JP5388897B2 - Catalyst for producing unsaturated aldehyde and / or unsaturated carboxylic acid, and method for producing unsaturated aldehyde and / or unsaturated carboxylic acid using the catalyst - Google Patents

Description

  The present invention relates to a catalyst for producing an unsaturated aldehyde and / or unsaturated carboxylic acid, specifically, contact using molecular oxygen of propylene, isobutylene or tertiary butyl alcohol (hereinafter sometimes referred to as “TBA”). The present invention relates to a catalyst suitable for producing a corresponding unsaturated aldehyde and / or unsaturated carboxylic acid by gas phase oxidation, and a method for producing these unsaturated aldehyde and / or unsaturated carboxylic acid using the catalyst.

  Conventionally, a catalyst used for producing acrolein and / or acrylic acid by catalytic gas phase oxidation using molecular oxygen of propylene, or methacrolein and / or methacrylic acid by catalytic gas phase oxidation of isobutylene or TBA. Many proposals have been made with respect to the catalyst used for the purpose of improving the mechanical strength of the catalyst.

  For example, a coated catalyst characterized in that an inert substrate is immersed in a slurry in which a catalyst material or catalyst precursor or a carrier material or carrier precursor and inorganic or organic fibers are dispersed, and is dried or calcined (Patent Document 1), A supported catalyst using whisker having an average fiber diameter of 1 μm or less as a supporting aid (Patent Document 2), a supported catalyst containing molybdenum and bismuth as essential components, and an inorganic fiber having an average diameter of 2 to 200 μm is used as a supporting aid. In the conventional catalyst (Patent Document 3), a catalyst formed into a ring shape containing molybdenum and bismuth as essential components, a catalyst containing an inorganic fiber (Patent Document 4) is disclosed.

JP 56-44045 A JP 59-173140 A Japanese Patent Laid-Open No. 06-381 JP 2002-273229 A

  However, although all the above-mentioned catalysts have improved mechanical strength to some extent, the yields of the target unsaturated aldehyde and unsaturated carboxylic acid are not yet sufficient, so they have higher mechanical strength, and A catalyst capable of obtaining a target product with high yield is desired.

  The object of the present invention is to solve the above-mentioned problems of the prior art and produce the corresponding unsaturated aldehyde and / or unsaturated carboxylic acid by catalytic gas phase oxidation using molecular oxygen of propylene, isobutylene or TBA, respectively. An object of the present invention is to provide a suitable catalyst, specifically, a catalyst having excellent mechanical strength and capable of producing a target product in a high yield.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the corresponding unsaturated aldehyde and / or unsaturated carboxylic acid are obtained by catalytic gas phase oxidation using molecular oxygen of propylene, isobutylene or TBA, respectively. Molybdenum-bismuth-based catalyst for the production of the inorganic fiber for the purpose of improving its mechanical strength, the inorganic fiber that has not been noticed at all until now in a specific range, only the mechanical strength In other words, it was found that the target product can be produced in a high yield. Specifically, a catalyst containing a catalytically active component essentially containing molybdenum and bismuth and an inorganic fiber having an acid amount of 0.05 mmol / g or less has a high mechanical strength and a desired product in a high yield. Has been found to be able to be produced, leading to the present invention. Although the reason is not clear, it has been found by various studies that the activity and selectivity of the catalyst decrease when the acid amount of the inorganic fiber is outside the above range.

  Furthermore, it discovered that the bad influence to the catalyst performance of an inorganic fiber mentioned above could be suppressed by making content of an inorganic fiber 0.5 mass%-30 mass% with respect to a catalyst active component.

  According to the present invention, a catalyst having high mechanical strength for producing a corresponding unsaturated aldehyde and / or unsaturated carboxylic acid can be obtained by catalytic gas phase oxidation of propylene, isobutylene or TBA, respectively, The product can be produced with high yield.

  Hereinafter, the catalyst for producing an unsaturated aldehyde and / or unsaturated carboxylic acid according to the present invention and the method for producing an unsaturated aldehyde and / or unsaturated carboxylic acid using the catalyst will be described in detail. It is not restrained by description of this, It can change suitably and implement in the range which does not impair the meaning of this invention except the following illustration.

The unsaturated aldehyde and / or unsaturated carboxylic acid production catalyst in the present invention contains a catalytically active component having molybdenum and bismuth as essential components and an inorganic fiber having an acid amount of 0.05 mmol / g or less. As the catalytically active component having molybdenum and bismuth as essential components, the following general formula (1)
_{Mo 12 Bi a Fe b A c} B d C e D f O x (1)
(Where Mo is molybdenum, Bi is bismuth, Fe is iron, A is at least one element selected from cobalt and nickel, B is at least one element selected from alkali metals, alkaline earth metals and thallium, C is at least one element selected from tungsten, silicon, aluminum, zirconium and titanium, D is at least one element selected from phosphorus, tellurium, antimony, tin, cerium, lead, niobium, manganese, arsenic, boron and zinc The element, O is oxygen, a, b, c, d, e, f and x represent the atomic ratios of Bi, Fe, A, B, C, D and O, respectively, and 0 <a ≦ 10, 0 < b ≦ 20, 2 ≦ c ≦ 20, 0 <d ≦ 10, 0 ≦ e ≦ 30, 0 ≦ f ≦ 4, and x is a numerical value determined by the oxidation state of each element. In catalytically active component represented are preferred.

  As said inorganic fiber, the acid amount should just be 0.05 mmol / g or less, Preferably it is 0.03 mmol / g or less. In the present invention, an ammonia adsorption temperature programmed desorption method is employed as a method for measuring the acid amount. This method is a general technique among those skilled in the art, for example, after measuring a sample in advance and measuring the weight, passing ammonia through the sample, then raising the temperature, and measuring the amount of ammonia discharged It is. Specifically, by TPD (temperature-programmed desorption method), ammonia gas was aerated in an atmosphere of 50 to 120 ° C. in a sample previously dried at 120 to 300 ° C. for 1 to 4 hours, and saturated adsorption was performed on the sample. A method of measuring the amount of ammonia desorbed by raising the temperature to 400 to 700 ° C. is then mentioned.

  The kind of the inorganic fiber is not particularly limited as long as its acid amount is 0.05 mmol / g or less, and glass fiber, ceramic fiber, metal fiber, mineral fiber, carbon fiber and the like can be used. The crystal structure may be polycrystalline or monocrystalline. Among these, glass fiber, alumina fiber, silica fiber, and silica-alumina fiber are preferable from the viewpoint of versatility. As the inorganic fiber, two or more kinds may be used in appropriate combination, or those having different acid amounts and those having different average fiber length and average fiber diameter, which will be described later, may be used in appropriate combination.

  Moreover, as said inorganic fiber, what has content of an alkali component of less than 1 mass% is preferable. The reason for this is not clear, but it is presumed that the alkali component contained in the inorganic fiber is eluted into the catalytically active component, thereby adversely affecting the activity and selectivity of the catalyst.

  About content of the alkali component in an inorganic fiber, it can measure according to the measuring method of the alkali content rate as described in JISR3420.

  As the size of the inorganic fibers, those having an average fiber diameter of 0.5 μm to 50 μm, preferably 2 μm to 20 μm, and an average fiber length of 10 μm to 1000 μm, preferably 30 μm to 500 μm are suitable. The average fiber length may be within the above-mentioned range in the catalyst, and even if inorganic fibers having an average fiber length of 10 μm to 1000 μm are used in advance, or inorganic fibers having an average fiber length exceeding 1000 μm are used as one of the catalytic active components. After mixing with part or all, the fibers may be cut by vigorous stirring so that the average fiber length falls within the range of 10 μm to 1000 μm. However, in the latter case, since the dispersibility of the inorganic fibers deteriorates, it is preferable to use inorganic fibers having an average fiber length of 10 μm to 1000 μm in advance.

  Furthermore, the content of the inorganic fiber is preferably in the range of 0.5% by mass to 30% by mass and more preferably in the range of 1% by mass to 15% by mass with respect to the amount of the catalytically active component. If the content is less than the above range, the effect of improving the mechanical strength is not sufficient, and if the content is more than the above range, the amount of the catalytic active component contained in the catalyst is reduced, the catalyst performance is deteriorated and the catalyst life is reduced. Is also not preferable.

  The catalyst of the present invention is generally used for the preparation of known unsaturated aldehyde and / or unsaturated carboxylic acid production catalysts except that it contains inorganic fibers having an acid amount of 0.05 mmol / g or less. It can be produced according to the method.

  Specifically, as a raw material of the catalytically active component represented by the general formula (1), salts such as oxides, hydroxides, ammonium salts, nitrates, carbonates, sulfates, and organic acid salts of each component element, These aqueous solutions, sols, and the like, or compounds containing a plurality of elements are mixed with water to form an aqueous solution or an aqueous slurry (hereinafter sometimes referred to as “starting raw material mixture”).

  Next, if necessary, the obtained starting material mixture is dried by various methods such as heating and decompression to obtain a catalyst precursor. As a drying method by heating, for example, a powdered catalyst precursor can be obtained using a spray dryer, a drum dryer or the like, or heated in an air stream using a box-type dryer, a tunnel-type dryer or the like. Block or flake catalyst precursors can also be obtained. Also, once the starting material mixture is concentrated and evaporated to dryness to obtain a cake-like solid, the solid can be further heat-treated, and the obtained catalyst precursor is further calcined. Thus, a method of forming a fired product can also be adopted. As a drying method by reduced pressure, for example, a block or powdery catalyst precursor can be obtained using a vacuum dryer.

  The obtained catalyst precursor or calcined product is sent to a subsequent molding step through a pulverization step and a classification step for obtaining a powder having an appropriate particle size as required. The particle size of the powder of the catalyst precursor or the calcined product is not particularly limited, but is preferably 500 μm or less from the viewpoint of excellent moldability.

  As a method for molding the catalyst, a method of molding the catalyst precursor, the calcined product or a mixture of them with a powdery inert carrier into a fixed shape by an extrusion molding method or a tableting molding method, Although there is a supporting method for supporting on an arbitrary inert carrier, it is preferable that the thickness of the catalyst itself is small in order to suppress the sequential reaction of the product. Therefore, the supporting method for supporting the latter on the inert carrier is preferable. preferable.

  The method for adding the inorganic fiber is not particularly limited, and any method can be used as long as the inorganic fiber can be uniformly dispersed and contained in the catalytically active component. For example, even if an inorganic fiber is added to the starting material mixture of the catalytically active component represented by the general formula (1), or the catalyst precursor obtained after drying or further firing the starting material mixture of the catalytically active component Inorganic fibers may be added. In the latter case, the catalyst precursor powder and the inorganic fiber may be mixed in a granular state or may be mixed in a solvent such as water. Especially, it is preferable from the surface of the dispersibility of an inorganic fiber to mix with the starting raw material liquid mixture of a catalyst active component. Further, the inorganic fiber may be added all at once or may be added separately, for example, a catalyst precursor obtained by adding a part of the inorganic fiber to the starting material mixture and drying or further firing the remainder. You may add to.

  In the case of an extrusion molding method or a tableting molding method, the shape is not particularly limited, and may be any shape such as a spherical shape, a cylindrical shape, a ring shape, and an indeterminate shape. Of course, in the case of a spherical shape, it does not need to be a true sphere and may be substantially spherical, and the cross-sectional shape does not have to be a perfect circle in the same way for a cylindrical shape and a ring shape, and may be substantially a circular shape.

  As the loading method, for example, a method in which a starting material mixture is evaporated to dryness while heating and stirring to an inert carrier having a certain shape described in JP-B-49-11371, and attached to the carrier, Japanese Patent Application Laid-Open No. Sho 59. -173140 or JP-A-6-381, a method of carrying a slurry of a starting material mixture by adhering it to an inert carrier while simultaneously evaporating and carrying a solvent, JP-A-62-200839, It can be produced according to a method of supporting the catalyst precursor or the calcined product in a powder form on an inert carrier described in JP-A No. 10-28877 or JP-A No. 2004-136267.

  Examples of the inert carrier include alumina, silica, silica-alumina, titania, magnesia, steatite, cordierite, silica-magnesia, silicon carbide, silicon nitride, zeolite, and the like. There is no restriction | limiting in particular also about the shape, The thing of well-known shapes, such as spherical shape, cylindrical shape, and ring shape, can be used. The amount of the catalytically active component supported on the inert carrier is not particularly limited, but is preferably in the range of 20% by mass to 300% by mass, and more preferably in the range of 50% by mass to 200% by mass. If the supported amount is less than the above range, there is a concern that the catalyst life will be reduced, and if it is more than the above range, the mechanical strength at the time of loading may decrease.

  In the molding step, a molding aid or binder for improving moldability, a pore forming agent for forming appropriate pores in the catalyst, or the like can be used. Specific examples include organic compounds such as ethylene glycol, glycerin, propionic acid, maleic acid, benzyl alcohol, propyl alcohol, butyl alcohol or phenols, water, nitric acid, ammonium nitrate, and ammonium carbonate.

  The molded body or carrier obtained in the molding process is sent to the subsequent firing process. The firing temperature is 350 ° C to 600 ° C, preferably 400 ° C to 550 ° C, more preferably 420 ° C to 500 ° C, and the firing time is preferably 1 to 10 hours. The firing atmosphere may be an oxidizing atmosphere, but a molecular oxygen-containing gas atmosphere is preferable, and it is particularly preferable to perform the firing step under the flow of the molecular oxygen-containing gas. Air is suitably used as the molecular oxygen-containing gas.

  In addition, there is no restriction | limiting in particular as a baking furnace used by a baking process, What is necessary is just to use the box-type baking furnace or tunnel type baking furnace etc. which are generally used.

  In the present invention, the reactor used for producing the corresponding unsaturated aldehyde and / or unsaturated carboxylic acid by catalytic gas phase oxidation using molecular oxygen of propylene, isobutylene or TBA is a fixed bed reactor. Although there is no particular limitation, a fixed bed multi-tubular reactor is particularly preferable. The inner diameter of the reaction tube is usually 15 to 50 mm, more preferably 20 to 40 mm, and still more preferably 22 to 38 mm.

  Each reaction tube of the fixed-bed multitubular reactor does not necessarily need to be filled with a single catalyst, and a plurality of conventionally known types of catalysts (each may be referred to as a “reaction zone”) are provided. It is also possible to fill as much as possible. For example, a method of filling a plurality of catalysts having different occupied volumes as disclosed in JP-A-4-217932 so that the occupied volume decreases from the raw material gas inlet side to the outlet side, or JP-A-10-168003 A method of filling a plurality of catalysts having different loading rates such as from the raw material gas inlet side to the outlet side so that the loading rate increases, or a part of the catalyst as disclosed in JP-A-2005-320315 is inactive. A method of diluting with a simple carrier or a combination of these may be employed. At this time, the number of reaction zones is appropriately determined depending on the reaction conditions and the scale of the reactor. However, if the number of reaction zones is too large, problems such as complicated packing of the catalyst may occur. About 2-6 is desirable.

The reaction conditions in the present invention are not particularly limited, and any conditions generally used for this type of reaction can be used. For example, the raw material gas is 1-15% by volume, preferably 4-12% by volume propylene, isobutylene or TBA, 0.5-25% by volume, preferably 2-20% by volume molecular oxygen, 0-30% by volume. Preferably, a mixed gas consisting of 0 to 25% by volume of water vapor and the balance of an inert gas such as nitrogen is 300 to 5,000 Hr ⁻¹ under a pressure of 0.1 to 1.0 MPa in a temperature range of 250 to 450 ° C. The catalyst may be contacted at a space velocity of (STP).

  The grade as the reaction raw material gas is not particularly limited. For example, when propylene is used as the raw material, polymer grade or chemical grade propylene can be used. Also, a propylene-containing mixed gas obtained by propane oxidative dehydrogenation reaction can be used. If necessary, air or oxygen can be added to this mixed gas.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Hereinafter, for convenience, “parts by mass” may be simply referred to as “parts”. The conversion rates and yields in the examples and comparative examples were determined by the following equations.
Conversion rate [mol%]
= (Mol number of reacted starting material) / (mol number of supplied raw material) x 100
Yield [mol%]
= (Total number of moles of unsaturated aldehyde produced and unsaturated carboxylic acid produced) / (Number of moles of supplied starting material) x 100
[Measurement method of acid amount]
The acid amount was measured by the ammonia TPD method (temperature programmed desorption method) using a catalyst analyzer BEL-CAT manufactured by Nippon Bell Co., Ltd. under the following conditions.
Sample amount: about 0.1g
Carrier gas: Helium detector: TCD (thermal conductivity detector)
Pretreatment temperature / time: 200 ° C. × 2 hours Ammonia adsorption temperature: 100 ° C.
Temperature rise range: 100 ° C to 600 ° C
Temperature increase rate: 10 ° C / min
[Measuring method of mechanical strength of catalyst]
A stainless steel reaction tube having an inner diameter of 25 mm and a length of 5000 mm is installed in the vertical direction, and the lower end of the reaction tube is closed with a stainless steel receiving plate having a thickness of 1 mm. About 50 g of the catalyst is dropped into the reaction tube from the upper end of the reaction tube, the stainless steel receiving plate at the lower end of the reaction tube is removed, and the catalyst is gently extracted from the reaction tube. The extracted catalyst was sieved with a sieve having an opening of 5 mm, and the mass of the catalyst remaining on the sieve was weighed.

Catalyst strength [mass%]
= Mass of catalyst remaining on sieve / mass of catalyst dropped from top of reaction tube x 100
<Example 1>
(Catalyst preparation)
500 parts of ammonium paramolybdate and 1.9 parts of potassium nitrate were dissolved in 3000 parts of distilled water (solution A). Separately, 20 parts of 65 wt% nitric acid was added to 300 parts of distilled water, and 91.6 parts of bismuth nitrate, 426 parts of cobalt nitrate, 143 parts of iron nitrate and 227 parts of nickel nitrate were dissolved (Liquid B). B liquid was added to the obtained A liquid, and stirring was continued for 30 minutes. Thereafter, silica-alumina fiber having an acid amount of 0.027 mmol / g, an average fiber diameter of 4 μm, and an average fiber length of 50 μm was added to 3% by mass with respect to the catalytically active component, and stirring was further continued for 2 hours to obtain a slurry. It was. The obtained slurry was heated and stirred to form a cake-like solid, and the obtained solid was dried at 200 ° C. for about 5 hours in an air atmosphere. The dried solid was pulverized to 500 μm or less to obtain catalyst powder. After 390 parts of a silica-alumina spherical carrier having an average particle size of 4.5 mm was put into a rolling granulator, and then catalyst powder was gradually put together with a 15% by mass aqueous ammonium nitrate solution as a binder and supported on the carrier. The catalyst 1 was obtained by calcination at 470 ° C. for 6 hours in an air atmosphere. The supported rate of the catalyst 1 was about 150% by mass, and the metal element composition excluding oxygen was as follows.
Catalyst 1: Mo ₁₂ Bi _0.8 Co _6.2 Fe _1.5 Ni _3.3 K _0.08
The loading rate was determined by the following formula.

Support rate [mass%] = mass of supported catalyst active component / mass of support used × 100
[Reactor]
A reactor composed of a SUS reaction tube having a total length of 3000 mm and an inner diameter of 25 mm and a shell for flowing a heat medium covering the SUS reaction tube was prepared in the vertical direction. The catalyst 1 obtained from the upper part of the reaction tube was dropped and filled so that the layer length was 2900 mm.
[Oxidation reaction]
From the bottom of the reaction tube filled with the catalyst, a mixed gas consisting of 8.3% by volume of propylene, 15% by volume of oxygen, 3% by volume of water vapor, and the balance of an inert gas such as nitrogen is introduced at a space velocity of 2100 hr ⁻¹ (STP). Then, propylene oxidation reaction was performed. At that time, the heat medium temperature (reaction temperature) was adjusted so that the propylene conversion was about 97 mol%. The results are shown in Table 1.
<Comparative Example 1>
A catalyst 2 was obtained in the same manner as in Example 1 except that the silica-alumina fiber was not added and the amount of the silica-alumina spherical support was changed to 490 parts. The supporting rate of the catalyst 2 was about 120% by mass, and the metal element composition excluding oxygen was the same as in Example 1. The obtained catalyst 2 was charged into a reactor in the same manner as in Example 1, and an oxidation reaction was performed under the same conditions. The results are also shown in Table 1. As shown in Table 1, since the mechanical strength was weak, the catalytic active component collapsed when the catalyst was charged, the pressure loss during the reaction increased, and the conversion rate could not be adjusted.
<Comparative example 2>
In Example 1, except that the silica-alumina fiber has an acid amount of 0.084 mmol / g, an average fiber diameter of 2 μm, and an average fiber length of 70 μm, and the amount of the silica-alumina spherical carrier is changed to 490 parts. Was prepared in the same manner as in Example 1 to obtain Catalyst 3. The supporting rate of the catalyst 3 was about 120% by mass, and the metal element composition excluding oxygen was the same as that in Example 1. The obtained catalyst 3 was charged into a reactor in the same manner as in Example 1, and an oxidation reaction was performed under the same conditions. The results are also shown in Table 1.
<Example 2>
Liquid A and liquid B were prepared in the same manner as in Example 1. B liquid was added to the obtained A liquid, and it stirred for 2 hours, and obtained the slurry. The obtained slurry was heated and stirred to form a cake-like solid, and the obtained solid was dried at 200 ° C. for about 5 hours in an air atmosphere. The dried solid was pulverized to 500 μm or less to obtain catalyst precursor powder. To the obtained catalyst precursor powder, the same silica-alumina fiber as in Example 1 was added to 3% by mass with respect to the catalytically active component, and powder mixing was performed to obtain a catalyst powder. After 490 parts of a silica-alumina spherical carrier having an average particle diameter of 4.5 mm was put into a rolling granulator, and then catalyst powder was gradually put together with a 15% by mass aqueous ammonium nitrate solution as a binder and supported on the carrier. The catalyst 4 was obtained by calcination at 470 ° C. for 6 hours in an air atmosphere. The supported rate of the catalyst 4 was about 120% by mass, and the metal element composition excluding oxygen was the same as that in Example 1. The reactor was charged in the same manner as in Example 1, and the oxidation reaction was performed under the same conditions. The results are also shown in Table 1.
<Example 3>
Liquid A and liquid B were prepared in the same manner as in Example 1. B liquid was added to the obtained A liquid, and it stirred for 2 hours, and obtained the slurry. The obtained slurry was heated and stirred to obtain a cake-like solid, and the obtained solid was dried in an air atmosphere at 200 ° C. for about 5 hours, and further calcined at 490 ° C. for 6 hours. The fired solid matter was pulverized to 500 μm or less to obtain a fired powder. Subsequently, 800 parts of distilled water and the same silica-alumina fiber as in Example 1 were added to the obtained fired powder so as to be 3% by mass with respect to the catalytically active component, and then stirred for 30 minutes to form a slurry (liquid C). It was. Into a rotating drum heated to about 200 ° C. by a heat transfer heater, 490 parts of a silica-alumina spherical carrier having an average particle diameter of 4.5 mm was charged. While the carrier was allowed to flow in the rotating drum, the liquid C was gradually blown using a spray nozzle to carry the carrier while vaporizing and evaporating the water, and then the carrier was dried at 120 ° C. for 3 hours to obtain catalyst 5. It was. The supporting rate of the catalyst 5 was about 120% by mass, and the metal element composition excluding oxygen was the same as in Example 1. The reactor was charged in the same manner as in Example 1, and the oxidation reaction was performed under the same conditions. The results are also shown in Table 1.
<Example 4>
(Catalyst preparation)
500 parts of ammonium paramolybdate and 1.4 parts of potassium nitrate were dissolved in 3000 parts of distilled water (solution A). Separately, 20 parts of 65% by weight nitric acid was added to 300 parts of distilled water to dissolve 195 parts of bismuth nitrate, 522 parts of cobalt nitrate and 172 parts of iron nitrate (Liquid B). B liquid was added to the obtained A liquid, and stirring was continued for 30 minutes. Thereafter, an alumina fiber having an acid amount of 0.043 mmol / g, an average fiber diameter of 7 μm and an average fiber length of 30 μm was added so as to be 5% by mass with respect to the catalytically active component, and stirring was further continued for 2 hours to obtain a slurry. The obtained slurry was heated and stirred to form a cake-like solid, and the obtained solid was dried at 150 ° C. for about 5 hours in an air atmosphere. The dried solid was pulverized to 500 μm or less to obtain catalyst powder. 460 parts of a silica-alumina spherical carrier having an average particle diameter of 4.5 mm was put into a rolling granulator, and then a catalyst powder was put together with a 15% by mass ammonium nitrate aqueous solution as a binder and supported on the carrier. The catalyst 6 was obtained by calcination at 480 ° C. for 6 hours in an atmosphere. The supported rate of the catalyst 6 was about 130% by mass, and the metal element composition excluding oxygen was as follows.
Catalyst 6: Mo ₁₂ Bi _1.7 Co _7.6 Fe _1.8 K _0.06
[Oxidation reaction]
The reactor was charged in the same manner as in Example 1, and the oxidation reaction was performed under the same conditions. The results are also shown in Table 1.
<Comparative Example 3>
Example 4 is the same as Example 4 except that an alumina fiber having an acid amount of 0.11 mmol / g, an average fiber diameter of 5 μm, and an average fiber length of 10 μm is added to 8% by mass with respect to the catalytically active component. In the same manner, catalyst 7 was obtained. The supported rate of the catalyst 7 was about 130% by mass, and the metal element composition excluding oxygen was the same as that in Example 4. The obtained catalyst 7 was charged into a reactor in the same manner as in Example 1, and an oxidation reaction was performed under the same conditions. The results are also shown in Table 1.
<Example 5>
(Catalyst preparation)
500 parts of ammonium paramolybdate and 2.9 parts of potassium nitrate were dissolved in 3000 parts of distilled water (solution A). Separately, 65 parts by weight of 65% nitric acid was added to 300 parts of distilled water, and 149 parts of bismuth nitrate, 364 parts of cobalt nitrate, 114 parts of iron nitrate and 182 parts of nickel nitrate were dissolved (Liquid B). B liquid was added to the obtained A liquid, and stirring was continued for 30 minutes. Thereafter, an acid amount of 0.003 mmol / g, an average fiber diameter of 10 μm, and an average fiber length of 420 μm of glass fiber (Asahi Fiber Glass Co., Ltd. milled fiber) were added so as to be 12% by mass with respect to the catalytically active component. The mixture was further stirred for 2 hours to obtain a slurry. The obtained slurry was heated and stirred to obtain a cake-like solid, and the obtained solid was dried at 180 ° C. for about 5 hours in an air atmosphere. The dried solid was pulverized to 500 μm or less to obtain catalyst powder. 300 parts of a silica-alumina spherical carrier having an average particle size of 4.5 mm was put into a rolling granulator, and then a catalyst powder was put together with a 15% by mass ammonium nitrate aqueous solution as a binder to be supported on the carrier, and then air The catalyst 8 was obtained by calcination at 470 ° C. for 6 hours in an atmosphere. The supported rate of the catalyst 8 was about 190% by mass, and the metal element composition excluding oxygen was as follows.
Catalyst 8: Mo ₁₂ Bi _1.3 Co _5.3 Fe _1.2 Ni _2.5 K _0.12
[Oxidation reaction]
The reactor was charged in the same manner as in Example 1, and the oxidation reaction was performed under the same conditions. The results are also shown in Table 1.

Claims (4)

An unsaturated aldehyde comprising: a catalytically active component represented by the following general formula (1) having molybdenum and bismuth as essential components; and an inorganic fiber having an acid amount of 0.05 mmol / g or less. Or a catalyst for the production of unsaturated carboxylic acids.
_{Mo 12 Bi a Fe b A c} B d C e D f O x (1)
(Wherein Mo is molybdenum, Bi is bismuth, Fe is iron, A is at least one element selected from cobalt and nickel, B is at least one element selected from alkali metals, alkaline earth metals and thallium, C is at least one element selected from tungsten, silicon, aluminum, zirconium and titanium; D is at least one element selected from phosphorus, tellurium, antimony, tin, cerium, lead, niobium, manganese, arsenic and zinc; O is oxygen, and a, b, c, d, e, f and x represent the atomic ratio of Bi, Fe, A, B, C, D and O, respectively, and 0 <a ≦ 10, 0 <b ≦ (20, 2 ≦ c ≦ 20, 0 <d ≦ 10, 0 ≦ e ≦ 30, 0 ≦ f ≦ 4, and x is a numerical value determined by the oxidation state of each element.)   2. The catalyst according to claim 1, wherein the content of the inorganic fiber is in the range of 0.5% by mass to 30% by mass with respect to the catalytically active component.   The catalyst according to claim 1 or 2, wherein the catalyst active component and the inorganic fiber are supported on an inert carrier.   In producing a corresponding unsaturated aldehyde and / or unsaturated carboxylic acid by catalytic vapor phase oxidation of propylene, isobutylene or tertiary butyl alcohol with molecular oxygen, respectively. A method for producing an unsaturated aldehyde and / or an unsaturated carboxylic acid, characterized by using the catalyst described in 1.