RU2575346C2 - Oxide catalyst - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention discloses an oxide catalyst for use in an olefin and/or alcohol oxidation reaction, a method of producing said catalyst and a method of producing a saturated aldehyde in the presence of said catalyst. The catalyst has the following formula (1): Mo₁₂Bi_aFe_bCo_cCe_dA_eB_fO_q (1), where Mo is molybdenum, Bi is bismuth, Fe is iron, Co is cobalt, Ce is cerium, A is at least one element selected from a group consisting of cerium and rubidium, B is at least one element selected from a group consisting of copper, nickel, magnesium and lead, a-f denote the atomic ratio of each of the elements to 12 Mo atoms; 2≤a≤6, 2.5<b≤5, 2≤c≤8, 0.4≤b/c≤2.5, 0.5≤d≤6, 0.01≤e≤2 and 0≤f<2, and g is the number of oxygen atoms, defined by the valence of the constituent element other than oxygen, wherein when the parameter d of a cerium and molybdenum composite oxide, which indicates a peak at 33.50° on an X-ray diffraction pattern, is taken as the reference, the level of change of d is 5000-9000 ppm. The method of producing the catalyst includes the following steps: ageing a suspension of the starting material containing molybdenum, bismuth, iron, cobalt and cerium at a temperature higher than room temperature; drying the aged suspension of the starting material; pre-calcining the dried product at 120°C or higher and 350°C or lower; and final calcining of the pre-calcined product at 400°C or higher and 700°C or lower.

EFFECT: oxide catalyst causes less formation of subsequent oxide in an olefin and/or alcohol oxidation reaction and can improve selectivity of unsaturated aldehyde.

3 cl, 2 dwg, 9 tbl, 23 ex

Description

FIELD OF THE INVENTION

The present invention relates to an oxide catalyst used in the oxidation of an olefin and / or alcohol.

BACKGROUND OF THE INVENTION

As a method for producing methyl acrylate or methyl methacrylate in accordance with an oxidative esterification reaction in which at least one representative selected from propylene, isobutylene and tert-butyl alcohol is used as a starting material and an unsaturated aldehyde as an intermediate, two methods are known : a method called "direct meta-method", containing two reaction stages; and a method called a “direct oxidation method” comprising three reaction steps. According to "Sekiyu Kagaku Purosesu (Petrochemical Processes)" (edited by the Japan Petroleum Institute, pages 172-176, Kodansha Scientific, Ltd.), the direct oxidation process is a three-step process for producing methyl acrylate or methyl methacrylate. The first oxidation step is the step of exposing at least one starting material selected from propylene, isobutylene and tert-butanol, a gas-phase catalytic oxidation reaction of molecular oxygen in the presence of a catalyst to produce acrolein or methacrolein. The second stage of oxidation is the stage of exposure to acrolein or methacrolein obtained in the first stage of oxidation, a gas-phase catalytic oxidation reaction of molecular oxygen in the presence of a catalyst to produce acrylic acid or methacrylic acid. The esterification step is a step for further processing the acrylic acid or methacrylic acid obtained in the second oxidation step by esterification using methanol as an alcohol to produce methyl acrylate or methyl methacrylate. Meanwhile, the direct meta-method involves two stages of a catalytic reaction, where the first reaction stage involves the treatment of propylene, isobutylene and / or tert-butanol as a starting material (s) with a gas-phase catalytic oxidation reaction with a gas containing molecular oxygen to produce acrolein or methacrolein and the second oxidation step involves reacting the resulting acrolein or methacrolein, for example methanol, as alcohol and molecular oxygen to produce methyl acrylate and methyl methacrylate in bottom stage.

As a catalyst for producing an unsaturated aldehyde as the main component, there is a catalyst found a long time ago by Sohio Company. Then, many complex oxide catalysts containing Mo and Bi as main components were introduced. For example, a catalyst focusing on Mo, Si, Ce, K, Fe, Co, Mg, Cs, and Rb as the metals contained in the catalyst is described in Patent Document 1. Catalysts for producing unsaturated aldehyde and unsaturated acid are also described in Patent Document 2. Among them, the catalyst represented by the following formula Sb _0.5 Cs _0.5 S _0.25 Ni _2.5 Co _4.5 Fe ₄ Bi ₁ Mo ₁₂ O _x provides maximum yield in one run.

Prototype list

Patent document

Patent Document 1: International Publication No. WO 95/35273

Patent Document 2: US Patent No. 4001317

SUMMARY OF THE INVENTION

Problems Solved by the Invention

The performance of the oxidation reaction described above is significantly affected by the concentration of the starting material and the reaction temperature. It is theoretically believed that productivity improves when the concentration of the starting material is high and the reaction temperature is high. However, in reality, when the reaction temperature and the concentration of the starting material are set excessively high, the problem of markedly reduced productivity arises.

For example, when an unsaturated aldehyde is obtained by a gas-phase catalytic oxidation reaction, if the concentration of the starting material is high, the partial oxygen pressure required during heat generation increases, which increases the formation of the subsequent oxide. Therefore, the selectivity for unsaturated aldehyde is significantly reduced, which significantly reduces productivity. Meanwhile, if the reaction temperature is about 350-370 ° C, selectivity for unsaturated aldehyde increases. However, if the reaction temperature is about 370 ° C or more, the selectivity for the unsaturated aldehyde is significantly reduced, which significantly reduces the productivity. Therefore, a catalyst is required having the high productivity of the desired product even under reaction conditions with a high concentration of the starting material and a high reaction temperature.

In the above observations, the oxide catalyst of the bismuth-molybdenum (Bi-Mo) system used in the art and the oxide catalyst of the system in which iron, cerium or the like were investigated. additionally introduced into the bismuth-molybdenum system, as described in patent document 1. As a result, it was found that in such a catalyst all metals do not form a complex oxide and the metals also exist as Bi ₂ Mo ₃ O ₁₂ , Ce ₂ Mo ₃ O ₁₂ , Fe ₂ Mo ₃ O ₁₂ , Bi ₂ O ₃ , Fe ₂ O ₃ and CeO ₂ according to the results of X-ray diffraction analysis or the like. These one-component oxides or two-component oxides have a relatively high oxidizing ability and therefore form a subsequent oxide, which is in a state where the desired product is additionally oxidized, creating the problem of reduced productivity on the desired product.

Then, the authors of the present invention as a result of studies on optimizing the oxidizing ability of the catalyst, it was found that the ratios of Mo, Bi, Fe, Co, and Ce in the catalyst are optimized, and the formation of non-complex oxide components from these components is suppressed by suppressing the formation of subsequent oxides, improving performance of the desired product. Thus, the authors have formulated the present invention.

That is, the present invention is as follows.

[1] An oxide catalyst for use in the oxidation reaction of an olefin and / or alcohol, which contains:

molybdenum, bismuth, iron, cobalt and cerium; where the atomic ratio of a bismuth to 12 molybdenum atoms is 2≤a≤6, the atomic ratio of b iron to 12 molybdenum atoms is 2.5 <b≤5, the atomic ratio of cobalt to 12 molybdenum atoms is 2≤c≤8, the atomic ratio d cerium to 12 molybdenum atoms is 0.5 d d 6 6, and the atomic ratio iron / cobalt is 0.4 b b / c 2 2.5.

in which, when the parameter d of the complex cerium and molybdenum oxide, showing a peak at 33.50 ° in the X-ray diffraction pattern, is taken as a reference, the level of change of d is 5000-9000 ppm.

[2] The oxide catalyst according to [1] above, where the oxide catalyst has a composition represented by the following formula of composition (1):

Mo ₁₂ Bi _a Fe _b Co _c Ce _d A _e B _f O _g (1),

in which Mo represents molybdenum, Bi represents bismuth, Fe represents iron, Co represents cobalt, Ce represents cerium, A represents at least one element selected from the group consisting of cesium and rubidium, B represents at least one element selected from the group consisting of copper, nickel, magnesium and lead, af represents the atomic ratio of each of the elements to 12 Mo atoms and satisfy the values 2≤a≤6, 2.5 <b≤5, 2≤ s 8 8, 0.4 b b / c 2 2.5, 0.5 d d 6 6, 0.01 е ≤ 2, and 0 f f <2, and g is the number of oxygen atoms, determined by the valency of the constituent element other than oxygen.

[3] A method for producing an oxide catalyst according to [1] or [2] which comprises the following steps:

ripening a suspension of the starting material containing molybdenum, bismuth, iron, cobalt and cerium at a temperature higher than room temperature;

drying the ripened suspension of the starting material;

preliminary calcining the dried product at 120 ° C or higher and 350 ° C or lower; and

subsequent final calcination of the pre-calcined product at a temperature of 400 ° C or higher and 700 ° C or lower.

[4] A method for producing an unsaturated aldehyde comprising the step of oxidizing at least one olefin selected from the group consisting of propylene and isobutylene and / or tert-butyl alcohol using an oxide catalyst according to [1] or 2].

Beneficial effects of the invention

The present invention can provide a catalyst that provides high productivity of the desired product under the reaction conditions of a high concentration of the starting material and a high reaction temperature in the oxidation reaction of olefin and / or alcohol.

Brief Description of the Drawings

Figure 1 presents the x-ray with the corresponding peaks of the oxide catalysts in example 2 and comparative example 1.

Figure 2 presents an enlarged view of the interval 2θ = 32.5-35 ° of the peaks of the x-ray from figure 1.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the invention

An embodiment of the present invention is described in detail below (hereinafter referred to as “the present embodiment”). However, the present invention is not limited to the following options and can be variously modified within the scope of the invention.

[1] Oxidation catalyst for the oxidation reaction

The oxide catalyst according to the present invention is an oxide catalyst for use in the oxidation reaction of an olefin and / or alcohol, wherein the oxide catalyst comprises:

molybdenum, bismuth, iron, cobalt and cerium; the atomic ratio of bismuth to 12 molybdenum atoms is 2≤a≤6, the atomic ratio of iron b to 12 molybdenum atoms is 2.5 <b≤5, the atomic ratio of cobalt to 12 molybdenum atoms is 2≤c≤8, and the atomic ratio is d cerium to 12 molybdenum atoms is 0.5 d d 6 6, and the atomic ratio of iron / cobalt is 0.4 b b / c 2 2.5.

in which, when the parameter d of the complex cerium and molybdenum oxide, showing a peak at 33.50 ° in the X-ray diffraction pattern, is taken as a reference, the level of change of d is 5000-9000 ppm.

The selectivity of the desired product and the suppression of subsequent oxidation contribute to improving the performance of the desired product. The authors of the present invention believe that a complex oxide having a structure in which the level of variation of the parameter d is 5000-9000 ppm, contributes to the stability of the intermediate. The exclusion of oxidizable hydrogen forms a π-allyl intermediate of olefin and / or alcohol. In addition, the addition reaction or the dehydrogenation reaction modifies the π-allyl intermediate to give the desired product. The π-allyl intermediate is highly reactive and unstable, and therefore the π-allyl intermediate is immediately changed or decomposed into another compound under normal circumstances. However, it is believed that the oxide catalyst according to the present invention regulates the stability of the π-allyl intermediate, and the reaction gives preferably the desired product. When oxygen is introduced and forms a π-allyl intermediate, the latter changes to an aldehyde or carboxylic acid. When ammonia is introduced into the π-allyl intermediate, the π-allyl intermediate is converted to nitrile. When hydrogen is eliminated from the π-allyl intermediate, a double bond is formed, and an olefin is obtained from alcohol, and a diolefin or the like is obtained from an olefin. Therefore, various desired products can be obtained using the oxide catalyst according to the present invention with the appropriate selection of the starting material fed to the reactor.

Although the reason why the oxide catalyst of the present invention inhibits the formation of a subsequent oxide is not clear, the authors of the present invention conducted a study and confirmed that the subsequent oxide is reduced even if the unsaturated aldehyde is the desired product. Unsaturated aldehyde is a compound that is prone to extremely light oxidation. As an unexpected result, the subsequent oxide obtained from the unsaturated aldehyde is reduced even under conditions of a high concentration of the starting material and a high reaction temperature. Even if an unsaturated aldehyde, which is prone to extremely light oxidation, can be suppressed, it is believed that the formation of a subsequent oxide is also suppressed for other desired products. The subsequent oxide is a by-product that is not preferred in all oxidation reactions. If subsequent oxide formation can be suppressed, a significant improvement in performance can be expected.

In the present description, the subsequent oxide means a compound in a state where the desired product is additionally oxidized. Therefore, an unsaturated carboxylic acid is considered to be a type of subsequent oxide when the desired product is an unsaturated aldehyde, as in the first reaction step of the direct meta-method. Other examples of the subsequent oxide may include carbon dioxide, peroxides, diketones, and epoxy compounds.

(1) Composition

In the oxide catalyst of the present embodiment, from the point of view of metal oxide-forming elements in the Mo-Bi metal oxide system, Mo, Bi, Ce, and Fe necessarily exist. The atomic ratio of a bismuth to 12 molybdenum atoms is 2≤a≤6. From the point of view of further improving the selectivity of the desired product, the atomic ratio a is 2 ≤ a и 5, and more preferably 2. A 4 4. From the same point of view, the atomic ratio d of cesium is 0.5 d d 6 6, preferably 1 d d 5 5, and more preferably 1 d d 4 4. Bi and Mo similarly form complex oxides, such as Bi ₂ Mo ₃ O ₁₂ and Bi ₂ Mo ₃ O ₆ , which are active particles in gas-phase catalytic oxidation and ammoxidation reactions or the like. and have high catalytic activity. However, Bi and Mo have a low melting point and low heat resistance. However, it is difficult for Ce and Mo to form a complex oxide such as Ce ₂ Mo ₃ O ₁₂ . However, Ce and Mo have a high melting point and high heat resistance. If both, respectively, are oxide-forming, a Co-Di-Mo-O complex oxide system is formed, which has a complex structure, where Bi is solid-soluble in Ce ₂ Mo ₃ O ₁₂ having high heat resistance and has high activity and heat resistance.

From the point of view of improving catalytic activity without reducing the selectivity of the desired product, Fe is an indispensable element in order to industrially synthesize in both Mo and Bi. However, when the Fe content increases, Fe ₂ O _{3 is formed} and subsequent oxides, such as CO and CO ₂ , tend to increase. As a result, the selectivity of the desired product is reduced. In some cases, even if the Fe content increases, Fe ₂ O ₃ does not form. However, a complex oxide of the bicomponent Fe-Mo-O system is formed at this time. It is an inactive component that does not show catalytic activity. Therefore, usually the atomic ratio of iron to 12 molybdenum atoms is usually set at 0 <Fe≤2.5, in order to show a high yield. There is no intention of increasing the atomic ratio of Fe to 2.5 or more to form an effective crystalline phase. Meanwhile, the authors of the present invention found that the crystal structure with high characteristics of the four-component system Ce-Bi-Fe-Mo-O is formed with an increase not only in the content of Fe, but also in the content of Bi and Ce in the composition region beyond the upper limit of the atomic ratio Fe that is traditional general knowledge. The inventors of the present invention suggest that an oxide catalyst having a crystal of the Ce-Bi-Fe-Mo-O system gives a high yield of the desired product because the Mo-O bond energy of the Bi-O-Mo bond of a complex oxide such as Bi ₂ Mo ₃ O ₁₂ and Bi ₂ Mo ₃ O ₆ , as active particles, is suitable. The atomic ratio of iron b to 12 atoms of the molybdenum oxide catalyst according to the present embodiment is 2.5 <b≤5, preferably 2.5 <b≤4.5 and more preferably 2.5 <b≤4.

In the oxide catalyst according to the present embodiment, Co is an essential element for industrial synthesis of the desired product, as in Mo, Bi and Fe. Co forms a complex oxide CoMoO ₄ . Co serves as a carrier for highly dispersed active particles, such as Bi-Mo-O, and serves to introduce oxygen from the gas phase and supply it to Bi-Mo-O or the like. In order to obtain an unsaturated aldehyde in high yield, it is necessary to combine Co with Mo to form the complex oxide CoMoO ₄ . From the point of view of reducing the formation of a one-component oxide, such as Co ₃ O ₄ and CoO, the atomic ratio of cobalt to 12 molybdenum atoms is 2 с s ≤ 8, preferably 2.5 с s 6 6, more preferably 2.5 с s 4 4 . From the point of view of improving the activity of the catalyst, the atomic ratio b / c iron / cobalt is 0.4≤b / c≤2.5, preferably 0.7≤b / c≤2.0 and more preferably 1≤b / c≤1 ,5.

The oxide catalyst according to the present embodiment preferably has a composition represented by the following formula of composition (1):

Mo ₁₂ Bi _a Fe _b Co _c Ce _d A _e B _f O _g (1),

in which Mo represents molybdenum, Bi represents bismuth, Fe represents iron, Co represents cobalt, Ce represents cerium, A represents at least one element selected from the group consisting of cesium and rubidium, B represents at least one element selected from the group consisting of copper, nickel, magnesium and lead, af represents the atomic ratio of each of the elements to 12 Mo atoms; satisfy the values 2≤a≤6, 2,5 <b≤5, 2≤s≤8, 0,4≤b / c≤2,5, 0,5≤d≤6, 0,01≤е≤2 and 0≤f <2, and g is the number of oxygen atoms, determined by the valency of the constituent element other than oxygen.

In the above formula of composition (1), A represents cesium and / or rubidium, and it is believed that A plays the role of neutralizing the acidic region of MoO ₃ or the like, which does not form a complex, as a catalyst for producing an unsaturated aldehyde. When cesium and / or rubidium is / is contained, this does not affect the crystal structure of Ce-Bi-Fe-Mo-O described below. The atomic ratios of these elements to 12 Mo atoms are 0.01 ≤ e ≤ 2 in terms of catalytic activity. The atomic ratio e of element A is controlled in the indicated numerical range, since the catalyst is the main one when the amount of alkaline element increases to an interval or more, and the olefin or alcohol is hardly adsorbed on the catalyst as a starting material, which tends to block a sufficient manifestation of catalytic activity.

B represents at least one element selected from the group consisting of copper, nickel, magnesium and lead. It is believed that the element partially replaces cobalt in the oxide. Copper plays the role of improving catalyst activity. However, from the point of view of maintaining equilibrium with the formation of a Ce-Bi-Fe-Mo-O crystal showing the characteristics of the catalyst, the upper limit of the atomic ratio f of element B is preferably f <2. When the atomic ratio is f <2, nickel, magnesium and lead play the role of stabilizing the crystal structure of CoMoO ₄ with suppression of the phase transition or the like. according to pressure and temperature. Since the element represented by B improves the activity of the catalyst or stabilizes the crystal structure of CoMoO ₄ in the catalyst, the element does not affect the crystal structure of Ce-Bi-Fe-Mo-O and is positioned as an optional element whose content may be zero (f = 0).

Even if the elements represented by A and B are contained or not contained in the catalyst, a crystal structure is formed other than the crystal structure of Ce-Bi-Fe-Mo-O, and thus, the elements do not affect the crystal structure of Ce-Bi-Fe- Mo-O.

An oxide catalyst having a composition represented by the above composition formula (1) is characterized in that the selectivity of the unsaturated aldehyde is high. The oxide catalyst is suitably used in the first reaction step of the direct meta process. Since the product of the subsequent oxidation is an unsaturated carboxylic acid in the direct oxidation method, the direct oxidation method has a small characteristic of reducing methacrylic acid in the step of producing an unsaturated aldehyde as an intermediate. Thus, since the total yield of methacrolein and methacrylic acid is higher, it can be said that a catalyst is desirable. However, since the direct meta method forms an unsaturated aldehyde in the first reaction step and therefore forms an unsaturated carboxylic acid ester from the unsaturated aldehyde in the second reaction step, the step of forming an unsaturated carboxylic acid as the desired product does not exist. Therefore, in an oxidation method with a complex oxide catalyst, only unsaturated aldehyde is preferably formed, and the formation of an unsaturated carboxylic acid is desirably suppressed. That is, when the goal is to optimize the catalyst for the first reaction step of the direct meta-method, a catalyst is required that has a specific directional difference from the catalyst for the direct oxidation method, which provides a high yield of unsaturated aldehyde as the desired product and low yield of unsaturated carboxylic acid as a subsequent oxide.

(2) Crystal structure

When the X-ray diffraction range of 2θ = 5-60 ° is determined by X-ray diffraction (XRD), an oxide containing only cerium and molybdenum shows a peak at 33.50 °. If iron and bismuth additionally form a complex oxide with an oxide containing only cerium and molybdenum, a peak shift occurs. Since the oxide catalyst according to the present embodiment contains an oxide containing cerium and molybdenum and a metal obtained by complexing iron with bismuth, the oxide catalyst shows a peak not at 33.50 °, but at 33.50 ° + α ° (0 <α) .

When according to the formula of Bragg's law ("Kotai Hyoumen Kyarakutarizeshon no Jissai (Actual Condinions of Solid Surface Characterization)", edited by Yasuhiro Tanaka and Hiromi Yamashita, pages 13-25, Kodansha Scientific, Ltd.) the parameter d between the surfaces of the crystal, the angle the incidence and angle of reflection θ of X-rays on the crystal surface and the wavelength λ have the dependence of formula (II):

2dsinθ = nλ (n: integer) (II),

those. when the path difference between the incident and scattered X-rays is equal to a multiple of the integral wavelength of the incident X-rays, a diffraction phenomenon is observed. In the present embodiment, primary reflection is established and diffraction is established that satisfies the reflection condition n = 1. For example, when an element solidly dissolves upon substitution of a complex oxide in a multicomponent system and the x-ray diffraction angle (2θ) shifts to lower angles, the parameter d is in a state of divergence. When the x-ray diffraction angle (2θ) shifts toward higher angles, the parameter d is in a shortened state. For this reason, the shift of the peak that appears at 33.50 ° in the XDR towards higher angles (0 <α) means a change in the parameter d to the state of the parameter d of the oxide, which is shortened during the complexation of metals.

The degree of change in the parameter d can be represented by the following formula (III):

The degree of change d (ppm) = (d ⁰ -d ¹ ) / d ⁰ × 1,000,000 (III),

in which d ⁰ is a parameter of a complex cerium oxide and molybdenum showing a peak at 33.50 °, and d ¹ is a parameter of an oxide catalyst according to the present embodiment. In the oxide catalyst according to the present embodiment, the degree of change in the parameter d is 5000-9000 ppm. Since an oxide catalyst close to the two-component system of cerium and molybdenum is contained when the degree of change in the parameter d is less than 5000, the oxide catalyst has a high oxidizing ability, and when the oxide catalyst is used as a catalyst, the yield of the subsequent oxide increases. Meanwhile, when the degree of change in the parameter d is more than 9000, the activity decreases. From the point of view of obtaining the desired product with high activity and high yield, the degree of change in parameter d is more preferably 5500-8500 ppm and even more preferably 6000-8000 ppm.

The mechanism by which the parameter d changes is not clear. However, it is believed that this is due to additional solid dissolution of Fe in the complex oxide Ce, Bi, and Mo with the formation of a newly crystalline structure with high characteristics of the complex oxide four-component system Ce-Bi-Fe-Mo-O. A method of producing a catalyst for dispersing and complexing Bi or the like will be described in detail below. However, an excess ratio of the metal is also important in order to form such a crystalline structure. When the atomic ratio b of iron to 12 Mo atoms satisfies an interval of 2.5 <b≤5, a crystalline structure is formed. However, when the atomic ratio b is <2.5, the crystalline structure does not form, or even when the crystalline structure is formed, the amount of the crystalline structure is extremely small, and it is difficult for the obtained oxide catalyst to suppress the formation of the subsequent oxide. That is, when the atomic ratio b is b≤2.5, the yield of the subsequent oxide increases. When the atomic ratio b is b> 5, the yield of CO _x (CO ₂ and CO or the like) increases. As a result, the performance of the desired product is reduced.

As an indicator of the complexation of Ce-Bi-Fe-Mo-O, a shift of 33.50 ° is desirably taken as a reference. However, the effect caused by complexation also occurs for other peaks. The oxide catalyst according to the present embodiment has peaks at x-ray diffraction angles (2θ) of 28.17 ° ± 0.05 °, 33.50 ° ± α ° and 25.44 ° ± 0.05 ° in decreasing order of intensity. Among them, the peaks at 28.17 ° ± 0.05 ° and 33.50 ° ± α ° mainly come from Ce-Mo-O, and the peak at 25.44 ° ± 0.05 ° comes mainly from Co-Mo -ABOUT. From the point of view of suppressing the formation of subsequent oxide, the intensity of each of the peaks is preferably reduced according to the above order.

So for the peak of the x-ray diffraction angle (2θ) = 33.50 ° + α ° α represents the peak shift from 33.50 °. When the shear rate d is 5000-9000 ppm, 0.10 ° ≤α≤0.25 ° is set.

(3) Components other than metal oxide

The oxide catalyst for the oxidation reaction according to the present invention may contain a carrier for carrying metal oxide. A catalyst containing a carrier is preferred in that the catalyst provides high dispersion of the metal oxide and provides high wear resistance of the metal oxide on the carrier. Here, when the catalyst is extrusion molded, the catalyst preferably contains a carrier. However, when methacrolein is obtained in a fixed bed reactor and the catalyst is formed into tablets, the catalyst may not contain a carrier. Examples of a carrier may include, but are not limited to, silica, alumina, titanium dioxide, and zirconia. Typically, silicon dioxide itself is more inert than other carriers and has a good binding effect with metal oxide without compromising selectivity to the desired product, which is therefore the preferred carrier. In addition, a silica support is preferred because it likewise provides high wear resistance of the metal oxide on the support. When the catalyst is extrusion molded, the carrier content with respect to the entire catalyst is preferably 5-10% by weight.

Also, in the case of the catalyst used in the fluidized bed reactor, from the same point of view, as indicated above, silica is used as the support. From the point of view of optimizing the effect of Ce-Bi-Fe-Mo-O on the crystalline structure and apparent specific gravity with improved fluidity, the content of the carrier in the catalyst is preferably 80% by weight. or less with respect to the total weight of the catalyst, more preferably 70% of the mass. or less and even more preferably 60% of the mass. or less. In the case of a catalyst requiring strength for a fluidized-bed reactor or the like, from the point of view of showing practically sufficient crush resistance and wear resistance or the like, the carrier content in the catalyst is preferably 20% by weight. or more relative to the total weight of the catalyst, more preferably 30% of the mass. or more and even more preferably 40% of the mass. or more.

[2] A method for producing a catalyst for an oxidation reaction

As described above, the authors of the present invention have focused on the fact that it is not a single and / or two-component system of oxide Ct, Bi, Fe and Mo, but a complex oxide of the Ce-Bi-Fe-Mo-O system obtained by complexation of the four components, and comprehensively investigated the composition ratio and the method of its production.

Since Bi is an indispensable element for the formation of active particles with Mo, also called as a catalyst of the bismuth-molybdenum (Bi-Mo) system, from the point of view of activity, a large amount of Bi is preferred. However, when the Bi content increases, it is known that the catalyst is heterogeneous. For example, bismuth nitrate as a starting material Bi, which is traditionally used in industry, is a poorly soluble substance. Dissolution of bismuth nitrate requires a large amount of nitric acid. As a result, the catalyst composition after calcination is heterogeneous, and therefore, the conventional catalyst preparation technology has a limitation in increasing the Bi content. That is, a one-component oxide is formed, such as Bi ₂ O ₃ , and a homogeneous catalyst is not obtained, which adversely reduces the productivity of the desired product. From the point of view of improving catalytic activity without reducing the selectivity of the desired product, it has been recorded for many years that Fe is an indispensable element for the industrial synthesis of the desired product, as in the case of Mo and Bi. However, as indicated in International Publication No. WO 95/35273 (Pamphlet), a small amount of Fe is optimally introduced. When the Fe content increases, the formation of a subsequent oxide, such as CO and CO ₂ , tends to increase, which reduces the selectivity of the desired product.

As a result of many trial and error, in order to solve the problem, the authors of the present invention found that Ce is additionally introduced into the catalytic component containing Bi and Fe, more than usual in a catalyst containing a large amount of nitric acid, with the suppression of the formation of a single oxide during the first time, according to a new catalyst preparation technology, satisfying the three requirements of (a) a special ratio of components, (b) a method for ripening a special suspension of a metal salt, and (c) specifically method of calcination, and with the formation of the crystal Ce-Bi-Fe-Mo-O, obtained by complexation of four components. The required complexation does not occur only with an increase in bismuth nitrate and an increase in nitric acid. That is, the authors of the present invention found that the content of Bi and Fe increases in the catalyst containing a large amount of nitric acid, and Ce is additionally introduced into the catalyst to obtain a crystalline structure in which four components are combined, Ce-Bi-Fe-Mo- O at first.

That is, only when all three conditions (a) of the special ratio of the components, (b) of the ripening method of the special suspension of the metal salt and (c) of the special calcination method are satisfied, the crystal structure of the system combining the four components is formed, Ce-Bi-Fe- Mo-O, which gives a catalyst that provides a high yield of unsaturated aldehyde. When at least one of the three conditions is not satisfied, a complex oxide of a two-component system is formed, such as Ce-Mo-O, Bi-Mo-O and Fe-Mo-O, or a single oxide, such as Fe ₂ O ₃ , Bi ₂ O ₃ , MoO ₃ and CeO ₂ , and the interval of the degree of change of parameter d also occurs from the interval of 5000-9000 ppm, which results in a decrease in the yield of unsaturated aldehyde.

The oxide catalyst according to the present embodiment can be obtained by a method that comprises a first step for preparing a suspension of the starting material, a second step for spray drying the suspension of the starting material, and a third step for calcining the dried particles obtained in the second step. A preferred aspect of the process for producing an oxide catalyst having a first to third step is described below.

(1) Obtaining a suspension of starting material

In the first stage, the starting materials of the metal elements contained in the catalyst are mixed to obtain a suspension of the starting material. Examples of element sources for molybdenum, bismuth, series, iron, cobalt, rubidium, cesium, copper, nickel, magnesium and lead may include ammonium salt, nitrate salt, hydrochloride salt, organic acid salt, which are soluble in water or nitric acid. The source of the element may be an oxide, hydroxide, carbonate salt or the like. In the case of an oxide, a liquid dispersion is preferred in which the oxide is dispersed in water or in an organic solvent. An oxide dispersed in water is more preferred. When the oxide is dispersed in water in order to disperse the oxide, a dispersion stabilizer, such as a polymer, may be contained. The particle diameter of the oxide is preferably 1-500 nm and more preferably 10-80 nm. When a catalyst containing a carrier is prepared, silica sol is preferably introduced into the suspension of the starting material as the starting material of silicon dioxide.

From the point of view of homogeneous dispersion of the suspension, water-soluble polymers such as polyethylene glycol, methyl cellulose, polyvinyl alcohol, polyacrylic acid and polyacrylamide, multivalent carboxylic acids such as amines, aminocarboxylic acids, oxalic acid, malonic acid can also be respectively introduced into the suspension of the starting material. and succinic acid, and organic acids such as glycolic acid, malic acid, tartaric acid, and citric acid. The amount of organic acid introduced is not specifically limited. However, from the point of view of the balance between homogeneity and the amount obtained, the organic acid is preferably introduced in the range of 0-30% of the mass. in relation to the mass of metal oxide.

The method for preparing a suspension of the starting material is not particularly limited if the method is a method that is commonly used. For example, a suspension of the starting material can be obtained by mixing a solution in which the molybdenum ammonium salt is dissolved in hot water, with a solution obtained using bismuth, cerium, iron, cobalt or an alkali metal as a nitrate salt, and dissolving the nitrate salt in water or in aqueous solution of nitric acid. From the point of view of the balance between homogeneity and the amount obtained, the concentration of the metal element in the suspension after mixing is usually 1-50% by weight, preferably 10-40% by weight. and more preferably 20-40% of the mass.

When the ammonium salt and nitrate salt are mixed, a precipitate is formed, and probably with the formation of a suspension. However, the suspension of the starting material preferably matures in a state where the suspension of the starting material is suspended. As used herein, “ripening” means that the suspension is maintained in a state where the suspension of the starting material is suspended. Preferably, the suspension is continuously and / or periodically mixed in order to suspend the suspension. At this stage of mixing, the contained solid is crushed, which contributes to the formation of a catalyst precursor, which can form a suspension that is finer and more homogeneous. When the Bi content increases, a susceptible slurry is formed containing a large amount of nitric acid and having low dispersibility, and therefore, maturation is particularly preferably performed.

When the suspension has matured, the suspension is desirably heated to a temperature that is higher than room temperature and at which the suspension medium remains liquid in order to obtain the desired complex crystal and / or its precursor. In particular, the temperature is preferably 20-90 ° C, more preferably 30-80 ° C, and even more preferably 50-70 ° C. A conventional mixing device, such as a mixing paddle and a stirring bar, can be used to mix the suspension. Mixing speed varies depending on the viscosity of the suspension or the like. and is preferably 50-3000 rpm. The ripening time required for the formation of the catalyst precursor is different depending on the temperature and mixing energy of the suspension. When the temperature is high or the stirring energy is large, a suitable ripening time tends to be shortened. For example, when the temperature of the suspension is 20-90 ° C. and the stirring operation is performed using a stirrer, the ripening time is preferably 1-24 hours, in terms of productivity, more preferably 1-20 hours and even more preferably 1-10 hours

In the case of a suspension containing a large amount of dry matter, the dry matter in the suspension is preferably ground using a homogenizer or the like. before ripening. When the suspension has a composition having an increased Bi content, as described above, the nitric acid content of the suspension tends to be also increased and the dispersibility is prone to decrease. Therefore, homogenizing treatment is particularly effective. From the point of view of further fine grinding the dry matter, the speed of the homogenizer is preferably 5000-30000 rpm, more preferably 10000-20000 rpm and even more preferably 15000-20000 rpm. The processing time by the homogenizer is different depending on the number of revolutions or the amount of dry matter. Preferably, the time is usually from 5 minutes to 2 hours

When the suspension of the starting material is not homogeneous, the catalyst composition after calcination is heterogeneous and it is difficult to form a homogeneous complex crystal structure. Therefore, when the obtained oxide is not sufficiently complexed, the step for preparing the suspension is preferably optimized. The above step of preparing a suspension of the starting material is an example and is not limited. The methodology for introducing sources of elements can be changed; nitric acid concentration can be adjusted; or ammonia water may be introduced into the suspension to change the pH and viscosity of the suspension. It is important to form a homogeneous suspension in order to form a more crystalline structure of Ce-Bi-Fe-Mo-O. From this point of view, the pH of the suspension of the starting material is preferably 2.0 or less. The pH of the suspension of the starting material is more preferably 1.5 or less, and even more preferably 1.0 or less. When the pH of the suspension of the starting material is greater than 2.0, a precipitate of the bismuth compound may form, preventing the formation of the crystal structure of Ce-Bi-Fe-Mo-O.

(2) Drying

In the second stage, the suspension of the starting material obtained in the first stage is dried to obtain dried particles. The drying method is not particularly limited, and the drying can be performed in a manner that is commonly used. The drying method can be carried out by any method, such as a method of drying by evaporation, a method of spray drying and a method of drying under reduced pressure. The spray drying method can be carried out by a centrifugal type method, a type with a two-fluid nozzle and a type with a high-pressure nozzle, which is usually carried out in industry. Air heated by steam and an electric heater or the like is preferably used as a drying heat source. In this case, the inlet temperature of the spray dryer is usually 150-400 ° C, preferably 180-400 ° C, and more preferably 200-350 ° C.

(3) Calcination

In the third stage, the dried particles obtained in the second stage are calcined. Calcination can be carried out using a calcination furnace such as a rotary kiln, a tunnel kiln and a muffle furnace. The dried particles are preferably calcined in two stages of preliminary calcination and final calcination. In the first stage, pre-calcination is usually carried out in the temperature range 120-350 ° C, preferably 150-350 ° C and more preferably 200-350 ° C. The purpose of the preliminary calcination is to remove the nitric acid remaining in the dried particles, and to gradually burn out the ammonium nitrate and the contained organic substances originating from the starting material, which is the ammonium salt, and the starting material, which is the nitrate salt. Therefore, the dried particles can be heated to such an extent that the goal can be achieved in the first calcination step. The pre-calcination time is usually 0.1-72 hours, preferably 1-48 hours, and more preferably 3-24 hours. In the case of a low temperature of 150 ° C or lower, the preliminary calcination is carried out for a long period of time. In the case of a high temperature of 330 ° C or higher, pre-calcination is preferably carried out for a short period of time of 2 hours or less. When the pre-calcination temperature is too high or the time is too long, the oxide probably grows only in the two-component system of cerium and molybdenum in the pre-calcination stage, and as a result, the formation of the Ce-Bi-Fe-Mo-O crystal structure formed in the stage final calcination described below. Therefore, the upper limits of the temperature and time of preliminary calcination are set to such an extent that oxide of a two-component system of cerium and molybdenum is not formed.

In the case of pre-calcination, the rate of temperature increase is preferably slow also in terms of suppressing a quick combustion reaction. The oxide catalyst in the present embodiment is a multicomponent system. Therefore, for example, when metal nitrates are used as starting materials, the decomposition temperatures of metal nitrates are different from each other, and nitric acid is removed during the calcination, and therefore, the catalyst composition after calcination is prone to be heterogeneous. In particular, when the Bi content increases, the amount of bismuth nitrate, which is hardly soluble in water, increases, which increases the amount of nitric acid used for dissolution. For this reason, in order to form a structure that is more homogeneous, preferably the temperature rises slowly to remove components of combustion and decomposition, such as nitric acid and organic matter. The rate of temperature increase is usually 0.1-100 ° C / min, more preferably 0.1-75 ° C / min, and even more preferably 0.1-50 ° C / min.

After the preliminary calcination, the final calcination is preferably carried out in the form of a second stage. However, the goal is to facilitate the formation of the desired crystalline structure. Since the crystal structure is affected by the product of the calcination temperature and the calcination time, as established by the authors of the present invention, preferably, the calcination temperature and the calcination time are set accordingly. The final calcination temperature is preferably set higher than the preliminary calcination temperature at 700 ° C. or lower from the viewpoint of the formation of a Ce-Bi-Fe-Mo-O crystal. From the point of view of facilitating the formation of the Ce-Bi-Fe-Mo-O crystal structure, the calcination temperature of the final calcination is preferably 400-700 ° C, more preferably 400-650 ° C and even more preferably 450-600 ° C. From the point of view of optimizing the product of the calcination temperature and the calcination time, in order to promote the formation of a crystal when calcination is carried out at such a temperature, the final calcination time is usually 0.1-72 hours, preferably 2-48 hours and more preferably 3-24 hours. optimization view (calcination temperature) × (calcination time) to form a crystalline structure in the case of a low temperature of 400 ° C or lower, for example, the final calcination is preferably carried out over a length of nogo period of about 24-72 hours. In the case of high temperature of 600 ° C or higher, from the viewpoint of preventing a decrease in catalyst activity due to the excessive reduction of the surface area, the final calcination is preferably carried out in a short period of time of 1 h or less.

The crystal structure of the complex four-component Ce-Bi-Fe-Mo-O system is likely to form when all of the above steps are performed.

The formation of the crystal structure of the four-component Ce-Bi-Fe-Mo-O system at the stage of final calcination can be confirmed by X-ray diffraction analysis after the final calcination. If the crystal structure of the four-component system Ce-Bi-Fe-Mo-O is formed, then when the X-ray diffraction analysis is carried out after the final calcination, a peak is observed at 33.50 ° + α °. When an oxide crystal is formed containing only cerium and molybdenum, a peak appears at 33.50 °. However, in the case of a four-component Ce-Bi-Fe-Mo-O system, the peak is shifted and therefore crystal formation of the four-component system can be confirmed by using a shift as an indicator.

The shear value (α °) was investigated, and the parameter d of complex cerium oxide and molybdenum, showing a peak at 33.50 °, is taken as a reference. The level of change d is investigated using the following formulas:

2dsin θ = nλ (n: integer) (Ii) The degree of change d (ppm) = (d ⁰ -d ¹ ) / d ⁰ × 1,000,000 (III)

If the level of change in d is 5000-9000 ppm in the present embodiment, the crystal structure of the four-component Ce-Bi-Fe-Mo-O system is considered to be formed.

[3] A method for producing an unsaturated aldehyde

Unsaturated aldehyde can be obtained by using the oxide catalyst according to the present embodiment and by oxidizing at least one olefin selected from the group consisting of propylene and isobutylene and / or tert-butyl alcohol. A separate example will be described below. However, the production method according to the present embodiment is not limited to the following separate example.

(1) Method for the production of methacrolein

Methacrolein can be obtained, for example, by exposing isobutylene or tert-butyl alcohol to a gas-phase catalytic oxidation reaction using an oxide catalyst according to the present embodiment. In a gas-phase catalytic oxidation reaction, a gaseous feed material containing a mixed gas to which a gas containing molecular oxygen and a diluent gas are added is introduced into the catalytic bed in a fixed-bed reactor such that the concentration of molecular oxygen in isobutylene, tert-butyl alcohol or mixed gas their 1-10% vol. is 1-20% vol. The concentration of isobutylene or tert-butyl alcohol is usually 1-10% vol., Preferably 6-10% vol. and more preferably 7-9% vol. The reaction temperature is 300-480 ° C, preferably 350-450 ° C, and more preferably 400-450 ° C. The pressure is a normal pressure of up to 5 kg / cm ² and a gaseous feed can be introduced at a spatial speed of 400-4000 h ^-1 (under normal temperature / pressure (NTP)). From the point of view of controlling the concentration of oxygen at the outlet of the reactor, in order to improve the yield of unsaturated aldehyde, the molar ratio of oxygen to isobutylene or tert-butyl alcohol or their mixed gas is usually 1.0-2.0, preferably 1.1-1, 8 and more preferably 1.2-1.8.

Examples of a gas containing molecular oxygen may include gases containing molecular oxygen, such as pure oxygen gas, N ₂ O, or air. From an industrial point of view, air is preferred. Examples of diluent gas may include nitrogen, carbon dioxide, water vapor, and their mixed gas. As the mixing ratio of the molecular oxygen-containing gas and the diluent gas in the mixed gas, the condition 0.01 <molecular oxygen / ((molecular oxygen-containing gas) + diluent gas) <0.3 in a volume ratio is preferably satisfied. In addition, the concentration of molecular oxygen in the starting material is preferably 1-20% vol.

Water vapor in the gaseous starting material is required in terms of preventing coking of the catalyst. However, the concentration of water vapor in the diluent gas is preferably reduced as low as possible in order to suppress the post-formation of a carboxylic acid such as methacrylic acid and acetic acid. Water vapor in a gaseous feed is typically used in the range of 0-30% by volume.

(2) Method for producing acrolein

When acrolein is obtained by gas phase catalytic oxidation of propylene, a condition or the like. not specifically limited. Acrolein can be obtained by the method commonly used when acrolein is obtained by gas-phase catalytic oxidation of propylene. For example, a mixed gas containing 1-15% vol. propylene, 3-30% vol. molecular oxygen, 0-60% vol. water vapor and 20-80% vol. an inert gas, such as nitrogen and gaseous carbon dioxide or the like, can be introduced into the catalytic layer of the reactor at 250-450 ° C, a pressure of 0.1-1 MPa and a spatial velocity (SV) of 300-5000 h ^-1 . As a reactor, a fixed bed reactor, a fluidized bed reactor or a moving bed reactor are typically used.

Examples

Further, this option will be further described in detail with reference to examples. However, the present embodiment is not limited to the examples described below. The atomic ratio of oxygen atoms in the oxide catalyst is determined depending on the valence conditions of other elements. Therefore, in the examples and comparative examples, the atomic ratio of oxygen atoms is omitted in the formula representing the catalytic composition. The ratios of the elements of the composition of the oxide catalyst are calculated by the ratio of the charges of the composition.

X-ray diffraction angle determination

The XRD study determines the (111) plane and (200) plane of the LaB ₆ compound, defined as the standard reference substance 660 by the National Institute of Standards and Technology. Values are converted to 37.441 ° and 43.506 °, respectively.

The DS ADVANCE device (manufacturer - Bruker Corporation) is used as an XDR device. The established parameters of the XDR tests are: X-ray output: 40 kV - 49 mA, discrepancy gap (DS): 0.3 °, step width: 0.02 ° / step, counting time: 2.0 s and measurement interval: 2θ = 5-60 °.

In the examples and comparative examples, the degree of conversion, selectivity and yield used to show the reaction results are determined by the following formulas:

The degree of conversion = (number of moles of reacted starting material / number of moles of supplied starting material) × 100

Selectivity = (number of moles of compound formed / number of moles of reacted starting material) × 100

Yield = (number of moles of compound formed / number of moles of feed) × 100

The productivity of the desired product is determined according to the following formula by calculating the amount of the desired product formed per 1 ton of each of the catalysts, and then assuming that a continuous operation is performed using 10 tons of catalyst for 8000 hours.

Productivity (t) = ({number of moles (mol / h) of feed per hour × yield / amount (t) of catalyst} × 10 (t) × 8000 (h) / molecular weight of the desired product

Example 1

65.7 g of ammonium heptamolybdate are dissolved in 197.0 g of hot water at a temperature of about 90 ° C (liquid A). 43.8 g of bismuth nitrate, 25.5 g of cerium nitrate, 36.4 g of iron nitrate, 0.66 g of cesium nitrate and 34.5 g of cobalt nitrate are dissolved in 42.4 g of 18% of the mass. an aqueous solution of nitric acid and 205.0 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The treated mixture is then ripened with continuous stirring using a magnetic stirrer at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C / min from room temperature and the catalyst precursor was preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 530 ° C for 8 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a jacketed stainless steel tubular reactor having a diameter of 14 mm was filled with 4.0 g of catalyst. Mixed gas containing 8% vol. isobutylene, 12.8% vol. oxygen, 3.0% vol. water vapor and 76.2% vol. nitrogen, saturated with air at a flow rate of 120 ml / min (NTP) at a reaction temperature of 430 ° C with the implementation of the methacrolein synthesis reaction. The results of the reaction assessment are shown in table 3.

Example 2

68.8 g of ammonium heptamolybdate are dissolved in 206.3 g of hot water at a temperature of about 90 ° C (liquid A). 33.2 g of bismuth nitrate, 29.6 g of cerium nitrate, 44.7 g of iron nitrate, 0.57 g of cesium nitrate and 32.3 g of cobalt nitrate are dissolved in 42.6 g of 18% of the mass. an aqueous solution of nitric acid and 196.2 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C./min from room temperature, and the catalyst precursor was preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 520 ° C. for 14 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2. X-ray diffraction patterns are presented. s in figures 1 and 2. The analysis is carried out using the STEM-EDX method (scanning transmission electron microscopy - energy dispersive x-ray spectroscopy) of the Bi-enriched phase of the catalyst. As a result, if the atomic ratio of Bi is defined as 1, the atomic ratio of Ce is 0.32, the atomic ratio of Fe is 0.16, the atomic ratio of Mo is 1.1. Ce, Fe, and Mo exist in a region in which a large number of Bi exists, and the crystal structure of the four-component Ce-Bi-Fe-Mo-O system is formed.

To assess the reactivity of the catalyst, a tubular reactor was filled with 3.5 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 3

67.4 g of ammonium heptamolybdate are dissolved in 202.3 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 50.3 g of iron nitrate, 0.56 g of cesium nitrate and 28.0 g of cobalt nitrate are dissolved in 42.7 g of 18% of the mass. an aqueous solution of nitric acid and 201.5 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 540 ° C. for 3 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tubular reactor was filled with 3.5 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 4

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C / min from room temperature and the catalyst precursor was preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 530 ° C for 8 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tubular reactor was filled with 3.5 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 5

67.2 g of ammonium heptamolybdate are dissolved in 201.6 g of hot water at a temperature of about 90 ° C (liquid A). 40.2 g of bismuth nitrate, 23.4 g of cerium nitrate, 60.4 g of iron nitrate, 0.55 g of cesium nitrate, 18.6 g of cobalt nitrate and 1.0 g of lead nitrate are dissolved in 37.9 g of 18% of the mass . an aqueous solution of nitric acid and 203.9 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the resulting spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C./min from room temperature, and the catalyst precursor was preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 540 ° C. for 5 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 3.6 g of catalyst was filled in the tubular reactor, and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Example 6

66.2 g of ammonium heptamolybdate are dissolved in 198.56 g of hot water at a temperature of about 90 ° C (liquid A). 39.6 g of bismuth nitrate, 23.0 g of cerium nitrate, 59.5 g of iron nitrate, 0.36 g of cesium nitrate, 18.3 g of cobalt nitrate and 9.1 g of nickel nitrate are dissolved in 38.4 g of 18% of the mass . an aqueous solution of nitric acid and 210.0 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C./min from room temperature, and the catalyst precursor was preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 520 ° C. for 14 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tube reactor was filled with 3.0 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 7

67.4 g of ammonium heptamolybdate are dissolved in 202.1 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.4 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate, 22.3 g of cobalt nitrate and 1.5 g of copper nitrate are dissolved in 37.9 g of 18% of the mass . an aqueous solution of nitric acid and 203.1 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the resulting spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor was preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 550 ° C. for 3 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a 3.2 g catalyst was filled in the tubular reactor, and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Example 8

67.0 g of ammonium heptamolybdate are dissolved in 202.1 g of hot water at a temperature of about 90 ° C (liquid A). 44.7 g of bismuth nitrate, 26.1 g of cerium nitrate, 37.2 g of iron nitrate, 0.51 g of rubidium nitrate, 18.5 g of cobalt nitrate and 14.6 g of magnesium nitrate are dissolved in 37.7 g of 18% of the mass . an aqueous solution of nitric acid and 203.1 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 540 ° C. for 3 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tubular reactor was filled with 3.1 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 9

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the resulting spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor was preliminarily calcined at 150 ° C. for 36 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 520 ° C. for 8 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 3.9 g of catalyst is filled in the tubular reactor and the methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Example 10

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 75 ° C / min from room temperature, and the catalyst precursor was preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 530 ° C for 4 hours. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 3.9 g of catalyst is filled in the tubular reactor and the methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Example 11

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 400 ° C. for 48 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a 3.2 g catalyst was filled in the tubular reactor, and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Example 12

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The suspension is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 640 ° C. for 30 min The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a 5.4 g catalyst was filled in the tubular reactor, and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Example 13

The same catalyst was used as in Example 3. To evaluate the reactivity of the catalyst, 6.4 g of catalyst was filled in the tubular reactor and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1, except that the reaction temperature was changed to 400 ° C. The results of the reaction assessment are shown in table 3.

Example 14

The same catalyst was used as in Example 3. To evaluate the reactivity of the catalyst, 3.0 g of catalyst was filled in the tubular reactor and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1, except that the reaction temperature was changed to 460 ° C. The results of the reaction assessment are shown in table 3.

Example 15

69.5 g of ammonium heptamolybdate are dissolved in 208.5 g of hot water at a temperature of about 90 ° C (liquid A). 32.0 g of bismuth nitrate, 7.2 g of cerium nitrate, 39.9 g of iron nitrate, 1.3 g of cesium nitrate, 43.2 g of cobalt nitrate and 24.2 g of nickel nitrate are dissolved in 38.3 g of 18% of the mass . an aqueous solution of nitric acid and 208.5 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The treated mixture is then ripened with stirring and mixing at a temperature of about 60 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 280 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 550 ° C. for 10 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 4.0 g of the catalyst was filled in the tubular reactor and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 16

Both liquid A and liquid B are mixed into the same composition as in example 1, and the mixture is ripened with continuous stirring using a magnetic stirrer at a temperature of about 65 ° C for about 1 hour without performing a homogenizer treatment to obtain a suspension of the starting material . A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C / min from room temperature and the catalyst precursor was preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 530 ° C for 8 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 4.0 g of the catalyst was filled in the tubular reactor and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 17

Both liquid A and liquid B are mixed into the same composition as in example 1, and the mixture is ripened with continuous stirring using a magnetic stirrer at a temperature of about 65 ° C for about 24 hours without performing homogenizing treatment to obtain a suspension of the starting material . A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C / min from room temperature and the catalyst precursor was preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 530 ° C for 8 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 4.0 g of the catalyst was filled in the tubular reactor and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Example 18

The same catalyst was used as in Example 1, and to evaluate the reactivity of the catalyst, 4.5 g of catalyst was filled in the tubular reactor, and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1, except that the reaction temperature was set at 350 ° C. The results of the reaction assessment are shown in table 3.

Example 19

The same catalyst was used as in Example 1, and to assess the reactivity of the catalyst, 4.0 g of catalyst was filled in the tubular reactor, and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1, except that the reaction temperature was set at 480 ° C. The results of the reaction assessment are shown in table 3.

Example 20

The same catalyst was used as in Example 1, and 4.0 g of catalyst was filled in the tubular reactor to evaluate the reactivity of the catalyst. Mixed gas containing 6% vol. isobutylene, 9.6% oxygen, 3.0% vol. water vapor and 81.4% vol. nitrogen, saturated with air at a flow rate of 100 ml / min (NTP) at a reaction temperature of 430 ° C with the implementation of the synthesis reaction of methacrolein. The results of the reaction assessment are shown in table 3.

Example 21

The same catalyst was used as in Example 1, and 4.0 g of catalyst was filled in the tubular reactor to evaluate the reactivity of the catalyst. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 20, except that the reaction temperature is set at 350 ° C. The results of the reaction assessment are shown in table 3.

Comparative Example 1

72.8 g of ammonium heptamolybdate are dissolved in 218.4 g of hot water at a temperature of about 90 ° C (liquid A). 26.8 g of bismuth nitrate, 7.5 g of cerium nitrate, 19.5 g of iron nitrate, 2.0 g of cesium nitrate and 79.5 g of cobalt nitrate are dissolved in 42.1 g of 18% of the mass. an aqueous solution of nitric acid and 177.8 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The treated mixture is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 520 ° C. for 5 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2. X-ray diffraction patterns are presented. in Figures 1 and 2.

STEM-EDX analysis of the Bi-rich phase of the catalyst is carried out. As a result, if the atomic ratio of Bi is defined as 1, the atomic ratio of Ce is 0.07, the atomic ratio of Fe is 0.06, and the atomic ratio of Mo is 1.1. The content of Ce, Fe to Bi is lower than in Example 2, and a two-component Bi-Mo-O system is formed. The amount of the four-component crystal structure Ce-Bi-Fe-Mo-O formed is small.

To assess the reactivity of the catalyst, a tube reactor is filled with 4.2 g of catalyst and the methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Reference Example 2

66.0 g of ammonium heptamolybdate are dissolved in 197.9 g of hot water at a temperature of about 90 ° C (liquid A). 39.5 g of bismuth nitrate, 23.0 g of cerium nitrate, 75.7 g of iron nitrate, 0.54 g of cesium nitrate and 15.5 g of cobalt nitrate are dissolved in 42.1 g of 18% of the mass. an aqueous solution of nitric acid and 214.4 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The treated mixture is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C / min from room temperature, and the catalyst precursor is preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 540 ° C for 5 hours. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tube reactor was filled with 4.3 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Reference Example 3

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed to form a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the resulting spray dried catalyst precursor was further increased with a temperature rise rate of 1.4 ° C./min from room temperature, and the catalyst precursor was preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor was calcined finally at 540 ° C. for 5 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tube reactor was filled with 4.6 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Reference Example 4

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The treated mixture is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 105 ° C. for 12 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 530 ° C. for 8 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 4.9 g of catalyst is filled in the tubular reactor and the methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Reference Example 5

67.4 g of ammonium heptamolybdate are dissolved in 202.2 g of hot water at a temperature of about 90 ° C (liquid A). 40.3 g of bismuth nitrate, 23.5 g of cerium nitrate, 55.4 g of iron nitrate, 0.56 g of cesium nitrate and 24.2 g of cobalt nitrate are dissolved in 42.9 g of 18% of the mass. an aqueous solution of nitric acid and 202.7 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. The treated mixture is then ripened with stirring and mixing at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C / min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 720 ° C for 30 min The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tube reactor was filled with 5.9 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Reference Example 6

The catalyst was prepared in the same manner as in Example 15, except that the suspension of the starting material was not ripened. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, a tubular reactor was filled with 4.5 g of catalyst and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The results of the reaction assessment are shown in Table 3.

Reference Example 7

The catalyst is obtained in the same manner as in example 1, except that the suspension of the starting material is not subjected to maturation. Using the obtained catalyst, and to evaluate the reactivity of the catalyst, 4.0 g of catalyst was filled in the tubular reactor. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Reference Example 8

The catalyst is obtained in the same manner as in example 1, except that the suspension of the starting material is not subjected to maturation. The resulting catalyst was used and 5.0 g of catalyst were filled in to the tube reactor to evaluate the reactivity of the catalyst. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 18. The reaction evaluation results are shown in Table 3.

Reference Example 9

The catalyst is obtained in the same manner as in example 1, except that the suspension of the starting material is not subjected to maturation. Using the obtained catalyst, and to evaluate the reactivity of the catalyst, 4.0 g of catalyst was filled in the tubular reactor. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 19. The reaction evaluation results are shown in Table 3.

Reference Example 10

The catalyst is obtained in the same manner as in example 1, except that the suspension of the starting material is not subjected to maturation. The resulting catalyst was used and 5.0 g of catalyst were filled in to the tube reactor to evaluate the reactivity of the catalyst. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 20. The reaction evaluation results are shown in Table 3.

Reference Example 11

The catalyst is obtained in the same manner as in example 1, except that the suspension of the starting material is not subjected to maturation. The resulting catalyst is used and 6.0 g of catalyst are filled in to the tube reactor to evaluate the reactivity of the catalyst. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 21. The reaction evaluation results are shown in Table 3.

Reference Example 12

71.2 g of ammonium heptamolybdate are dissolved in 213.7 g of hot water at a temperature of about 90 ° C (liquid A). 32.8 g of bismuth nitrate, 14.6 g of cerium nitrate, 34.1 g of iron nitrate, 2.6 g of cesium nitrate, 49.2 g of cobalt nitrate and 0.35 g of potassium nitrate are dissolved in 37.0 g of 18% of the mass . an aqueous solution of nitric acid and 183.2 g of hot water with a temperature of about 90 ° C (liquid B) are added to this. Both liquid A and liquid B are mixed to form a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 510 ° C. for 3 h. The composition of the obtained oxide catalyst is shown in table 1, and the results of determination of x-ray diffraction of the powder are shown in table 2.

To assess the reactivity of the catalyst, 3.8 g of the catalyst was filled in the tubular reactor and the methacrolein synthesis reaction was carried out under the same reaction conditions as in Example 1. The reaction evaluation results are shown in Table 3.

Table 1 Example Number Atomic composition Mo Bi Fe Co Ce A B Fe / (Co + B) ratio Fe / Co ratio Other items Example 1 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Example 2 12.0 2.1 3.4 3.4 2.1 Cs0.09 0 1.00 1.00 Example 3 12.0 2.6 3.9 3.0 1.7 Cs0.09 0 1.30 1.30 Example 4 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Example 5 12.0 2.6 4.7 2.0 1.7 Cs0.06 Pb0,1 2.24 2,35 Example 6 12.0 2.6 4.7 2.0 1.7 Cs0.09 Ni1.0 1,57 2,35 Example 7 12.0 2.6 4.3 2,4 1.7 Cs0.09 Cu0,2 1.65 1.79 Example 8 12.0 2.9 2.9 2.0 1.9 Rb0.11 Mg1.8 0.76 1.45 Example 9 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Example 10 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Example 11 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Example 12 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Example 13 12.0 2.6 3.9 3.0 1.7 Cs0.09 0 1.30 1.30 Example 14 12.0 2.6 3.9 3.0 1.7 Cs0.09 0 1.30 1.30 Example 15 12.0 2.0 3.0 4,5 0.5 Cs0.2 Ni2.5 0.43 0.67 Example 16 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Example 17 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Example 18 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Example 19 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Example 20 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Example 21 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Comparative Example 1 12.0 1,6 1.4 7.9 0.5 Cs0.3 0 0.18 0.18 Reference Example 2 12.0 2.6 6.0 1.7 1.7 Cs0.09 0 3.53 3.53 Reference Example 3 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Reference Example 4 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Reference Example 5 12.0 2.6 4.3 2.6 1.7 Cs0.09 0 1.65 1.65 Reference Example 6 12.0 2.0 3.0 4,5 0.5 Cs0.2 Ni2.5 0.43 0.67 Reference Example 7 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Reference Example 8 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Reference Example 9 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Reference Example 10 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Reference Example 11 12.0 2.9 2.9 3.8 1.9 Cs0.11 0 0.76 0.76 Reference Example 12 12.0 2.0 2.5 5,0 1,0 Cs0.4 0 0.50 0.50 K0.1

table 2 X-ray diffraction angle 2θ (order of decreasing intensity) The level of change in parameter d, ppm Example Number The first Second Third Example 1 28.17 33.64 26,42 6385 Example 2 28.18 33.68 26.44 7543 Example 3 28.12 33.68 26,42 7543 Example 4 28.12 33.70 26,42 8103 Example 5 28.14 33.70 26,42 8103 Example 6 28.14 33.70 26,42 8103 Example 7 28.12 33.70 26,42 8103 Example 8 28.17 33.64 26,42 6385 Example 9 28.12 33.72 26,42 8663 Example 10 28.15 33.72 26,42 8663 Example 11 28.12 33.70 26.43 8103 Example 12 28.16 33.70 26.44 8103 Example 13 28.12 33.68 26,42 7543 Example 14 28.12 33.68 26,42 7543 Example 15 28.12 33.60 26,42 5240 Example 16 28.16 33.62 26,42 5815 Example 17 28.16 33.60 26,42 5240 Comparative Example 1 26.40 28.14 33.58 4667 Reference Example 2 28.14 33.77 26,42 10119 Reference Example 3 28.12 33.55 26,42 3809 Reference Example 4 28.12 33.53 26,42 3249 Reference Example 5 28.13 33.51 26.43 2651 Reference Example 6 28.12 33,50 26,42 2356 Reference Example 7 28.16 33.58 26,42 4667 Reference Example 12 26,42 28.14 33.55 3809

Example 22

Using the catalyst obtained in example 1, and to assess the reactivity of the catalyst, a tubular stainless steel jacketed reactor having a diameter of 14 mm was filled with 4.0 g of catalyst. Mixed gas containing 8% vol. tert-butyl alcohol, 12.8% vol. oxygen, 3.0% vol. water vapor and 76.2% vol. nitrogen, saturated with air at a flow rate of 120 ml / min (NTP) at a reaction temperature of 430 ° C with the implementation of the methacrolein synthesis reaction. The results of the reaction assessment are shown in table 4.

Reference Example 12

Use the catalyst obtained in comparative example 1, and to assess the reactivity of the catalyst, a tube reactor was filled with 4.2 g of catalyst. The methacrolein synthesis reaction is carried out under the same reaction conditions as in Example 22. The reaction evaluation results are shown in Table 4.

Example 23

The catalyst obtained in Example 1 was used and, to evaluate the reactivity of the catalyst, a jacketed stainless steel tubular reactor having an inner diameter of 15 mm was filled with 20 ml of catalyst. The starting material is a gas having a propylene concentration of 10% vol., A concentration of 17.0% vol. water vapor and a concentration of 73% vol. air, pass during the contact time of 2.3 seconds at normal pressure with the implementation of the reaction of synthesis of acrolein at a reaction temperature of 430 ° C. The results of the reaction assessment are shown in table 5.

Reference Example 13

Using the catalyst obtained in comparative example 1, and to assess the reactivity of the catalyst, the tubular reactor is filled with 20 ml of catalyst. The acrolein synthesis reaction is carried out under the same reaction conditions as in Example 23. The results of the reaction assessment are shown in Table 5.

To further illustrate the differences of the present invention and the technical results it provides, the following reference examples are also provided.

Reference example 1

The catalyst was obtained in the same manner as described in example 9 of document EP 1459803 of the prior art. The resulting catalyst was subjected to the same X-ray diffraction angle measurements as described above. The measurement results are shown in table A below.

As can be seen from table A, in reference example 1, where the catalyst has a composition in which the ratio of the components satisfy those specified in paragraph 1 of the claims of the present invention, but in which antimony is also present as a component in the composition of the oxide catalyst, the required according to the present invention, the level of change in the parameter d (step of the crystal lattice) 5000-9000 ppm

Reference example 2

The catalyst was obtained in the same manner as described in example 4 in JP 2000-237592 (see JP 2000-237592, paragraph [0027]). The resulting catalyst was subjected to the same X-ray diffraction angle measurements as described above.

As a result, the obtained catalyst had no peaks at diffraction angles 2θ of 28.17 ± 0.5 °, 33.50 + a °, in order of decreasing intensity, so that the level of change in parameter d could not be determined.

Reference example 3

66.8 g of ammonium heptamolybdate are dissolved in 200.41 g of hot water at a temperature of about 90 ° C (liquid A). 44.6 g of bismuth nitrate, 26.0 g of cerium nitrate, 28.1 g of iron nitrate, 0.67 g of cesium nitrate and 35.1 g of cobalt nitrate are dissolved in 36.8 g of 18% of the mass. an aqueous solution of nitric acid and 197.0 g of hot water with a temperature of about 90 ° C. (liquid B) are added to this. Both liquid A and liquid B are mixed and the mixture is treated at 20,000 rpm for 1 hour using a homogenizer. Then, the treated mixture is ripened with continuous stirring using a magnetic stirrer at a temperature of about 65 ° C for about 4 hours to obtain a suspension of the starting material. A suspension of the starting material is fed to a spray dryer and spray dried at an inlet temperature of 250 ° C. and an outlet temperature of about 140 ° C. The temperature of the obtained spray dried catalyst precursor is further increased with a temperature rise rate of 1.4 ° C./min from room temperature and the catalyst precursor is preliminarily calcined at 250 ° C. for 3 hours. The resulting preliminarily calcined catalyst precursor is calcined finally at 530 ° C. for 8 hours

The composition of the obtained oxide catalyst was determined based on the masses of the loaded starting components, and it is shown in table B-1 below.

The resulting catalyst was subjected to the same X-ray diffraction angle measurements as described above. The results of these measurements are shown in table B-2.

To evaluate the reactivity of the catalyst, the same methacrolein synthesis reaction was carried out as in Example 1, which was described above, but 4.4 g of the obtained oxide catalyst were loaded into the tubular reactor. The results of the reactivity assessment are shown in Table B-3.

The results of this example confirm that an essential feature of the present invention is the iron content in the range of b values from above 2.5 to 5.

As can be seen from the above reaction evaluation results, the oxide catalyst according to the present embodiment causes less formation of a subsequent oxide in the oxidation of olefin and / or alcohol and can improve the selectivity of the unsaturated aldehyde.

This application is based on the Japanese Patent Application filed June 28, 2011 (Japanese Patent Application No. 2011-143284), the contents of which are therefore incorporated herein by reference.

Industrial applicability

The oxide catalyst according to the present invention can be used in industry as a catalyst used in the oxidation of olefin and / or alcohol.

Claims (3)

1. An oxide catalyst for use in the oxidation reaction of an olefin and / or alcohol, which has a composition represented by the following formula of composition (1):
$$M{o}_{12}B{i}_{a}F{e}_{b}C{o}_{c}C{e}_d{A}_e{B}_f{O}_g\left(\text{one}\right)$$

,
in which Mo represents molybdenum, Bi represents bismuth, Fe represents iron, Co represents cobalt, Ce represents cerium, A represents at least one element selected from the group consisting of cesium and rubidium, B represents at least one element selected from the group consisting of copper, nickel, magnesium and lead, af represents the atomic ratio of each of the elements to 12 Mo atoms; the values 2≤a≤6, 2,5 <b≤5, 2≤s≤8, 0,4≤b / c≤2,5, 0,5≤d≤6, 0,01≤е≤ 2 and 0≤f <2, and g represents the number of oxygen atoms, determined by the valency of the constituent element other than oxygen,
in which, when the parameter d of the complex cerium and molybdenum oxide, showing the peak at 33.50 ° in the x-ray, is taken as a reference, the level of change of d is 5000-9000 ppm,
moreover, the specified oxide catalyst is obtained by a method comprising the step of ripening a suspension of a starting material containing molybdenum, bismuth, iron, cobalt and cerium at a temperature higher than room temperature. 2. A method of producing an oxide catalyst according to claim 1, which includes the following stages:
ripening a suspension of the starting material containing molybdenum, bismuth, iron, cobalt and cerium at a temperature higher than room temperature;
drying the ripened suspension of the starting material;
preliminary calcining the dried product at 120 ° C or higher and 350 ° C or lower; and
subsequent final calcination of the pre-calcined product at a temperature of 400 ° C or higher and 700 ° C or lower. 3. A method of producing an unsaturated aldehyde, comprising the step of oxidizing at least one olefin selected from the group consisting of propylene and isobutylene and / or tert-butyl alcohol using an oxide catalyst according to claim 1.

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