JPH0649568B2 - Solid acid substance, method for producing the same, and method for decomposing hydrocarbon using the solid acid substance - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a ZrO ₂ —SiO ₂ -based solid acid substance, a method for producing the same, and a hydrocarbon decomposition method using the solid acid substance.

TECHNICAL BACKGROUND OF THE INVENTION AND PROBLEMS OF THE INVENTION Attempts have been made for a long time to obtain industrially useful fractions having 3 to 4 carbon atoms in high yield from petroleum hydrocarbon compounds represented by naphtha. In this case, it is known that the solid acid catalyst is useful. Further, it is known that the solid acid catalyst is used for various reactions such as isomerization, alkylation and dealkylation of hydrocarbons. One of the properties that characterize such a solid acid is the acid strength of the solid acid, and a solid superacid having extremely strong acidity may be required depending on the reaction.

As such a solid superacid, conventionally, SbF₅Such as gold
Fluoride SiO_Two-Al_TwoO_ThreeEvaporated on metal oxide
Things (catalyst21(4), 220, (1979)), Io
Exchange resin and AlCl_Three(J. Cataly
sis46, 266 (1977)), CuSO_FourOr
CuCl_TwoAnd AlCl_ThreeA mixture of (catalyst21
(4), 233 (1979)), ZrO_Two, Fe_TwoO_Three
Treated with sulfuric acid (catalyst22(4), 232,
(1980)) and the like are known.

These solid superacids are ZrO ₂ · SO ₄ ²⁻ or Fe ₂ O obtained by treating ZrO ₂ or Fe ₂ O ₃ with sulfuric acid.
Except for ₃ · SO ₄ ²⁻ , it cannot be easily decomposed and regenerated by contact with water, and the temperature range in which it can be used as a catalyst is extremely narrow, making it difficult to apply it as an industrial catalyst. There was a problem.

The object of the present invention is to solve the problems associated with the prior art as described above, and it has extremely strong acid strength and easily decomposes super-strong acid points even when contacted with water. No
Moreover, it is an object of the present invention to provide a novel solid acid substance which can be used as a catalyst in a wide temperature range and is therefore expected to have a wide range of uses as an industrial catalyst.

Another object of the present invention is to provide a novel method for producing a solid acid substance as described above.

Still another object of the present invention is to provide a method for decomposing hydrocarbons using the above novel solid acid substance as a catalyst.

SUMMARY OF THE INVENTION A novel solid acid substance according to the present invention is (xZrO ₂ · ySiO ₂ ).
-ZF-mS [In the formula, x and y represent the number of moles of ZrO ₂ and SiO ₂ ,
The value of x / y indicates the atomic ratio of Zr / Si. Further, z and m represent the weight% of F atom and the weight% of S atom with respect to the weight of (xZrO ₂ · ySiO ₂ ), respectively. And x
/ Y is 99.9 / 0.1-10 / 90, and z is 0.
1 to 10 and m is in the range of 0.01 to 5. ] The acid strength (Ho) is-
It is characterized by having a strong acid point of 8.2 or less.

This solid acid substance, when measured by X-ray diffraction and X-ray photoelectron spectroscopy, is found to be a novel substance which is clearly different from the complex metal oxide of ZrO ₂ —SiO ₂ .

In addition, the method for producing a composite metal oxide which is the novel solid acid according to the present invention is a method in which the composite metal oxide represented by xZrO ₂ · ySiO ₂ is subjected to SF at a temperature of 300 to 800 ° C.
It is characterized by processing in ₆ .

Further, the method for decomposing hydrocarbons according to the present invention is a hydrocarbon containing a paraffin having 5 to 10 carbon atoms or the paraffin as a main component in the presence of the above-mentioned novel solid acid substance [these hydrocarbons a)]] to produce a lower aliphatic hydrocarbon (b) mainly containing paraffin having 3 to 4 carbon atoms.

The above formula (xZrO ₂ · ySi obtained by the present invention
The solid acid substance represented by O ₂ ) .zF.mS has extremely strong acid strength, its strong acid sites are not easily decomposed even when it comes into contact with water, and the temperature range in which it can be used as a catalyst is wide.

Hydrocarbons containing paraffins having 5 to 10 carbon atoms (a)
When reacted in the presence of the above solid acid substance, it has 3 to 4 carbon atoms.
The lower aliphatic hydrocarbon containing paraffin as a main component is obtained in high yield.

DETAILED DESCRIPTION OF THE INVENTION A novel solid acid substance according to the present invention, a method for producing the same, and a hydrocarbon decomposition reaction using the solid acid substance as a catalyst will be specifically described below.

Solid acid substance composition The novel solid acid substance according to the present invention is (xZrO ₂ · ySiO ₂ ).
A ZrO ₂ —SiO ₂ -based mixed metal oxide represented by zF · mS, which has a super strong acid point with an acid strength (H 2 _{O 2} ) of −8.2 or less, and in some cases −12.7 or less. There is. In the above formula, x and y represent the number of moles of ZrO ₂ and SiO ₂ , and x /
The value of y indicates the atomic ratio of Zr / Si. And z and m
Indicates the weight% of F atoms and the weight% of S atoms with respect to the weight of (xZrO ₂ .ySiO ₂ ). And x / y
Is 99.9 / 0.1 to 10/90, and z is 0.1 to
10 and m is in the range of 0.01-5. In the present specification, F in the solid acid substance according to the present invention is used.
The ratios of S and S are shown as an average value of the whole solid acid substance. In this mixed metal oxide, Zr and Si
The atomic ratio (Zr / Si) of x is represented by x / y, but in the present invention, the value is in the range of 99.9 / 0.1 to 10/90, in which 90/10 to 50/50 It is preferably in the range. Such (xZrO ₂ · ySiO ₂ )
Since the solid acid substance of the present invention represented by zF · mS is obtained by treating a composite oxide of ZrO ₂ —SiO ₂ with SF ₆ as described below, the concentration of F and S on the surface of the solid is Is considered to be usually higher than the ratio in the above range.

In the present invention, (xZrO ₂ · ySiO ₂ ) · zF
In the solid acid substance represented by mS, when the atomic ratio of Zr / Si is usually larger than 99.9 / 0.1, the value of acid strength Ho becomes large and the acid strength becomes usually weak, and Zr
Even when the atomic ratio of / Si is 10/90 or less, the acid strength is usually weak, so that the atomic ratio (x / y) of Zr / Si is set in the above range in the present invention.

In the present invention, the solid acid substances Zr, Si,
The F and S contents are determined by the method described below.

Analysis of F and S: By oxygen flask combustion method.

Zr analysis: The sample is melted with an acid to form a nitric acid solution, and then analyzed by ICP plasma emission spectrometry.

Si analysis: The sample is alkali-melted to form an aqueous solution,
ICP plasma is based on emission analysis.

Acid Strength (Ho) The novel solid acid substance represented by the above formula has acid strength (Ho)
Has a strong acid point of -8.2 or less, but the acid strength (H
The measurement of o) was carried out by the method described in Catalyst 24 , (3) 241, (1982). Specifically, it is performed as follows. Sulfuryl chloride SO ₂ Cl ₂ 20
Put 5 g of granular blue silica gel in cc and leave it for 1 day to dry the reagent. Into this dried sulfuryl chloride 3cc test tube, the catalyst is immediately added and submerged in the solution. A few drops of a 1% benzene solution of a Hammett indicator having a known pKa value are added to the solid acid substance, shaken lightly several times and then allowed to stand to observe the change in color of the catalyst surface. If the change is not clear, plug and leave for a few hours and wait. When commercially available 1,3,5-trinitrobenzene (pKa-16.04) is used, since the reagent usually contains a large amount of water, a 1% benzene solution is prepared and silica gel is added and left for several days. Use as an indicator after drying.

The relationship between the Hammett indicator used to measure the acid strength (Ho) of the solid acid substance in the present invention and its pKa value is shown in Table 1.
Shown in. The procedure for measuring Ho using the indicator can be performed according to a known method. Ie p
An indicator having a large K value and an indicator having a small pKa value are sequentially added to the sample, and the change in color of the sample is examined to obtain the highest acid strength Ho of the sample. For example, 2,4-dinitrotoluene (pKa = -13.75) as an indicator changes to an acidic color, but 2,4-dinitrofluorobenzene (pKa = -1).
4.52; basic color is colorless and acid color is yellow).
Is considered to be in the range of −14.52 <Ho <−13.75. As is well known, Ho is approximately equal to the pKa value.

The value of the acid strength (Ho) is a value measured immediately after heating the solid acid substance in N ₂ at 400 to 600 ° C. immediately before measurement and then cooling to room temperature in a dry atmosphere.

By the way, in the (xZrO ₂ · ySiO ₂ ) · zF · mS solid acid substance according to the present invention, the atomic ratio Zr to Si of the solid acid substance is Z.
By changing r / Si, the acid strength (Ho) as a solid acid changes.

The strongest acid strength (Ho) is Zr / Si atomic ratio 7/3
Obtained in the vicinity, in this case (xZrO ₂ · y
The acid strength (Ho) of SiO ₂ ) .zF.mS is -13.7.
It also reaches 5>Ho> -14.52.

XRD analysis Such a solid acid substance represented by (xZrO ₂ · ySiO ₂ ) · zF · mS has a powder X-ray diffraction spectrum (XR
When analyzed by D), it has a spectrum distinctly different from that of xZrO ₂ .ySiO ₂ .

(XZrO ₂ · ySiO ₂ ) · zF · mS according to the present invention
The XRD diffraction pattern of (atomic ratio 7: 3 of Zr and Si) is shown in FIG. 1, and xZrO ₂ · ySiO ₂ (Z
Fig. 2 shows the diffraction pattern of XRD with an atomic ratio of r to Si of 3: 7). In the solid acid substance according to the present invention shown in FIG. 1, a new oxide which is not found in the ZrO ₂ —SiO ₂ composite oxide shown in FIG. 3 around 2θ = 30 °, 50.5 ° and 60 °. Peaks are generated, (xZrO ₂ · ySiO ₂ ) · zF
-MS is shown to be structurally different from xZrO ₂ · ySiO ₂ .

That is, according to the examination in the present invention, Z
In the complex oxide of rO ₂ —SiO ₂ before undergoing the SF ₆ treatment, the atomic ratio of Zr and Si (Zr / Si) is usually 9
In the range of 9.9 / 0.1 to 10/90, no remarkable peak was observed in the XRD diffraction pattern of the composite oxide,
An XRD diffraction pattern having an amorphous crystal structure, which is almost the same as that shown in FIG. 3, is obtained. On the other hand, according to the present invention obtained by treating this ZrO ₂ —SiO ₂ composite oxide with SF ₆ (xZrO ₂ · ySiO ₂ ).
zF · mS (atomic ratio of Zr / Si is 99.9 / 0.1
In the solid acid substance of 10/90), a clear diffraction peak with a large intensity is 2θ = 28 in the XRD diffraction pattern.
°, 30 °, 31.4 °, 34 °, 35 °, 50 °, 6
It is found in the vicinity of 0 ° C. However, in this XRD spectrum, although the relative intensity ratio of the diffraction peaks may be slightly different depending on the difference in the atomic ratio of Zr / Si and the processing conditions of SF ₆ , the peak of relatively strong intensity is almost the same as described above. Appears in the same position. The new diffraction peak appearing by this SF ₆ treatment belongs to ZrO ₂ , and from these XRD spectra, ZrO ₂
It is speculated that when the —SiO ₂ composite oxide is treated with SF ₆ , ZrO _{2 in the} composite oxide may approach a metastable tetragonal system. Moreover, in the composite oxide according to the present invention, SiO ₂
Peak of XRD attributed is usually not observed in, SF ₆
It was considered that SiO ₂ was not crystallized unlike ZrO ₂ even when treated.

The XRD analysis carried out in the present invention was carried out by preparing a powder sample in a dry nitrogen atmosphere under the following conditions and measuring it under the atmosphere.

Voltage: 40kv Current: 100mA Current Full: 800cps Time Constant: 0.5sec Scanning Speed: 4 ° C / min Divergency: 1/2 ° Receiving Slit: 0.15mm X-ray: CuKα (1.54A) XPS analysis Also according to the present invention. Related (xZrO ₂ · ySiO ₂ ) · zF ·
The difference between mS and ZrO ₂ —SiO ₂ is also shown by X-ray photoelectron spectroscopy (XPS). XPS charts before and after treating ZrO ₂ —SiO ₂ with SF ₆ show Zr 3d
Fig. 4 for electrons, Fig. 5 for IS electrons of F, Fig. 6 for 2p electrons of Si, and IS of O
The electrons are shown in FIG. From these figures, it is found that in the solid acid substance according to the present invention, the 1s electron spectrum of the fluorine atom is detected and the main spectrum of the 2p electron of the silicon atom is shifted to the high energy side of 1 to 2eV. .

In the present invention, XPS analysis is performed at room temperature at 35-8.
A 0 mesh sample was used and MgKα or AlKα was used as an X-ray source under a vacuum degree of about 1 × 10 ⁻⁶ Pa.

Preparation method of solid acid substance Next, (xZrO ₂ · ySiO ₂ ) · zF ·
A method for producing a solid acid substance represented by mS will be described.

The solid acid substance as described above according to the present invention treats the composite metal oxide represented by ZrO ₂ —SiO ₂ obtained by a usual method with SF ₆ at a temperature of 300 to 800 ° C., preferably 400 to 700 ° C. It is obtained by

To obtain a composite metal oxide represented by ZrO ₂ —SiO ₂ , for example, ZrO (NO ₃ ) ₂ · 2H ₂ O and Si (OC ₂ H _2
5 ) ₄ is obtained by thoroughly mixing Zr (OH) ₄ and Si (OH) ₄ obtained by hydrolysis of ₄ with aqueous ammonia, washing with water, filtering and drying, and then calcining. Additional _{ZrO (NO 3) 2 · 2H} 2 O
ZrOCl ₂ .8H ₂ O may be used instead of Si, and ordinary silica gel may be used instead of Si (OC ₂ H ₅ ) ₄ .

In the present invention, ZrO ₂ —SiO _{2 used} for SF ₆ treatment is used.
The method for obtaining the composite metal oxide represented by is not limited to the above-mentioned method, and may be prepared by a commonly known coprecipitation method, impregnation method, or the like. The atomic ratio of Zr and Si is
As described above, it is 99.9 / 0.1-10 / 90, preferably 90 / 10-50 / 50. This ZrO ₂ -SiO
_The mixed metal oxide represented by 2 is treated with SF ₆ at a temperature of 300 to 800 ° C., preferably 400 to 700 ° C., but prior to the treatment with SF ₆ , the treatment temperature is higher than or equal to the above treatment temperature. It is preferable to heat and evacuate the ZrO ₂ —SiO ₂ composite metal oxide.

When the ZrO ₂ —SiO ₂ mixed metal oxide is treated with SF ₆ , a treatment temperature of less than 300 ° C. is obtained (xZ
It is not preferable because rO ₂ · ySiO ₂ ) · zF · mS is unlikely to have a super strong acid point. On the other hand, when the temperature exceeds 800 ° C., similarly obtained (xZrO ₂ · ySiO ₂ ) · zF · mS is unlikely to have a super strong acid point. Therefore, it is not preferable.

Here, xZrO ₂ · ySiO ₂ mixed metal oxide is added to SF ₆
Table 2 shows the relationship between the treatment temperature and the acid strength (Ho) and the relation between the treatment temperature and the weights of F and S introduced into the oxide when treated with. Z in ZrO ₂ —SiO ₂ used
The atomic ratio of r to Si is 7/3, and the firing temperature is 600.
℃.

Method for Decomposing Hydrocarbon Next, (xZrO ₂ · ySiO ₂ ) .zF.
A hydrocarbon decomposition reaction using a solid acid substance represented by mS as a catalyst will be described.

The hydrocarbon decomposition reaction according to the present invention is performed by the above-mentioned (x
ZrO ₂ · ySiO ₂ ) · zF · mS in the presence of a solid acid substance, a paraffin having 5 to 10 carbon atoms or a hydrocarbon containing the paraffin as a main component (these are referred to as hydrocarbon (a)). To produce a lower aliphatic hydrocarbon containing a paraffin having 3 to 4 carbon atoms as a main component (these are referred to as hydrocarbon (b)).

The hydrocarbon (a) used as a raw material in the catalytic reaction of the present invention is a paraffin having 5 to 10 carbon atoms or a hydrocarbon containing this paraffin as a main component. Examples of paraffins having 5 to 10 carbon atoms include n-pentane, 2-methylbutane, n-hexane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, n-heptane, 2- Methylhexane, 3-methylhexane, 3-ethylpentane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 2,2,3-trimethylbutane, n-octane, 3-ethyl Hexane, 2,5-dimethylhexane,
Nonane, decane, etc. are specifically exemplified, and among them, n-hexane, 3-methylpentane, 2,3-dimethylbutane, n-heptane, 2-methylhexane, 3-methylhexane, 3-ethylpentane. , 2,2-dimethylpentane, 2,3-dimethylpentane and 2,4-dimethylpentane are preferably used.

In the present invention, not only the paraffins described above can be catalytically decomposed by mixing them alone or in combination of two or more, but also in addition to such paraffins, aromatic compounds such as cyclohexane, cyclohexene, benzene, decalin, tetralin, hexene and octene can be used. A hydrocarbon mixture containing other hydrocarbons such as a component, a naphthene component and an olefin component, and the content of paraffins having 5 to 10 carbon atoms is usually 30% by weight or more can also be used as a raw material. Examples of such a hydrocarbon mixture raw material include light naphtha having a boiling point range of usually 30 to 130 ° C. obtained by distillation separation of crude oil or catalytic cracking.

Such a reaction is usually carried out under the following conditions using a known vapor phase catalytic reactor.

The reaction is usually 100 to 600 ° C., preferably 200 to 60
It is carried out at a temperature in the range of 0 ° C. If the reaction temperature is lower than 100 ° C, it is not preferable because a sufficient conversion cannot be obtained. On the other hand, if the reaction temperature is higher than 600 ° C, the production of C ₁ and C ₂ fractions, which will be described later, increases, which is not preferable.

In the present invention, the raw material hydrocarbon (a) is fed into the reactor through the preheater in a predetermined amount. In this case, the feed amount is room temperature and normal pressure, and when the raw material is a liquid, the feed amount is Is expressed as a liquid space velocity (LHSV), and this value is usually 0.01 to 10 hr ^-1 , preferably
It is in the range of 0.1 to 5 hr ^-1 . In addition, gas space velocity (GHS
V), it is usually 10 to 10,000 hr-
1, preferably in the range of 100 to 1,000 hr ^-1 .

Regarding the reaction pressure, it is usually carried out under atmospheric pressure, but if necessary, it may be carried out by appropriately increasing the pressure.
In the present invention, in carrying out the reaction, an appropriate amount of an inert gas such as nitrogen can be accompanied in the reactor if necessary.

After cooling the reaction product leaving the reactor, it is separated into a gas product and a liquid product, and then analyzed by gas chromatography.

(XZrO ₂ · ySiO ₂ ) · zF · mS according to the present invention
When a hydrocarbon (a) having a carbon number of 5 to 10 is reacted by using as a catalyst, butane, pentane and propane are produced with a high selectivity, and the conversion rate of the hydrocarbon (a) as a raw material is extremely high. It shows a high value.

EFFECT OF THE INVENTION The above formula xZrO ₂ .ySiO ₂ .obtained by the present invention
The solid acid substance represented by zF · mS has extremely strong acid strength, does not easily decompose the super strong acid point even when it comes into contact with water, and has a wide temperature range in which it can be used as a catalyst.

Hydrocarbons containing paraffins having 5 to 10 carbon atoms (a)
When reacted in the presence of the above solid acid substance, it has 3 to 4 carbon atoms.
The lower aliphatic hydrocarbon containing paraffin as a main component is obtained in high yield.

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

Example 1 112.3 g (0.4%) of ZrO (NO ₃ ) ₂ .2H ₂ O
2 mol) was dissolved in 1 of distilled water, and NH ₃ water was added thereto to adjust the pH of the solution to 8 to 10 to obtain Zr (OH) ₄ . On the other hand, 37.5 g of Si (OC ₂ H ₅ ) ₄ (0.18 mo
l) was dissolved in 500 cc of CH ₃ OH, and NH ₃ water was added thereto to obtain Si (OH) ₄ . The two gels were mixed as such and stirred for an additional 30 minutes at room temperature. These mixed gels were thoroughly washed with water, filtered, kneaded with a kneader for 1 hour, and then dried at 100 ° C. for 15 hours. After drying, the obtained powder was classified into 35 to 80 mesh and calcined in air at 600 ° C. for 3 hours to prepare a ZrO ₂ —SiO ₂ composite oxide. A quartz reaction tube was filled with 2 g of this ZrO ₂ —SiO ₂ composite oxide, and after vacuum evacuation treatment at 600 ° C. for 1 hour, SF ₆ gas was introduced until it was cooled to room temperature and then brought to normal pressure. In this state, the reaction tube was heated to 600 ° C. and kept for 1 hour. After that, the inside of the system of the reaction tube was replaced with N ₂ and then vacuum exhaust was performed at 600 ° C. for 1 hour.

Table 3 shows the results of measuring F and S in the obtained (ZrO ₂ .SiO ₂ ) .F.S and measuring the specific surface area. Table 3 also shows the specific surface area of ZrO ₂ —SiO ₂ before being treated with SF ₆ . Also, before processing with SF ₆ 2
The specific surface area of rO ₂ —SiO ₂ is also shown in Table 3. Furthermore, when the acid strength (Ho) of this substance was measured by the indicator method by the method described in the specification, it was -13.75.
>Ho> -14.52, indicating that this material is a solid superacid. Zr and Si in the obtained substance
The atomic ratio of and is 7: 3 as can be seen from the raw material mixture ratio.

Example 2 The procedure of Example 1 was repeated, except that the atomic ratio of Zr: Si: was changed from 7: 3 to 9: 1. F and S and the specific surface area in the obtained substance were measured and shown in Table 3.
The acid strength (Ho) of this substance was measured in the same manner as in Example 1.

Example 3 The procedure of Example 1 was repeated, except that the atomic ratio of Zr: Si: was changed from 7: 3 to 1: 1. F in the obtained substance
Table 3 shows the results of measuring S and S and the specific surface area. The acid strength (Ho) of this substance was measured in the same manner as in Example 1.

Example 4 Example 1 except that the atomic ratio of Zr: Si was changed to 3: 7.
Same as. Table 3 shows the results of measuring F and S and the specific surface area of the obtained substance. The acid strength (Ho) of this substance was measured in the same manner as in Example 1.

From Table 3, it can be seen that when the Zr / Si atomic ratio is around 7/3, an extremely strong super strong acid point with an acid strength of -13.75 or less occurs in (xZrO ₂ · ySiO ₂ ) · zF · mS. Recognize.

Example 5 Using the solid superacid having a Zr: Si atomic ratio of 7/3 obtained in Example 1 as a catalyst, n-
Hexane was decomposed.

A pulse reactor directly connected to a gas chromatograph was used as a reactor, and 100 mg of a catalyst was packed in this pulse reactor,
The reaction pressure was 1 kg / cm ² G, the reaction temperature was 200 ° C., and 0.5 μl of n-hexane was supplied to carry out the reaction.

Analysis of reaction products and conversion of n-hexane were carried out by gas chromatography directly connected to a pulse reactor.

Example 6 A pulse reactor was charged before the decomposition reaction of n-hexane using the solid superacid having a Zr: Si atomic ratio of 7/3 obtained in Example 1 as a catalyst. After injecting 0.5 μl of water into the catalyst for 10 pulses at 600 ° C. to bring the catalyst into contact with steam, N ₂ was kept at the same temperature for 30 minutes.
The results of carrying out the reaction at 200 ° C. after flowing the gas are shown in Table 4. It can be seen that the activity of the solid acid substance of the present invention as a catalyst hardly changes even when it comes into contact with water.

Example 7 A decomposition reaction of n-hexane was carried out in the same manner as in Example 5 except that the reaction temperature was 250 ° C.

The results are shown in Table 4.

Example 8 A decomposition reaction of n-hexane was carried out in the same manner as in Example 5 except that the reaction temperature was 300 ° C.

The results are shown in Table 4.

Comparative Examples 1 to 3 In the catalysts used in Examples 5 to 8, ZrO ₂ —SiO ₂ without SF ₆ treatment for obtaining the catalyst was used.
A reaction was carried out in the same manner as in the above example using (Zr / Si = 7/3), but in this case, the reaction did not occur.

In Example 9-10 Example _{1, ZrO (NO 3) 2} · 2H 2 O and Si
The ZrO ₂ —SiO ₂ composite oxide obtained from (OC ₂ H ₅ ) ₄ and ₆ was calcined at 700 ° C. for 2 hours, and then 6 with SF ₆ gas.
ZrO ₂ —SiO ₂ · F after treatment for 1 hour at a temperature of 00 ° C
・ Preparation of S catalyst and reaction temperature of 2
The decomposition reaction of n-hexane was performed in the same manner as in Example 5 except that the temperature was set to 00 ° C, 300 ° C, and 350 ° C.

The results are shown in Table 5.

ZrO In Examples 12 to 14 Example _{1 (NO 3) 2 · 2H} 2 O and Si
The ZrO ₂ —SiO ₂ composite oxide obtained from (OC ₂ H ₅ ) ₄ and ₅ was calcined at 600 ° C. for 2 hours, and then 5 with SF ₆ gas.
ZrO ₂ · SiO ₂ · F after treatment at a temperature of 00 ° C for 1 hour
-Prepare S catalyst and use this solid superacid at 250 ° C,
The decomposition reaction of n-hexane was carried out in the same manner as in Example 5 except that the temperature was 300 ° C and 350 ° C.

The results are shown in Table 6.

[Brief description of drawings]

1 and 2 show (xZrO ₂ .ySiO ₂ ) .zF
・ A powder X-ray diffraction spectrum of mS (x / y = 7/3, 3/7), and FIG. 3 shows xZrO ₂ · ySiO ₂ (x /
It is an X-ray diffraction spectrum of y = 7/3). Further, in FIG. 4, Zr before and after SF ₆ treatment of xZrO ₂ · ySiO ₂ is shown.
Shows a spectrum of 3d electrons by X-ray photoelectron spectroscopy,
FIG. 5 shows spectra of F1S electrons of xZrO ₂ .ySiO ₂ before and after SF ₆ treatment by X-ray photoelectron spectroscopy, and FIG. 6 shows x-rays of Si2p electrons of xZrO ₂ .ySiO ₂ before and after SF ₆ treatment. FIG. 7 shows spectra obtained by photoelectron spectroscopy, and FIG. 7 shows spectra obtained by X-ray photoelectron spectroscopy of O1S electrons before and after SF ₆ treatment of xZrO ₂ · ySiO ₂ .

Claims (3)

[Claims] 1. A formula (xZrO ₂ · ySiO ₂ ) · zF · mS ......
[I] [In the formula, x and y represent the number of moles of ZrO ₂ and SiO _2.
The value of / y indicates the atomic ratio of Zr / Si. Further, z and m are F with respect to the weight of (xZrO ₂ · ySiO ₂ ), respectively.
The weight% of atoms and the weight% of S atoms are shown. And x /
y is 99.9 / 0.1-10 / 90 and z is 0.1
-10 and m is in the range of 0.01-5. ] The acid strength (H 2 _{O 2} ) of the mixed metal oxide represented by
Z having a strong acid point of 8.2 or less, Z
rO ₂ —SiO ₂ type solid acid substance. 2. A ZrO ₂ —SiO ₂ mixed metal oxide is used.
The acid strength (Ho) represented by the following formula [I] is −6, which is characterized by treating with SF ₆ at a temperature of 0 to 800 ° C.
Method for producing ZrO ₂ —SiO ₂ -based solid acid substance having strong acid point of 8.2 or less: Formula (xZrO ₂ · ySiO ₂ ) · zF · mS ... [I] [wherein, x and y are ZrO ₂ and Indicates the number of moles of SiO ₂ x
The value of / y indicates the atomic ratio of Zr / Si. Further, z and m are F with respect to the weight of (xZrO ₂ · ySiO ₂ ), respectively.
The weight% of atoms and the weight% of S atoms are shown. And x /
y is 99.9 / 0.1-10 / 90 and z is 0.1
-10 and m is in the range of 0.01-5. ] 3. A paraffin having 5 to 10 carbon atoms or a hydrocarbon containing the paraffin as a main component (these are referred to as hydrocarbon (a)) is represented by the following formula [I]: ZrO ₂ -S.
When reacted with the presence of the iO ₂ -based solid acid substance, the carbon number of 3 to
4. A method for decomposing a hydrocarbon (a), characterized in that a lower aliphatic hydrocarbon (b) containing paraffin as a main component of 4 is produced: Formula (xZrO ₂ · ySiO ₂ ) · zF · mS ...... [I [Wherein x and y represent the number of moles of ZrO ₂ and SiO ₂ ,
The value of x / y indicates the atomic ratio of Zr / Si. Further, z and m represent the weight% of F atom and the weight% of S atom with respect to the weight of (xZrO ₂ · ySiO ₂ ), respectively. And x
/ Y is 99.9 / 0.1-10 / 90, and z is 0.
1 to 10 and m is in the range of 0.01 to 5. ]