temperatures but also at high temperatures.

Example 11 The carrier according to the present invention shown in Example 1 is impregnated with a mixed solution of ammonium molybdate and nickel nitrate, dried and then calcined at 500C for 5 hours. The composition of this catalyst is MoO31
5% by weight, and 5% by weight of Ni. This catalyst 40 m
A reaction tube with an inner diameter of 15+ m is filled with about I L / m.
Reduction was carried out at 450C for 5 hours by flowing hydrogen at a flow rate of i. After reduction, 400C.

Under conditions of 10 atm, H2 was supplied onto the catalyst at a flow rate of 300 mt/min, and a synthetic raw material prepared by adding 100 ppm by weight of thiophene as S to n-hexane was supplied onto the catalyst at a flow rate of 100 mt/h. When the sulfur concentration in n-hexane after the reaction was measured using a gas chromatograph, it was found to be 0.1 ppm by weight or less as S even after 100 hours.

Example 12 The carrier according to the present invention shown in Example 1 is impregnated with a chloroplatinic acid solution, dried and then calcined at 900C for 2 hours. p of this catalyst
The t content is 1% by weight. A reaction tube was filled with 5 cc of this catalyst, and methyl ethyl ketone, a representative of malodorous components, was added.
A gas containing 100 p·pm of each of the three components, toluene and formalin, is introduced into the catalyst layer together with air. Reaction temperature 5o
At o'c, the organic substances at the outlet of the catalyst layer were measured and found to be 0.4 ppm of methyl ethyl ketone and 0.4 ppm of toluene.
3 ppm, formalin 0.8 ppm, and it was found that this catalyst is very effective in removing malodorous components.

Example 13 Catalyst i obtained by kneading and drying the fine powder of the carrier according to the present invention shown in Example 1 and β-stannic acid slurry, and calcining the mixture at 500C for 3 hours.
g of heavy oil was added to 20 g of heavy oil, filled into an autoclave, and heated at 100 Kf/d at 400 C while flowing H2 for 30
Allowed to react for minutes. After the reaction was completed, the product was separated into various fractions by vacuum distillation.

The results are shown in the table below. It can be seen that this catalyst exhibits excellent performance in lightening heavy oil.

Boiling Point Range Composition ~200 9cm 200-350C39cm 350-550C37cm Residue 15cm Example 14 The carrier according to the present invention shown in Example 1 was impregnated with a solution of copper chloride and calcined at 500C for 2 hours. The composition of this catalyst is Cu
The photoresistance is 20% by weight. Using this catalyst, Probile/
An oxidation reaction was carried out. C as a reaction gas to 20mt of catalyst
a Ha 25%, Ox 10'16. A gas having a composition of Nz residue was introduced at a temperature of 450C, and the generated gas was analyzed. As a result, the conversion rate of C5Hs was 98 H, and the selectivity to acrolein was 88 H. It can thus be seen that the oxidation rate of this catalyst is extremely high.

Example 15 The carrier according to the present invention shown in Example 1 was impregnated with a mixed solution of cobalt nitrate and ferric nitrate, and calcined at 800C for 5 hours. The composition of this catalyst is 12% by weight of COo.

Fe2Og is 8% by weight. CO to 40ml of this catalyst
Gas consisting of 40 cm and H260 cm is 300050/
When the reaction was carried out under the conditions of 7, the conversion rate of (CO + H2) was 88%.In addition, when the selectivity was investigated from the analysis of the product, the gas components from 01 to C5 were 48%, and the gasoline fraction was 21%. , 12% of oxygen-containing compounds, and 29% of heavy oil.The above results show that this catalyst is suitable for synthesizing organic compounds from CO and H2.

Example 16 The carrier according to the present invention shown in Example 1 was impregnated with a mixed solution of copper nitrate and zinc nitrate, and calcined at 50 (I') for 2 hours.

A mixed gas consisting of 75% hydrogen and 2596 carbon monoxide was introduced into the catalyst at a temperature of 3001:' and a pressure of xo OK g/i, and the resulting gas was analyzed (the conversion rate of CO1Hz:J was 90%, and the conversion rate of methanol was 90%). The selectivity was 92%. From the above, it can be seen that this catalyst is suitable for synthesizing methanol from CO and H2.

Example 17 The carrier according to the invention shown in Example 1 is impregnated with a nickel nitrate solution and calcined at 500C for 2 hours.

The composition of this catalyst is determined by weight of Ni015. When the isomerization reaction of n-butane was carried out at a temperature of 100C using this catalyst, the yield to isobutane was 69%. Thus, it can be seen that the present catalyst is effective for isomerization reactions.

Example 18 Iron chloride was used as the carrier according to the present invention shown in Example 1.

After impregnating with a mixed solution of potassium chloride and copper chloride and drying,
It was fired at 700C for 2 hours. The composition of this catalyst is Fe5Oa
20wt'It, Ka02%, CuO2%. When this catalyst was brought into contact with 75% N2 and 25% N2 at a temperature of 550°C and a pressure of 250 kg/-, CH2
Ten N! ) conversion rate was 95 h. From this experiment,
The catalyst of the present invention is N! It can be seen that it is effective for ammonia synthesis by hydrogenation of

〔Effect of the invention〕

As described above in detail, the catalyst of the present invention is stable over a wide temperature range, and has an extremely large specific surface area at high temperatures. Therefore, it can be used in various chemical reactions and has high catalytic activity.

[Brief explanation of the drawing]

FIG. 1 shows La2'5-AtzO according to an embodiment of the present invention.
A process diagram showing the preparation method of a-based carrier, Figure 2 is LazOa-
Characteristic diagrams showing the relationship between the composition and specific surface area of the AtaOs-based carrier, Figures 3a to 3d are: [, azos-A12os
An X-ray diffraction diagram showing the crystal structure of the system carrier, Figure 4 is Lax
03Atz Characteristic diagram showing the relationship between the composition of the Os-based carrier and the firing temperature, Figure 5 is p d -Lazos・A t2
A characteristic diagram showing the relationship between reaction temperature and CH4 conversion rate in CH4 oxidation reaction using 0 m catalyst, Figure 6 is P d
-L a20x ・At2'03 A characteristic diagram showing the relationship between the composition of the carrier and the amount of pd adsorption in the catalyst, Figure 7 is P d
-Lashs It is a characteristic diagram showing the relationship between combustion time and CH4 conversion rate in methane combustion using an At20s catalyst. 11*12, 13-La2O5/At5Os-based carrier, 22.23.24. zs・-・pct-La203
"AtzOs-based catalyst, 32"・P d -L ax
0s-Altos catalyst. Drop I Roof, γ (D 10 20 JO's 50 y
O. La/(lat4-1), Mo, l/% 3 m? θ 40 60
gDzQ, tie5 c (J-Kd packed 4/f
I L(1/(Otsu(1+A1.), -f-tl/%
CL (lz03) No. S Repetition Bar Shrimp 477 ("c Tsuka Otsu Figure Lσ/<Latl:) (j(, '/. Kano Gang (Hara 0 Inventor Matsu 1) Omi Taira Kodasho, Hitachi City

Claims (1)

[Claims] 1. Consisting of a carrier and a catalytically active component supported on the carrier, at least a portion of which is a composite oxide of aluminum and at least one rare earth element selected from lanthanum, neodymium, and praseodymium. and the composite oxide has a specific surface area of at least 10 m^2/g, and the composite oxide substantially has the same property as the rare earth element β-alumina when heated at 1000°C or higher for less than 2 hours. A catalyst stable at high temperatures, characterized in that it consists of a mixture with a precursor capable of converting the rare earth element to β-alumina. 2. In claim 1, the composite oxide contains 1 to 20 mol% of at least one selected from lanthanum, neodymium, and praseodymium as an oxide,
A catalyst that is stable at high temperatures, with the remainder being alumina. 3. In claim 1, the composite oxide contains 3 to 10 mol% of at least one selected from lanthanum, neodymium, and praseodymium as an oxide,
A catalyst that is stable at high temperatures, with the remainder being alumina. 4. A catalyst stable at high temperatures according to claim 1, wherein the composite oxide has a specific surface area of 20 to 100 m^2/g. 5. A catalyst stable at high temperatures according to claim 1, wherein the carrier has a honeycomb structure. 6. A catalyst stable at high temperatures according to claim 1, characterized in that the carrier comprises a portion supporting a catalytically active component and a support for the carrier. 7. A catalyst stable at high temperatures according to claim 6, characterized in that the support is selected from a metal plate, a wire mesh, and a spongy metal. 8. A catalyst stable at high temperatures according to claim 1, characterized in that the surface of the carrier is coated with a composite oxide supporting an active ingredient. 9. In claim 1, the catalytic active component includes Group VIII of the periodic table, manganese, chromium, zirconium, rare earth elements, tin, zinc, copper, magnesium,
A catalyst stable at high temperatures, characterized by supporting at least one of barium, strontium, vanadium, tungsten, molybdenum, titanium, gallium, indium, lead, bismuth, antimony, silver, and calcium. 10. Consisting of a carrier and a catalytically active component supported on the carrier, at least a portion of the carrier is a composite oxide of aluminum and at least one rare earth element selected from lanthanum, neodymium, and praseodymium, and the composite The oxide has a specific surface area of at least 10 m^2/g and a content of chromium, strontium and cerium of 1% by weight.
and contains 1 to 20 mol% of at least one selected from lanthanum, neodymium, and praseodymium as an oxide, the balance being alumina, and is substantially a mixture of the rare earth element β-alumina and a precursor thereof. A catalyst that is stable at high temperatures and is characterized by consisting of: 11. Claim 10 is characterized in that the composite oxide contains 3 to 10 mol% of one or more selected from lanthanum, neodymium, and praseodymium as an oxide, and the remainder is alumina. Catalyst stable at high temperatures. 12. A catalyst stable at high temperatures according to claim 10, wherein the composite oxide has a specific surface area of 20 to 100 m^2/g. 13. Consisting of a carrier and a catalytically active component supported on the carrier, at least a portion of the carrier is a composite oxide of aluminum and at least one rare earth element selected from lanthanum, neodymium, and praseodymium, and the composite The oxide has a specific surface area of at least 10 m^2/g, and for alumina α-, γ-, θ-, η-, κ-, χ-, ρ
-, has a crystal structure other than the δ- form, and has an amount of chromium, strontium, and cerium of 1% by weight or less, and the rare earth element β-alumina and the rare earth element β-alumina are heated at 1000°C within 2 hours. 1 to 2 oxides of at least one of lanthanum, neodymium, and praseodymium.
A catalyst that is stable at high temperatures, characterized in that it contains 0 mol% and the balance is alumina. 14. In claim 13, the composite oxide is stable at high temperatures, characterized in that it contains 3 to 10 mol% of at least one of lanthanum, neodymium, and praseodymium as an oxide, and the balance is alumina. A catalyst. 15. A catalyst stable at high temperatures according to claim 13, wherein the composite oxide has a specific surface area of 20 to 100 m^2/g. 16. Consisting of a carrier and a catalytically active component supported on the carrier, at least a portion of the carrier is a composite oxide of aluminum and at least one rare earth element selected from lanthanum, neodymium, and praseodymium, and the composite The oxide has a specific surface area of at least 10 m^2/g, the content of chromium, strontium, and cerium is 1% by weight or less, and substantially 100% of the rare earth element β-alumina is present.
It consists of a mixture with a precursor that can be converted into the rare earth element β-alumina by heating at 0°C for within 2 hours, and contains 1 to 20 mol% of at least one of lanthanum, neodymium, and praseodymium as an oxide, and the balance is A catalyst that is stable at high temperatures and is characterized by being alumina. 17. A catalyst stable at high temperatures according to claim 16, wherein the composite oxide contains 3 to 10 mol% of at least one of lanthanum, neodymium, and praseodymium, and the balance is alumina. 18. A catalyst stable at high temperatures according to claim 16, wherein the composite oxide has a specific surface area of 20 to 100 m^2/g. 19. Adding an alkali to a mixed solution of an aluminum salt and at least one salt of a rare earth element selected from lanthanum, neodymium, and praseodymium to precipitate a coprecipitate of the mixture; separating the coprecipitate; A step of molding the separated coprecipitate into various shapes, consisting of a composite oxide of aluminum and the rare earth element, the composite oxide having a specific surface area of at least 10 m^2/g or more, and containing the rare earth element β- The molded body is mixed with alumina and a precursor that can be converted into the rare earth element β-alumina by heating at 1000°C within 2 hours, or a mixture of the precursor.
1. A method for preparing a catalyst that is stable at high temperatures, the method comprising the step of firing at a temperature of 000° C. or higher. 20, consisting of a carrier and a catalytically active component supported on the carrier, at least a portion of the carrier being a composite oxide of at least one rare earth element selected from lanthanum, neodymium, and praseodymium and aluminum; The oxide has a specific surface area of at least 10 m^2/g, has a content of chromium, strontium, and cerium of 1% by weight or less, and is substantially combined with the rare earth element β-alumina at 1000°C within 2 hours. When heated, the rare earth element β
- A catalytic chemical reaction process characterized in that a reactant is brought into contact with a catalyst which is a precursor or essentially a mixture of these precursors capable of converting into alumina. 21. Claim 20 is characterized in that the composite oxide contains 1 to 20 mol% of at least one selected from lanthanum, neodymium, or praseodymium as an oxide, and the remainder is alumina. Catalytic chemical reaction method. 22, consisting of a carrier and a catalytically active component supported on the carrier; at least a portion of the carrier is a composite oxide of aluminum and at least one rare earth element selected from lanthanum, neodymium, and praseodymium; The oxide has a specific surface area of at least 10 m^2/g, the content of chromium, strontium, and cerium is 1% by weight or less, and the oxide is substantially oxidized with at least one of the rare earth elements β-alumina at 1000°C. The composite oxide is a precursor or substantially a mixture of precursors that can be converted into the rare earth element β-alumina upon heating within a period of time, and the composite oxide contains at least one of lanthanum, neodymium, and praseodymium.
A catalytic chemical reaction method comprising bringing a reactant into contact with a catalyst having 1 to 20 mol% of a species as an oxide and the balance being alumina. 23. The catalytic chemical reaction according to claim 22, wherein the composite oxide contains 3 to 10 mol% of at least one of lanthanum, neodymium, and praseodymium as an oxide, and the remainder is alumina. Method. 24. The catalytic chemical reaction method according to claim 22, wherein the composite oxide has a specific surface area of 20 to 100 m^2/g. 25. The catalytic chemical reaction method according to claim 22, wherein the carrier is made of a composite oxide. 26. The catalytic chemical reaction method according to claim 22, wherein the carrier has a honeycomb structure. 27. The catalytic chemical reaction method according to claim 22, wherein the carrier and the catalytically active component are supported by a support. 28. A catalytic chemical reaction method according to claim 22, characterized in that the surface of the carrier is coated with a composite oxide on which an active ingredient is supported. 29. The catalytic chemical reaction method according to claim 27, characterized in that the support is selected from a metal plate, a wire mesh, and a spongy metal. 30. In claim 22, the catalytic active component is selected from Group VIII of the periodic table, manganese, chromium, zirconium, rare earth elements, tin, zinc, copper, magnesium, barium, strontium, and calcium. A catalytic chemical reaction method characterized by using one or more types. 31. A catalytic chemical reaction method according to claim 22, characterized in that catalytic combustion is performed by bringing the catalyst into contact with a fuel and an oxidizing agent. 32. Claim 31, wherein the fuel is at least one of hydrogen, carbon monoxide, alcohol, and hydrocarbons.
A catalytic chemical reaction method characterized in that the fuel contains seeds. 33. The catalytic chemical reaction method according to claim 32, wherein the hydrocarbon is methane, and the catalytically active component contains at least one member of Group VIII of the Periodic Table. 34. Claim 22, wherein the catalytic active component is a group VIII element of the periodic table, manganese, a rare earth element,
Exhaust gas from an internal combustion engine is brought into contact with a catalyst supporting at least one of chromium, vanadium, tin, zirconium, magnesium, calcium, and strontium to oxidize carbon monoxide and hydrocarbons contained in the gas, and to produce nitrogen oxides. A catalytic chemical reaction method characterized by reducing. 35. A catalytic chemical reaction method according to claim 22, characterized in that exhaust gas containing nitrogen oxides and ammonia are brought into contact with the catalyst at 150 to 1000°C to render the nitrogen oxides harmless. 36. A catalytic chemical reaction method according to claim 35, wherein the catalytically active component comprises at least one of tungsten, vanadium, titanium, tin, cerium, iron, nickel, and cobalt. 37. A catalytic chemical reaction method according to claim 22, characterized in that the dehydrogenation reaction is carried out by bringing hydrocarbons into contact with the catalyst at 500 to 1000°C. 38. A catalytic chemical reaction method according to claim 37, characterized in that methanol is dehydrogenated at 800 to 1000°C. 39. Claim 22, wherein the catalyst carrying at least one of molybdenum, tungsten, nickel, and cobalt as the catalytic active component is heated with a hydrocarbon oil containing a sulfur compound at 1 to 100 atmospheres and 250 to 500°C. A catalytic chemical reaction method comprising hydrodesulfurizing the hydrocarbon oil by contacting it with hydrogen at a reaction temperature. 40, Claim 22, wherein the catalytically active component includes Group VIII of the periodic table, manganese, zinc, copper,
A catalyst supporting at least one of rare earth elements, tungsten, chromium, vanadium, titanium, and zirconium is charged with a gas containing organic compounds and oxygen, which are malodorous components, at 100 to 1
A catalytic chemical reaction method characterized in that the organic compound is removed by contacting at a temperature of 500°C. 41, Claim 22, wherein the catalytically active component includes Group VIII of the periodic table, titanium, zirconium,
Vanadium, molybdenum, tungsten, manganese, copper, zinc, gallium, indium, tin, lead, bismuth,
In the presence of a catalyst supporting at least one type of antimony, heavy oil, asphalt, or coal and hydrogen are heated at a temperature of 350 to 800°C and a pressure of 1 to 500 kg/cm.
A catalytic chemical reaction method characterized by obtaining light oil by contacting with ^2. 42. Claim 22, wherein the catalytic active component is at least one of Group VIII of the periodic table, manganese, chromium, zirconium, rare earth elements, tin, zinc, copper, silver, magnesium, barium, strontium, and calcium. A catalytic chemical reaction method characterized in that an oxidation reaction is carried out by contacting a catalyst supported with oxygen with a gas containing oxygen at a temperature of 1500° C. or lower. 43. In claim 22, the catalytically active component includes Group VIII of the periodic table, manganese, zinc, copper,
A catalyst supporting at least one of rare earth elements, tungsten, titanium, molybdenum, tin, lead, bismuth, and vanadium at a temperature of 1000°C or less, 1 to 200 kg/cm
Bringing gas containing carbon monoxide and hydrogen into contact at a pressure of ^2,
A catalytic chemical reaction method characterized by synthesizing hydrocarbons. 44. In claim 43, the catalytic active component includes Group VIII of the periodic table, manganese, molybdenum, chromium, zirconium, rare earth elements, tin, zinc, copper,
Synthesizing alcohol by contacting a catalyst carrying at least one of silver, magnesium, barium, strontium, and calcium with a mixed gas of carbon monoxide and hydrogen at a temperature of 600°C or less and a pressure of 1 to 200 kg/cm^2. A catalytic chemical reaction method characterized by: 45. In claim 22, the catalyst supports at least one of Group VIII of the periodic table, molybdenum, tungsten, zirconium, silicon, boron, chromium, zinc, copper, tin, and titanium as the catalytic active component. 700 to
1. A catalytic chemical reaction method comprising isomerizing hydrocarbons by contacting them at a temperature of .degree. C. or lower. 46. Claim 22, wherein at least one of Group VIII of the periodic table, tungsten, molybdenum, zinc, copper, rare earth elements, lead, bismuth, boron, silicon, titanium, and vanadium is supported as the catalytic active component. The catalyst is brought into contact with hydrocarbons at a temperature of 1000°C or less,
A catalytic chemical reaction method characterized by cracking petroleum-based heavy oil. 47, Claim 22, wherein the catalyst supporting at least one of Group VIII of the periodic table, copper, chromium, zinc, vanadium, tungsten, tin, potassium, and rare earth elements as the catalytic active component is an organic Compounds and/or nitrogen and hydrogen at a temperature of 800°C or less and a pressure of 500 kg/
A catalytic chemical reaction method characterized by carrying out a hydrogenation reaction by contacting at a pressure of cm^2 or less.