Propylene oxidation catalyst as well as preparation method and application thereof

Abstract

The invention relates to a propylene oxidation catalyst, the catalyst comprises a carrier and an active metal oxide component, the active metal oxide component comprises Mo, Bi, Fe, X, Y, Z and O. The component X is selected from at least one of Ag, Zr, Ni, Mn and Mg; the component Y is selected from at least one of K, Cs, Rb, Li and Na; the component Z is selected from at least one of Co, Ce and La; preferably, the molar ratio of the components Mo to Bi to Fe to X to Y to Z is 12 to (0.3 to 4.2) to (0.4 to 4.0) to (0.6 to 9.0) to (0.1 to 0.8) to (0.5 to 5.8); and / or the mole number of the component O is the total number of oxygen atoms required for meeting the valence of other components. The invention also provides a preparation method and application of the propylene oxidation catalyst.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a propylene oxidation catalyst and a preparation method and application thereof. Background Art

[0002] The selective oxidation of olefins to prepare unsaturated aldehydes and unsaturated acids is an important chemical process, wherein the production of unsaturated aldehydes uses a catalyst containing Mo and Bi as active components.

[0003] Chinese patent CN107282056A provides a catalyst for propylene oxidation to synthesize acrolein and acrylic acid. The catalyst uses a carrier with a large number of macroporous structures and a catalyst with highly dispersed active components, which has obvious benefits in improving the effect of propylene oxidation reaction and heat dissipation of the catalyst bed.

[0004] Chinese patent CN114650880A provides a method for producing a multiphase mixed oxide catalyst, which comprises at least one active phase based on bismuth molybdate and a co-catalyst based on iron molybdate and at least one of cobalt and nickel, and produces the above-mentioned type of catalyst by replacing the above-mentioned hydrothermal reaction with a microwave-assisted hydrothermal reaction; and has high reactivity.

[0005] In order to improve the conversion rate and selectivity of olefin oxidation reaction, the prior art mainly improves the catalyst structure, catalyst components, reaction method, etc. However, the prior art does not improve the technology from the aspect of increasing the lattice oxygen migration speed in the catalyst. Summary of the invention

[0006] In view of the deficiencies of the prior art, the present invention provides a propylene oxidation catalyst and a preparation method and application thereof.

[0007] To this end, the first aspect of the present invention provides a propylene oxidation catalyst, which includes a carrier and an active metal oxide component, wherein the active metal oxide has the following components: Mo, Bi, Fe, X, Y, Z and O, wherein the component X is selected from at least one of Ag, Zr, Ni, Mn and Mg; the component Y is selected from at least one of K, Cs, Rb, Li and Na; and the component Z is selected from at least one of Co, Ce and La.

[0008] In some embodiments of the present invention, the molar ratio of the components Mo, Bi, Fe, X, Y and Z is 12:(0.3-4.2):(0.4-4.0):(0.6-9.0):(0.1-0.8):(0.5-5.8); and / or, the molar number of the component O is the total number of oxygen atoms required to satisfy the valence of the other components.

[0009] In some embodiments of the present invention, in the active metal oxide component, the molar ratio of component Z to component Fe is 4.0-10.0, preferably 5.5-8.2.

[0010] In some embodiments of the present invention, the active metal oxide 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 Ag, Zr, Ni, Mn, and Mg; Y is selected from at least one of K, Cs, Rb, Li, and Na; and Z is selected from at least one of Co, Ce, and La.

[0011] In some embodiments of the present invention, in the general formula of the active metal oxide component, a is in the range of 0.3-4.2; b is in the range of 0.4-4.0; c is in the range of 0.6-9.0; d is in the range of 0.1-0.8; e is in the range of 0.5-5.8; and χ is the total number of oxygen atoms required to satisfy the valence of other elements.

[0012] In some embodiments of the present invention, the value range of e / b is 4.0-10.0, preferably 5.5-8.2.

[0013] In some embodiments of the present invention, the catalyst is used in a propylene pulse test, and when the pulse interval is greater than 60 seconds, the propylene conversion rate decreases by less than 10% in the first three propylene pulse tests. When the propylene conversion rate decreases by less than 10% in the first three propylene pulse tests, it indicates that the lattice oxygen migration rate of the catalyst is relatively fast.

[0014] In the oxidation reaction between the catalyst and propylene, the active lattice oxygen on the surface and shallow layer of the catalyst is consumed, the catalyst activity decreases, and the lattice oxygen in the bulk phase of the catalyst migrates to the shallow layer of the catalyst through the lattice to restore the catalyst activity. The lattice oxygen migration rate of the catalyst can be represented by the change in the conversion rate of propylene in the continuous propylene pulse test. The propylene conversion rate is calculated by the amount of unreacted propylene in the tail gas after the pulse test and the amount of propylene fed in the pulse test. In the propylene pulse test of the present invention, the propylene conversion rate decrease rate in the first three times is less than 10%.

[0015] In some embodiments of the present invention, the carrier is selected from at least one of SiO2, Al2O3 and TiO2.

[0016] In some embodiments of the present invention, the specific surface area of ​​the carrier is 70-120 m 2 / g; and / or, the pore volume of the carrier is 0.06-0.11mL / g.

[0017] In some embodiments of the present invention, based on the total weight of the catalyst, the content of the carrier is 5 wt%-20 wt%; and / or the content of the active metal oxide component is 80 wt%-95 wt%.

[0018] The second aspect of the present invention provides a method for preparing the catalyst as described in the first aspect, the method comprising: mixing an active metal oxide precursor with a carrier precursor, and performing aging and calcining to obtain the catalyst.

[0019] In some embodiments of the present invention, the calcining atmosphere is air.

[0020] In some embodiments of the present invention, the oxygen content of the air is less than 30%, preferably less than 20%.

[0021] In some embodiments of the present invention, the air flow rate is 10-18 mL / (min·gcat), preferably 12-17 mL / (min·gcat).

[0022] In the present invention, the air flow rate unit "mL / (min·gcat)" means that the air flow rate is milliliter per minute per gram of catalyst.

[0023] In some embodiments of the present invention, the calcination includes two-stage calcination.

[0024] In some embodiments of the present invention, the method comprises the following specific steps:

[0025] S1, mixing an active metal oxide precursor and a carrier precursor to obtain a slurry;

[0026] S2, aging the obtained slurry, drying and crushing it to obtain a catalyst precursor;

[0027] S3, calcining the obtained catalyst precursor in two stages to obtain a catalyst;

[0028] In some embodiments of the present invention, the active metal oxide component of the active metal oxide precursor is Fe, which is added separately at the end for mixing.

[0029] In some embodiments of the present invention, the conditions of the two-stage roasting include: the first-stage roasting temperature is 300-400° C., preferably 320-390° C.; and the roasting time is 60-90 min.

[0030] In some embodiments of the present invention, the conditions of the two-stage roasting include: the second-stage roasting temperature is 450-550° C., preferably 460-520° C.; the roasting time is 100-450 min, preferably 120-380 min.

[0031] In some embodiments of the present invention, the aging conditions include: an aging temperature of 60-80° C., such as 70° C.; and an aging time of 8-50 h, such as 24 h.

[0032] In some embodiments of the present invention, the drying conditions include: a drying temperature of 120-150° C., such as 135° C.; and a drying time of 16-30 h, such as 20 h.

[0033] In some embodiments of the present invention, the active metal oxide precursor comprises a soluble salt of a metal element represented by the general formula, obtained by compounding, wherein the general formula is Mo 12 Bi a Fe b X c Y d Z e O χ , wherein X is selected from at least one of Ag, Zr, Ni, Mn, and Mg; Y is selected from at least one of K, Cs, Rb, Li, and Na; and Z is selected from at least one of Co, Ce, and La.

[0034] In some embodiments of the present invention, the carrier precursor includes but is not limited to silicon dioxide, silica sol or titanium oxide.

[0035] In some embodiments of the present invention, the amount of the soluble salt of the metal element represented by the general formula and the carrier precursor in the active metal oxide precursor is calculated by the general formula, wherein the general formula is Mo 12 Bi a Fe b X c Y d Z e O χ , wherein X is selected from at least one of Ag, Zr, Ni, Mn, and Mg; Y is selected from at least one of K, Cs, Rb, Li, and Na; Z is selected from at least one of Co, Ce, and La; a is in the range of 0.3-4.2; b is in the range of 0.4-4.0; c is in the range of 0.6-9.0; d is in the range of 0.1-0.8; e is in the range of 0.5-5.8; and χ is the total number of oxygen atoms required to satisfy the valence of other elements.

[0036] In some embodiments of the present invention, the soluble salt of the metal element represented by the general formula comprises a nitrate of the metal element represented by the general formula.

[0037] The third aspect of the present invention provides a propylene oxidation catalyst prepared by the preparation method described in the second aspect.

[0038] In some embodiments of the present invention, the catalyst comprises a carrier and an active metal oxide component, wherein the active metal oxide 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 Ag, Zr, Ni, Mn, and Mg; Y is selected from at least one of K, Cs, Rb, Li, and Na; and Z is selected from at least one of Co, Ce, and La.

[0039] In some embodiments of the present invention, in the general formula of the active metal oxide component, a is in the range of 0.3-4.2; b is in the range of 0.4-4.0; c is in the range of 0.6-9.0; d is in the range of 0.1-0.8; e is in the range of 0.5-5.8; and χ is the total number of oxygen atoms required to satisfy the valence of other elements.

[0040] In some embodiments of the present invention, the value range of e / b is 4.0-10.0, preferably 5.5-8.2.

[0041] In some embodiments of the present invention, the catalyst is used in a propylene pulse test. When the pulse interval is greater than 60s, the propylene conversion rate decreases by less than 10% in the first three propylene pulse tests; and the catalyst has a fast lattice oxygen migration rate.

[0042] In some embodiments of the present invention, the carrier is selected from at least one of SiO2, Al2O3 and TiO2.

[0043] In some embodiments of the present invention, based on the total weight of the catalyst, the content of the carrier is 5 wt%-20 wt%; and / or the content of the active metal oxide component is 80 wt%-95 wt%.

[0044] The fourth aspect of the present invention provides use of the catalyst described in the first aspect or the catalyst described in the third aspect in the preparation of acrolein and acrylic acid by oxidation of propylene.

[0045] Beneficial effects:

[0046] 1. The catalyst of the present invention has a fast lattice oxygen migration rate and is used in a pulse test of propylene selective oxidation reaction. It has a high propylene conversion rate and a low rate of decrease in the propylene conversion rate in multiple interval tests.

[0047] 2. In the catalyst preparation process of the present invention, air with a specific flow rate is used as the calcination atmosphere, and the catalyst calcination conditions are optimized to be two-stage calcination combined with other specific calcination conditions such as calcination temperature and calcination time, so that a catalyst with a fast lattice oxygen migration rate can be prepared. DETAILED DESCRIPTION

[0048] In order to make the present invention more easily understood, the present invention will be described in detail below in conjunction with embodiments. These embodiments are only for illustration and are not intended to limit the application scope of the present invention.

[0049] Example 1

[0050] This embodiment provides a method for preparing a propylene oxidation catalyst, comprising: 24 ·4H2O is added to 400g of 70℃ warm water, stirred to dissolve it completely, and then 1.26g of KNO3 and 1.84g of CsNO3 are added to obtain material 1; then 71.6g of Bi(NO3)3·5H2O, 185g of Co(NO3)2·6H2O, 194g of Ni(NO3)2·6H2O, 70.4g of Mn(NO3)2 (50%), 196g of Ce(NO3)3·3H2O and 8.8g of La(NO3)3·3H2O are weighed, and 60g of 70℃ hot water is added and stirred to dissolve to obtain material 2; 30g of 70℃ hot water is added to 80g of Fe(NO3)3·9H2O and stirred to dissolve to obtain material 3.

[0051] Add 120g of 40wt% silica sol to material 1, then add material 2 to material 1 under rapid stirring to form a preliminary slurry, add material 3 after 5 minutes, then age at 70℃ for 24h, transfer to an oven and dry at 135℃ for 20h, and crush; a) take the powder sieved with 20-40 mesh and use it for pulse test after two-stage roasting, b) take the remaining powder and slice to obtain 5*5*2 Raschig ring catalyst precursor; take 600g of the obtained catalyst precursor and roast it in two stages; the conditions of the two-stage roasting are: the first stage roasting temperature is 350℃, the roasting time is 70min; the second stage roasting temperature is 480℃, the roasting time is 200min; the roasting atmosphere is air, the flow rate is 15mL / (min·gcat), and the finished catalyst is obtained after roasting. The components of the catalyst are:

[0052] Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.27 Mn 1.05 Ce 2.0 La 0.09 K0.16 Cs 0.05 +8.6% SiO2.

[0053] a) Catalyst propylene pulse test

[0054] Take 2g of the catalyst after 20-40 mesh sieving and two-stage calcination and load it into the reaction tube, raise the temperature to 360°C, pass N2 for 30min to purge until the oxygen adsorbed on the catalyst surface is completely desorbed, and then perform propylene pulse test three times (5mL / time), pulse interval 90s, reaction temperature 360°C, wherein the amount of unreacted propylene is quantified by gas chromatography TCD external standard method. The propylene conversion rate is calculated from the amount of unreacted propylene and the amount of feed propylene, propylene conversion rate (%) = 1-(unreacted propylene C mole number / feed propylene C mole number) × 100%.

[0055] The propylene conversions in the three propylene pulse tests were 95%, 92% and 90% respectively.

[0056] Example 2

[0057] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing the catalyst in Example 1, except that 167 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.27 Mn 1.05 Ce 1.7 La 0.45 K 0.16 Cs 0.05 +8.6% SiO2.

[0058] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three propylene pulse tests were 95%, 92% and 90% respectively.

[0059] Example 3

[0060] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing the catalyst in Example 1, except that 167 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 62 g of Mg(NO3)2·6H2O is added. The catalyst components are:

[0061] Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.27 Mn1.05 Mg 1.24 Ce 1.7 La 0.45 K 0.16 Cs 0.05 +8.6% SiO2.

[0062] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three propylene pulse tests were 96%, 93% and 92% respectively.

[0063] Example 4

[0064] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing the catalyst in Example 1, except that 167 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 93 g of Mg(NO3)2·6H2O is added. The components of the catalyst are:

[0065] Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.27 Mn 1.05 Mg 1.86 Ce 1.7 La 0.45 K 0.16 Cs 0.05 +8.6% SiO2.

[0066] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three propylene pulse tests were 95%, 94% and 91% respectively.

[0067] Example 5

[0068] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing Example 1, except that 139 g of Ni(NO3)2·6H2O, 152 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 62 g of Mg(NO3)2·6H2O is added. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.04 Ni 2.50 Co 3.27 Mn 1.05 Mg 1.24 Ce 1.55 La 0.4 5K 0.16 Cs 0.05 +8.6% SiO2.

[0069] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 93% and 91% respectively.

[0070] Example 6

[0071] This embodiment provides a preparation method of a propylene oxidation catalyst which is the same as the preparation method of Example 1, with the only difference being that 82.6 g of Bi(NO3)3·5H2O, 154 g of Ni(NO3)2·6H2O, 35.2 g of Mn(NO3)2 (50%), 167 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 62 g of Mg(NO3)2·6H2O is added. The components of the catalyst are:

[0072] Mo 12 Bi 0.90 Fe 1.04 Ni 2.78 Co 3.27 Mn 0.58 Mg 1.24 Ce 1.7 La 0.45 K 0.16 Cs 0.05 +9.4% SiO2.

[0073] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 96%, 94% and 93% respectively.

[0074] Example 7

[0075] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing the catalyst in Example 1, except that 204 g of Co(NO3)2·6H2O, 128 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 62 g of Mg(NO3)2·6H2O is added. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.60 Mn 1.05 Mg 1.24 Ce 1.30 La 0.4 5K 0.16 Cs 0.05 +8.6% SiO2.

[0076] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 93% and 91% respectively.

[0077] Example 8

[0078] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing Example 1, with the only difference being that 92 g of Co(NO3)2·6H2O, 87.2 g of Mn(NO3)2 (50%), 192 g of Ce(NO3)3·3H2O and 66 g of La(NO3)3·3H2O are added, and 62 g of Mg(NO3)2·6H2O is added. 180 g of 40 wt% silica sol is added to material 1. The components of the catalyst are:

[0079] Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 1.62 Mn 1.30 Mg 1.24 Ce 1.95 La 0.67 K 0.16 Cs 0.05 +12.2% SiO2.

[0080] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 93% and 92% respectively.

[0081] Example 9

[0082] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing the catalyst in Example 1, except that 169 g of Co(NO3)2·6H2O, 182 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 83 g of Mg(NO3)2·6H2O is added. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.00 Mn 1.05 Mg 1.6 Ce 1.85 La 0.4 5K 0.16 Cs 0.05 +8.6% SiO2.

[0083] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 96%, 92% and 91% respectively.

[0084] Example 10

[0085] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing Example 1, except that 167 g of Ce(NO3)3·3H2O and 66 g of La(NO3)3·3H2O are added, and 124 g of Mg(NO3)2·6H2O is added. 164 g of 40 wt% silica sol is added to material 1. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.27 Mn 1.05 Mg 2.48 Ce 1.7 La 0.68 K 0.16 Cs 0.05 +10.1% SiO2.

[0086] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 96%, 94% and 93% respectively.

[0087] Embodiment 11

[0088] This embodiment provides a method for preparing a propylene oxidation catalyst which is the same as the method for preparing the catalyst in Example 1, except that 1.40 g of KNO3 is added; 213.3 g of Co(NO3)2·6H2O, 83 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 62 g of Mg(NO3)2·6H2O is added. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.04 Ni 3.50 Co 3.77 Mn 1.05 Mg 1.24 Ce 0.85 La 0.45 K 0.18 Cs 0.05 +8.6%SiO2.

[0089] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 94% and 91% respectively.

[0090] Example 12

[0091] This embodiment provides a preparation method of a propylene oxidation catalyst which is the same as the preparation method of Example 1, with the only difference being that 82.6 g of Bi(NO3)3·5H2O, 169.4 g of Co(NO3)2·6H2O, 108 g of Ni(NO3)2·6H2O, 169.4 g of Ce(NO3)3·3H2O and 44 g of La(NO3)3·3H2O are added, and 93 g of Mg(NO3)2·6H2O is added. The components of the catalyst are:

[0092] Mo 12 Bi 0.90 Fe 1.04 Ni 1.95 Co 2.99 Mn 1.05 Mg 1.86 Ce 1.72 La 0.45 K 0.16 Cs 0.05 +8.6% SiO2.

[0093] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 93% and 91% respectively.

[0094] Embodiment 13

[0095] This example provides the same propylene oxidation catalyst prepared by the same propylene oxidation catalyst preparation method as Example 12.

[0096] The catalyst was subjected to a propylene pulse test according to the method of Example 1, with the only difference being that the pulse interval was 60 seconds. The propylene conversion rates in the three propylene pulse tests were 95%, 93% and 90% respectively.

[0097] Comparative Example 1

[0098] The catalyst preparation method of this comparative example is the same as that of Example 1, with the only difference being that 100 g of Fe(NO3)3·9H2O and other substances are added to 60 g of 70°C hot water and stirred to dissolve to prepare material 2. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.30 Ni 3.50 Co 3.27 Mn 1.05 Ce 2.0 La 0.09 K 0.16 Cs 0.05 +8.6% SiO2.

[0099] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 94%, 87% and 79% respectively.

[0100] Comparative Example 2

[0101] The catalyst preparation method of this comparative example is the same as that of Example 1, except that 30 g of 70°C hot water is added to 120 g of Fe(NO3)3·9H2O and stirred to dissolve to obtain material 3. The components of the catalyst are: Mo 12 Bi 0.78 Fe 1.56 Ni 3.50 Co 3.27 Mn 1.05 Ce 2.0 La 0.09 K 0.16 Cs 0.05 +8.6% SiO2.

[0102] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 87% and 82% respectively.

[0103] Comparative Example 3

[0104] The catalyst preparation method of this comparative example is the same as that of Example 1, with the only difference being that the catalyst is subjected to one-stage calcination at a temperature of 480° C. for 200 min.

[0105] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 95%, 88% and 81% respectively.

[0106] Comparative Example 4

[0107] The catalyst preparation method of this comparative example is the same as that of Example 1, with the only difference being that the calcination atmosphere is oxygen-enriched air with an oxygen content of 30%.

[0108] The catalyst was subjected to a propylene pulse test according to the method of Example 1. The propylene conversion rates in the three pulse tests were 94%, 89% and 80% respectively.

[0109] Test Example 1

[0110] 300 g of the catalysts prepared in Examples 1-12 and Comparative Examples 1-4 were loaded into a fixed bed reactor, the inner diameter of the fixed bed reactor was 25.4 mm, and the length of the reactor was 1300 mm; the raw materials propylene: air: water vapor = 10:73:17 were introduced into the fixed bed reactor, and the temperature was 375 ° C and the pressure was 0.1 kg / cm 2 , airspeed 1200h -1The reaction was carried out for 2000 hours under the conditions of 0°C; the reaction product was absorbed by 0°C dilute acid, the product was analyzed by gas chromatography, and the carbon balance was calculated. When the carbon balance was inactivated at 95%-105%, it was considered valid data. After product analysis, the following calculation was performed:

[0111] Propylene conversion rate (%) = 1-(unreacted propylene C mole number / total product C mole number) × 100%

[0112] Yield of a product (%) = moles of a certain product C generated / moles of all products C × 100%

[0113] Selectivity of a certain product (%) = Yield of a certain product / Propylene conversion rate × 100%

[0114] The results are shown in Table 1.

[0115] Table 1 Product analysis results

[0116]

[0117]

[0118] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A propylene oxidation catalyst, comprising a carrier and an active metal oxide component, characterized in that: The active metal oxide has the following components: Mo, Bi, Fe, X, Y, Z and O, wherein the component X is selected from at least one of Ag, Zr, Ni, Mn and Mg; the component Y is selected from at least one of K, Cs, Rb, Li and Na; the component Z is selected from at least one of Co, Ce and La; Preferably, the molar ratio of the components Mo, Bi, Fe, X, Y and Z is 12:(0.3-4.2):(0.4-4.0):(0.6-9.0):(0.1-0.8):(0.5-5.8); and / or, the molar number of the component O is the total number of oxygen atoms required to satisfy the valence of the other components.

2. The catalyst according to claim 1, characterized in that In the active metal oxide component, the molar ratio of component Z to component Fe is 4.0-10.0, preferably 5.5-8.

2.

3. The catalyst according to claim 1 or 2, characterized in that The catalyst is used in a propylene pulse test. When the pulse interval is greater than 60 seconds, the propylene conversion rate decreases at a rate of less than 10% in the first three propylene pulse tests.

4. The catalyst according to any one of claims 1 to 3, characterized in that The carrier is selected from at least one of SiO2, Al2O3 and TiO2; Preferably, the specific surface area of ​​the carrier is 70-120 m 2 / g; and / or, the pore volume of the carrier is 0.06-0.11mL / g.

5. The catalyst according to any one of claims 1 to 4, characterized in that Based on the total weight of the catalyst, the content of the carrier is 5 wt%-20 wt%; and / or the content of the active metal oxide component is 80 wt%-95 wt%.

6. A method for preparing a catalyst according to any one of claims 1 to 5, characterized in that: include: The active metal oxide precursor is mixed with the carrier precursor, and the mixture is aged and calcined to obtain a catalyst; Preferably, the calcination atmosphere is air; And / or, the roasting comprises two stages of roasting; Preferably, the air flow rate is 10-18 mL / (min·gcat), preferably 12-17 mL / (min·gcat); Preferably, the active metal oxide precursor comprises a soluble salt of a metal element represented by the general formula of the active metal oxide component, obtained by compounding; and / or, the carrier precursor comprises silicon dioxide, silica sol or titanium oxide.

7. The preparation method according to claim 6, characterized in that: The active metal oxide component of the active metal oxide precursor is Fe, which is added separately at the end for mixing.

8. The preparation method according to claim 6 or 7, characterized in that: The two-stage roasting conditions include: the first stage roasting temperature is 300-400°C, preferably 320-390°C; the roasting time is 60-90min; and / or, the second stage roasting temperature is 450-550°C, preferably 460-520°C; the roasting time is 100-450min, preferably 120-380min.

9. A propylene oxidation catalyst prepared by the preparation method according to any one of claims 6 to 8.

10. Use of the catalyst according to any one of claims 1 to 5 or the catalyst according to claim 9 in the preparation of acrolein and acrylic acid by oxidation of propylene.

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