A catalyst for synthesizing acrylic acid, its preparation method and application

Abstract

The present invention discloses a catalyst for synthesizing acrylic acid, a preparation method thereof and an application thereof. The catalyst of the present invention comprises a carrier and an active component, and the surface of the catalyst has a chrysanthemum-shaped cluster structure. The novel catalyst of the present invention has the advantages of high acrylic acid yield and long service life.

Description

Technical Field

[0001] The present invention relates to the field of acrylic acid catalysts, and particularly to a catalyst for synthesizing acrylic acid, a preparation method thereof, and an application thereof. Background Art

[0002] Acrylic acid is the simplest unsaturated carboxylic acid and an important organic chemical raw material, mainly used to manufacture multifunctional polymer materials such as acrylic esters. Common acrylic esters include methyl acrylate, butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate. Due to the increasing market demand for acrylic acid worldwide, the production of acrylic acid has always been a research hotspot. Currently, the industrial production mainly adopts the two-step method of propylene, that is, propylene is first oxidized to acrolein, and then further oxidized to acrylic acid. The active component of the catalyst used for the oxidation of acrolein to acrylic acid is generally an oxide of the Mo-V series, and other elements used to improve the catalyst performance are added, such as Fe, Co, Cu, Nb, Sb, etc.

[0003] US7456129 discloses a carrier for a gas-phase oxidation catalyst suitable for the selective oxidation of acrolein to acrylic acid and a production method thereof. This method improves the catalyst performance by controlling the acid strength of the carrier and increases the selectivity of acrylic acid, but the yield of acrylic acid still needs to be further improved. US7220698B discloses a catalyst for catalytic gas-phase oxidation of acrolein and a method for producing acrylic acid by catalytic gas-phase oxidation using this catalyst. This method uses a catalyst with Mo-V as essential components, and by introducing trace amounts of catalyst poisons into the catalyst preparation process, the hot spot of the catalyst reaction bed layer is controlled, the thermal degradation of the catalyst is inhibited, and thus the conversion rate of acrolein is increased. CN111659408A proposes a preparation method for a catalyst for the oxidation of acrolein to acrylic acid. This method is based on Mo element, adding elements such as V, Ni, Cu, etc., and performing coprecipitation reaction or physical blending with their salts or corresponding oxides, and adopting geometric shapes such as spherical, cylindrical, or special-shaped, and finally calcining to endow the catalyst with activity to form a catalyst product.

[0004] The research and development of new catalysts with high acrylic acid yield and long life has always been a research hotspot in this field. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the present invention provides a catalyst for synthesizing acrylic acid, a preparation method thereof, and an application thereof. The novel catalyst of the present invention has the advantages of high acrylic acid yield and long life.

[0006] In the first aspect of the present invention, a catalyst for synthesizing acrylic acid is provided. The catalyst includes a carrier and an active component, and the surface of the catalyst has a chrysanthemum-shaped cluster structure.

[0007] Further, in the catalyst, each chrysanthemum-shaped cluster structure is composed of a central "stamen" and outwardly extending "slender needles".

[0008] Further, in the catalyst, a three-dimensional network-like porous structure is formed between each chrysanthemum-shaped cluster structure.

[0009] Further, in the catalyst, the active components include oxides of Mo, V, W, and Ce, transition metal oxides, and oxides selected from alkali metals and / or alkaline earth metals.

[0010] Further, the general formula of the active components is expressed as: V2O5·aMoO3·bWO3·cCeO2·dXO m ·eZO n , where X is a transition metal element, including at least one selected from Ru, Os, Rh, Ir, Pd, and Pt, Z is at least one selected from alkali metal or alkaline earth metal elements, including one or more selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba; a is the molar ratio of MoO3 to V2O5, and the value of a is 3.0 - 12.0; b is the molar ratio of WO3 to V2O5, and the value of b is 0.1 - 1.0; c is the molar ratio of CeO2 to V2O5, and the value of c is 0.1 - 1.0; d is the molar ratio of XO m to V2O5, and the value of d is 0.1 - 1.0; e is the molar ratio of ZO n to V2O5, and the value of e is 0.1 - 1.0; m and n are the number of moles of oxygen atoms required to satisfy the element valence in the active components.

[0011] Further, the carrier is selected from at least one of lithium oxide, magnesium oxide, aluminum oxide, zirconium dioxide, silicon dioxide, titanium dioxide, vanadium dioxide, diatomite, kaolin, and pumice.

[0012] Further, based on the total weight of the catalyst, the carrier content in the catalyst is 10% - 60%, preferably 20% - 40%, and the active component content is 40% - 90%, preferably 60% - 80%.

[0013] The second aspect of the present invention provides a preparation method of a catalyst for synthesizing acrylic acid, comprising the following steps:

[0014] (1) Mix the solutions containing the active element precursors to obtain a mixed solution I;

[0015] (2) Add P123 and F127 to the mixed solution I obtained in step (1) to obtain a mixed solution II;

[0016] (3) Mix the mixed solution II with the catalyst carrier, and after drying and calcination, obtain the catalyst for synthesizing acrylic acid.

[0017] Further, in step (1), the active element precursor is selected from vanadium-containing compounds (preferably at least one of ammonium metavanadate and vanadyl sulfate), molybdenum-containing compounds (preferably at least one of ammonium molybdate and molybdenum oxide), tungsten-containing compounds (preferably at least one of ammonium paratungstate and ammonium metatungstate), cerium-containing compounds (preferably at least one of cerium nitrate and ammonium cerium nitrate), transition metal-containing compounds (preferably nitrates or oxides of transition metals), and alkali metal or alkaline earth metal-containing compounds (preferably nitrates or carbonates of alkali metals or alkaline earth metals).

[0018] Further, in step (2), the mass ratio of P123 (polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer) to F127 (polyoxyethylene polyoxypropylene ether block copolymer) is 0.1 - 1.0:1, preferably 0.2 - 0.5:1. The total amount of P123 and F127 is 0.1% - 0.8% of the total mass content of the active components in the catalyst, preferably 0.2 - 0.5%.

[0019] Further, in step (2), it is preferred to first add P123 and F127 to water for mixing, and then add them to the mixed solution I.

[0020] Further, in step (2), the pH value of the obtained mixed solution II is controlled to be 3 - 6, preferably 4 - 5. It can be adjusted by nitric acid or ammonia water.

[0021] Further, in step (3), it is preferred to first let the mixed solution II stand for a certain time and then mix it with the catalyst support. The standing time is 1 - 48 hours, preferably 6 - 18 hours; the standing temperature is 30 - 90°C, preferably 40 - 60°C; an oxygen-containing atmosphere such as air should be introduced during the standing stage of the mixed solution II.

[0022] Further, in step (3), the drying temperature is 50 - 150°C and the drying time is 1 - 48 hours. The calcination temperature is 300 - 500°C and the calcination time is 1 - 48 hours.

[0023] The third aspect of the present invention also provides the use of the above catalyst or the catalyst prepared by the above method in the oxidation of acrolein to acrylic acid.

[0024] The use is as follows: in the presence of the catalyst and a diluent gas-phase material, acrolein is contacted with an oxygen-containing gas to obtain acrylic acid.

[0025] Further, the diluent gas-phase material is water vapor. The oxygen-containing gas is air, pure oxygen or oxygen-enriched air.

[0026] Further, the conditions for the contact include: the temperature is 200°C to 350°C; the volume ratio of the acrolein to the oxygen-containing gas is 1:(1 to 12); the volume ratio of the acrolein to the diluting gas-phase material is 1:(0.5 to 5), and the overall volume space velocity is 800 h -1 ~3000 h -1 .

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] Using the catalyst of the present invention, when the total space velocity of the raw material gas is 2200 h -1 , the acrylic acid yield can reach more than 91%, and the catalyst life can reach more than 80 months, achieving good technical effects and can be used in the industrial production of acrylic acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 SEM diagram of the catalyst prepared for Comparative Example 1.

[0030] Figure 2 and Figure 3 are respectively the SEM diagram and the enlarged SEM diagram of the catalyst prepared for Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0031] The surface morphologies of the catalysts obtained in the examples and comparative examples of the present invention were measured by scanning electron microscopy (SEM), model: ZEISS Merlin, high voltage: 3.0 kV, WD working distance: 4 mm.

[0032] The evaluation methods of the catalysts obtained in the examples and comparative examples of the present invention are as follows:

[0033] Reactor: Fixed-bed micro-reactor, inner diameter 10 mm, reactor length 330 mm;

[0034] Catalyst filling amount: 2 g;

[0035] Reaction temperature: 270°C;

[0036] Reaction time: 4 hours;

[0037] Raw material volume ratio: acrolein: air: water vapor = 1:8:2;

[0038] Total space velocity of the raw material gas: 2200 h -1 .

[0039]

Comparative Example 1

[0040] 1. Mix the active element liquids of each component to obtain a mixed solution I

[0041] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 mole of MoO3, ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41 ) containing 0.05 mole of WO3, cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 mole of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 mole of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 mole of CaO are respectively dissolved in hot water at 80°C. After uniformly mixing all the active component solutions, the mixture is stirred and evaporated at 80°C until the concentration of the active components V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO in the mixed material solution is 0.5 g / g, obtaining the active component mixed solution I.

[0042] 2. Obtaining the mixed solution II and adjusting the pH value

[0043] Take 200 g of the above-mentioned active component mixed solution I, cool it to room temperature, and use nitric acid with a concentration of 0.1 mole / liter to adjust the pH value to 4.5, and place it at 50°C for 10 hours to obtain the mixed solution II.

[0044] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0045] Mix the above-mentioned mixed solution II uniformly with 50 g of alumina powder carrier, and after forming, obtain the catalyst precursor I. Dry the catalyst precursor I in an oven at 80°C for 4 hours, and then calcine it in a muffle furnace at 400°C for 4 hours to obtain a catalyst with the following composition:

[0046] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0047]

Comparative Example 2

[0048] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0049] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 mole of MoO3, ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41) Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO were respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, the mixture was stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO, obtaining the active component mixed solution I.

[0050] 2. Obtaining the mixed solution II and adjusting the pH value

[0051] 0.3 g of P123 and 0.1 g of F127 were mixed in deionized water at 80 °C and then mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, the pH value was adjusted to 4.5 using 0.1 mol / L nitric acid, and it was left standing at 50 °C for 10 hours. Air was introduced during the standing stage, obtaining the mixed solution II.

[0052] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0053] The above-mentioned mixed solution II was mixed evenly with 50 g of alumina powder carrier, and after shaping, the catalyst precursor I was obtained. The catalyst precursor I was dried in an oven at 80 °C for 4 hours and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0054] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0055]

Comparative Example 3

[0056] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0057] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41) Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO are separately dissolved in hot water at 80 °C. After uniformly mixing all the active component solutions, stirring and evaporating at 80 °C until the concentration of the active components equivalent to V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO in the mixed material solution is 0.5 g / g, an active component mixed solution I is obtained.

[0058] 2. Obtaining mixed solution II and adjusting the pH value

[0059] Mix 0.1 g of P123 and 0.3 g of F127 in deionized water at 80 °C, and mix them with 200 g of the above-mentioned active component mixed solution I. Stir until room temperature, and use 0.1 mol / L ammonia water to adjust the pH value to 8.0. Place it at 50 °C for 10 hours, and pass air during the placement stage to obtain mixed solution II.

[0060] 3. Mixing mixed solution II with the carrier, drying and calcining

[0061] Mix the above-mentioned mixed solution II uniformly with 50 g of alumina powder carrier, and obtain catalyst precursor I after forming. Dry catalyst precursor I in an oven at 80 °C for 4 hours, and then calcine it in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0062] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0063]

Example 1

[0064] 1. Mixing each component of the active element solution to obtain mixed solution I

[0065] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41) Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO are respectively dissolved in hot water at 80°C. After mixing all the active component solutions evenly, they are stirred and evaporated at 80°C until the concentration of the active components equivalent to V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO in the mixed material solution is 0.5 g / g, obtaining mixed solution I.

[0066] 2. Obtaining mixed solution II and adjusting the pH value

[0067] Mix 0.1 g of P123 and 0.3 g of F127 in deionized water at 80°C, and mix them with 200 g of the above-mentioned active component mixed solution I. Stir until room temperature, and use 0.1 mole / liter of nitric acid to adjust the pH value to 4.5. Place it at 50°C for 10 hours, and air needs to be introduced during the placement stage to obtain mixed solution II.

[0068] 3. Mixing mixed solution II with the carrier, drying and calcining

[0069] Mix the above-mentioned mixed solution II evenly with 50 g of alumina powder carrier, and obtain catalyst precursor I after forming. Dry catalyst precursor I in an oven at 80°C for 4 hours, and then calcine it in a muffle furnace at 400°C for 4 hours to obtain a catalyst with the following composition:

[0070] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0071]

Example 2

[0072] 1. Mixing active element solutions of each component to obtain mixed solution I

[0073] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), cerium nitrate containing 0.05 moles of CeO2 (molecular formula: Ce(NO3)3), rhodium nitrate containing 0.05 moles of Rh2O3 (molecular formula: Rh(NO3)3), and calcium hydroxide containing 0.05 moles of CaO (molecular formula: Ca(OH)2) were respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, they were stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO, obtaining the active component mixed solution I.

[0074] 2. Obtaining the mixed solution II and adjusting the pH value

[0075] 0.1 g of P123 and 0.3 g of F127 were mixed in deionized water at 80 °C and mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, nitric acid with a concentration of 0.1 mol / L was used to adjust the pH value to 3.0, and it was left standing for 10 hours at 50 °C. Air was introduced during the standing stage to obtain the mixed solution II.

[0076] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0077] The above-mentioned mixed solution II was mixed evenly with 50 g of alumina powder carrier, and after shaping, the catalyst precursor I was obtained. The catalyst precursor I was dried in an oven at 80 °C for 4 hours, and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0078] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0079]

Example 3

[0080] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0081] Ammonium metavanadate containing 0.1 moles of V2O5 (molecular formula: NH4VO3), ammonium molybdate containing 0.6 moles of MoO3 (molecular formula: (NH4)2MoO4), ammonium tungstate containing 0.05 moles of WO3 (molecular formula: (NH4) 10 W 12 O 41) Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO were respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, they were stirred and evaporated at 80 °C until the concentration of the active components equivalent to V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO in the mixed material solution was 0.5 g / g, obtaining the active component mixed solution I.

[0082] 2. Obtaining the mixed solution II and adjusting the pH value

[0083] 0.1 g of P123 and 0.3 g of F127 were mixed in deionized water at 80 °C and mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, the pH value was adjusted to 6.0 using 0.1 mol / L ammonia water and left standing at 50 °C for 10 hours. Air was introduced during the standing stage to obtain the mixed solution II.

[0084] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0085] The above-mentioned mixed solution II was mixed evenly with 50 g of alumina powder carrier, and after forming, the catalyst precursor I was obtained. The catalyst precursor I was dried in an oven at 80 °C for 4 hours and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0086] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0087]

Example 4

[0088] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0089] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO were respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, the mixture was stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO, obtaining the active component mixed solution I.

[0090] 2. Obtaining the mixed solution II and adjusting the pH value

[0091] 0.2 g of P123 and 0.2 g of F127 were mixed in deionized water at 80 °C and mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, the pH value was adjusted to 4.5 using 0.1 mol / L nitric acid, and it was left standing for 10 hours at 50 °C. Air was introduced during the standing stage, obtaining the mixed solution II.

[0092] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0093] The above-mentioned mixed solution II was mixed evenly with 50 g of alumina powder carrier, and after forming, the catalyst precursor I was obtained. The catalyst precursor I was dried in an oven at 80 °C for 4 hours, and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0094] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0095]

Example 5

[0096] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0097] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO were respectively dissolved in hot water at 80 °C. After uniformly mixing all the active component solutions, the mixture was stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO, obtaining the active component mixed solution I.

[0098] 2. Obtaining the mixed solution II and adjusting the pH value

[0099] 0.036 g of P123 and 0.36 g of F127 were mixed in deionized water at 80 °C and then mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, the pH value was adjusted to 4.5 using 0.1 mol / L nitric acid, and it was left standing at 50 °C for 10 hours. Air was introduced during the standing stage, obtaining the mixed solution II.

[0100] 3. Mixing the mixed solution II with the carrier, drying, and calcining

[0101] The above-mentioned mixed solution II was uniformly mixed with 50 g of alumina powder carrier, and after forming, the catalyst precursor I was obtained. The catalyst precursor I was dried in an oven at 80 °C for 4 hours and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0102] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Al2O3.

[0103]

Example 6

[0104] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0105] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41) Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, palladium nitrate (molecular formula: Pd(NO3)2) containing 0.1 moles of PdO, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO are respectively dissolved in hot water at 80°C. After uniformly mixing all the active component solutions, the mixture is stirred and evaporated at 80°C until the concentration of the active components in the mixed material solution is equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·PdO·0.5CaO, obtaining the active component mixed solution I.

[0106] 2. Obtaining the mixed solution II and adjusting the pH value

[0107] 0.1 g of P123 and 0.3 g of F127 are mixed in deionized water at 80°C and mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, nitric acid with a concentration of 0.1 mol / L is used to adjust the pH value to 4.5, and it is left standing for 10 hours at 50°C. Air is introduced during the standing stage to obtain the mixed solution II.

[0108] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0109] The above-mentioned mixed solution II is uniformly mixed with 50 g of alumina powder carrier, and after forming, the catalyst precursor I is obtained. The catalyst precursor I is dried in an oven at 80°C for 4 hours, and then calcined in a muffle furnace at 400°C for 4 hours to obtain a catalyst with the following composition:

[0110] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·PdO·0.5CaO + 33 w% Al2O3.

[0111]

Example 7

[0112] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0113] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 moles of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and potassium hydroxide (molecular formula: KOH) containing 0.05 moles of K2O were respectively dissolved in hot water at 80 °C. After uniformly mixing all the active component solutions, the mixture was stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5K2O, obtaining the active component mixed solution I.

[0114] 2. Obtaining the mixed solution II and adjusting the pH value

[0115] 0.1 g of P123 and 0.3 g of F127 were mixed in deionized water at 80 °C and mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, the pH value was adjusted to 4.5 using 0.1 mol / L nitric acid, and it was left standing for 10 hours at 50 °C. Air was introduced during the standing stage, obtaining the mixed solution II.

[0116] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0117] The above-mentioned mixed solution II was uniformly mixed with 50 g of alumina powder carrier, and after forming, the catalyst precursor I was obtained. The catalyst precursor I was dried in an oven at 80 °C for 4 hours, and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0118] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5K2O + 33 w% Al2O3.

[0119]

Example 8

[0120] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0121] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.2 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO are respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, stir and evaporate at 80 °C until the concentration of the active components in the mixed material solution is equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·2Rh2O3·0.5CaO, obtaining the active component mixed solution I.

[0122] 2. Obtaining the mixed solution II and adjusting the pH value

[0123] Mix 0.1 g of P123 and 0.3 g of F127 in deionized water at 80 °C, and mix with 200 g of the above-mentioned active component mixed solution I. Stir until it reaches room temperature, and use 0.1 mole / liter of nitric acid to adjust the pH value to 4.5. Place it at 50 °C for 10 hours, and air needs to be introduced during the placement stage to obtain the mixed solution II.

[0124] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0125] Mix the above-mentioned mixed solution II evenly with 50 g of alumina powder carrier, and obtain the catalyst precursor I after forming. Dry the catalyst precursor I in an oven at 80 °C for 4 hours, and then calcine it in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0126] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·2Rh2O3·0.5CaO + 33 w% Al2O3.

[0127]

Example 9

[0128] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0129] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.2 moles of CaO were respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, the mixture was stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·2CaO, obtaining the mixed solution I of active components.

[0130] 2. Obtaining the mixed solution II and adjusting the pH value

[0131] 0.1 g of P123 and 0.3 g of F127 were mixed in deionized water at 80 °C and then mixed with 200 g of the above-mentioned mixed solution I of active components. After stirring to room temperature, nitric acid with a concentration of 0.1 mol / L was used to adjust the pH value to 4.5, and it was left standing at 50 °C for 10 hours. Air was introduced during the standing stage, obtaining the mixed solution II.

[0132] 3. Mixing the mixed solution II with the carrier, drying and calcining

[0133] The above-mentioned mixed solution II was mixed evenly with 50 g of alumina powder carrier, and the catalyst precursor I was obtained after forming. The catalyst precursor I was dried in an oven at 80 °C for 4 hours, and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0134] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·2CaO + 33 w% Al2O3.

[0135]

Example 10

[0136] 1. Mixing the active element solutions of each component to obtain the mixed solution I

[0137] Ammonium metavanadate (molecular formula: NH4VO3) containing 0.1 mole of V2O5, ammonium molybdate (molecular formula: (NH4)2MoO4) containing 0.6 moles of MoO3, and ammonium tungstate (molecular formula: (NH4) 10 W 12 O 41), Ammonium metavanadate containing 0.1 mole of V2O5 (molecular formula: NH4VO3), ammonium molybdate containing 0.6 mole of MoO3 (molecular formula: (NH4)2MoO4), ammonium tungstate containing 0.05 mole of WO3 (molecular formula: (NH4)

[0138] 2. Obtaining Mixed Solution II and Adjusting pH Value

[0139] Mix 0.1 g of P123 and 0.3 g of F127 in deionized water at 80 °C, and mix with 200 g of the above-mentioned active component mixed solution I. Stir until room temperature is reached. Use 0.1 mol / L nitric acid to adjust the pH value to 4.5, and place it at 50 °C for 10 hours. Air needs to be introduced during the placement stage to obtain mixed solution II.

[0140] 3. Mixing Mixed Solution II with the Support, Drying and Calcining

[0141] Mix the above-mentioned mixed solution II evenly with 50 g of lithium oxide powder support, and obtain catalyst precursor I after forming. Dry catalyst precursor I in an oven at 80 °C for 4 hours, and then calcine it in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0142] 67 w% V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 33 w% Li2O.

[0143]

Example 11

[0144] 1. Mixing Active Element Liquids of Each Component to Obtain Mixed Solution I

[0145] Ammonium metavanadate containing 0.1 mole of V2O5 (molecular formula: NH4VO3), ammonium molybdate containing 0.6 mole of MoO3 (molecular formula: (NH4)2MoO4), ammonium tungstate containing 0.05 mole of WO3 (molecular formula: (NH4) 10 W 12 O 41), Cerium nitrate (molecular formula: Ce(NO3)3) containing 0.05 moles of CeO2, rhodium nitrate (molecular formula: Rh(NO3)3) containing 0.05 moles of Rh2O3, and calcium hydroxide (molecular formula: Ca(OH)2) containing 0.05 moles of CaO were respectively dissolved in hot water at 80 °C. After mixing all the active component solutions evenly, the mixture was stirred and evaporated at 80 °C until the concentration of the active components in the mixed material solution was equivalent to 0.5 g / g of V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO, obtaining mixed solution I.

[0146] 2. Obtaining mixed solution II and adjusting the pH value

[0147] 0.1 g of P123 and 0.3 g of F127 were mixed in deionized water at 80 °C and then mixed with 200 g of the above-mentioned active component mixed solution I. After stirring to room temperature, nitric acid with a concentration of 0.1 mol / L was used to adjust the pH value to 4.5, and it was left standing at 50 °C for 10 hours. Air was introduced during the standing stage to obtain mixed solution II.

[0148] 3. Mixing mixed solution II with the carrier, drying and calcining

[0149] The above-mentioned mixed solution II was mixed evenly with 150 g of alumina powder carrier, and after forming, catalyst precursor I was obtained. Catalyst precursor I was dried in an oven at 80 °C for 4 hours, and then calcined in a muffle furnace at 400 °C for 4 hours to obtain a catalyst with the following composition:

[0150] 40w%V2O5·6MoO3·0.5WO3·0.5CeO2·0.5Rh2O3·0.5CaO + 60w%Al2O3.

[0151] Table 1 Composition and evaluation results of the catalysts obtained in the examples and comparative examples

[0152]

[0153]

Claims

1. A catalyst for synthesizing acrylic acid, the catalyst comprising a carrier and an active component, characterized in that: The surface of the catalyst has a chrysanthemum-shaped cluster structure; the general formula of the active component is expressed as: V2O5·aMoO3·bWO3·cCeO2·dXO m ·eZO n , where X is a transition metal element, including at least one selected from Ru, Os, Rh, Ir, Pd, and Pt, and Z is at least one selected from alkali metal or alkaline earth metal elements, including one or more selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba; a is the molar ratio of MoO3 to V2O5, and the value of a is 3.0 - 12.0; b is the molar ratio of WO3 to V2O5, and the value of b is 0.1 - 1.0; c is the molar ratio of CeO2 to V2O5, and the value of c is 0.1 - 1.0; d is the molar ratio of XO m to V2O5, and the value of d is 0.1 - 1.0; e is the molar ratio of ZO n to V2O5, and the value of e is 0.1 - 1.0; m and n are the number of moles of oxygen atoms required to satisfy the element valence in the active component; In the catalyst, each chrysanthemum-shaped cluster structure is composed of a central "stamen" and outward-extending "slender needles"; a three-dimensional network-like loose structure is formed between the chrysanthemum-shaped cluster structures.

2. The catalyst according to claim 1, characterized in that: The carrier is selected from at least one of lithium oxide, magnesium oxide, aluminum oxide, zirconium dioxide, silicon dioxide, titanium dioxide, vanadium dioxide, diatomite, kaolin, and pumice.

3. The catalyst according to claim 1, characterized in that: Based on the total weight of the catalyst, the carrier content in the catalyst is 10% - 60%, and the active component content is 40% - 90%.

4. The catalyst according to claim 3, characterized in that: Based on the total weight of the catalyst, the carrier content in the catalyst is 20% - 40%, and the active component content is 60% - 80%.

5. The preparation method of the catalyst for synthesizing acrylic acid according to any one of claims 1 - 4 includes the following steps: (1) Mix the solutions containing the active element precursors to obtain a mixed solution I; (2) Add P123 and F127 to the mixed solution I obtained in step (1) to obtain a mixed solution II; (3) Mix the mixed solution II with the catalyst carrier, and after drying and calcination, obtain the catalyst for synthesizing acrylic acid.

6. The method according to claim 5, characterized in that: In step (2), the mass ratio of P123 to F127 used is 0.1 - 1.0:1; the total amount of P123 and F127 is 0.1% - 0.8% of the total mass content of the active components in the catalyst.

7. The method according to claim 6, characterized in that: In step (2), the mass ratio of P123 to F127 used is 0.2 - 0.5:1; the total amount of P123 and F127 is 0.2% - 0.5% of the total mass content of the active components in the catalyst.

8. The method according to claim 5, wherein: In step (2), control the pH value of the obtained mixed solution II to be 3 - 6.

9. The method according to claim 8, wherein: In step (2), control the pH value of the obtained mixed solution II to be 4 - 5.

10. The method according to claim 5, characterized in that: In step (3), first place the mixed solution II for a certain time, and then mix it with the catalyst carrier. The placement time is 1 - 48 hours; the placement temperature is 30 - 90 °C.

11. The method according to claim 10, wherein: The placement time is 6 - 18 hours; the placement temperature is 40 - 60 °C.

12. The method according to claim 5, characterized in that: In step (3), the drying temperature is 50 - 150 °C, and the drying time is 1 - 48 hours; the calcination temperature is 300 - 500 °C, and the calcination time is 1 - 48 hours.

13. The application of the catalyst according to any one of claims 1 - 4 or the catalyst prepared by the method according to any one of claims 5 - 12 in the oxidation of acrolein to acrylic acid.

Images