WO2022196717A1 - Catalyst, methhod for producing catalyst, method for producing diene compound, method for producing polymer, method for producing polymer molded article, method for measuring catalyst performance, and method for prolonging service life - Google Patents

Abstract

[Problem] To provide: a catalyst which has, for example, a high conversion efficiency from a starting material that contains an alcohol to a diene compound (namely, a high yield of a diene compound); a method for producing this catalyst; a method for producing a diene compound, the method using this catalyst; a method for producing a polymer; a method for producing a polymer molded article; and a method for measuring catalyst performance. [Solution] A catalyst according to the present invention is characterized by containing a catalytically active element and a carrier that supports the catalytically active element, while being also characterized in that the heating efficiency represented by formula (1) is 5-6.5%.　

Description

Catalyst, method for producing catalyst, method for producing diene compound, method for producing polymer, method for producing polymer molded product, method for measuring catalyst performance and method for extending service life

The present invention relates to a catalyst, a method for producing a catalyst, a method for producing a diene compound, a method for producing a polymer, a method for producing a polymer molded article, a method for measuring catalyst performance, and a method for extending the service life.

A diene compound such as 1,3-butadiene, which is a typical example of a diene compound, is used as a raw material for styrene-butadiene rubber (SBR) and the like. Traditionally, butadiene was purified from the C4 fraction. The C4 fraction is a by-product of naphtha cracking to produce ethylene from petroleum. However, oil usage has decreased as shale gas usage has increased. As a result, the production of butadiene from naphtha cracking of petroleum is also decreasing. Therefore, there is a need for alternative methods for producing diene compounds.

For example, Patent Document 1 describes a method for producing 1,3-butadiene in which 1,3-butadiene is obtained by bringing a raw material containing ethanol into contact with a catalyst under heating. In addition, in Patent Document 1, the used catalyst is heated to about 350 to 500 ° C. in a reactor, air is circulated, and a regeneration treatment is performed for 1 to 24 hours, thereby reducing the catalytic activity to unused. It is also described that the catalyst can be recovered to 90% or more and reused.

Patent Document 2 discloses a catalyst comprising a porous support, an oxide of a metal element A, and an oxide of a metal element B, wherein at least a portion of the oxide of the metal element A binds to the porous support. It is Further, FIG. 1, paragraphs 0037 to 0038 of Patent Document 2 disclose a catalyst having a configuration in which the surface of a porous support (silica) is coated with an oxide of metal element A and an oxide of metal element B. ing.

Patent Document 3 describes a metal-impregnated silica catalyst for selectively converting ethanol to butadiene, that is, a catalyst for butadiene synthesis. More specifically, the catalyst for butadiene synthesis of Patent Document 3 contains hafnium (Hf) and two or more catalytically active metals M1 and M2, wherein the catalytically active metals M1 and M2 are different from each other, It is stated to be selected from the group consisting of zinc (Zn), copper (Cu) and combinations thereof.

JP 2015-034151 A WO2019/139071 WO2014/199349

In the production method disclosed in Patent Document 1, when continuously producing 1,3-butadiene, a reaction process using a catalyst and a catalyst regeneration process are repeatedly performed. At this time, if the heating temperature in the reaction process and the heating temperature in the regeneration process are different, it is necessary to repeatedly raise and lower the temperature of the catalyst between these processes.
In this case, if the efficiency of temperature rise or temperature drop of the catalyst is too low, the time required for temperature rise or temperature drop will be long. As a result, the time for the regeneration process becomes longer than the time for the reaction process (the time the catalyst can be used as a catalyst), which may reduce the productivity of 1,3-butadiene.

On the other hand, if the efficiency of temperature rise or temperature drop of the catalyst is too high, it becomes difficult to precisely control the temperature of the catalyst.
For example, if the temperature rise efficiency of the catalyst is too high, the temperature of the catalyst will rise more than necessary in the regeneration process, which is often an exothermic process. The structure may collapse. Further, in this case, the temperature of the reaction tube filled with the catalyst may exceed the endurable temperature and the reaction tube may deteriorate.

Further, as a result of the inventors' examination of the catalyst described in Patent Document 2, the oxide of the metal element A and the oxide of the metal element B that exhibit catalytic activity are present only on the surface of the porous support and inside the porous support. However, the initial performance (initial yield of the diene compound) is high, but the lifetime is extremely short. Furthermore, when the present inventors examined the butadiene synthesis catalyst described in Patent Document 3, either or both of the ethanol conversion rate and butadiene selectivity are low, so the yield of butadiene is also low. I found out. Therefore, improving the yield of butadiene deserves further investigation.

The present invention has been made in view of such circumstances, and an object thereof is, for example, a catalyst with high conversion efficiency (i.e., diene compound yield) and high productivity from raw materials containing alcohol to diene compounds, and Catalysts with high initial performance and long life, methods for producing these catalysts, methods for producing diene compounds using such catalysts, methods for producing polymers and methods for producing polymer molded articles, and catalyst performance based on the characteristics of various catalysts It is to provide a measuring method and a method for prolonging the service life.

Such objects are achieved by the present invention described below.
(1) The catalyst of the present invention contains a catalytically active element and a carrier supporting the catalytically active element, and has a temperature elevation efficiency represented by the following formula (1) of 5 to 6.5%. Characterized by

(2) The catalyst of the present invention contains a catalytically active element and a carrier that supports the catalytically active element, and has a cooling efficiency represented by the following formula (2) of 2.6 to 4.5%. characterized by

(3) The catalyst of the present invention contains a catalytically active element and a carrier that supports the catalytically active element, and has a whiteness ratio represented by the following formula (3) of 98 to 130%. do.

(4) The catalyst of the present invention is a catalyst in which the support is composed of an oxide containing element X, and the catalytically active element supported on the surface and inside of the support, It is preferable that the amount of the catalytically active element contained in a region from the surface of the catalyst to a predetermined depth is larger than the amount of the catalytically active element contained inside the region of the catalyst.
(5) In the catalyst of the present invention, it is preferable that the predetermined depth region is a region up to 60 μm from the surface of the catalyst.
(6) In the catalyst of the present invention, A is the molar ratio of the catalytically active element to the element X in the entire catalyst, and B is the molar ratio of the catalytically active element to the element X in the region up to the predetermined depth. Then, B/A is preferably 1-9.
(7) In the catalyst of the present invention, the molar ratio of the catalytically active element to the element X is preferably determined by measurement using a scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX method). .
(8) In the catalyst of the present invention, the catalytically active element is preferably at least one element belonging to groups 2 to 6, 11 and 12 of the periodic table.

(9) In the catalyst of the present invention, the carrier is preferably a porous carrier.
(10) In the catalyst of the present invention, the carrier preferably comprises an oxide containing at least one element X selected from Groups 13 and 14 of the periodic table.

(11) The catalyst of the present invention contains hafnium (Hf) and at least one element M selected from titanium (Ti) and zirconium (Zr), and the molar ratio of the element M to the hafnium (Hf) ( M/Hf) is more than 20 and 500 or less.
(12) In the catalyst of the present invention, the element M is preferably zirconium (Zr).

(13) The catalyst of the present invention is an oxide further supporting the hafnium (Hf) and the element M and containing at least one element X selected from groups 13 and 14 of the periodic table. It is preferred to include a carrier composed of:
(14) The catalyst of the present invention is a catalyst containing the hafnium (Hf) and the element M supported on the surface and inside of the carrier, and contained in a region from the surface of the catalyst to a predetermined depth. It is preferable that the amounts of the hafnium (Hf) and the element M contained in the catalyst are larger than the amounts of the hafnium (Hf) and the element M contained inside the region of the catalyst.
(15) In the catalyst of the present invention, the element X is preferably silicon (Si).
(16) In the catalyst of the present invention, the molar ratio (M/X) of the element M to the element X is preferably 0.0001 to 0.5.

(17) The catalyst of the present invention is preferably subjected to a reaction process of converting into a second compound by contact with the first compound and a regeneration process of regenerating the catalyst after the reaction process.
(18) The catalyst of the present invention preferably satisfies B>A and BA=50 to 400° C., where A is the heating temperature in the reaction process and B is the heating temperature in the regeneration process.
(19) In the catalyst of the present invention, the heating temperature in the reaction process is preferably 200-600°C.
(20) In the catalyst of the present invention, the heating temperature in the regeneration process is preferably 200-600°C.

(21) The catalyst of the present invention is preferably a diene compound synthesis catalyst for synthesizing a diene compound from an alcohol-containing raw material.
(22) In the catalyst of the present invention, the raw material preferably contains at least one of ethanol and acetaldehyde.

(23) One aspect of the method for producing the catalyst of the present invention is
a step of preparing a solution obtained by dissolving the compound containing the catalytically active element in a solvent and the carrier;
contacting and impregnating the carrier with the solution;
calcining the carrier impregnated with the solution;
A non-explosive solvent is used as the solvent.

(24) Another aspect of the method for producing a catalyst of the present invention is
A solution obtained by dissolving the compound containing hafnium (Hf) in a solvent and a solution obtained by dissolving the compound containing the element M in a solvent, or the compound containing the hafnium (Hf) and the compound containing the element M are combined into a solvent. A step of preparing a solution dissolved in and the carrier;
contacting the solution with the carrier;
and calcining the carrier contacted by the solution,
A non-explosive solvent is used as the solvent.

(25) In the method for producing a catalyst of the present invention, the carrier is preferably a porous carrier.
(26) In the method for producing a catalyst of the present invention, it is preferable that the carrier is composed of an oxide containing at least one element X selected from Groups 13 and 14 of the periodic table.

(27) The method for producing a diene compound of the present invention is characterized in that the catalyst of the present invention is brought into contact with an alcohol-containing raw material to produce a diene compound.
(28) The method for producing a polymer of the present invention is characterized by producing a polymer using at least part of the diene compound produced by the method for producing a diene compound of the present invention as a polymer raw material.
(29) The method for producing a polymer molded product of the present invention is characterized by molding the polymer produced by the method for producing a polymer of the present invention.

(30) The method for measuring the catalytic performance of a catalyst suitable for synthesizing a diene compound according to the present invention is characterized by measuring at least one selected from temperature rising efficiency, cooling efficiency and whiteness ratio.

(31) The life extension method of the present invention is a method for extending the life of a catalyst comprising a carrier composed of an oxide containing element X and a catalytically active element supported on the surface and inside of the carrier. There is
By making the amount of the catalytically active element contained in a region from the surface of the catalyst to a predetermined depth greater than the amount of the catalytically active element contained inside the region of the catalyst, The life of the catalyst is extended as compared with other catalysts in which the catalytically active element is supported only in the region of .
(32) In the method for extending the service life of the present invention, when the raw materials of the catalyst and the other catalyst are brought into contact with raw materials containing alcohol to produce a diene compound by reacting the raw materials, the Therefore, it is preferable that the decrease in the initial yield of the diene compound is suppressed and the reaction maintenance rate for maintaining the initial yield is increased.
(33) In the method for extending service life of the present invention, it is preferable that the initial yield is 80% or more of the other catalyst and the reaction maintenance rate is twice or more that of the other catalyst.

According to the present invention, for example, a diene compound can be produced from an alcohol-containing raw material at a high yield over a long period of time from the initial stage.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the manufacturing apparatus of a diene compound.

Hereinafter, the catalyst, method for producing a catalyst, method for producing a diene compound, method for producing a polymer, method for producing a polymer molded product, method for measuring catalyst performance, and method for extending the service life of the present invention will be described in detail based on preferred embodiments. do.
[catalyst]
The catalyst of the present invention is used, for example, as a diene compound synthesis catalyst for synthesizing a diene compound (second compound) by contact with a raw material containing an alcohol (first compound). In addition, although the performance (activity) of the catalyst to which the carbon or carbon compound produced during the synthesis of the diene compound adheres is lowered, the carbon or carbon compound is removed by combustion and regenerated by heating in an oxygen-containing atmosphere. (recover activity).

Such a catalyst is preferably subjected to a reaction process for converting an alcohol (first compound) into a diene compound (second compound) and a regeneration process for regenerating the catalyst after undergoing this reaction process, more preferably a reaction process. and the regeneration process repeatedly. Thereby, a diene compound can be continuously produced from a raw material containing alcohol.
Here, the raw material preferably contains at least one of ethanol and acetaldehyde, more preferably ethanol. As the diene compound, 1,3-butadiene is preferable as described later.

One aspect of the catalyst of the present invention includes a catalytically active element and a carrier that supports this catalytically active element. Such a catalyst preferably satisfies one of conditions I to III shown below, more preferably satisfies two conditions, and further preferably satisfies three conditions.

Condition I: The heating efficiency represented by the following formula (1) is 5 to 6.5%.

Condition II: The cooling efficiency represented by the following formula (2) is 2.6 to 4.5%.

Condition III: The whiteness ratio represented by the following formula (3) is 98 to 130%.

By satisfying the condition I or the condition II, the temperature rising efficiency or the temperature falling efficiency of the catalyst becomes moderate, so that the time required for the temperature rising or falling of the catalyst can be prevented from becoming unnecessarily long. As a result, the time of the reaction process (time during which the catalyst can be used) can be made longer than the time of the regeneration process, so that the desired amount of 1,3-butadiene can be produced continuously and stably. .
In addition, since the temperature of the catalyst can be easily controlled, even if the regeneration process is an exothermic process, it is possible to prevent the temperature of the catalyst from rising more than necessary during the regeneration process. Therefore, aggregation of the catalytically active element and sintering of the carrier are less likely to occur, and collapse of the catalyst structure can be prevented. Furthermore, it is possible to prevent the temperature of the reaction tube filled with the catalyst from exceeding the endurable temperature, thereby suppressing deterioration of the reaction tube.

In addition, according to the study of the present inventors, it was found that a catalyst that satisfies condition III easily satisfies condition I and/or condition II.
Here, the temperature rising efficiency under condition I may be 5 to 6.5%, preferably 5.2 to 6.4%, more preferably 5.4 to 6%.
The temperature lowering efficiency under condition II may be 2.6 to 4.5%, preferably 2.8 to 4.2%, more preferably 3 to 4%.
The whiteness ratio under condition III may be 98 to 130%, preferably 100 to 125%, more preferably 102 to 115%.
Therefore, when at least one of the above conditions is satisfied, the above effects can be further enhanced.

According to the studies of the present inventors, the above conditions I to III are the quantitative ratio of the catalytically active element and the carrier, the selection of the catalytically active element and the type of the carrier, the conditions of the carrier (average pore diameter, total fineness Pore volume, specific surface area, mesopore volume ratio, etc.), catalyst production conditions (method of contacting a solution of a compound containing a catalytically active element with a support, contact time, type of washing liquid, etc.). I also know

From the viewpoint of further increasing the specific surface area of the catalyst, the carrier is preferably a porous carrier, preferably a porous carrier having mesopores. In this case, not only is it easy to produce a catalyst that satisfies the above conditions I to III, but also the catalytically active element is supported on the pore walls forming the mesopores, so the specific surface area (active site) of the catalyst can be increased. can be increased.
Also, in this case, for example, the raw material alcohol (ethanol) and its intermediate (crotonaldehyde) enter the mesopores, increasing the collision frequency and improving the reactivity.
Furthermore, by setting the number, size, etc. of mesopores of the porous carrier, the resulting catalyst can more reliably satisfy the conditions I to III.

The average pore diameter of mesopores is preferably 2 to 50 nm, more preferably 2 to 30 nm, even more preferably 2 to 20 nm, and particularly preferably 2 to 15 nm.
As used herein, the "average pore diameter" can be a value calculated from the total pore volume (the total pore volume of the porous carrier) and the BET specific surface area.
Specifically, a calculation method (BJH method) can be used that assumes that the shape of the mesopores is cylindrical. In this case, if the side area of the cylinder is defined as the BET specific surface area A1 and the volume of the cylinder is defined as the total pore volume V1, the average pore diameter of the mesopores can be calculated by 4V1/A1.

The total pore volume of the porous carrier is preferably 0.1 to 10 mL/g, more preferably 0.1 to 5 mL/g, and 0.1 to 2 mL/g. More preferred. By setting the total pore volume of the porous support within the above range, not only is it easy to produce a catalyst that satisfies the above conditions I to III, but also the diffusibility of the raw material into the porous support is improved, and the raw material and the catalyst The contact area between (catalytically active element) is increased, and thus the yield of the diene compound can be further increased.
In addition, in this specification, the value measured by the gas adsorption method can be adopted as the "total pore volume" of the porous carrier.
Here, the gas adsorption method is a method in which nitrogen gas is used as an adsorption gas, nitrogen molecules are adsorbed on the surface of a porous carrier, and the pore size distribution is measured from the condensation of the molecules.

The specific surface area of the carrier is preferably 100 to 10,000 m ² /g, more preferably 200 to 5,000 m ² /g, still more preferably 200 to 1,500 m ² /g, and 700 to 1,200 m ² /g. is particularly preferred. By setting the specific surface area of the carrier within the above range, it is possible not only to easily produce a catalyst that satisfies the above conditions I to III, but also to sufficiently increase the number of active sites, and the raw material and the catalyst (catalytically active element ), thus increasing the yield of the diene compound. As a result, high conversion of the feed is maintained even when the alcohol or both alcohol and aldehyde content in the feed is high.
In this specification, the "specific surface area" of the carrier means the BET specific surface area measured by the BET gas adsorption method using nitrogen as the adsorption gas.

The product of the total pore volume and the specific surface area of the porous carrier is preferably 10 to 100,000 mL·m ² /g ² , more preferably 20 to 25,000 mL·m ² /g ² , and 20 to 2,000 mL. - It is more preferable that it is m< ² >/g< ² >. By setting the product of the total pore volume and the specific surface area of the porous support within the above range, not only is it easy to produce a catalyst that satisfies the above conditions I to III, the number of active sites is sufficiently increased, and The diffusibility of the raw material into the porous carrier is improved, and the contact area between the raw material and the catalyst (catalytically active element) is increased, thereby further increasing the yield of the diene compound.

The mesopore volume ratio (total mesopore volume/total pore volume x 100) of the porous carrier is preferably 50% or more, more preferably 50 to 100%, and 80 to 100%. It is more preferable to be 1, and particularly preferably 90 to 100%. By setting the mesopore volume ratio within the above range, not only is it easy to produce a catalyst that satisfies the above conditions I to III, but also a sufficient number of mesopores are present in the porous support, and the diffusibility of the raw material is improved. Therefore, the yield of the diene compound can be further increased.

The ratio of the mesopore volume ratio can be controlled by the ratio of raw materials (such as compounds containing the element X) used in the method for producing the catalyst described below, the calcination temperature in the calcination step, and the like.
Further, the shape of the mesopores of the porous carrier and whether or not the pore walls forming the mesopores have a crystal structure can be confirmed by observing diffraction peaks by X-ray diffraction. .
Furthermore, the shape and regularity of mesopores can be confirmed by observing the porous carrier with a transmission electron microscope (TEM).

The shape of the carrier is not particularly limited, but is preferably granular, for example. If it is granular, it is easy to moderately adjust the packing density of the catalyst of the present invention.
Here, "granular" is a concept including powdery, particulate, lumpy, pellet-like, etc., and its shape may be any of spherical, plate-like, polygonal, crushed, columnar, needle-like, scale-like, etc. .
The average particle size of the carrier is preferably 150 μm to 30 mm, more preferably 200 μm to 20 mm, even more preferably 300 μm to 10 mm. With a carrier having such an average particle size, the packing density of the catalyst of the present invention tends to be moderate.

In this specification, "average particle size" means the average value of particle sizes of arbitrary 200 catalysts in one field observed with an electron microscope.
In this case, "particle size" means the maximum length of the distance between two points on the outline of the catalyst. When the carrier is columnar, the maximum length of the distance between two points on the contour line of the end face is defined as the "particle diameter".
Further, the average particle size is, for example, in the form of lumps, and means the average particle size of the secondary particles when the primary particles are agglomerated.

In the present invention, the carrier that supports the catalytically active element is preferably composed of an oxide containing at least one element X selected from Groups 13 and 14 of the periodic table. By supporting a catalytically active element on such a carrier, the specific surface area of the catalyst (catalytically active element) can be increased, the performance of the catalyst can be further improved, and the yield of the diene compound can be further increased.

Examples of the element X include elements belonging to Group 13 such as aluminum (Al), gallium (Ga), and indium (In), carbon (C), silicon (Si), germanium (Ge), tin (Sn), and the like. and elements belonging to Group 14 of Among them, the element X is preferably an element belonging to Group 14, more preferably carbon or silicon, and still more preferably silicon. The carrier composed of the oxide containing the element X easily stably supports the catalytically active element. The carrier may contain the above element X singly or in combination of two or more.

By selecting and combining the catalytically active element and the element X (support) from the list above, it is easy to produce a catalyst that satisfies the conditions I to III.
A particularly preferred combination of the catalytically active element and the element X is hafnium as the catalytically active element and silicon as the element X.

The packing density of the catalyst of the present invention is preferably 1.1 g/mL or less, more preferably 0.4 to 1 g/mL, and further preferably 0.5 to 0.9 g/mL. preferable. If the packing density is too low, the feedstock passes too fast and the contact time between the catalyst and the feedstock is reduced. As a result, the yield of the diene compound tends to decrease. On the other hand, if the packing density is too high, the passage speed of the raw materials becomes too slow, making it difficult for the reaction to proceed or requiring a long time to produce the diene compound.

One aspect of the catalyst of the present invention includes a support, preferably a porous support, composed of an oxide containing element X, and a catalytically active element supported on the surface and inside of the porous support.
In one aspect of the catalyst of the present invention, the amount of the catalytically active element contained in the region from the surface of the catalyst to a predetermined depth (hereinafter also referred to as "region near the surface") is (hereinafter also referred to as "inner region").
The catalyst of the present invention has a sufficient amount of catalytically active element in the region near the surface, so that the initial yield of the diene compound (initial performance of the catalyst) is high, and the inner region also has the catalytically active element. As a result, a high diene compound yield (catalyst performance) is maintained over a long period of time (that is, the life of the catalyst is extended).
Here, the initial yield of the diene compound means the yield of the diene compound one hour after starting the supply of the raw materials, as will be described later in Examples.

The predetermined depth region (region near the surface) is preferably a region from the surface of the catalyst up to 60 μm, more preferably up to 50 μm, and further preferably up to 30 μm. preferable. Such a region is the region on the outermost surface side of the catalyst, and by having sufficient catalytically active elements in this region, the initial yield of the diene compound can be further improved.
The extent to which the catalytically active element is unevenly distributed in the region near the surface of the catalyst is determined by the relationship between the molar ratio A of the catalytically active element to the element X in the entire catalyst and the molar ratio B of the catalytically active element to the element X in the region near the surface. can be stipulated.

Specifically, B/A (molar ratio of catalytically active element to element X in the region near the surface/molar ratio of catalytically active element to element X in the entire catalyst) is preferably 1 to 9, preferably 2 to 8 is more preferred, and 3 to 7 is even more preferred. In this case, the balance between the initial yield of the diene compound and the reaction maintenance rate (lifetime) becomes better.
Here, the reaction maintenance rate is the initial yield of the diene compound, that is, the yield of the diene compound after 1 hour from the start of supply of the raw material is C1 [%], and the yield of the diene compound after 20 hours is C2 [%]. , the value is expressed by C2/C1×100.

The molar ratio of the catalytically active element to the element X can be obtained by measuring the molar amounts of the element X and the catalytically active element in the object to be measured using a predetermined method and dividing the measured values.
Predetermined methods include, for example, energy dispersive X-ray spectroscopy (EDX method), inductively coupled plasma emission spectroscopy (ICP method), X-ray fluorescence spectroscopy (XRF method), and X-ray photoelectron spectroscopy (XPS method). etc. Among them, the above method is preferably scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX method), transmission electron microscope-energy dispersive X-ray spectroscopy (TEM-EDX method), More preferred is the SEM-EDX method. According to such a method (particularly, the SEM-EDX method), the molar ratio can be obtained more accurately and simply.

Although the specific value of the molar ratio A is not particularly limited, it is preferably 0.2-10, more preferably 0.5-5. On the other hand, although the specific value of the molar ratio B is not particularly limited, it is preferably 0.5-20, more preferably 1-10.

The catalytically active element is preferably at least one of the elements belonging to Groups 2 to 6, 11 and 12 of the periodic table. It is more preferably at least one of the belonging elements, and more preferably at least one of magnesium (Mg), tantalum (Ta), hafnium (Hf) and zirconium (Zr). Selection of these elements can improve the yield of the diene compound in particular.

A preferred embodiment of the catalyst of the present invention also contains hafnium (Hf) and at least one element M selected from titanium (Ti) and zirconium (Zr).
Hafnium has a high raw material conversion rate and diene compound selectivity (hereinafter collectively referred to as "diene compound yield"), but is a metal element that is inexpensive and difficult to obtain in large quantities. . Therefore, in a preferred embodiment of the catalyst of the present invention, hafnium is used in combination with at least one element M of titanium and zirconium, which are metal elements belonging to the same group (group 4) of the periodic table. . Thereby, the production cost can be reduced while maintaining high performance of the catalyst (yield of diene compound).

Especially in the catalyst of the present invention, the molar ratio (M/Hf) of the element M to hafnium (Hf) is set in the range of more than 20 to 500 or less. This can prevent hafnium (single element) or its compound (eg, oxide) from being embedded in the element M (single element) or its compound (eg, oxide). Therefore, the stronger interaction between hafnium and the element M increases the number of active sites, and the high performance of the catalyst can be sufficiently maintained.
On the other hand, when the molar ratio (M/Hf) exceeds 500, hafnium or its compound is embedded in the element M or its compound. Further, when the molar ratio (M/Hf) is 20 or less, the interaction between hafnium and the element M is weakened, resulting in a decrease in the number of active sites. Therefore, the performance of the catalyst deteriorates when the molar ratio (M/Hf) deviates from the above range either upwards or downwards.

The molar ratio (M/Hf) may be more than 20 and 500 or less, preferably more than 50 and 400 or less, more preferably more than 100 and 400 or less, more preferably more than 100 and 300 or less. . In this case, the performance of the catalyst can be further improved.
The element M may be at least one of titanium and zirconium, preferably zirconium. Zirconium strongly interacts with hafnium among the elements belonging to group 4 of the periodic table. Therefore, the number of active sites is increased, and the high performance of the catalyst is more reliably maintained.
Such a catalyst of the present invention preferably contains a carrier on which hafnium and the element M are supported. The details of the oxide containing the element X that constitutes the carrier and the porous carrier that is a suitable carrier are the same as those described above.
A particularly preferable combination of the element M and the element X is that the element M is zirconium and the element X is silicon.

In the catalyst of the present invention, the molar ratio (M/X) of element M to element X is preferably 0.0001 to 0.5, more preferably 0.0005 to 0.4, and more preferably 0.0005 to 0.4. 001 to 0.4, and particularly preferably 0.001 to 0.3. If the above range is deviated downward, depending on the combination of the element M and the element X, the interaction between the element M and the element X may be weakened, resulting in a decrease in the number of active sites. If the above range is deviated upward, the surface of the carrier may be coated with the element M and the specific surface area may decrease depending on the type, size, etc. of the carrier used. Therefore, if the molar ratio (M/X) is within the above range, the performance of the catalyst is likely to be improved regardless of the combination of the element M and the element X.

When the element M is contained in combination of two or more types, the sum thereof is used, and when the element X is contained in combination of two or more types, the sum thereof is used to calculate the molar ratio (M/X).
In the catalyst of the present invention, the molar ratio of Hf to element X (Hf/X) is preferably 0.00001 to 0.1, more preferably 0.00001 to 0.01. By using Hf within this range, the catalyst can be produced at low cost while maintaining high performance of the catalyst.

Since the catalyst of the present invention satisfies the above conditions I to III, the temperature of the catalyst can be precisely controlled.
Therefore, the catalyst of the present invention satisfies B>A and BA=50 to 400° C. (especially 100 to 400° C.), where A is the heating temperature in the reaction process and B is the heating temperature in the regeneration process. It is preferable to subject it to a reaction process and a regeneration process.
According to the catalyst of the present invention, even when subjected to such a reaction process and a regeneration process, a diene compound can be produced efficiently by securing a sufficient time for the reaction process (time during which the catalyst can be used). be able to. In addition, the occurrence of inconveniences such as collapse of the catalyst structure due to agglomeration of catalytically active elements and quenching of the carrier, and deterioration of the reaction tube due to the temperature of the reaction tube filled with the catalyst exceeding the endurance temperature should be preferably prevented. can be done.

The specific value of the heating temperature in the reaction process is not particularly limited, but it is preferably 100 to 600 ° C., preferably 200 to 600 ° C., more preferably 200 to 500 ° C., 250 to It is more preferably 500°C, even more preferably 250 to 450°C, even more preferably 300 to 450°C.
On the other hand, the specific value of the heating temperature in the regeneration process is not particularly limited, but it is preferably 200 to 600°C, more preferably 300 to 575°C, and even more preferably 400 to 550°C. .
When used in reaction processes and regeneration processes that are carried out at such relatively high heating temperatures, the catalyst of the present invention can favorably exhibit the effects described above.

[Method for producing catalyst]
A catalyst in which a catalytically active element is supported on a carrier can be produced through, for example, a preparation step, a contact step and a calcination step. Each step of the catalyst production method of the present embodiment will be described below.
(Preparation process)
First, a compound containing a catalytically active element (catalytically active element precursor) is dissolved in a solvent to prepare a solution (impregnation liquid).

Compounds containing a catalytically active element include, for example, inorganic salts such as chlorides, chloride oxides, sulfides, nitrates, and carbonates of the catalytically active element, oxalates, acetylacetonate salts, and dimethylglyoxime salts. , organic salts such as ethylenediamine acetate, chelate compounds, carbonyl compounds, cyclopentadienyl compounds, ammine complexes, alkoxide compounds, alkyl compounds and the like.
Among them, the above compound is preferably a chloride or a chloride oxide. Moreover, you may use a hydrate for the said compound as needed.

Specific examples of compounds containing catalytically active elements include hafnium chloride (HfCl ₄ ), titanium chloride (TiCl ₂ , TiCl ₃ , TiCl ₄ ), titanium alkoxide, zirconium chloride (ZrCl ₄ ), and zirconium chloride oxide (ZrCl ₂ O). , zirconium alkoxide, hafnium alkoxide and the like.
In addition, the said compound may be used individually or may use 2 or more types together.

Examples of the solvent include, but are not particularly limited to, organic solvents such as water, aliphatic linear alcohols such as methanol, ethanol, n-propanol, and n-hexanol. These solvents may be used individually by 1 type, and may use 2 or more types together.
Among them, from the viewpoint of ease of handling, the solvent is preferably water alone or a mixed solvent of water and methanol or ethanol.
The water is preferably deionized water from which metal ions or the like have been removed, or distilled water.
When the solvent contains an organic solvent, the amount of the organic solvent used is preferably 10 to 100% by volume, more preferably 10 to 50% by volume, relative to 100% by volume of water.

The solvent is preferably a non-explosive solvent. A non-explosive solvent is a solvent containing a combustible organic solvent in a concentration outside the explosive range when vaporized. For example, since the explosive range of ethanol is 2-20% by volume, ethanol can be can be considered as non-explosive solvents. In addition, since the explosive range of methanol is 7 to 40% by volume, methanol can be can also be considered non-explosive solvents.

The polarity parameter of the solvent is preferably 40-80, more preferably 50-70. By using a solvent having a polarity parameter within this range, it becomes easier to produce a catalyst that satisfies the conditions I to III. As the polarity parameter of the solvent, the ET (30) value in Table SI-1 of Supporting information of Journal of Physical Organic Chemistry, volume 27, issue 6, pages 512-518 can be referred to.
The amount of the solvent used is preferably 10 to 10,000 mol %, more preferably 100 to 5,000 mol %, relative to the amount (100 mol %) of the compound containing the catalytically active element. By setting the amount of the solvent to be used within the above range, the compound can be sufficiently hydrolyzed, and the solid content generated by the hydrolysis can be made difficult to dissolve.
The amount of the compound containing a catalytically active element used is preferably 0.1 to 100 parts by mass, more preferably 1 to 60 parts by mass, and more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the carrier. It is even more preferable to have

(Contact process)
The solution is then brought into contact with the carrier.
When the solution is brought into contact with the carrier, the carrier may be added to the solution, or the solution may be added (for example, dropwise) to the carrier, but the latter is preferred. According to the latter method, especially when the carrier is a porous carrier, the carrier can be slowly permeated with the solution, and the carrier can be impregnated with the solution to the inside. Therefore, when the carrier is a porous carrier, this step can also be called an impregnation step.
After one of the solution and the carrier is added to the other, the carrier is preferably immersed in the solution.

The time for which the carrier is immersed in the solution may be appropriately set according to the configuration of the carrier, the viscosity of the solution, and the like, and is not particularly limited, but is preferably from 0.1 hour to 5 days, and from 1 hour to 3 days. It is more preferable to have At this time, the pressure of the atmosphere may be increased or decreased. The pressure of the atmosphere is also not particularly limited, but is preferably 0 to 2 MPa, more preferably 0 to 1 MPa.
In addition, the amount of the solution may be appropriately set according to the configuration of the carrier, the viscosity of the solution, etc., and is not particularly limited, but is preferably 1 to 500 mL, more preferably 5 to 350 mL, per 1 g of the carrier. preferable.
By bringing the solution into contact with the carrier under such conditions, a sufficient amount of the catalytically active element can be supported on the carrier.
In this case, external energy such as vibration (ultrasonic vibration) or rocking may be applied to the solution.

(Baking process)
The support contacted by the solution is then separated from the solution, dried and then calcined. Thereby, the catalytically active element is immobilized on the carrier, and a catalyst can be obtained. The catalytically active element may be present on the surface of the carrier as it is (simple substance) or through an oxygen element (as an oxide).
Separation of the carrier (catalyst) from the solution can be carried out, for example, by filtration, decantation, centrifugation, or the like.
The drying temperature is preferably 20 to 200°C, more preferably 50 to 150°C. The drying time is preferably 1 hour to 10 days, more preferably 2 hours to 5 days.

The firing temperature is preferably 200 to 800°C, more preferably 400 to 600°C. The firing time is preferably 10 minutes to 2 days, more preferably 1 to 10 hours.
By carrying out the calcination under such conditions, it is possible to firmly bond the catalytically active element directly or via the oxygen element to the carrier while leaving no or almost no impurities in the catalyst.
When no carrier is used, the catalyst is composed of hafnium alone, element M alone, hafnium oxide, element M oxide, or a composite thereof.

In the present embodiment, a solution prepared by dissolving both the compound containing hafnium and the compound containing element M in one solvent was used. A second solution prepared by dissolving a compound containing M in a solvent may be individually prepared and used.
In this case, the first solution and the second solution may be brought into contact with the carrier simultaneously or sequentially, but are preferably brought into contact with the carrier sequentially. When contacting the carrier sequentially, either the first solution or the second solution may be used first.
Through the steps described above, a catalyst that satisfies the conditions I to III can be produced.

The catalyst obtained by calcination was analyzed by X-ray photoelectron spectroscopy (XPS), inductively coupled plasma emission spectroscopy (ICP-AES), scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDX), and X-ray diffraction. After analysis by (XRD) or the like, the diene compound may be produced. By performing the analysis, it is possible to suppress variations in the characteristics of the manufactured catalyst and ensure a certain level of quality.
The analysis may be performed on the catalyst as it is, on the catalyst after crushing, or on the catalyst after cleaving.

[Device for producing diene compound]
A diene compound production apparatus (hereinafter simply referred to as "production apparatus") includes a reaction tube filled with the catalyst of the present invention. Such a production apparatus produces a diene compound from raw materials containing alcohol.
An example of such a manufacturing apparatus will be described below with reference to FIG.
A manufacturing apparatus 10 shown in FIG.

The reaction tube 1 has a reaction bed 2 inside. The reaction bed 2 is packed with the above catalyst.
A supply pipe 3 is connected to the upstream side of the reaction tube 1, and a discharge pipe 4 is connected to the downstream side thereof.
A temperature control unit 5 is connected to the reaction tube 1 .
A pressure control unit 6 is arranged in the middle of the discharge pipe 4 .
The reaction bed 2 may contain only the catalyst of the present invention, or may contain other catalysts together with the catalyst of the present invention.

Moreover, the reaction bed 2 may further have a diluent. This diluent prevents the catalyst from overheating. Examples of diluents include quartz sand, alumina balls, aluminum balls, and aluminum shots.
When the reaction bed 2 is filled with a diluent, the mass ratio of the diluent to the catalyst (diluent/catalyst) is appropriately set according to the type and specific gravity of each material, and is not particularly limited, but is 0.1 to 5. It is preferably 0.5 to 5, more preferably 0.5 to 5.
Incidentally, the reaction bed 2 may be any of a fixed bed, a moving bed, a fluidized bed and the like.

The reaction tube 1 is preferably made of a material that is inert to the starting material and the diene compound. Further, it is preferable that the reaction tube 1 can withstand heating at about 100 to 600° C. and pressurization at about 10 MPa.
Therefore, the reaction tube 1 is composed of, for example, a substantially cylindrical tubular body made of stainless steel.
The supply pipe 3 is supply means for supplying raw materials into the reaction tube 1 . The supply pipe 3 is made of, for example, a tubular body made of stainless steel or the like.
On the other hand, the discharge pipe 4 is discharge means for discharging the gas containing the diene compound produced in the reaction bed 2 . The discharge pipe 4 is configured by a tubular body made of stainless steel or the like, for example.

The temperature control unit 5 may set the temperature of the reaction bed 2 in the reaction tube 1 to an arbitrary temperature. The temperature control unit 5 controls the temperature of, for example, an electric furnace (not shown) arranged around the reaction tube 1 to adjust the reaction bed 2 inside the reaction tube 1 to an arbitrary temperature.
The pressure control unit 6 should be able to set the pressure inside the reaction tube 1 to an arbitrary pressure. The pressure control unit 6 is composed of, for example, a pressure valve or the like.
Note that the manufacturing apparatus 10 may include a gas flow rate adjusting unit or the like capable of adjusting the gas flow rate, such as a mass flow.

[Method for producing diene compound]
In the method for producing a diene compound of the present invention, the catalyst of the present invention is brought into contact with an alcohol-containing raw material to produce a diene compound.
The amount of the catalyst used is preferably 0.1 to 10 g/g·h, more preferably 1 to 5 g/g·h, relative to the raw material. By setting the amount of the catalyst to be used within the above range, it is possible to improve the conversion rate of the raw material while suppressing the formation of by-products.
The raw material contains alcohol. In addition, the raw material may further contain aldehyde, inert gas, and the like. The raw material preferably contains at least one of ethanol and acetaldehyde.
Moreover, it is preferable that the raw material is gaseous (also referred to as "raw material gas") at least during the reaction.

The alcohol is not particularly limited, but includes, for example, alcohols having 1 to 6 carbon atoms. Specific examples of alcohols include methanol, ethanol, propanol, butanol, pentanol, hexanol, 3-buten-2-ol, 2-buten-1-ol, 3-hydroxybutanal, 1-ethoxyethanol, butane- 1,3-diol and the like.
In principle, the diene compound obtained differs depending on the alcohol used. For example, when ethanol is used, butadiene (1,3-butadiene) is obtained. Also, when propanol is used, hexadiene is obtained. Furthermore, when butanol is used, octadiene is obtained.
The alcohols may be used alone or in combination of two or more, but from the viewpoint of suppressing side reactions, it is preferable to use them alone.

The content of alcohol in the raw material is preferably 10% by volume or more, more preferably 15% by volume or more, further preferably 20% by volume or more, and 30% by volume with respect to 100% by volume of the raw material. % or more is particularly preferred.
In addition, when using 2 or more types of alcohol together, it is preferable that the sum is contained in the said range.
By using the catalyst of the present invention, the reaction can proceed efficiently even when the alcohol content in the raw material is high.

Aldehydes are usually oxides of alcohols. Specific examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, crotonaldehyde and the like.
When the raw material contains an aldehyde, it usually contains the aldehyde corresponding to the alcohol. Specifically, methanol is formaldehyde, ethanol is acetaldehyde, propanol is propionaldehyde, butanol is butyraldehyde, and pentanol is valeraldehyde.
However, the above aldehydes may contain aldehydes other than the aldehydes corresponding to alcohols.

The content of aldehyde in the raw material is preferably 1% by volume or more, more preferably 5% by volume or more, further preferably 10% by volume or more, with respect to 100% by volume of the raw material. % or more is particularly preferred.
In addition, when using 2 or more types of aldehydes together, it is preferable that the sum is contained in the said range.
The total content of alcohol and aldehyde in the raw material is preferably 15% by volume or more, more preferably 20% by volume or more, and 20 to 40% by volume relative to 100% by volume of the raw material. More preferred.

Examples of the inert gas include, but are not particularly limited to, nitrogen gas, argon gas, and the like. These inert gases may be used alone or in combination of two or more.
The content of the inert gas in the raw material is preferably 90% by volume or less, more preferably 30 to 90% by volume, and 50 to 90% by volume with respect to 100% by volume of the raw material. More preferably, it is particularly preferably 60 to 80% by volume.
The manner in which the catalyst and raw material are brought into contact is not particularly limited. For example, the raw material is allowed to pass through the reaction bed 2 in the reaction tube 1 shown in FIG. is preferred.

The temperature (heating temperature in the reaction process; reaction temperature) at which the catalyst and raw materials are brought into contact with each other is preferably 100 to 600° C., more preferably 200 to 600° C., more preferably 200 to 500° C., as described above. °C, more preferably 250 to 500°C, even more preferably 250 to 450°C, and particularly preferably 300 to 450°C. Further, the pressure (reaction pressure) when the catalyst and raw materials are brought into contact is preferably 0.1 to 10 MPa, more preferably 0.1 to 3 MPa.
By contacting the catalyst and the raw material under the above conditions, the reaction rate is sufficiently increased, the diene compound can be produced more efficiently, and the deterioration of the catalyst can be prevented or suppressed.
The space velocity (SV) of the raw material in the reaction bed is not particularly limited because it is usually adjusted appropriately according to the reaction pressure and reaction temperature, but it can be 0.1 to 10000 h ^-1 in terms of standard conditions. preferable.

For example, when manufacturing a diene compound using the manufacturing apparatus 10 shown in FIG. 1, it can be performed as follows.
First, the temperature control unit 5 and the pressure control unit 6 set the inside of the reaction tube 1 to an arbitrary temperature and an arbitrary pressure.
Next, the gasified raw material 20 is supplied from the supply pipe 3 into the reaction tube 1 . At this time, the raw material comes into contact with the catalyst in the reaction tube 1 and reacts to produce a diene compound such as butadiene.
After that, the produced gas 22 containing the produced diene compound is discharged from the discharge pipe 4 . The generated gas 22 may contain compounds such as acetaldehyde, propylene, and ethylene.

If necessary, the generated gas 22 may be subjected to purification such as gas-liquid separation or distillation to remove unreacted raw materials and by-products.
Moreover, in the present invention, the environmental load can be reduced by producing a diene compound from bioethanol.
In addition, when the activity (performance) of the catalyst is lowered, an oxygen-containing gas (for example, air) is supplied into the reaction tube 1 from the supply pipe 3 or the discharge pipe 4 to perform a regeneration process for regenerating the catalyst. may be provided.
For example, after the diene compound is produced, the catalyst is heated to 400 to 550 ° C. while circulating an oxygen-containing gas at a space velocity of 0.1 to 10000 h ⁻¹ in the reaction tube 1 to 0.1 to 10 MPa. The regeneration treatment may be carried out by burning off the carbon-containing impurities accumulated on the surface under a pressure of . In that case, the regeneration treatment may be performed by switching the gas circulating (supplied) in the reaction tube 1, and the catalyst is taken out from the reaction tube 1 and placed in the air or in an oxygen-containing atmosphere (oxygen-containing gas) having a predetermined oxygen concentration. You may perform reproduction|regeneration processing by . Thereby, the catalyst can be reused.

The temperature at which the catalyst is brought into contact with the oxygen-containing gas (heating temperature in the regeneration process) is also preferably 200 to 600°C, more preferably 300 to 575°C, more preferably 400 to 550°C, as described above. It is more preferable to have The pressure (regeneration pressure) when the catalyst and the oxygen-containing gas are brought into contact is preferably 0.1 to 10 MPa, more preferably 0.1 to 3 MPa.
By bringing the catalyst into contact with the oxygen-containing gas under the above conditions, the catalyst can be smoothly regenerated.
The space velocity (SV) of the oxygen-containing gas is usually adjusted appropriately according to the reaction pressure and reaction temperature, so it is not particularly limited, but it is preferably 0.1 to 100000 h ⁻¹ in terms of standard conditions.

[Polymer production method]
In the method for producing a polymer of the present invention, a polymer is produced using at least part of the diene compound produced by the method for producing a diene compound of the present invention as a polymer raw material.
That is, the method for producing a diene compound of the present invention is applied to produce a diene compound by bringing a raw material into contact with the catalyst of the present invention. Then, the produced diene compound is separated from the reaction product by appropriate separation treatment or the like, and at least part thereof is used as a raw material to be converted into a polymer.

As a method for separating the diene compound from the reaction product, the reaction product is passed through a cooled condenser to separate raw materials such as unreacted alcohol, and the reaction product after separation is bubbled into an organic solvent, It is preferable to dissolve the diene compound (monomer) in a solvent and recover it as a solution.
It is preferable that the recovered solution containing the diene compound is used as it is, or after further adding an organic solvent or the like, various types of polymerization are performed to produce a polymer from the diene compound. At this time, the recovered diene compound may be mixed with a monomer other than the diene compound to carry out various polymerizations.

As the polymerization method, for example, a solution polymerization method, a suspension polymerization method, a liquid-phase bulk polymerization method, an emulsion polymerization method, or the like can be used. Moreover, when a solvent is used in the polymerization reaction, the solvent may be inert in the polymerization reaction, and examples thereof include hexane, cyclohexane, toluene, and mixtures thereof.
Although the temperature of the polymerization reaction is not particularly limited, it is preferably -100 to 300°C. Although the pressure of the polymerization reaction is not particularly limited, it is preferably 0.1 to 10.0 MPa. The polymerization reaction time is also not particularly limited, but may be appropriately set according to conditions such as the temperature of the polymerization reaction, and is usually preferably from 1 second to 10 days.

Examples of monomers other than diene compounds include aromatic vinyl compounds, olefins, and combinations thereof.
Examples of aromatic vinyl compounds include styrene, α-methylstyrene, p-methylstyrene, vinylnaphthalene and the like. Examples of olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and the like.
In addition to the above monomers, various additives may be added to the diene compound depending on the application.

The polymer produced by the method for producing a polymer of the present invention is not particularly limited, but is preferably a polymer having a skeleton derived from butadiene, such as polybutadiene (cis-1,4-polybutadiene), styrene-butadiene copolymer, and the like. more preferred.

[Method for producing polymer molded product]
In the method for producing a polymer molded article of the present invention, the polymer produced by the method for producing a polymer of the present invention is molded.
That is, the method for producing a diene compound of the present invention is applied to produce a diene compound by bringing a raw material into contact with the catalyst of the present invention. Moreover, the method for producing a polymer of the present invention is applied to produce a polymer using at least part of the produced diene compound as a polymer raw material. The produced polymer is then molded according to the shape of the desired polymer molded article.

Examples of polymer molded products include tire rubber members such as treads, base treads, sidewalls, side reinforcements, and bead fillers, tires, anti-vibration rubbers, seismic isolation rubbers, belts (conveyor belts), and rubber crawlers. , various hoses, etc., and rubber members of tires and tires are preferable.

[Method for measuring catalyst performance]
By measuring at least one selected from the temperature increase efficiency, temperature decrease efficiency, and whiteness ratio, it is possible to measure catalyst performance suitable for synthesizing a diene compound and select an appropriate catalyst. By using a catalyst selected based on the measurement results, a diene compound can be continuously produced at a high yield.

[Long life method]
The life extension method of the present invention comprises a catalyst (hereinafter referred to as This is a method for extending the life of the catalyst (referred to as "the catalyst").
Then, the amount of the catalytically active element contained in the region from the surface of the catalyst to a predetermined depth (region near the surface) is larger than the amount of the catalytically active element contained inside the region near the surface (region inside). By doing so, the life of the catalyst is extended compared to other catalysts in which the catalytically active element is supported only in the region near the surface.
The configuration, materials, etc. of the porous carrier and the catalytically active element in the life extension method of the present invention are the same as those described for the catalyst of the present invention.

In addition, in the method for extending the life of the present invention, when the raw materials of the catalyst and other catalysts are brought into contact with raw materials containing alcohol, and the raw materials are reacted to produce a diene compound, compared with other catalysts, the diene It is preferable that the reduction in the initial yield of the compound is suppressed and the reaction maintenance rate that maintains the initial yield is increased. Thereby, the overall yield of the diene compound can be increased.
Furthermore, in the life extension method of the present invention, the initial yield is 80% or more (preferably 85% or more, more preferably 90% or more) of other catalysts, and the reaction maintenance rate is twice that of other catalysts. or more (preferably 3 times or more, more preferably 4 times or more).

As described above, the catalyst of the present invention, the method for producing the catalyst, the method for producing the diene compound, the method for producing the polymer, the method for producing the polymer molded article, the method for measuring the catalyst performance, and the method for extending the life of the catalyst have been described. It is not limited.
For example, the catalyst, method for producing a catalyst, method for producing a diene compound, method for producing a polymer, method for producing a polymer molded product, method for measuring catalyst performance, and method for extending service life of the present invention are, with respect to the above embodiments, It may have any other additional configuration, may be replaced with any configuration that exhibits a similar function, or may be partially omitted.
Further, the catalyst of the present invention includes, in addition to a diene compound synthesis catalyst for synthesizing a diene compound from a raw material containing alcohol, for example, an alcohol dimerization reaction, an aldehyde dimerization reaction catalyst, an olefin dimerization reaction catalyst, It can also be used as a catalyst for dehydrogenation reaction of saturated compounds, a catalyst for dehydration reaction of alcohol, and the like.

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

1. Production of catalyst (Comparative Example 1)
First, 1.0 g of hafnium chloride (HfCl ₄ : manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 2.0 mL of water to prepare a solution.
Next, this solution was added to 2.0 g of a porous carrier (silica porous particles manufactured by Fuji Silysia Chemical Co., Ltd., average particle size: 1.77 mm, average pore diameter: 10 nm, total pore volume: 1.01 mL /g, specific surface area: 283 m ² /g).
Next, after leaving the solution in which the porous carrier was immersed for 1 hour, the solution was separated by filtration.
The recovered porous material was dried at 110° C. for 3 hours and then calcined at 400° C. for 4.5 hours to produce a catalyst.

(Example 1)
A catalyst was produced in the same manner as in Comparative Example 1, except that the amount of hafnium chloride (HfCl ₄ ) used was changed to 0.9 g.

(Example 2)
A catalyst was produced in the same manner as in Comparative Example 1, except that the amount of hafnium chloride (HfCl ₄ ) used was changed to 0.7 g.

(Example 3)
A catalyst was produced in the same manner as in Comparative Example 1, except that the amount of hafnium chloride (HfCl ₄ ) used was changed to 0.5 g.

(Example 4)
A catalyst was produced in the same manner as in Comparative Example 1, except that the amount of hafnium chloride (HfCl ₄ ) used was changed to 0.4 g.

(Example 5)
First, 2.0 g of hafnium chloride (HfCl ₄ : manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 100 mL of ethanol to prepare a solution.
Next, this solution was added to 2.0 g of a porous carrier (silica porous particles manufactured by Fuji Silysia Chemical Co., Ltd., average particle size: 1.77 mm, average pore diameter: 10 nm, total pore volume: 1.01 mL /g, specific surface area: 283 m ² /g).
Next, the solution in which the porous carrier was immersed was stirred with an ultrasonic cleaner for 1 hour, and the solution was separated by filtration.
The recovered porous material was dried at 110° C. for 3 hours and then calcined at 400° C. for 4.5 hours to produce a catalyst.

(Comparative example 2)
A catalyst was produced in the same manner as in Example 5, except that the amount of hafnium chloride (HfCl ₄ ) used was changed to 1.0 g.

(Example 6)
First, 1.0 g of hafnium chloride (HfCl ₄ : manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 1000 mL of water to prepare a solution.
Next, this solution was added to 2.0 g of a porous carrier (silica porous particles manufactured by Fuji Silysia Chemical Co., Ltd., average particle size: 1.77 mm, average pore diameter: 10 nm, total pore volume: 1.01 mL /g, specific surface area: 283 m ² /g).
Next, the solution in which the porous carrier was immersed was stirred under atmospheric pressure with an ultrasonic cleaner for 1 hour, and the solution was separated by filtration.
The recovered porous material was dried at 110° C. for 4 hours and then calcined at 400° C. for 4.5 hours to produce a catalyst.

(Example 7)
A catalyst was produced in the same manner as in Example 6, except that the amount of solution used was changed to 100 mL and the mixture was stirred under reduced pressure (0.01 MPa).

(Example 8)
A catalyst was produced in the same manner as in Example 6, except that the stirring time was changed to 3 days.

(Example 9)
A catalyst was produced in the same manner as in Example 6, except that the amount of solution used was changed to 500 mL.

(Comparative Example 3)
A catalyst was produced in the same manner as in Example 6, except that the stirring time was changed to one week.

(Comparative Example 4)
A catalyst was produced in the same manner as in Example 6, except that the amount of solution used was changed to 100 mL.

(Comparative Example 5)
First, 4 g of a surfactant (manufactured by BASF, "P123") and 8.5 g of tetraethoxysilane were placed in a beaker, and 150 g of a 2 mol/L hydrochloric acid aqueous solution was added thereto, followed by stirring at room temperature for 20 hours. hydrolysis was carried out.
Next, the solid content in the hydrolyzed solution was separated by filtration and dried in the atmosphere at 30° C. for 6 hours.
After that, the dried solid content was calcined at 500° C. for 14 hours using an electric furnace under an air atmosphere. As a result, a porous carrier (silica porous particles, average particle diameter: 300 μm, average pore diameter: 2.8 nm, total pore volume: 1.09 mL/g, specific surface area: 995 m ² /g) was obtained.

Next, 0.6 g of hafnium chloride (HfCl ₄ : manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 100 mL of water to prepare a solution.
Next, 2.0 g of porous carrier was added to this solution.
Next, the solution in which the porous carrier was immersed was stirred at room temperature for 4 hours, and then separated from the solution by suction filtration.
The recovered porous material was dried in the atmosphere at 80° C. for 4 hours and then calcined at 400° C. for 6 hours to obtain a catalyst.

(Comparative Example 6)
First, a porous carrier (silica porous particles manufactured by Fuji Silysia Chemical Co., Ltd., average particle diameter: 1.77 mm, average pore diameter: 10 nm, total pore volume: 1.01 mL / g, specific surface area: 283 m ² / g) was calcined at 1000° C. for 10 hours. Thus, a nonporous carrier (average particle size: 1.77 mm, specific surface area: >10 m ² /g) was produced.
Next, 1.0 g of hafnium chloride (HfCl ₄ : manufactured by Kojundo Chemical Laboratory Co., Ltd.) was dissolved in 100 mL of water to prepare a solution. This solution was then added dropwise to 2.0 g of non-porous carrier.

Next, the solution in which the porous carrier was immersed was stirred under atmospheric pressure with an ultrasonic cleaner for 1 hour, and the solution was separated by filtration.
The recovered porous material was dried at 110° C. for 4 hours and then calcined at 400° C. for 4.5 hours to produce a catalyst.

(Example 10)
First, 0.20 g of zirconium chloride oxide octahydrate (ZrCl _{2 O.8H 2 O} : manufactured by Kojundo Chemical Laboratory Co., Ltd.) and 0.007 g of hafnium chloride (HfCl ₄ : Kojundo Chemical Laboratory Co., Ltd. ) was dissolved in 100 mL of water to prepare a solution.
Next, this solution was added to 2.0 g of a porous carrier (silica porous particles manufactured by Fuji Silysia Chemical Co., Ltd., average particle size: 1.77 mm, average pore diameter: 10 nm, total pore volume: 1.01 mL /g, specific surface area: 283 m ² /g).
Next, the solution in which the porous carrier was immersed was stirred under atmospheric pressure with an ultrasonic cleaner for 1 hour, and the solution was separated by filtration.
The recovered porous material was dried at 110° C. for 4 hours and then calcined at 400° C. for 4.5 hours to produce a catalyst.

(Example 11)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 0.69 g.

(Example 12)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 1.4 g.

(Example 13)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 2.1 g.

(Example 14)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 2.8 g.

(Example 15)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 3.5 g.

(Example 16)
Instead of 0.20 g of zirconium chloride oxide octahydrate, 1.7 g of zirconium oxynitrate _dihydrate (ZrO(NO ₃ ) 2.2H ₂ O: manufactured by Kishida Chemical Co., Ltd.) was used. A catalyst was prepared in the same manner as in Example 10.

(Example 17)
A catalyst was prepared in the same manner as in Example 10, except that 1.2 g of a titanium chloride solution ( _TiCl4 : manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used instead of 0.20 g of zirconium chloride oxide octahydrate. manufactured.

(Comparative Example 7)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 0.14 g.

(Comparative Example 8)
A catalyst was produced in the same manner as in Example 10, except that the amount of zirconium chloride oxide octahydrate was changed to 4.2 g.

(Comparative Example 9)
Instead of 0.69 g of zirconium chloride oxide octahydrate, 0.018 g of zinc nitrate hexahydrate (Zn(NO ₃ ) ₂ 6H ₂ O: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used. manufactured the catalyst in the same manner as in Example 10.

2. Measurement and Evaluation of Catalyst 2-1. Measurement of Temperature Raising Efficiency First, the catalysts produced in each example and each comparative example were filled in a reaction tube having an inner diameter of 7 mm at a height of 2 cm in the center in the longitudinal direction. At this time, a thermocouple was also inserted into the reaction tube and set so that its tip was positioned at the center of the catalyst.
Next, the reaction tube in this state was set in an electric furnace, and the temperature was raised until the temperature of the thermocouple reached 350°C. When the temperature of the thermocouple inside the reaction tube reached 350° C. (±0.1° C.), the temperature was raised at a rate of 100° C./min. This time was defined as the temperature rise start time of 0 minutes.

The temperature was raised until the temperature of the thermocouple reached 500° C., and the time when the temperature reached 500° C. was defined as the end time of the temperature rise, and the heating of the electric furnace was stopped.
The heating efficiency (%) was calculated according to the following formula (1).

2-2. Measurement of Temperature-Lowering Efficiency First, the catalysts produced in each example and each comparative example were filled in a reaction tube having an inner diameter of 7 mm at a height of 2 cm in the central portion in the longitudinal direction. At this time, a thermocouple was also inserted into the reaction tube and set so that its tip was positioned at the center of the catalyst.
Next, the reaction tube in this state was set in an electric furnace, and the temperature was raised until the temperature of the thermocouple reached 500°C. When the temperature of the thermocouple inside the reaction tube reached 500° C. (±0.1° C.), the heating of the electric furnace was stopped. This time was defined as 0 minutes of temperature drop start time.

The temperature was raised until the temperature of the thermocouple reached 350°C, and the time when the temperature reached 350°C was defined as the cooling end time.
The temperature drop efficiency (%) was calculated according to the following formula (2).

2-3. Measurement of Whiteness Ratio First, 1 g of the catalyst or porous carrier produced in each example and each comparative example was weighed and placed in a 20 cc screw vial (manufactured by AS ONE).
Next, the vial containing the catalyst or the porous carrier was placed directly in the measurement opening of a portable whiteness meter (manufactured by Ogawa Seiki Co., Ltd., "OSK97BX216"), and the power was turned on to start measuring the whiteness. .
It waited for 3 minutes until the numerical value stabilized, and the value at that time was recorded as the whiteness index.

2-4. Measurement of Heating Efficiency First, the catalysts produced in Examples 1 to 5 and Comparative Examples 1 and 2 were packed in the longitudinal center of a reaction tube with an inner diameter of 7 mm to a height of 2 cm to form a reaction bed. .
Next, the reaction temperature (temperature of the reaction bed) was set to 325° C., and the reaction pressure (pressure of the reaction bed) was set to 0.1 MPa.
In this state, the raw material was supplied to the reaction tube at a space velocity (SV) of 12000 h ⁻¹ to obtain a product gas containing 1,3-butadiene. That is, a reaction process was performed.
As a raw material, a mixed gas of 30% by volume of ethanol (converted to gas) and 70% by volume of nitrogen (converted to gas) was used. Also, the supply of raw materials was continued for 2 hours.

After being used for 2 hours, the catalyst was filled to a height of 2 cm in the longitudinal central portion of a reaction tube having an inner diameter of 7 mm. At this time, a thermocouple was also inserted into the reaction tube and set so that its tip was positioned at the center of the catalyst.
Next, the reaction tube in this state was set in an electric furnace, and the temperature was raised until the temperature of the thermocouple reached about 500°C.
After completion of the temperature rise, air (oxygen-containing gas) was introduced at a space velocity (SV) of 60000 h ^-1 while the temperature of the electric furnace was maintained at 500°C. That is, the regeneration process was performed.

Then, it was observed that the temperature inside the reaction tube rose, and the maximum temperature was recorded.
The heating efficiency ( ^O / _OOO ) was calculated according to the following formula (4) and evaluated according to the following criteria.

[Evaluation criteria]
Good: The heating efficiency is less than 10300 ^O / _OOO .
x: The heating efficiency is 10300 ^O / _OOO or more.

2-5. Examination of process time (reaction process time)
For the catalysts produced in Examples 1-5 and Comparative Examples 1-2, the yield of 1,3-butadiene one hour after the start of the reaction process in 2-4 was taken as the standard (100%), and 1,3- The time until the yield of butadiene decreased to 80% was taken as the reaction process time.
(playback process time)
For the catalysts produced in Examples 1 to 5 and Comparative Examples 1 and 2, the temperature rise time (temperature rise end time - temperature rise start time) and temperature drop time (temperature drop end time) measured in 2-1 and 2-2 - temperature drop start time) was taken as the regeneration process time.

Then, the relationship between the reaction process time and the regeneration process time was evaluated according to the following criteria.
+: Reaction process time>Regeneration process time.
-: Reaction process time<regeneration process time.

2-6. Synthesis of Diene Compounds Ethanol was converted to 1,3-butadiene (hereinafter also referred to as “BD”) using the catalysts produced in Examples and Comparative Examples, and the yield of BD was determined.
Specifically, 3.4 g of catalyst was first packed into a stainless steel cylindrical reaction tube having a diameter of 1/2 inch (1.27 cm) and a length of 15.7 inches (40 cm) to form a reaction bed. .
Next, the reaction temperature (temperature of the reaction bed) was set to 325° C., and the reaction pressure (pressure of the reaction bed) was set to 0.1 MPa.
In this state, the raw material was supplied to the reaction tube at a space velocity (SV) of 1200 h ⁻¹ to obtain a generated gas containing BD.
As a raw material, a mixed gas of 30% by volume of ethanol (converted to gas) and 70% by volume of nitrogen (converted to gas) was used. Moreover, the supply of raw materials was continued for 20 hours.

Then, after 1 hour from the start of supply of the raw material, the produced gas was recovered, and 1 mL of the recovered produced gas was collected while being kept at 200°C.
Next, the fractionated generated gas is analyzed by gas chromatography with a hydrogen flame ionization detector (manufactured by Shimadzu Corporation, "GC-2014"), and a data processing device (manufactured by Shimadzu Corporation, "Chromatopak C-R8A ”) to calculate the peak area.
The column oven temperature was maintained at 60°C for 11.5 minutes, heated to 100°C at 10°C/min, then maintained at 100°C for 14.5 minutes, and heated to 280°C at 10°C/min. After that, the temperature-rising analysis was programmed to hold at 280°C for 2 minutes.

The conditions for gas chromatography are shown below.
Column: "Rt-Q-BOND (inner diameter: 0.32 mm, length: 30 m, film thickness: 10 μm)" manufactured by Restek
Detector temperature: 300°C
Inlet temperature: 270°C
Carrier gas: Helium Inlet pressure: 69.2 kPa
Linear velocity: 30cm/s
Split ratio: 75
Mode: Linear velocity control mode

The yield of BD was calculated according to the following formula and evaluated according to the following criteria.
Yield of BD (%) =
(area of peak derived from BD)/(sum of areas of all detected peaks) x 100
[Evaluation criteria]
⊚: The yield of BD is 55% or more.
A: The yield of BD is 45% or more and less than 55%.
O: The yield of BD is 35% or more and less than 45%.
Δ: The yield of BD is 30% or more and less than 35%.
x: Yield of BD is less than 30%.
In addition, the "initial yield of BD" means the yield of BD one hour after starting the supply of such raw materials.
Also, the reaction maintenance rate (%) was calculated according to the following formula.
Reaction maintenance rate (%) = yield of BD after 20 hours/yield of BD after 1 hour × 100

3. Calculation of molar ratio of catalytically active element to element X 3-1. Entire Catalyst First, 100 mg of the catalyst produced in each example and each comparative example was randomly sampled and pulverized to a particle size of 50 μm or less.
Next, a part of this pulverized material is sampled, a portion where at least 10 or more pulverized materials exist within a range of 1 mm × 1 mm is selected, and the SEM-EDX method is used to measure all existing within the above range. The amounts of the element X and the catalytically active element in the pulverized product were measured.
Then, based on the measured values, the molar ratio A of catalytically active element to element X in the whole catalyst was calculated.

3-2. Area from the surface of the catalyst to 60 μm (area near the surface)
First, three particles were randomly selected from the catalysts produced in each example and each comparative example, and the selected particles were cut in half.
Next, the cut surface of the cut particles was set vertically upward, and carbon paste was used to fix the particles to a sample plate to prepare a measurement sample.
After that, using the SEM-EDX method, the cut surface of the particle is used to select a range of 50 μm × 50 μm in the area included in the region near the surface of the catalyst. The amounts of element X and catalytically active elements were measured.
Then, based on the measurements, the molar ratio B of catalytically active element to element X in the region near the surface of the catalyst was calculated.
B/A was determined from the obtained molar ratio A and the molar ratio.

These results are shown in Tables 1 to 3 below.

The catalyst of each example, in which the heating efficiency, cooling efficiency, and whiteness ratio were in the preferred range, the reaction process time exceeded the regeneration process time (+), and BD was continuously produced while maintaining a high yield. was possible.
The catalytically active element is supported on the surface and inside of the porous carrier, and the amount of the catalytically active element contained in the region near the surface of the catalyst is greater than the amount of the catalytically active element contained in the inner region. , BD yield (initial yield) and reaction retention rate were both high.
In addition, by changing B (molar ratio of catalytically active element to element X in the region near the surface) / A (molar ratio of catalytically active element to element X in the entire catalyst), the yield of BD and the reaction maintenance rate could be better balanced.
Furthermore, when using the catalysts of Examples 10 to 17 in which the molar ratio (M/Hf) of the element M to hafnium (Hf) is more than 20 and 500 or less, the yield of BD was high. Also, by changing the type and amount of the element M, the yield of BD could be further increased.

On the other hand, the catalyst of Comparative Example 1, in which the efficiency of temperature rise and efficiency of temperature drop deviated from the preferred range, had a high whiteness ratio. In addition, the reaction process time of the catalyst of Comparative Example 1 was shorter than the regeneration process time (-), and the time during which the reaction could not be used occurred, resulting in a decrease in BD production efficiency.
The catalyst of Comparative Example 2, in which the temperature rising efficiency and the temperature falling efficiency deviated upward from the preferred range, had a low whiteness ratio. In addition, the catalyst of Comparative Example 2 had an excessively high heating efficiency. This encourages overshooting of the heating temperature in the regeneration process, making it easier for the catalyst structure to change and the reaction tube to deteriorate.
Further, in Comparative Example 3, the catalytically active element was supported on the surface and inside of the porous carrier, and the amount of the catalytically active element contained in the region near the surface of the catalyst was less than the amount of the catalytically active element contained in the inner region. The catalyst (B/A less than 1) also had a low whiteness ratio and a low yield of BD.
On the other hand, the catalysts of Comparative Examples 5 and 6, in which the catalytically active element was selectively supported only on the surface of the porous carrier, had a high BD yield, but a low reaction retention rate.
Since the catalyst of Comparative Example 7 had an M/Hf of 20 and a B/A of less than 1, the yield of BD was low.
The catalyst of Comparative Example 8 had a M/Hf of more than 500, a high whiteness ratio, and a B/A of less than 1, so that the yield of BD was low and the reaction retention rate was low.
The catalyst of Comparative Example 9 has a temperature rising efficiency, a temperature cooling efficiency, and a whiteness ratio within a suitable range, but the M/Hf is as small as 2.8 and the B/A is less than 1, so the yield of BD is extremely low. was low.

REFERENCE SIGNS LIST 1 reaction tube 2 reaction bed 3 supply tube 4 discharge tube 5 temperature control section 6 pressure control section 10 manufacturing apparatus

Claims (33)

1. comprising a catalytically active element and a carrier supporting the catalytically active element,
   A catalyst characterized by having a temperature rising efficiency represented by the following formula (1) of 5 to 6.5%.
   

   
2. comprising a catalytically active element and a carrier supporting the catalytically active element,
   A catalyst characterized by having a temperature lowering efficiency represented by the following formula (2) of 2.6 to 4.5%.
   

   
3. comprising a catalytically active element and a carrier supporting the catalytically active element,
   A catalyst characterized by having a whiteness ratio represented by the following formula (3) of 98 to 130%.
   

   
4. The carrier is a carrier composed of an oxide containing element X, and the catalyst contains the catalytically active element supported on the surface and inside of the carrier,
   The amount of the catalytically active element contained in a region from the surface of the catalyst to a predetermined depth is greater than the amount of the catalytically active element contained inside the region of the catalyst. 4. The catalyst according to any one of 3.
5. The catalyst according to claim 4, wherein said predetermined depth region is a region up to 60 µm from said surface of said catalyst.
6. When the molar ratio of the catalytically active element to the element X in the entire catalyst is A, and the molar ratio of the catalytically active element to the element X in the region up to the predetermined depth is B, B/A is 1 to 6. A catalyst according to claim 4 or 5, which is 9.
7. 7. The method according to any one of claims 4 to 6, wherein the molar ratio of said catalytically active element to said element X is determined by measurement using a scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX method). Catalyst as described.
8. The catalyst according to any one of claims 1 to 7, wherein the catalytically active element is at least one of elements belonging to Groups 2 to 6, 11 and 12 of the periodic table. .
9. The catalyst according to any one of claims 1 to 8, wherein the carrier is a porous carrier.
10. The catalyst according to any one of claims 1 to 9, wherein the support is composed of an oxide containing at least one element X selected from groups 13 and 14 of the periodic table.
11. hafnium (Hf) and at least one element M selected from titanium (Ti) and zirconium (Zr);
    A catalyst, wherein the molar ratio (M/Hf) of the element M to the hafnium (Hf) is more than 20 and 500 or less.
12. The catalyst according to claim 11, wherein said element M is said zirconium (Zr).
13. Further comprising a carrier comprising an oxide supporting the hafnium (Hf) and the element M and containing at least one element X selected from groups 13 and 14 of the periodic table. The catalyst according to 11 or 12.
14. A catalyst containing the hafnium (Hf) and the element M supported on the surface and inside of the carrier,
    The amounts of the hafnium (Hf) and the element M contained in a region from the surface of the catalyst to a predetermined depth are greater than the amounts of the hafnium (Hf) and the element M contained inside the region of the catalyst. 14. A catalyst according to claim 13, characterized in that it is numerous.
15. The catalyst according to claims 4 to 10, 13 and 14, wherein said element X is silicon (Si).
16. The catalyst according to any one of claims 13 to 15, wherein the molar ratio (M/X) of said element M to said element X is 0.0001 to 0.5.
17. Any one of claims 1 to 16, wherein the catalyst is subjected to a reaction process of converting to a second compound by contact with the first compound, and a regeneration process of regenerating the catalyst after undergoing the reaction process. Catalyst according to paragraph.
18. The catalyst according to claim 17, which satisfies B>A and BA=50 to 400° C., where A is the heating temperature in the reaction process and B is the heating temperature in the regeneration process.
19. The catalyst according to claim 17 or 18, wherein the heating temperature in the reaction process is 200-600°C.
20. The catalyst according to any one of claims 17-19, wherein the heating temperature in the regeneration process is 200-600°C.
21. The catalyst according to any one of claims 1 to 20, which is a diene compound synthesis catalyst for synthesizing a diene compound from a raw material containing alcohol.
22. The catalyst according to claim 21, wherein the raw material contains at least one of ethanol and acetaldehyde.
23. A method for producing the catalyst according to any one of claims 1 to 10 and claims 17 to 22,
    a step of preparing a solution obtained by dissolving the compound containing the catalytically active element in a solvent and the carrier;
    contacting and impregnating the carrier with the solution;
    calcining the carrier impregnated with the solution;
    A method for producing a catalyst, wherein a non-explosive solvent is used as the solvent.
24. A method for producing the catalyst according to any one of claims 13 to 16,
    A solution obtained by dissolving the compound containing hafnium (Hf) in a solvent and a solution obtained by dissolving the compound containing the element M in a solvent, or the compound containing the hafnium (Hf) and the compound containing the element M are combined into a solvent. A step of preparing a solution dissolved in and the carrier;
    contacting the solution with the carrier;
    and calcining the carrier contacted by the solution,
    A method for producing a catalyst, wherein a non-explosive solvent is used as the solvent.
25. The production method according to claim 23 or 24, wherein the carrier is a porous carrier.
26. The production method according to any one of claims 23 to 25, wherein the support is composed of an oxide containing at least one element X selected from groups 13 and 14 of the periodic table.
27. A method for producing a diene compound, which comprises bringing an alcohol-containing raw material into contact with the catalyst according to any one of claims 1 to 22 to produce a diene compound.
28. A method for producing a polymer, which comprises producing a polymer using at least part of the diene compound produced by the method for producing a diene compound according to claim 27 as a polymer raw material.
29. A method for producing a polymer molded article, characterized by molding a polymer produced by the method for producing a polymer according to claim 28.
30. A method for measuring the catalytic performance of a catalyst suitable for synthesizing a diene compound, characterized by measuring at least one selected from temperature rise efficiency, temperature drop efficiency, and whiteness ratio.
31. A method for extending the life of a catalyst comprising a carrier composed of an oxide containing element X and a catalytically active element supported on and in the carrier, comprising:
    By making the amount of the catalytically active element contained in a region from the surface of the catalyst to a predetermined depth greater than the amount of the catalytically active element contained inside the region of the catalyst, A method for prolonging the service life of the catalyst, characterized by extending the service life of the catalyst as compared with other catalysts in which the catalytically active element is supported only in the region of .
32. When the raw materials of the catalyst and the other catalyst are brought into contact with raw materials containing alcohol to react the raw materials to produce a diene compound,
    32. The method for extending service life according to claim 31, wherein the decrease in the initial yield of the diene compound is suppressed and the reaction maintenance rate for maintaining the initial yield is increased as compared with the other catalyst.
33. The life extension method according to claim 32, wherein the initial yield is 80% or more of the other catalyst, and the reaction maintenance rate is twice or more that of the other catalyst.

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