Propylene oxidation catalysts, their preparation methods and applications

Abstract

This invention discloses a propylene oxidation catalyst, its preparation method, and its applications. The catalyst comprises a support and an active metal component, wherein the active lattice oxygen accounts for 10.78–11.30% of the total lattice oxygen in the catalyst. This catalyst possesses abundant active lattice oxygen, which can improve product selectivity and catalytic efficiency.

Description

Technical Field

[0001] This invention relates to catalysts for the oxidation of propylene to prepare acrolein and acrylic acid, their preparation methods, and applications. Background Technology

[0002] The selective oxidation of olefins to prepare α,β-unsaturated aldehydes and unsaturated acids is an important chemical process. The production of unsaturated aldehydes uses a catalyst whose active components contain Mo and Bi.

[0003] CN102992979A discloses a method for the selective oxidation of propylene to prepare acrolein. This method employs a fixed-bed single-tube reactor; the reactants are preheated before entering the reactor, which is loaded with a Mo-Bi based polymetallic oxide catalyst. The composition of this polymetallic oxide catalyst is represented by the following general formula (I). Mo a Bi b Fe c Ni d Co e Si f A g B h O i (I) Its production method can effectively reduce local heat accumulation in single-tube reactors, suppress the formation of hot spots, prevent catalyst from coking, and meet the requirements for long-term stable operation of the unit.

[0004] CN111068698A discloses a catalyst for the oxidation of propylene to acrolein and its application. The catalyst for the oxidation of propylene to acrolein includes a support and an active component supported on the support, wherein the active component has the general formula: BiMo. a Fe b Co c X d J e Z f O gWhere X is at least one element selected from the group consisting of Al, Ga, Ge, In, Sn, Sb, Ti, Pb, and Po; J is at least one element selected from the group consisting of Sc, Y, Ti, Zr, Hf, V, Nb, Ta, W, Tc, Re, Ru, Os, Rh, Ir, Pd, Pt, Ag, Au, Cd, La, and Nd; and Z is an element selected from Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra. The catalyst comprises at least one of the elements in the active component group; a is the molar ratio of Mo to Bi, with a value ranging from 1.0 to 8.0; b is the molar ratio of Fe to Bi, with a value ranging from 0.1 to 2.0; c is the molar ratio of Co to Bi, with a value ranging from 0.1 to 2.0; d is the molar ratio of X to Bi, with a value ranging from 0.1 to 2.0; e is the molar ratio of J to Bi, with a value ranging from 0.1 to 2.0; f is the molar ratio of Z to Bi, with a value ranging from 0.1 to 2.0; and g is the number of moles of oxygen atoms required to satisfy the valence of each element in the active component. The catalyst preparation method includes: preparing a mixed solution of active component elements; mixing the mixed solution of active component elements with a support; and calcining to form the catalyst.

[0005] Based on the aforementioned existing technologies, to improve catalyst activity and stability, current techniques primarily focus on enhancing catalyst selectivity and lifetime through methods such as catalyst composition and the creation of activity gradients in catalyst loading. However, existing technologies do not address the issue of increasing the content of active lattice oxygen directly involved in selective oxidation within the catalyst to improve its activity. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies, this invention provides a novel propylene oxidation catalyst and its preparation method. This catalyst possesses abundant active lattice oxygen, which, when used in pulse experiments for the selective oxidation of propylene, improves product selectivity and catalytic efficiency. This invention enhances catalyst activity by increasing the content of active lattice oxygen directly involved in selective oxidation. The active lattice oxygen accounts for 10.78–11.30% of the total lattice oxygen in the catalyst, achieving superior results.

[0007] The first aspect of the present invention provides a propylene oxidation catalyst, the catalyst comprising a support and an active metal component, wherein the active lattice oxygen of the catalyst accounts for 10.78 to 11.30% of the total lattice oxygen of the catalyst.

[0008] In this invention, the method for determining the active lattice oxygen content of the catalyst is as follows: the total lattice oxygen content of the catalyst is the sum of all oxygen elements combined with metal oxides in the catalyst; the active lattice oxygen of the catalyst is defined as the lattice oxygen that is reactive for propylene oxidation under the reaction conditions. It is calculated based on the total propylene consumed in the reaction under the reaction conditions using a propylene pulse test. Specific implementation plan: 2g of catalyst is loaded into a reaction tube, and a propylene pulse test (5ml / time) is performed until the propylene conversion rate is less than 3%. The pulse interval is 3min, the reaction temperature is 360℃, and the amount of unreacted propylene is quantified by gas chromatography-TCD external standard method.

[0009] According to the above embodiments, preferably, the support is at least one of SiO2, Al2O3 and TiO2.

[0010] According to the above embodiments, preferably, the active metal component is represented by the following general formula: Mo 12 Bi a Fe b X c Y d Z e O χ Wherein, X is selected from at least one of V, Nb, Cr, W, Mg, Ca, Ba, Sr, Co, Sn, Cu, Pb and Mn; Y is selected from at least one of Ag, K, Rb, Na, Li, Tl and Cs; Z is selected from at least one of Al, La, Ce, Sc, Sm and Th; where a ranges from 0.2 to 5.5; b ranges from 0.2 to 4.5; c ranges from 0.7 to 9.5; d ranges from 0.1 to 1.0; e ranges from 0.2 to 3.5; and χ is the total number of oxygen atoms required to satisfy the valence of other elements.

[0011] According to the above embodiments, preferably, based on the total weight of the catalyst, the content of the support is 5% to 20% by weight, and the content of the active metal component is 80% to 95% by weight.

[0012] The propylene oxidation catalyst for acrolein and acrylic acid of the present invention has abundant active lattice oxygen. When used in pulse experiments of selective oxidation of propylene, its active lattice oxygen accounts for up to 11.30% of the total lattice oxygen of the catalyst.

[0013] A second aspect of the present invention provides a method for preparing a propylene oxidation catalyst, comprising:

[0014] a) Mix the material containing the active metal component precursor with the carrier precursor to obtain a slurry;

[0015] b) The slurry obtained in step a) is aged, dried, and pulverized to obtain the catalyst precursor;

[0016] c) Calcining the catalyst precursor obtained in step b) yields the catalyst;

[0017] The roasting atmosphere is an oxygen-enriched gas with a flow rate of 10–20 ml / (min·gcat) and an oxygen content of 21–60% by volume.

[0018] In this invention, the unit "ml / (min·gcat)" refers to the flow rate of oxygen-enriched gas in milliliters per minute relative to one gram of catalyst. For example, 20 ml / (min·gcat) means that the flow rate of oxygen-enriched gas is 20 milliliters per minute relative to one gram of catalyst.

[0019] According to the above embodiments, preferably, the flow rate of the oxygen-enriched gas is 12-19 ml / (min·gcat), more preferably 14-16 ml / (min·gcat).

[0020] According to the above embodiments, preferably, the calcination conditions include: a temperature of 420-540℃, more preferably 440-520℃; and a time of 50-150 min, more preferably 60-130 min.

[0021] According to the above embodiments, preferably, the oxygen content in the oxygen-enriched gas is 26-42% by volume, and most preferably 28-39% by volume. In the oxygen-enriched gas, the gas other than oxygen can be N2 or other inert gases.

[0022] According to the above embodiments, the carrier precursor can be, but is not limited to, silicon dioxide, silica sol, titanium dioxide, etc.

[0023] According to the above embodiments, preferably, the precursor containing the active metal component can be a soluble salt containing an element represented by a general formula, obtained by compounding, wherein the general formula is Mo. 12 Bi a Fe b X c Y d Z e O χ X is selected from at least one of V, Nb, Cr, W, Mg, Ca, Ba, Sr, Co, Sn, Cu, Pb and Mn; Y is selected from at least one of Ag, K, Rb, Na, Li, Tl and Cs; and Z is selected from at least one of Al, La, Ce, Sc, Sm and Th.

[0024] According to the above embodiments, the aging conditions may include, but are not limited to: a temperature of 70-90°C and a time of 1-3 hours.

[0025] A third aspect of the present invention provides a propylene oxidation catalyst obtained by the above-described preparation method. The catalyst comprises a support and an active metal component, wherein the active lattice oxygen of the catalyst accounts for 10.78–11.30% of the total lattice oxygen of the catalyst.

[0026] According to the above embodiments, preferably, the support is at least one of SiO2, Al2O3 and TiO2.

[0027] According to the above embodiments, preferably, the active metal component is represented by the following general formula: Mo 12 Bi a Fe b X c Y d Z e O χ Wherein, X is selected from at least one of V, Nb, Cr, W, Mg, Ca, Ba, Sr, Co, Sn, Cu, Pb and Mn; Y is selected from at least one of Ag, K, Rb, Na, Li, Tl and Cs; Z is selected from at least one of Al, La, Ce, Sc, Sm and Th; where a ranges from 0.2 to 5.5; b ranges from 0.2 to 4.5; c ranges from 0.7 to 9.5; d ranges from 0.1 to 1.0; e ranges from 0.2 to 3.5; and χ is the total number of oxygen atoms required to satisfy the valence of other elements.

[0028] According to the above embodiments, preferably, based on the total weight of the catalyst, the content of the support is 5% to 20% by weight, and the content of the active metal component is 80% to 95% by weight.

[0029] The fourth aspect of this invention provides the application of the above-described catalyst in the oxidation of propylene to prepare acrolein and acrylic acid.

[0030] The beneficial effects of this invention are:

[0031] (1) The catalyst of the present invention has abundant active lattice oxygen and is used in pulse tests of selective oxidation reaction of propylene. Its active lattice oxygen accounts for as much as 10.78 to 11.30% of the total lattice oxygen of the catalyst.

[0032] (2) In the preparation process of existing catalysts, there are usually no special restrictions on the calcination conditions, as long as the specific compound form of the active element can be calcined into the form of an oxide. Usually, the calcination atmosphere is air. In the preparation process of the present invention, oxygen-enriched gas with a specific concentration range and a specific flow rate is used as the calcination atmosphere. Under these conditions, the oxygen content of the active lattice of the catalyst can be effectively increased, thereby improving the catalyst activity. Detailed Implementation

[0033] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0034] The testing method and equipment used in this invention are as follows:

[0035] (1) Specific test methods for propylene pulse test

[0036] 2g of catalyst was loaded into a reaction tube, heated to 360℃, and purged with N2 for 30 minutes until all adsorbed oxygen on the catalyst surface was desorbed. Then, a propylene pulse test was performed (5ml / time) until the propylene conversion was less than 3%. The pulse interval was 3 minutes, and the reaction temperature was 360℃. The amount of unreacted propylene was quantified by gas chromatography-TCD external standard method. The percentage of active lattice oxygen in the catalyst to the total lattice oxygen in the catalyst = (total propylene conversion × 5 × 2 ÷ 22.4) / catalyst lattice oxygen content × 100%.

[0037]

Example 1

[0038] (1) Preparation of catalyst

[0039] 200 grams of (NH4)6Mo7O 24 • Add 4H2O to 200g of warm water at 70℃ and stir until completely dissolved. Then add 0.63g of KNO3 and 0.92g of CsNO3 to obtain material 1.

[0040] Add 71.4 g of Fe(NO3)3·9H2O to 30 g of 70°C hot water, stir to dissolve, then add 35.8 g of Bi(NO3)3·5H2O, 84.0 g of Co(NO3)2·6H2O, 97.0 g of Ni(NO3)2·6H2O, 35.2 g of Mn(NO3)2 (50%), 9.8 g of Ce(NO3)3·3H2O and 4.4 g of La(NO3)3·3H2O, stir to dissolve, and then prepare material 2.

[0041] Add 60g of 40% (wt.) silica sol to material 1, and then add material 2 to material 1 under rapid stirring to form a catalyst slurry. After aging the slurry at 80℃ for 1.5 hours, transfer it to an oven and dry it at 160℃ for 20 hours. Then, pulverize it and sieve it through a 20-40 mesh screen.

[0042] Calcination conditions: Calcination temperature 493℃; Calcination time 105 min; Calcination atmosphere was oxygen-enriched air with an oxygen content of 29 vol% (29 vol% O2, 71 vol% N2), and a flow rate of 15 ml / (min·gcat). The resulting catalyst was composed of Mo. 12 Bi 0.78 Fe 1.85 Ni3.50 Co 2.97 Mn 1.05 Ce 0.20 K 0.16 Cs 0.05 +8.6% SiO2.

[0043] (2) Propylene pulse test on catalyst

[0044] Take 2g of catalyst and perform propylene pulse tests (5ml / time) until the propylene conversion rate is less than 3%. The pulse interval is 3min, the reaction temperature is 360℃, and the amount of unreacted propylene is quantified by TCD external standard method.

[0045] Results: The cumulative total conversion rate of propylene was 710%, the lattice oxygen consumed was 3.16 mmol, and the total lattice oxygen contained in 2g of catalyst was 28.2 mmol; the active lattice oxygen accounted for 11.24% of the total lattice oxygen in the catalyst.

[0046]

Example 2

[0047] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 488℃; calcination time 100min; calcination atmosphere was oxygen-enriched air with an oxygen content of 33% by volume (67% by volume was N2) and a flow rate of 15ml / (min·gcat) to obtain the catalyst.

[0048] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 702%, the lattice oxygen consumed was 3.13 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.11% of the total lattice oxygen of the catalyst.

[0049]

Example 3

[0050] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 485℃; calcination time 95min; calcination atmosphere was oxygen-enriched air with an oxygen content of 25% by volume (75% by volume was N2) and a flow rate of 15ml / (min·gcat) to obtain the catalyst.

[0051] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 706%, the lattice oxygen consumed was 3.14 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.18% of the total lattice oxygen of the catalyst.

[0052]

Example 4

[0053] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 490℃; calcination time 90min; calcination atmosphere was oxygen-enriched air with an oxygen content of 38% by volume (62% by volume was N2) and a flow rate of 15ml / (min·gcat) to obtain the catalyst.

[0054] (2) The catalyst was subjected to a propylene pulse test according to the method in Example 1. The results showed that the cumulative total conversion rate of propylene was 699%, the lattice oxygen consumed was 3.11 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.07% of the total lattice oxygen of the catalyst.

[0055]

Example 5

[0056] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 486℃; calcination time 85min; calcination atmosphere was oxygen-enriched air with an oxygen content of 35% by volume (65% by volume was N2) and a flow rate of 15ml / (min·gcat) to obtain the catalyst.

[0057] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 706%, the lattice oxygen consumed was 3.09 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.18% of the total lattice oxygen of the catalyst.

[0058]

Example 6

[0059] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 500℃; calcination time 100min; calcination atmosphere was oxygen-enriched air with an oxygen content of 25% by volume (75% by volume was N2) and a flow rate of 15ml / (min·gcat) to obtain the catalyst.

[0060] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 691%, the lattice oxygen consumed was 3.07 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 10.94% of the total lattice oxygen of the catalyst.

[0061]

Example 7

[0062] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were changed to: calcination temperature 478℃; calcination time 108min; calcination atmosphere was oxygen-enriched air with an oxygen content of 29% by volume (71% by volume was N2) and a flow rate of 13ml / (min·gcat) to obtain the catalyst.

[0063] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 709%, the lattice oxygen consumed was 3.09 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.22% of the total lattice oxygen of the catalyst.

[0064]

Example 8

[0065] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 496℃; calcination time 85min; calcination atmosphere was oxygen-enriched air with an oxygen content of 29% by volume (71% by volume was N2) and a flow rate of 18ml / (min·gcat) to obtain the catalyst.

[0066] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 708%, the lattice oxygen consumed was 3.15 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.21% of the total lattice oxygen of the catalyst.

[0067]

Example 9

[0068] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 486℃; calcination time 96min; calcination atmosphere was oxygen-enriched air with an oxygen content of 29% by volume (71% by volume was N2) and a flow rate of 14ml / (min·gcat) to obtain the catalyst.

[0069] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 698%, the lattice oxygen consumed was 3.11 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 11.05% of the total lattice oxygen of the catalyst.

[0070]

Example 10

[0071] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were replaced as follows: calcination temperature 496℃; calcination time 96min; calcination atmosphere was oxygen-enriched air with an oxygen content of 29% by volume (71% by volume was N2) and a flow rate of 16ml / (min·gcat) to obtain the catalyst.

[0072] (2) The catalyst was subjected to a propylene pulse test according to the method in Example 1. The results showed that the cumulative total conversion rate of propylene was 684%, the lattice oxygen consumed was 3.05 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 10.83% of the total lattice oxygen of the catalyst.

[0073]

Example 11

[0074] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were changed to: calcination temperature 505℃; calcination time 80min; calcination atmosphere was oxygen-enriched air with an oxygen content of 27% by volume (73% by volume was N2) and a flow rate of 13ml / (min·gcat) to obtain the catalyst.

[0075] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 687%, the lattice oxygen consumed was 3.06 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 10.88% of the total lattice oxygen of the catalyst.

[0076]

Example 12

[0077] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were changed to: calcination temperature 482℃; calcination time 115min; calcination atmosphere was oxygen-enriched air with an oxygen content of 29% by volume (71% by volume was N2) and a flow rate of 17ml / (min·gcat) to obtain the catalyst.

[0078] (2) The catalyst was subjected to a propylene pulse test according to the method of Example 1. The results showed that the cumulative total conversion rate of propylene was 681%, the lattice oxygen consumed was 3.03 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 10.78% of the total lattice oxygen of the catalyst.

[0079] Comparative Example 1

[0080] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were changed to: calcination temperature 493℃; calcination time 105min; calcination atmosphere was oxygen-enriched air with an oxygen content of 29% (71% by volume of N2) and a flow rate of 30ml / (min·gcat) to obtain the catalyst.

[0081] (2) The catalyst was subjected to a propylene pulse test according to the method in Example 1. The results showed that the cumulative total conversion rate of propylene was 656%, the lattice oxygen consumed was 2.92 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 10.39% of the total lattice oxygen of the catalyst.

[0082] Comparative Example 2

[0083] (1) The catalyst product was prepared according to the method of Example 1, except that the calcination conditions were changed to: calcination temperature 493℃; calcination time 105min; calcination atmosphere was air (oxygen content of 21% by volume) and flow rate of 15ml / (min·gcat) to obtain the catalyst.

[0084] (2) The catalyst was subjected to a propylene pulse test according to the method in Example 1. The results showed that the cumulative total conversion rate of propylene was 648%, the lattice oxygen consumed was 2.89 mmol, the total lattice oxygen contained in 2g of catalyst was 28.2 mmol, and the active lattice oxygen of the catalyst accounted for 10.26% of the total lattice oxygen of the catalyst.

[0085] [Test Example]

[0086] The catalysts obtained in the examples and comparative examples were evaluated under the following conditions:

[0087] Reactor: Fixed-bed single-tube reactor, inner diameter 25.4 mm, reactor length 3000 mm

[0088] Catalyst: 600 grams

[0089] Reaction temperature: 375℃

[0090] Reaction pressure: 0.1 kg / cm² 2

[0091] Reaction time: 4000 hours

[0092] Raw material ratio: propylene / air / water vapor = 10 / 73 / 17

[0093] Reaction space velocity: 1200 hours -1

[0094] The reaction product was absorbed with dilute acid at 0℃, analyzed by gas chromatography, and the carbon balance was calculated. Data with carbon balance between 95% and 105% inactivation was considered valid.

[0095] Definitions of propylene conversion, product yield, and selectivity:

[0096] Propylene conversion rate (%) = 1 - (number of moles of unreacted propylene C / number of moles of C in all products) × 100%

[0097] Yield of a certain product (%) = (Number of moles of C of the product produced / Total number of moles of C of all products) × 100%

[0098] Product selectivity (%) = Product yield / Propylene conversion rate × 100%

[0099] The catalyst evaluation results are shown in Table 1.

[0100] Table 1

[0101]

[0102]

[0103] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. A propylene oxidation catalyst, comprising a support and an active metal component, wherein the active lattice oxygen of the catalyst accounts for 10.78-11.30% of the total lattice oxygen of the catalyst. The active metal component is represented by the following general formula: Mo 12 Bi a Fe b X c Y d Z e O χ ,in, X is selected from at least one of V, Nb, Cr, W, Mg, Ca, Ba, Sr, Co, Ni, Sn, Cu, Pb, and Mn; Y is selected from at least one of Ag, K, Rb, Na, Li, Tl, and Cs; Z is selected from at least one of Al, La, Ce, Sc, Sm, and Th; wherein, the value of a ranges from 0.2 to 5.5; the value of b ranges from 0.2 to 4.5; the value of c ranges from 0.7 to 9.5; the value of d ranges from 0.1 to 1.0; the value of e ranges from 0.2 to 3.5; χ is the total number of oxygen atoms required to satisfy the valence of other elements. Based on the total weight of the catalyst, the content of the active metal component is 80% to 95% by weight. The method for preparing the propylene oxidation catalyst includes: a) Mix the material containing the active metal component precursor with the carrier precursor to obtain a slurry; b) The slurry obtained in step a) is aged, dried, and pulverized to obtain the catalyst precursor; c) Calcining the catalyst precursor obtained in step b) yields the catalyst; The roasting atmosphere is an oxygen-enriched gas with a flow rate of 10-20 ml / (min•gcat) and an oxygen content of 25-52% by volume.

2. The catalyst according to claim 1, characterized in that, The support is selected from at least one of SiO2, Al2O3 and TiO2.

3. The catalyst according to any one of claims 1-2, characterized in that, Based on the total weight of the catalyst, the content of the support is 5% to 20% by weight.

4. A method for preparing the propylene oxidation catalyst according to any one of claims 1-3, comprising: a) The material containing the active metal component precursor is mixed with the carrier precursor to obtain a slurry; b) The slurry obtained in step a) is aged, dried, and pulverized to obtain the catalyst precursor; c) Calcining the catalyst precursor obtained in step b) yields the catalyst; The roasting atmosphere is an oxygen-enriched gas with a flow rate of 10-20 ml / (min•gcat) and an oxygen content of 25-52% by volume.

5. The preparation method according to claim 4, characterized in that, The flow rate of oxygen-enriched gas is 12~19 ml / (min•gcat).

6. The preparation method according to claim 5, characterized in that, The flow rate of oxygen-enriched gas is 14~16 ml / (min•gcat).

7. The preparation method according to any one of claims 4-6, characterized in that, The roasting conditions include: a temperature of 420~540℃ and a time of 50~150min.

8. The preparation method according to claim 7, characterized in that, The roasting conditions include: a temperature of 440~520℃ and a time of 60~130min.

9. The preparation method according to any one of claims 4-6, characterized in that, The oxygen content in oxygen-enriched gas is 26-42% by volume.

10. The preparation method according to claim 9, characterized in that, The oxygen content in oxygen-enriched gas is 28-39% by volume.

11. The use of the catalyst according to any one of claims 1-3 in the oxidation of propylene to prepare acrolein and acrylic acid.

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