JP2000178242A - Catalyst and production method for unsaturated nitril using this catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst capable of remarkably increasing yield of an unsaturated nitril by including a specific metal in the catalyst supported on silica. SOLUTION: This catalyst is supported by 20-60 wt. % silica and components except silica are composed of the formula (X is Te and/or Sb; Z is Ti, W, Cr, Ta, Sn, Y, Yb, La or the like; p, q, r, s, t and n show an atomic ratio based on 1 atom of Mo, 0.1<=p<=0.6, 0.01<=q<=0.6, 0.01<=r<=0.6, 0.001<=s<=0.3, 0<=t<=1; n is an atomic ratio of oxygen determined by oxidation number of a constituted metallic element). The catalyst is used when propane or isobutane is catalytically ammoxidized in vapor phase to give an unsaturated nitril. Preferably the catalyst is prepared using a niobium solution in which molar ratio of dicarboxylic acid to niobium is 1-8. For example, the catalyst can be produced by spray-drying a mixed solution of a raw material containing a catalyst component and burning the resultant dried powder at 500-700 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a catalyst used for gas phase catalytic ammoxidation of propane or isobutane, and a method for producing an unsaturated nitrile using the catalyst.

[0002]

2. Description of the Related Art Recently, attention has been focused on a method for producing unsaturated nitriles by an ammoxidation reaction in which propane or isobutane is brought into gaseous contact with ammonia and oxygen instead of propylene or isobutylene. For example,
Catalysts containing Mo-V-Nb-Te are disclosed in JP-A-2-257, JP-A-5-148212, and JP-A-5-20.
8136, JP-A-6-227819, JP-A-6-285372, JP-A-7-144132, JP-A-7-289907, JP-A-7-23
No. 2071, JP-A-8-57319, JP-A-8-141401, JP-A-10-28862 and the like. Among these, JP-A-7-17-1
JP-A-44132, JP-A-7-289907, JP-A-8-57319, JP-A-8-141401, and JP-A-10-28862 disclose a catalyst supported on silica. Also, Mo-V-
Catalysts containing Sb-Nb are disclosed in JP-A-5-213848, JP-A-9-157241, and JP-A-10-28.
862 and the like. Among them, JP-A-10-28862 discloses a catalyst supported on silica.

[0003] The gas phase catalytic ammoxidation reaction of propane or isobutane is a reaction that generates a large amount of heat.
Therefore, in order to avoid heat storage and keep the temperature distribution uniform, a fluidized bed reaction system is preferred. For use in a fluidized bed reaction, it is necessary to use a catalyst supported on silica in order to impart catalyst strength.

However, JP-A-7-144132, JP-A-7-289907, and JP-A-8-57
As disclosed in JP-A-319 and JP-A-8-141401, the catalyst supported on silica obtained through a catalyst raw material preparation step-drying step-calcination step has a problem that the yield is reduced. Was. JP-A-8-14140
No. 1 and JP-A-7-144132 teach that the catalyst is supported on 20% by weight or more of silica in order to have catalyst strength.
In the case of the catalyst supported on weight% silica, the yield of unsaturated nitrile is significantly reduced.

In JP-A-8-57319 and JP-A-8-141401, in order to improve the yield of a catalyst supported on silica, a catalyst obtained through a calcination step is treated with an aqueous oxalic acid solution. A method is disclosed in which a washing step is performed, a filtration step is performed, and firing is performed again. This method has a problem that the catalyst manufacturing process itself becomes complicated, and a step of treating a large amount of waste oxalic acid aqueous solution containing a metal component washed and eluted is required. Further, the activity of the catalyst obtained by washing is remarkably increased as the surface area is increased. Therefore, the catalyst generates a large amount of heat in the reactor, and requires a process in order to remove the heat.

[0006] Japanese Patent Application Laid-Open No. 10-28862 discloses a method in which a metal component is impregnated, dried, and fired again. The disclosed catalyst has low silica content and low strength, and this method also has a problem that the catalyst production process is complicated. Further, since it is not easy to impregnate a large amount of catalyst uniformly, there is a problem that quality control of the catalyst is difficult. Mo-V-Nb-T
In a catalyst system comprising e or Mo-V-Nb-Sb,
It has been desired to produce a catalyst having a high strength and a high yield of unsaturated nitrile without going through a complicated catalyst production process.

[0007]

An object of the present invention is to provide a strong catalyst supported on silica for producing an unsaturated nitrile by an ammoxidation reaction in which propane or isobutane is brought into gaseous contact with ammonia and oxygen. Another object of the present invention is to provide a catalyst having a high yield of unsaturated nitrile without going through a complicated catalyst production process.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies on a catalyst for producing unsaturated nitrile by subjecting propane or isobutane to gas-phase catalytic ammoxidation. As a result, the catalyst supported on silica showed Mo, The inventors have found that when Zr is further added to V, Nb, Te and / or Sb, the yield of unsaturated nitrile is remarkably improved, and the present invention has been accomplished.

That is, the present invention relates to (1) a catalyst used for producing unsaturated nitrile by subjecting propane or isobutane to gas phase catalytic ammoxidation, wherein the catalyst is supported on 20 to 60% by weight of silica; the catalyst component composition other than silica is characterized by being represented by the following formula, in _{Mo 1 V p X q Nb r} Zr s Z t O n ( wherein, X is Te and / or Sb, Z is T
i, W, Cr, Ta, Sn, Y, Yb, La, Ce, B
i, Hf, Mn, Re, Fe, Ru, Co, Rh, N
i, Pd, Pt, Ag, Zn, B, Al, Ga, In,
Ge, Pb, P, Pr, Nd, Sm, Gd, Pm, E
u, Tb, Dy, Ho, Er, Tm, Lu and at least one element selected from alkaline earth metals, and p, q, r, s, t and n represent an atomic ratio per Mo atom. , 0.1 ≦ p ≦ 0.6, 0.01 ≦ q ≦
0.6, 0.01 ≦ r ≦ 0.6, 0.001 ≦ s ≦ 0.
3, 0 ≦ t ≦ 1, and n is the atomic ratio of oxygen determined by the oxidation number of the constituent metal element. (2) The catalyst according to (1), wherein the raw material preparation liquid is produced using a niobium raw material liquid having a dicarboxylic acid / niobium molar ratio of 1 to 8. (3) 20 to 60 A catalyst supported by weight% of silica and having a composition other than silica represented by the formula is obtained by spray-drying a raw material preparation liquid containing the components of the catalyst to substantially contain oxygen. The catalyst according to (1) or (2), wherein the catalyst is produced by calcining at 500 to 700 ° C. in an atmosphere of no gas, and (4) a raw material mixture is a hydroxide or oxide of zirconium; (5) The catalyst according to any one of (1) to (3), wherein at least one compound selected from dibasic oxyzirconates and tetrabasic salts is used.
A method for producing an unsaturated nitrile, comprising producing an unsaturated nitrile by subjecting propane or isobutane to gas phase catalytic ammoxidation in the presence of the catalyst according to any one of (1) to (4).

Hereinafter, the present invention will be described in detail. The catalyst of the present invention is a catalyst used for producing unsaturated nitriles by subjecting propane or isobutane to gas-phase catalytic ammoxidation. The catalyst is supported on 20 to 60% by weight of silica, and has a component composition other than silica. Is a catalyst represented by the following formula: Mo in _{1 V p X q Nb r Zr} s Z t O n ( wherein, X is Te and / or Sb, Z is T
i, W, Cr, Ta, Sn, Y, Yb, La, Ce, B
i, Hf, Mn, Re, Fe, Ru, Co, Rh, N
i, Pd, Pt, Ag, Zn, B, Al, Ga, In,
Ge, Pb, P, Pr, Nd, Sm, Gd, Pm, E
u, Tb, Dy, Ho, Er, Tm, Lu and at least one element selected from alkaline earth metals, and p, q, r, s, t and n represent an atomic ratio per Mo atom. , 0.1 ≦ p ≦ 0.6, 0.01 ≦ q ≦
0.6, 0.01 ≦ r ≦ 0.6, 0.001 ≦ s ≦ 0.
3, 0 ≦ t ≦ 1, and n is the atomic ratio of oxygen determined by the oxidation number of the constituent metal element. In the present invention,
p is 0.1 ≦ p ≦ 0.6, preferably 0.15 ≦ p ≦
0.5, particularly preferably 0.2 ≦ p ≦ 0.4, and q
Is 0.01 ≦ q ≦ 0.6, preferably 0.05 ≦ q ≦
0.4, particularly preferably 0.1 ≦ q ≦ 0.3, and r
Is 0.01 ≦ r ≦ 0.6, preferably 0.02 ≦ r ≦
0.4, particularly preferably 0.03 ≦ r ≦ 0.3,
s is 0.001 ≦ s ≦ 0.3, preferably 0.01 ≦ s
≦ 0.2, particularly preferably 0.02 ≦ s ≦ 0.08. When s <0.001, the yield of unsaturated nitrile is low, and when s> 0.3, the yield of unsaturated nitrile is low.

In the present invention, the amount of silica (% by weight of silica) used as a carrier is defined by the following formula, where the weight of the oxide of the above formula is W ₁ and the weight of silica is W ₂ . W ₁ is the weight calculated based on the oxidation number of charge composition and the charge of the metal component. W ₂ is the weight calculated based on the charged composition. Silica wt% = 100 × W ₂ / (W ₁ + W ₂ ) The catalyst of the present invention is supported on 20 to 60 wt%, preferably 25 to 40 wt% of silica. If it is less than 20% by weight, the strength is low, and if it is more than 60% by weight, the strength is high, but the yield of unsaturated nitrile is low.

The following compounds can be used as raw materials for component metals for producing the catalyst of the present invention. Molybdenum raw material is ammonium heptamolybdate, vanadium raw material is ammonium metavanadate, vanadium pentoxide, tellurium raw material is telluric acid, antimony raw material is antimony oxide, and niobium raw material is niobic acid. Can be used.

As the raw material of zirconium, hydroxides and oxides such as zirconium (IV) hydroxide and zirconium (IV) oxide, dibasic compounds such as zirconium dinitrate hydrate and zirconium dichloride hydrate are used. Oxyzirconate salts, zirconium halides such as zirconium (IV) chloride, tetrabasic salts such as zirconium (IV) nitrate and the like can be used, and preferred are oxyzirconium salts, oxides and hydroxides. More preferably, it is a hydroxide. Ti, W, Cr, Ta, Sn, Y, Y
b, La, Ce, Bi, Hf, Mn, Re, Fe, R
u, Co, Rh, Ni, Pd, Pt, Ag, Zn, B,
Al, Ga, In, Ge, Pb, P, Pr, Nd, S
m, Gd, Pm, Eu, Tb, Dy, Ho, Er, T
As raw materials for m, Lu and alkaline earth metals, nitrates, oxalates, acetates, hydroxides, oxides, ammonium salts, carbonates and the like of these metals can be used.

As a raw material of silica, a silica sol can be suitably used. It is preferable to use a sol stabilized with ammonium ions rather than a silica sol stabilized with alkali metal ions. The catalyst of the present invention can be produced through the following three steps of raw material preparation, drying and calcination.

(Raw material preparation step) Ammonium heptamolybdate, ammonium metavanadate and telluric acid are dissolved in water to prepare a mixed solution (A). When using antimony, ammonium heptamolybdate is added to a solution obtained by heating a slurry in which antimony oxide powder is dispersed in an aqueous solution of ammonium metavanadate under reflux conditions, and if necessary, further adding telluric acid. To prepare a mixture (A ′). A niobium raw material liquid is prepared by dissolving niobic acid and dicarboxylic acid in water or aqueous ammonia. Oxalic acid is preferred as the dicarboxylic acid. The molar ratio of oxalic acid / niobium in the niobium raw material liquid is 1 to 8, preferably 2 to 4, and particularly preferably 2 to 3. The molar ratio of (NH ₃ + NH ₄ ⁺ ) / niobium is 2 or less, preferably 1 or less. When there is insoluble niobic acid, it is preferable to separate and remove insoluble components by filtration or the like.

Ti, W, Cr, Ta, Sn, Y, Yb,
La, Ce, Bi, Hf, Mn, Re, Fe, Ru, C
o, Rh, Ni, Pd, Pt, Ag, Zn, B, Al,
Ga, In, Ge, Pb, P, Pr, Nd, Sm, G
d, Pm, Eu, Tb, Dy, Ho, Er, Tm, Lu
When alkaline earth metals are used, nitrates, oxalates, acetates, hydroxides, oxides, ammonium salts, carbonates and the like of these metals are dissolved and / or dispersed in water to form a mixed solution (B ) Is prepared. A silica sol and a niobium raw material liquid are sequentially added to the mixed liquid (A) or the mixed liquid (A ′).

The zirconium raw material is added in any of the steps in the above-mentioned mixing order. The conditions for adding the raw materials are not particularly limited, but it is desirable that the raw materials be easily dispersed in water by a method such as raiding in advance.
After adding the zirconium raw material, the mixed liquid is stirred for 30 minutes or more to obtain a raw material preparation liquid. The stirring time is preferably 30 minutes or more. More preferably, it is within 6 hours. Finally, in some cases, the mixture (B) is added, and the mixture is further stirred for 1 hour to obtain a raw material mixture.

(Drying Step) The preparation liquid obtained in the raw material preparation step is spray-dried to obtain a dry powder. Atomization can be performed by employing a centrifugal method, a two-fluid nozzle method, or a high-pressure nozzle method. As the drying heat source, air heated by steam, an electric heater, or the like can be used. Hot air dryer inlet temperature is 150 ~ 300 ℃
Is preferred. Spray drying is conveniently performed at 100 to 300 ° C.
It can also be carried out by spraying the raw material mixture onto an iron plate heated to a temperature.

(Firing step) A catalyst can be obtained by firing the dry powder obtained in the drying step. The calcination is carried out under an inert gas atmosphere such as nitrogen substantially free of oxygen, preferably while flowing an inert gas.
It can be carried out at 700 ° C, preferably 550 to 650 ° C. In the present invention, substantially containing no oxygen means that the oxygen concentration is 1000 ppm or less as measured by gas chromatography or a trace oxygen analyzer. The firing time is 0.5 to 5 hours, preferably 1 to 5 hours.
3 hours. The oxygen concentration in the inert gas was measured by gas chromatography or a trace oxygen analyzer to be 1000
ppm or less, preferably 100 ppm or less, particularly preferably 50 ppm or less. The firing can be performed using a rotary furnace, a tunnel furnace, a tubular furnace, a fluidized firing furnace, or the like.
Firing can be repeated. Before this firing, at 200 to 350 ° C. for 10 minutes in an air atmosphere or under air circulation.
Pre-baking can be performed for 5 hours. Moreover, after baking, baking can be performed at 200 to 400 ° C. for 5 minutes to 5 hours in an air atmosphere.

In the presence of the catalyst thus produced,
Propane or isobutane can be subjected to gas phase catalytic ammoxidation to produce unsaturated nitriles. The feedstocks of propane or isobutane and ammonia need not be of high purity, and industrial grade gases can be used. Air, oxygen-enriched air, or pure oxygen can be used as the supply oxygen source. Further, helium, argon, carbon dioxide, water vapor, nitrogen or the like may be supplied as a diluting gas.

The molar ratio of ammonia supplied to the reaction to propane or isobutane is 0.1 to 1.5, preferably 0.2 to 1.2. The molar ratio of molecular oxygen supplied to the reaction to propane or isobutane is from 0.2 to
6, preferably 0.4 to 4. Reaction pressure is 0.1 ~
10 atm, preferably 1-3 atm. The reaction temperature is from 350 to 600C, preferably from 380 to 470C. The contact time is 0.1 to 30 sec · g / cc, preferably 0.5 to 10 sec · g / cc. As the reaction system, a fixed bed, a fluidized bed, a moving bed and the like can be adopted, but a fluidized bed is preferred. The reaction can be performed in a single-flow system or a recycling system.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described with reference to an example of an ammoxidation reaction of propane. In each case, the propane conversion, acrylonitrile selectivity, and acrylonitrile yield follow the following definitions, respectively. Propane conversion (%) = (number of moles of propane reacted)
/ (Mol number of propane supplied) × 100 Acrylonitrile selectivity (%) = (mol number of acrylonitrile formed) / (mol number of reacted propane) ×
100 Acrylonitrile yield (%) = (mol number of acrylonitrile generated) / (mol number of supplied propane) × 10
0

[0023]

Example 1 (Preparation of catalyst) 30% by weight of SiO_TwoCarried on
The composition formula is Mo₁V_0.33Nb_{0. 11}Te_0.22Zr
_0.05O_nWas prepared as follows. water
720 g of ammonium heptamolybdate [(NH
_Four)₆Mo₇O_{twenty four}・ 4H_TwoO] 180.0 g, metabana
Ammonium formate [NH_FourVO_Three39.4 g and
Telluric acid [H₆TeO₆] 51.5 g, and under stirring,
The mixture was dissolved by heating to 60 ° C. to obtain a mixed solution (A). Water 1
70 g, Nb_TwoO_Five71.0% by weight as
21.0 g of niobic acid and oxalic acid dihydrate [H_TwoC_TwoO_Four
・ 2H _TwoO] 38.2 g and heated to 70 ° C. with stirring
After cooling to 30 ° C, clear niobium
A raw material liquid was obtained. At this time, the molar ratio of oxalic acid / niobium is
2.7. Containing silica while stirring the mixture (A)
331 g of 30% by weight silica sol was added, followed by d.
And a zirconium hydroxide (Zr
(OH)_Four, ZrO_Two8.1g added (content 77.4%)
Then, the mixture was stirred to obtain a raw material mixture. Transfer the obtained raw material mixture
Using a core spray dryer, inlet temperature 240 ° C and outlet temperature 1
Drying was performed under the condition of 45 ° C. to obtain a microspherical dry powder. Profit
5 g of the obtained dry powder is filled in a quartz tube having an inner diameter of 20 mm,
350 Ncc / min. At 600 ° C under nitrogen gas flow
The catalyst was obtained by calcining for 2 hours. Oxygen concentration of nitrogen gas used
Is a trace oxygen analyzer (306WA type, Teledyne analysis)
Tikal Instrument Co., Ltd.)
As a result, it was 1 ppm. Major manufacturing factors (zirconium
Raw materials, Zr / Mo ratio and firing method) are described in Table 1.
Was.

(Test for Ammoxidation of Propane) The obtained catalyst was filled in a fixed-bed reaction tube having an inner diameter of 4 mm and W = 0.35 g, and the reaction temperature was set at T = 415 ° C .; propane: ammonia: oxygen: helium = 1: 1.2: 2.9: 1
A mixed gas having a molar ratio of 4.5 was supplied at a flow rate of F = 2.0 Ncc / m.
in. Flowed away. The reaction pressure P was 1 atm. The contact time was 4.1 (= W / F × 60 × 273 / (273+
T) × P) sec · g / cc. The analysis of the reaction gas was performed using online chromatography. The results obtained are shown in Table 1 using propane conversion, acrylonitrile selectivity and acrylonitrile yield as indices.

(Catalyst strength test) Micro compression tester (MCT)
M-500 type, Shimadzu Corporation), a load is applied to the particles, and the strength F (gf) and the particle diameter D when the particles are broken are obtained.
(Μm), the compressive strength was measured. Using particles of 40 to 50 μm, the compressive strength was calculated from the average value of 10 points by an equation. Compressive strength (MPa) = 12490 × F / D ^{2 The} results are shown in Table 1.

[0026]

EXAMPLE 2 supported on SiO ₂ (Catalyst Preparation) 30 wt%, the composition formula _{Mo 1 V 0.33 Nb 0. 11 Te} 0.22 Zr
The catalyst represented by _0.10 O _n, except that the amount of zirconium hydroxide was 16.2 g, was obtained by repeating the catalyst preparation of Example 1. (Propane ammoxidation reaction test) The obtained catalyst was subjected to a propane ammoxidation reaction at a mixed gas flow rate of 2.9 Ncc / min. (Contact time 4.1 sec.g
/ Cc), but under the same conditions as in Example 1. Table 1 shows the obtained results. (Catalyst Strength Test) The compression strength of the catalyst was measured by repeating Example 1. Table 1 shows the results.

[0027]

Example 3 supported on SiO ₂ (Catalyst Preparation) 30 wt%, the composition formula _{Mo 1 V 0.33 Nb 0. 11 Te} 0.22 Zr
The catalyst represented by _0.08 O _n, dinitrate oxide, zirconium dihydrate as zirconium material (ZrO (NO _{3) 2} ·
2H ₂ O, except for using 21.8g of ZrO ₂ content 46.1%) was obtained by repeating the catalyst preparation of Example 1. (Propane Ammoxidation Test) Propane ammoxidation reaction was performed on the obtained catalyst under the same conditions as in Example 2. Table 1 shows the obtained results. (Catalyst Strength Test) The compression strength of the catalyst was measured by repeating Example 1. Table 1 shows the results.

[0028]

EXAMPLE 4 supported on SiO ₂ (Catalyst Preparation) 30 wt%, the composition formula _{Mo 1 V 0.33 Nb 0. 11 Te} 0.22 Zr
The catalyst represented by _0.04 O _n, except for using 10.9g of dinitrate oxide, zirconium dihydrate as zirconium starting material was obtained by repeating the catalyst preparation of Example 1. (Propane Ammoxidation Test) Propane ammoxidation reaction was performed on the obtained catalyst under the same conditions as in Example 2. Table 1 shows the obtained results. (Catalyst Strength Test) The compression strength of the catalyst was measured by repeating Example 1. Table 1 shows the results.

[0029]

Example 5 (Preparation of catalyst) 100 g of the dry powder obtained by the preparation of the catalyst of Example 2 was filled in a stainless steel tube having a diameter of 1 inch, and 150 Ncc / min. Under nitrogen gas flow of 60
The catalyst was obtained by calcining at 0 ° C. for 2 hours. (Propane ammoxidation reaction test) A Vycor glass fluidized bed type reaction tube having an inner diameter of 25 mm was filled with 50 g of the obtained catalyst, and propane: ammonia: oxygen: helium = 1: 1.
A mixed gas having a molar ratio of 2: 3: 12 is supplied at 390 Ncc / mi.
n. At a flow rate of Contact time is 3.0 sec · g / c
c. The analysis of the reaction gas was performed using online chromatography. Table 1 shows the obtained results. (Catalyst Strength Test) The obtained catalyst was measured in the same manner as in the catalyst strength test of Example 1. Table 1 shows the results.

[0030]

Comparative Example 1 (Catalyst preparation) No zirconium was added
The catalyst preparation of Example 1 was repeated except that
SiO_TwoHas a composition formula of Mo₁V_0.33Nb
_0.11Te _0.22O_nThe catalyst represented by was obtained. (Propane ammoxidation test)
The propane ammoxidation reaction was carried out under the same conditions as in Example 2.
I went to. Table 1 shows the obtained results. (Catalyst strength test) Measurement of the compressive strength of the catalyst
Performed repeatedly. Table 1 shows the results.

[0031]

[Comparative Example 2] was supported on SiO ₂ (Catalyst Preparation) 10 wt%, the catalyst composition formula is represented by _{Mo 1 V 0.33 Nb 0.11 Te 0.22} O n, without the addition of Zr raw material, silica content 30
Example 1 except that 86 g of the silica sol of weight% was added.
Was obtained by repeating the catalyst preparation. (Propane ammoxidation reaction test) The obtained catalyst was subjected to a propane ammoxidation reaction at a mixed gas flow rate of 4.7 Ncc / min. (The contact time was 1.8 sec · g / cc), but the same conditions as in Example 1 were used. Table 1 shows the obtained results. (Catalyst Strength Test) The compression strength of the catalyst was measured by repeating Example 1. Table 1 shows the results.

[0032]

[Table 1]

[0033]

Industrial Applicability The catalyst of the present invention is a catalyst which can be obtained without going through a complicated catalyst production process, and has a high strength and a high yield of propane or isobutane to unsaturated nitrile. is there.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/88 B01J 23/88 Z 27/057 27/057 Z 27/199 27/199 Z C07C 253/24 C07C 253/24 // C07B 61/00 300 C07B 61/00 300 F term (reference) 4G069 AA03 BA02A BA02B BB04B BB06A BB06B BC08A BC16A BC17A BC18A BC21A BC22A BC23A BC25A BC26A BC32A BC35A BC42A BC42A BC42A BC52A BC58A BC59A BC59B BC60A BC62A BC64A BC66A BC67A BC68A BC70A BC71A BC72A BC75A BD03A BD07A BD10A BD10B CB54 DA05 FB30 4H006 AA02 AC12 AC54 BA10 BA12 BA13 BA14 BA15 BA30 BA55 BA81 BE14 BE30 QN24 4H039 CA70

Claims (5)

[Claims] 1. A catalyst used for producing unsaturated nitrile by subjecting propane or isobutane to gas phase catalytic ammoxidation, wherein the catalyst is supported on 20 to 60% by weight of silica,
And a catalyst having a composition other than silica represented by the following formula. Mo in _{1 V p X q Nb r Zr} s Z t O n ( wherein, X is Te and / or Sb, Z is T
i, W, Cr, Ta, Sn, Y, Yb, La, Ce, B
i, Hf, Mn, Re, Fe, Ru, Co, Rh, N
i, Pd, Pt, Ag, Zn, B, Al, Ga, In,
Ge, Pb, P, Pr, Nd, Sm, Gd, Pm, E
u, Tb, Dy, Ho, Er, Tm, Lu and at least one element selected from alkaline earth metals, and p, q, r, s, t and n represent an atomic ratio per Mo atom. , 0.1 ≦ p ≦ 0.6, 0.01 ≦ q ≦
0.6, 0.01 ≦ r ≦ 0.6, 0.001 ≦ s ≦ 0.
3, 0 ≦ t ≦ 1, and n is the atomic ratio of oxygen determined by the oxidation number of the constituent metal element. ) 2. The catalyst according to claim 1, wherein the raw material mixture is produced using a niobium raw material liquid having a dicarboxylic acid / niobium molar ratio of 1 to 8. 3. supported on 20 to 60% by weight of silica,
And, a catalyst whose component composition other than silica is represented by the formula,
The dry powder obtained by spray-drying the raw material preparation liquid containing the components of the catalyst, under a gas atmosphere containing substantially no oxygen,
The catalyst according to claim 1, wherein the catalyst is produced by calcining at 500 to 700 ° C. 4. 4. A raw material preparation liquid comprising at least one compound selected from the group consisting of hydroxides and oxides of zirconium, dibasic oxyzirconates and tetrabasic salts. 4. The catalyst according to any one of 1 to 3. 5. A method for producing an unsaturated nitrile, comprising producing an unsaturated nitrile by subjecting propane or isobutane to gas phase catalytic ammoxidation in the presence of the catalyst according to any one of claims 1 to 4.