Oxidation catalyst, process for its preparation and use and process for the preparation of propenal

Abstract

The application belongs to the technical field of catalysts, and particularly relates to an oxidation catalyst, a preparation method and application thereof, and a preparation method of propenal. The catalyst comprises an active component of general formula MoBi a Fe b X c Y d Z e Q f O j ·g NiMoO4; wherein X is at least one selected from Mg, Co, Ca, Cu, Zn and Mn; Y is at least one selected from Nb, Sb and W; Z is at least one selected from K, Rb, Na, Li and Cs; and Q is at least one of La, Ce and Sm. The catalyst is used in an olefin oxidation reaction, such as propylene oxidation to prepare propenal, and has the advantages of high total yield of propenal and propenoic acid, and good stability of the catalyst structure.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to an oxidation catalyst, its preparation method and application, and a method for preparing acrolein. Background Technology

[0002] The selective oxidation of olefins to produce unsaturated acids is an important chemical process. Industrially, olefins are typically oxidized first to obtain unsaturated aldehydes, which are then oxidized to unsaturated acids. This process usually employs a two-stage production method, using two reactors and two catalysts under different reaction conditions. The first stage reaction mainly produces acrolein, with approximately 20% acrylic acid. The active component of the catalyst is a complex Mo / Bi composite oxide system. Catalyst improvements primarily focus on enhancing activity and stability. For example, adding transition metals to the active component can improve activity and increase product yield; adding rare earth elements can improve redox capabilities; and adding elements such as Fe, Co, and Ni can inhibit Mo sublimation, stabilize the active component, and extend catalyst lifespan. Furthermore, due to the intense exothermic reaction, controlling the catalyst bed temperature is crucial. Hot spots not only degrade reaction performance but also shorten catalyst lifespan and affect the stable operation of the plant.

[0003] It is generally believed that in the first step of the propylene oxidation reaction to produce acrolein, the olefin is adsorbed onto the catalyst surface, and an α-H atom is removed by a metal oxide, forming a free radical intermediate. This intermediate then generates the product through oxygen-nitrogen intercalation. During this process, the catalyst undergoes a redox cycle, losing the oxygen atom involved in the intercalation reaction, becoming reduced, and then re-oxidized by oxygen in the reaction gas. The active oxygen site is replenished through oxygen migration. Therefore, the catalyst must possess good oxygen migration energy to maintain the catalyst structure and redox balance. Transition metal composite oxides such as Mo, V, Bi, Te, Nb, and Fe are commonly used (Catalysis Today 49 (1999) 141-153).

[0004] US4224187 and US4248803 propose improving olefin conversion and target product yield by modifying the composition and dosage ratio of catalysts and catalyst preparation methods. However, their application in the selective oxidation of isobutylene suffers from low reaction selectivity. While the isobutylene conversion is as high as 99%, the overall yield of methacrolein and methacrylic acid is only 73.6%.

[0005] US6268529 discloses a propylene oxidation catalyst with a propylene conversion of 98.1%, an acrolein yield of 65.3%, an acrylic acid yield of 20.8%, and a total yield of 86.1% for acrolein and acrylic acid.

[0006] CN1564709 improves catalyst performance by adding an organic carboxylic acid to overcome the catalyst inhomogeneity caused by stratification between metal salts during the co-precipitation process. It is used for the selective oxidation of propylene, achieving a propylene conversion of up to 98.12%, a selectivity of up to 82.53% for acrolein, and a total yield of 91.05% for acrolein and acrylic acid.

[0007] CN1210511A, CN1283604A, and CN1314331A achieve the goal of controlling reaction hotspots and extending catalyst stability by configuring multiple catalyst layers with gradually increasing reactivity along the reactor axis from the reactant gas inlet to the outlet. However, the structural stability of these catalysts needs further improvement. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of low yield and low structural stability of target products in existing oxidation catalysts. This invention provides an oxidation catalyst, its preparation method and application, and a method for preparing acrolein. The catalyst is used in the oxidation of olefins, such as the oxidation of propylene to prepare acrolein, and has the advantages of high total yield of acrolein and acrylic acid, and good structural stability.

[0009] To achieve the above objectives, a first aspect of the present invention provides an oxidation catalyst comprising a catalyst having the general formula MoBi. a Fe b X c Y d Z e Q f O j The active component of ·g NiMoO4;

[0010] Wherein, X is selected from at least one of Mg, Co, Ca, Cu, Zn and Mn;

[0011] Y is selected from at least one of Nb, Sb and W;

[0012] Z is selected from at least one of K, Rb, Na, Li and Cs;

[0013] Q is at least one of La, Ce, and Sm;

[0014] 'a' represents the molar ratio of Bi to Mo, and the value of 'a' ranges from 0.1 to 0.6.

[0015] b is the molar ratio of Fe to Mo, and the value of b ranges from 0.1 to 0.5;

[0016] c is the molar ratio of X to Mo, and the value of c ranges from 0.2 to 1.0;

[0017] d is the molar ratio of Y to Mo, and the value of d ranges from 0.1 to 0.5;

[0018] e is the molar ratio of Z to Mo, and the value of e ranges from 0.01 to 0.06;

[0019] f is the molar ratio of Q to Mo, and the value of f ranges from 0.1 to 0.6.

[0020] g represents NiMoO4 and MoBi a Fe b X c Y d Z e Q f O j The molar ratio, where g takes values ​​from 3 to 15;

[0021] j represents the total number of oxygen atoms required to satisfy the valences of other elements. In af, the molar content of Mo is expressed as MoBi. a Fe b X c Y d Z e Q f O j The conspiracy in.

[0022] A second aspect of the present invention provides a method for preparing the oxidation catalyst of the present invention, the method comprising:

[0023] According to the formula, a first solution containing Mo compound and Y compound is mixed with a second solution containing Bi compound, Fe compound, X compound, Z compound and Q compound to obtain a slurry. NiMoO4 is then added, and the mixture is dried and calcined.

[0024] A third aspect of the present invention provides the application of the oxidation catalyst described herein in the synthesis of aldehydes from olefins.

[0025] A fourth aspect of the present invention provides a method for preparing acrolein, the method comprising:

[0026] The propylene-containing feed gas and the oxygen-containing oxidizing gas are brought into contact with a catalyst, wherein the catalyst includes the oxidation catalyst described in this invention.

[0027] Through the above technical solution, the oxidation catalyst provided by this invention exhibits high oxidation activity and structural stability. This is presumably due to the use of NiMoO4 as a framework during catalyst preparation, which forms macroporous channels within the catalyst, accelerating the removal of heat and products. Furthermore, NiMoO4 itself enhances oxygen migration and redox equilibrium capabilities, thereby resulting in higher activity and selectivity. Simultaneously, NiMoO4 possesses a composition and structure similar to the composite oxides of the active components, enabling better cross-linking and bonding, leading to high catalyst structural strength and good stability.

[0028] According to a preferred embodiment of the present invention, controlling the particle size of NiMoO4 can further regulate the macroporous channels of the catalyst, further accelerate the removal of heat and products, avoid deep oxidation, and improve the performance of the catalyst.

[0029] The oxidation catalyst described in this invention is used to synthesize aldehydes (acrylaldehyde) from olefins (e.g., propylene), with high olefin (e.g., propylene) conversion and high total yield of acrolein and acrylic acid. Detailed Implementation

[0030] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0031] The first aspect of the present invention provides an oxidation catalyst comprising a catalyst having the general formula MoBi a Fe b X c Y d Z e Q f O j The active component of ·g NiMoO4;

[0032] Wherein, X is selected from at least one of Mg, Co, Ca, Cu, Zn and Mn;

[0033] Y is selected from at least one of Nb, Sb and W;

[0034] Z is selected from at least one of K, Rb, Na, Li and Cs;

[0035] Q is at least one of La, Ce, and Sm;

[0036] 'a' represents the molar ratio of Bi to Mo, and the value of 'a' ranges from 0.1 to 0.6.

[0037] b is the molar ratio of Fe to Mo, and the value of b ranges from 0.1 to 0.5;

[0038] c is the molar ratio of X to Mo, and the value of c ranges from 0.2 to 1.0;

[0039] d is the molar ratio of Y to Mo, and the value of d ranges from 0.1 to 0.5;

[0040] e is the molar ratio of Z to Mo, and the value of e ranges from 0.01 to 0.06;

[0041] f is the molar ratio of Q to Mo, and the value of f ranges from 0.1 to 0.6.

[0042] g represents NiMoO4 and MoBi a Fe b X c Y d Z e Q f O j The molar ratio, where g takes values ​​from 3 to 15;

[0043] j represents the total number of oxygen atoms required to satisfy the valences of other elements. In af, the molar content of Mo is expressed as MoBi. a Fe b X c Y d Z e Q f O j The amount of Mo is calculated. The oxidation catalyst provided by this invention has high oxidation activity and stable structure.

[0044] In this invention, in each molar ratio af, Mo does not contain the amount of Mo found in NiMoO4.

[0045] According to a preferred embodiment of the present invention, the macropore volume of the oxidation catalyst is 0.15–0.5 cm³. 3 / g, preferably 0.2-0.3cm 3 / g; This is beneficial for improving the strength and activity of the catalyst.

[0046] According to a preferred embodiment of the present invention, the average pore size of the oxidation catalyst is 100-500 nm, preferably 120-350 nm; this is beneficial for improving the strength and activity of the catalyst.

[0047] According to a preferred embodiment of the present invention, NiMoO4 exists in the oxidation catalyst in the form of a compound.

[0048] According to a preferred embodiment of the present invention, the particle size of NiMoO4 is 5 to 20 micrometers, preferably 7 to 15 micrometers.

[0049] According to a preferred embodiment of the present invention, the value of a in the catalyst is 0.2 to 0.4.

[0050] According to a preferred embodiment of the present invention, the value of b in the catalyst is 0.2 to 0.4.

[0051] According to a preferred embodiment of the present invention, the value of c in the catalyst is 0.3 to 0.7.

[0052] According to a preferred embodiment of the present invention, the value of d in the catalyst is 0.2 to 0.4.

[0053] According to a preferred embodiment of the present invention, the value of e in the catalyst is 0.02 to 0.05.

[0054] According to a preferred embodiment of the present invention, the value of f in the catalyst is 0.2 to 0.5.

[0055] According to a preferred embodiment of the present invention, the value of g in the catalyst is 5-10.

[0056] According to a preferred embodiment of the present invention, the value of a is 0.2 to 0.4; the value of b is 0.2 to 0.4; the value of c is 0.3 to 0.7; the value of d is 0.2 to 0.4; the value of e is 0.02 to 0.05; the value of f is 0.2 to 0.5; and the value of g is 5 to 10.

[0057] All the oxidation catalysts possessing the aforementioned properties can achieve the objectives of this invention. According to a preferred embodiment of this invention, a method for preparing the oxidation catalyst is provided, the method comprising:

[0058] According to the specified ratio, a first solution containing Mo and Y compounds is mixed with a second solution containing Bi, Fe, X, Z, and Q compounds to obtain a slurry. NiMoO4 is then added, followed by drying and calcination. In the catalyst preparation process, NiMoO4 is used as a framework to form macroporous channels, accelerating the removal of heat and products. Furthermore, because NiMoO4 itself can improve the oxygen migration and redox balance capabilities of the catalyst, it results in higher catalyst activity.

[0059] In this invention, the amount of each substance fed according to the proportions should satisfy the general formula of the catalyst described in this invention.

[0060] In this invention, the conditions for adding NiMoO4 to the slurry are relatively wide. According to a preferred embodiment of this invention, the slurry temperature is 50-80°C when NiMoO4 is added.

[0061] In this invention, there are no particular limitations on the drying conditions, as long as the water can be removed. According to a preferred embodiment of the invention, the drying conditions include: a temperature of 50 to 80°C, for example, 50°C, 60°C, 70°C, or 80°C; and a drying time determined according to actual needs, preferably 1 to 16 hours, for example, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 13 hours, or 15 hours.

[0062] In this invention, the roasting conditions are not particularly limited and can be conventional roasting conditions in the art. According to a preferred embodiment of the invention, the roasting conditions include: a temperature of 400-650°C, such as 400°C, 450°C, 500°C, 550°C, 600°C, and 650°C; and a roasting time that can be determined according to actual needs, preferably 1-12 hours, such as 1 hour, 2 hours, 4 hours, 8 hours, 10 hours, and 11 hours.

[0063] According to a preferred embodiment of the present invention, the roasting atmosphere is an oxygen-containing atmosphere, such as pure oxygen or air; however, from an economic point of view, the roasting atmosphere is preferably air. Unless otherwise specified, the roasting atmosphere in the present invention is always air.

[0064] According to a preferred embodiment of the present invention, the amount of water used in the first solution and the second solution has a wide range of selection, with the aim of fully dissolving the compound.

[0065] According to a preferred embodiment of the present invention, the solution after mixing of each process is a homogeneous solution, a suspension, or a mixture of solution and suspension.

[0066] According to the present invention, evaporation and concentration can be carried out before drying, preferably at 50-80°C.

[0067] In this invention, there are no special requirements for the types of Mo-containing compounds, Y-containing compounds, Bi-containing compounds, Fe-containing compounds, X-containing compounds, Z-containing compounds, and Q-containing compounds. For example, the Mo-containing compounds, Y-containing compounds, Bi-containing compounds, Fe-containing compounds, X-containing compounds, Z-containing compounds, and Q-containing compounds can be selected from at least one of nitrates, ammonium salts, sulfates, oxides, hydroxides, chlorides, and acetates.

[0068] According to a preferred embodiment of the present invention, the Mo compound may be selected from, but is not limited to, one or more of: ammonium molybdate, molybdenum trioxide, molybdenum nitrate, molybdic acid, and sodium molybdate.

[0069] According to a preferred embodiment of the present invention, the Bi compound may be selected from, but is not limited to, one or more of bismuth nitrate, bismuth trioxide, bismuth sulfate, bismuth chloride, and bismuth acetate.

[0070] According to a preferred embodiment of the present invention, the Fe compound may be selected from, but is not limited to, one or more of: ferric nitrate, ferric sulfate, ferric chloride, ferric oxide, and ferrous sulfate.

[0071] According to a preferred embodiment of the present invention, the X compound may be selected from, but is not limited to, one or more of: cobalt nitrate, cobalt sulfate, cobalt chloride, magnesium nitrate, magnesium sulfate, magnesium chloride, magnesium oxide, magnesium acetate, copper nitrate, zinc nitrate, and manganese nitrate.

[0072] According to a preferred embodiment of the present invention, the Y compound may be selected from, but is not limited to, one or more of the following: niobium oxalate, niobium pentoxide, niobium pentachloride, niobic acid, niobyl nitrate, antimony nitrate, ammonium tungstate, tungsten trioxide, tungstic acid, sodium tungstate, and ammonium metatungstate.

[0073] According to a preferred embodiment of the present invention, the Z compound may be selected from, but is not limited to, one or more of potassium nitrate, rubidium nitrate, sodium nitrate, sodium sulfate, sodium chloride, sodium acetate, sodium hydroxide, lithium nitrate, and cesium nitrate.

[0074] According to a preferred embodiment of the present invention, the Q compound may be selected from, but is not limited to, one or more of: lanthanum nitrate, cerium nitrate, cerium sulfate, cerium perchlorate, cerium dioxide, cerium acetate, and samarium nitrate.

[0075] A third aspect of the present invention provides the application of the oxidation catalyst described herein in the synthesis of aldehydes from olefins.

[0076] According to a preferred embodiment of the present invention, the olefin is a C2-C5 olefin, more preferably propylene and / or ethylene. The oxidation catalyst of the present invention is used for the synthesis of aldehydes (acrylaldehyde) from olefins (e.g., propylene), resulting in high olefin (e.g., propylene) conversion and high total yield of acrolein and acrylic acid.

[0077] A fourth aspect of the present invention provides a method for preparing acrolein, the method comprising:

[0078] The propylene-containing feed gas and the oxygen-containing oxidizing gas are brought into contact with a catalyst, wherein the catalyst includes the oxidation catalyst described in this invention.

[0079] According to a preferred embodiment of the present invention, the contact conditions include a temperature of 300-550°C, preferably 330-380°C.

[0080] According to a preferred embodiment of the present invention, the contact conditions include a pressure of 0.01 to 0.08 MPa, wherein the pressure is gauge pressure.

[0081] According to a preferred embodiment of the present invention, the contact conditions include: the volumetric hourly space velocity of the feed gas is 600-1200 mL / g·h.

[0082] According to a preferred embodiment of the present invention, the contact conditions include: propylene: oxygen-containing oxidizing gas = 1:(6-8) by volume.

[0083] According to a preferred embodiment of the present invention, in order to make the reaction more stable and controllable, it is preferable to carry out the reaction in the presence of a diluting gaseous material, wherein the raw material gas also contains a diluting gaseous material.

[0084] According to a preferred embodiment of the present invention, the volume ratio of propylene: oxygen-containing oxidizing gas: diluting gaseous material is 1:(6-8):(0.5-5).

[0085] According to a preferred embodiment of the present invention, the dilutive gaseous material is water vapor.

[0086] According to a preferred embodiment of the present invention, the oxygen-containing oxidizing gas can be pure oxygen or oxygen-enriched gas, but air is preferred from an economic point of view.

[0087] The present invention will now be described in detail with reference to embodiments. It should be understood that the embodiments and examples described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0088] In the following examples, NiMoO4 was purchased from Sinopharm Reagent Company;

[0089] In the following embodiments, the macropore volume was determined by mercury porosimetry;

[0090] In the following examples, the catalyst strength was tested using a particle strength tester (purchased from Taizhou Great Analytical Instruments Co., Ltd., model KC-3T) to measure the strength of 30 particles and calculate the average value.

[0091] In the following examples, the composition of the catalyst was calculated based on the feed ratio.

[0092] In the following examples, the catalyst evaluation conditions are as follows:

[0093] Reactor: Fixed-bed single-tube reactor, inner diameter 26.0 mm, reactor length 800 mm;

[0094] Catalyst: 200 grams;

[0095] Reaction temperature: 360℃;

[0096] Reaction pressure: 0.03 MPa (gauge pressure);

[0097] Propylene:Air (feedstock molar ratio) = 1:7.2;

[0098] Propylene:water vapor = 1:1.8;

[0099] Feed gas volumetric hourly space velocity: 1000 mL / g·h;

[0100] The reaction products were absorbed with dilute acid at 0°C and analyzed by gas chromatography (Agilent 7890A). The carbon balance was calculated, and data were considered valid when the carbon balance was between (95% and 105%).

[0101] The definitions of propylene conversion, product yield, and selectivity are as follows:

[0102]

[0103]

[0104]

[0105] Example 1

[0106] Solution 1 was prepared by dissolving 1 mol of ammonium molybdate (Mo) and 0.2 mol of ammonium niobate (Nb) in 3000 g of water. Solution 2 was prepared by dissolving 0.3 mol of bismuth nitrate (Bi), 0.3 mol of ferric nitrate (Fe), 0.5 mol of cobalt nitrate (Co), 0.04 mol of rubidium nitrate (Rb), and 0.3 mol of cerium nitrate (Ce) in 200 g of water. Solution 2 was then added to solution 1 to obtain a slurry. 7 mol of NiMoO4 (average particle size 12 μm) was then added and stirred until homogeneous. The slurry was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst MoBi. 0.3 Fe 0.3 Co 0.5 Nb 0.2 Rb 0.04 Ce 0. 3O j ·7NiMoO4.

[0107] Example 2

[0108] Solution 1 was prepared by dissolving 1 mol of ammonium molybdate (Mo) and 0.1 mol of ammonium metatungstate (W) in 3000 g of water. Solution 2 was prepared by dissolving 0.3 mol of bismuth nitrate (Bi), 0.3 mol of ferric nitrate (Fe), 0.5 mol of cobalt nitrate (Co), 0.04 mol of rubidium nitrate (Rb), and 0.3 mol of cerium nitrate (Ce) in 200 g of water. Solution 2 was then added to solution 1 to obtain a slurry, followed by the addition of 10 mol of NiMoO4 (average particle size 12 μm) and stirring until homogeneous. The slurry was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst MoBi. 0.1 Fe 0.3 Co 0.5 W 0.1 Rb 0.04 Ce 0.3 O j ·10NiMoO4.

[0109] Example 3

[0110] Solution 1 was prepared by dissolving 1 mol of ammonium molybdate (Mo) and 0.5 mol of antimony tartrate (Sb) in 3000 g of water. Solution 2 was prepared by dissolving 0.3 mol of bismuth nitrate (Bi), 0.3 mol of ferric nitrate (Fe), 0.5 mol of cobalt nitrate (Co), 0.04 mol of rubidium nitrate (Rb), and 0.3 mol of cerium nitrate (Ce) in 200 g of water. Solution 2 was prepared by adding solution 2 to solution 1, and then adding 5 mol of NiMoO4 (average particle size 12 μm) and stirring until homogeneous. The mixture was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst MoBi. 0.6 Fe 0.3 Co 0.5 Sb 0.5 Rb 0.04 Ce 0.3 O j ·5NiMoO4.

[0111] Example 4

[0112] The method of Example 1 was followed, except that the average particle size of NiMoO4 was 5 micrometers; the other conditions were the same as in Example 1.

[0113] Example 5

[0114] The method of Example 1 was followed, except that the average particle size of NiMoO4 was 20 micrometers; the other conditions were the same as in Example 1.

[0115] Example 6

[0116] Solution 1 was prepared by dissolving 1 mol of ammonium molybdate (Mo) and 0.5 mol of ammonium metatungstate (W) in 3000 g of water. Solution 2 was prepared by dissolving 0.1 mol of bismuth nitrate (Bi), 0.5 mol of ferric nitrate (Fe), 0.1 mol of cobalt nitrate (Co), 0.1 mol of magnesium nitrate (Mg), 0.01 mol of potassium nitrate (K), and 0.1 mol of samarium nitrate (Sm) in 200 g of water. Solution 2 was prepared by adding solution 2 to solution 1, resulting in a slurry. Then, 15 mol of NiMoO4 (average particle size 10 μm) was added and stirred until homogeneous. The slurry was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst MoBi. 0.1 Fe 0.5 Co 0.1 Mg 0.1 W 0.5 K 0.01 Sm 0.1 O j ·15NiMoO4.

[0117] Example 7

[0118] Solution 1 was prepared by dissolving 1 mol of ammonium molybdate (Mo) and 0.5 mol of ammonium metatungstate (W) in 3000 g of water. Solution 2 was prepared by dissolving 0.6 mol of bismuth nitrate (Bi), 0.1 mol of ferric nitrate (Fe), 1.0 mol of zinc nitrate (Zn), 0.06 mol of sodium nitrate (Na), 0.3 mol of cerium nitrate (Ce), and 0.3 mol of lanthanum nitrate (La) in 200 g of water. Solution 2 was then added to solution 1 to obtain a slurry. 3 mol of NiMoO4 (average particle size 10 μm) was then added and stirred until homogeneous. The slurry was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst MoBi. 0.6 Fe 0. 1Zn 1.0 W 0.5 Na 0.06 Ce 0.3 La 0.3 O j ·3NiMoO4.

[0119] Comparative Example 1

[0120] The method is the same as in Example 1, except that nickel molybdate is not added. Specifically:

[0121] Solution 1 was prepared by dissolving 1 mol of ammonium molybdate (Mo) and 0.2 mol of ammonium niobate (Nb) in 3000 g of water. Solution 2 was prepared by dissolving 0.3 mol of bismuth nitrate (Bi), 0.3 mol of ferric nitrate (Fe), 0.5 mol of cobalt nitrate (Co), 0.04 mol of rubidium nitrate (Rb), and 0.3 mol of cerium nitrate (Ce) in 200 g of water. Solution 2 was prepared by adding solution 2 to solution 1. The slurry was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst MoBi. 0.3 Fe 0.3 Co 0.5 Nb 0.2 Rb 0.04 Ce 0.3 O j .

[0122] Comparative Example 2

[0123] Solution 1 was prepared by dissolving 8 mol of ammonium molybdate (Mo) and 0.2 mol of ammonium niobate (Nb) in 3000 g of water. Solution 2 was prepared by dissolving 0.3 mol of bismuth nitrate (Bi), 0.3 mol of ferric nitrate (Fe), 7 mol of nickel nitrate (Ni), 0.5 mol of cobalt nitrate (Co), 0.04 mol of rubidium nitrate (Rb), and 0.3 mol of cerium nitrate (Ce) in 200 g of water. Solution 2 was prepared by adding solution 2 to solution 1. The slurry was concentrated to a viscous paste at 65 °C, dried at 80 °C for 6 hours, and then calcined in air at 550 °C for 2 hours to obtain the catalyst Mo8Bi.0.3 Fe 0.3 Ni7Co 0.5 Nb 0.2 Rb 0.04 Ce 0.3 O j .

[0124] Table 1

[0125]

[0126] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An oxidation catalyst, characterized in that, The catalyst comprises substances with the general formula MoBi. a Fe b X c Y d Z e Q f O j The active component of ·g NiMoO4; NiMoO4 forms the catalyst framework and exists in compound form. X is selected from at least one of Mg, Co, Ca, Cu, Zn, and Mn; Y is selected from at least one of Nb, Sb and W; Z is selected from at least one of K, Rb, Na, Li and Cs; Q is at least one of La, Ce, and Sm; 'a' represents the molar ratio of Bi to Mo, and the value of 'a' ranges from 0.1 to 0.

6. b is the molar ratio of Fe to Mo, and the value of b ranges from 0.1 to 0.

5. c is the molar ratio of X to Mo, and the value of c ranges from 0.2 to 1.0; d is the molar ratio of Y to Mo, and the value of d ranges from 0.1 to 0.5; e is the molar ratio of Z to Mo, and the value of e ranges from 0.01 to 0.06; f is the molar ratio of Q to Mo, and the value of f ranges from 0.1 to 0.

6. g represents NiMoO4 and MoBi a Fe b X c Y d Z e Q f O j The molar ratio, where g takes values ​​from 3 to 15; j represents the total number of oxygen atoms required to satisfy the valences of other elements. In af, the molar content of Mo is expressed as MoBi. a Fe b X c Y d Z e Q f O j The conspiracy in.

2. The oxidation catalyst according to claim 1, wherein, The macropore volume of the oxidation catalyst is 0.15~0.5 cm³. 3 / g; and / or Average pore size 100-500nm.

3. The oxidation catalyst according to claim 1 or 2, wherein, The macropore volume of the oxidation catalyst is 0.2-0.3 cm³. 3 / g; and / or The average pore size is 120~350nm.

4. The oxidation catalyst according to claim 1 or 2, wherein, The particle size of NiMoO4 is 5~20 micrometers.

5. The oxidation catalyst according to claim 4, wherein, The particle size of NiMoO4 is 7~15 micrometers.

6. The oxidation catalyst according to claim 1 or 2, wherein, The values ​​of a are 0.2 to 0.4; the values ​​of b are 0.2 to 0.4; the values ​​of c are 0.3 to 0.7; the values ​​of d are 0.2 to 0.4; the values ​​of e are 0.02 to 0.05; the values ​​of f are 0.2 to 0.5; and the values ​​of g are 5 to 10.

7. A method for preparing the oxidation catalyst according to any one of claims 1-6, characterized in that, The method includes: According to the formula, a first solution containing Mo compound and Y compound is mixed with a second solution containing Bi compound, Fe compound, X compound, Z compound and Q compound to obtain a slurry. NiMoO4 is then added, and the mixture is dried and calcined.

8. The preparation method according to claim 7, wherein, The preparation method further includes: evaporation and concentration before drying.

9. The preparation method according to claim 8, wherein, The evaporation and concentration temperature is 50~80℃.

10. The preparation method according to claim 7, wherein, Drying conditions include: a temperature of 50~80℃; and / or a time of 1~16h; The roasting conditions include: a temperature of 400~650℃; and / or a time of 1~12h.

11. The use of the oxidation catalyst according to any one of claims 1-6 in the synthesis of aldehydes from olefins.

12. The application according to claim 11, wherein, The olefins are C2-C5 olefins.

13. The application according to claim 12, wherein, The olefins are propylene and / or ethylene.

14. A method for preparing acrolein, characterized in that, The method includes: The propylene-containing feed gas and the oxygen-containing oxidizing gas are brought into contact with a catalyst, wherein the catalyst includes the oxidation catalyst according to any one of claims 1-6.

15. The preparation method according to claim 14, wherein, Exposure conditions include: The temperature is 300-550℃; The pressure is 0.01~0.08MPa, where the pressure is gauge pressure; The feed gas volumetric hourly space velocity is 600~1200 mL / g•h; and / or By volume ratio, propylene : oxygen-containing oxidizing gas = 1 : (6-8).

16. The preparation method according to claim 14, wherein, The raw material gas also contains diluting gaseous materials; by volume ratio, propylene: oxygen-containing oxidizing gas: diluting gaseous materials = 1: (6~8): (0.5~5).

17. The preparation method according to claim 16, wherein, The diluting gaseous material is water vapor; and / or The oxygen-containing oxidizing gas is one or more of oxygen and air.

18. The preparation method according to claim 17, wherein, The oxygen-containing oxidizing gas is air.

19. The preparation method according to claim 15, wherein, Contact conditions include a temperature of 330-380℃.

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