Reticular porous spherical aluminum oxide as well as preparation method and application thereof

Abstract

The invention relates to the technical field of catalyst carriers, and discloses reticular porous spherical aluminum oxide as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing an aluminum source, acid, a pore-forming agent, a surfactant and water to obtain pseudo sol; (2) performing ultrasonic treatment and oil ammonia column forming treatment on the pseudo sol obtained in the step (1) to obtain gamma-Al2O3 spherical gel beads; and (3) aging, washing, drying and calcining the gamma-Al2O3 spherical gel beads obtained in the step (2) to obtain the reticular porous spherical alumina. The spherical aluminum oxide prepared by the method has abundant communicated reticular pore channels, is obviously distributed in mesopore and macropore ranges, is beneficial to obviously improving dispersion and loading of a catalyst in an aluminum oxide carrier and improving the performance of petroleum reforming and propane dehydrogenation, and has industrial production utilization value and commercial value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst carrier, in particular to a reticular porous spherical alumina and a preparation method and application thereof. BACKGROUND

[0002] Nowadays, the consumption of fossil energy continues to rise. γ-Al2O3 is widely used in the field of petroleum and chemical catalysis due to its large specific surface area, excellent pore structure, high thermal stability, rich surface acid sites, excellent adsorption performance and other characteristics. γ-Al2O3 can be used as a carrier of active components or directly as a catalyst. Among various forms of alumina carriers, spherical alumina is most widely used in the field of petroleum and chemical industry due to its good rolling property, high bulk density, high mechanical strength and low wear rate.

[0003] Currently, the main forming methods of spherical alumina include rolling forming method, spray drying forming method, oil-ammonia column forming method, hot oil column forming method and water column forming method. However, it is still a challenge to prepare spherical alumina with high purity, narrow particle size distribution, high hydrothermal stability, high mechanical strength and suitable for industrial production.

[0004] CN116832797A reports a method for forming spherical alumina by chitosan regulation. Pseudoboehmite and α-Al2O3 are used as raw materials, chitosan and cellulose are added, and alumina sol is prepared by acidification; then spherical alumina is obtained by oil-ammonia column forming, washing and drying.

[0005] CN120247070A reports a method for preparing spherical alumina by oil-ammonia column forming process. The method obtains aluminum sol by acidifying pseudoboehmite, and obtains spherical alumina carrier by adding oil-ammonia column forming containing high molecular thickening agent, solidifying, drying and calcining.

[0006] The above existing technologies focus on controlling the external properties of spherical alumina such as particle size and sphericity, and lack of exploration of the internal structure of alumina. The internal pore structure is not deeply studied.

[0007] Therefore, it is necessary to focus on the regulation of the internal pore structure of spherical alumina to obtain alumina carriers with more abundant pore structure and high specific surface area. SUMMARY

[0008] The purpose of the present application is to overcome the problems existing in the prior art, and to provide a reticular porous spherical alumina and a preparation method and application thereof. The spherical alumina prepared by the present application has a size based on a regular pore former in the interior, an ordered framework is built in the interior, a large number of interconnected network pores are controllably obtained after calcination, and the thickness of the pores can be adjusted, thereby further improving the specific surface area and pore volume.

[0009] To achieve the above objectives, the first aspect of the present invention provides a method for preparing mesh-like porous spherical alumina, wherein the method includes the following steps: (1) A pseudo-sol is obtained by mixing aluminum source, acid, pore-forming agent, surfactant and water; (2) The pseudo sol obtained in step (1) was subjected to ultrasonic treatment and oil-ammonia column molding treatment to obtain γ-Al2O3 spherical gel beads; (3) The γ-Al2O3 spherical gel beads obtained in step (2) are aged, washed, dried and calcined to obtain the network porous spherical alumina.

[0010] A second aspect of the present invention provides a network porous spherical alumina obtained by the preparation method described in the first aspect.

[0011] A third aspect of the present invention provides the application of the network porous spherical alumina described in the second aspect as a catalyst support in petroleum reforming and propane dehydrogenation.

[0012] The beneficial technical effects achieved by the present invention through the above technical solution are as follows: (1) This invention introduces a pore-forming agent, such as a carbon-based spherical solid organic or inorganic material, and a surfactant into a pseudo sol, and controls the relevant dosage and ultrasonic treatment to make the pore-forming agent uniformly and fully dispersed in the sol to obtain a composite aluminum sol. After being solidified by oil-ammonia column molding, spherical alumina with a network pore structure is prepared, which significantly increases the specific surface area and pore volume. Compared with the past, the specific surface area is increased by 40%, and the pore volume is increased by at least 0.5 mL / g.

[0013] (2) The spherical alumina prepared by the present invention has abundant interconnected network channels, which are obviously distributed in both mesoporous and macroporous ranges. This helps to significantly improve the dispersion and loading of the catalyst inside the alumina support, improve the performance in petroleum reforming and propane dehydrogenation, and has industrial production utilization value and commercial value.

[0014] (3) The preparation method provided by the present invention is simple to operate, the production process is stable, and it is easy to produce on a large scale. Attached Figure Description

[0015] Figure 1 An optical photograph of the mesh-like porous spherical alumina prepared in Example 1 of this invention.

[0016] Figure 2 The image shows the XRD pattern of the mesh-like porous spherical alumina prepared in Example 1 of this invention.

[0017] Figure 3 SEM image of the mesh-like porous spherical alumina prepared in Example 1 of this invention.

[0018] Figure 4 The image shows the XRD pattern of the alumina prepared in Comparative Example 1.

[0019] Figure 5 SEM image of the alumina prepared for Comparative Example 1.

[0020] Figure 6 SEM image of the alumina prepared for Comparative Example 2.

[0021] Figure 7 SEM image of the alumina prepared for Comparative Example 3.

[0022] Figure 8 SEM image of the alumina prepared for Comparative Example 4.

[0023] Figure 9 SEM image of the alumina prepared for Comparative Example 5.

[0024] Figure 10 SEM image of the alumina prepared for Comparative Example 6.

[0025] Figure 11 SEM image of the alumina prepared for Comparative Example 7. Detailed Implementation

[0026] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0027] The first aspect of this invention provides a method for preparing a mesh-like porous spherical alumina, wherein the method includes the following steps: (1) A pseudo-sol is obtained by mixing aluminum source, acid, pore-forming agent, surfactant and water; (2) The pseudo sol obtained in step (1) was subjected to ultrasonic treatment and oil-ammonia column molding treatment to obtain γ-Al2O3 spherical gel beads; (3) The γ-Al2O3 spherical gel beads obtained in step (2) are aged, washed, dried and calcined to obtain the network porous spherical alumina.

[0028] The preparation method described in this invention creates a large number of interconnected network channels inside the spherical alumina, which greatly increases the specific surface area and pore volume. This is beneficial for the loading of the catalyst inside the alumina support and the exposure of more adsorption sites, thus making more efficient use of the internal space.

[0029] This invention uses ultrasonic treatment to drive the pore-forming agent to vibrate at high frequency, reducing agglomeration and fully dispersing it. After molding, curing and calcination, a rich network of interconnected pores is formed inside the alumina, resulting in high pore uniformity and a higher specific surface area.

[0030] In some embodiments of the present invention, the operation of step (1) includes: first mixing the pore-forming agent with water to obtain a suspension, then adding an aluminum source for dispersion, and finally adding an acid and a surfactant for mixing to obtain a pseudo sol.

[0031] In some embodiments of the present invention, the aluminum source is selected from at least one of boehmite, boehmite and gibbsite, preferably boehmite.

[0032] In some embodiments of the present invention, the acid is selected from at least one of concentrated nitric acid (e.g., with a mass concentration of 65-68%), acetic acid, and hydrochloric acid, preferably concentrated nitric acid.

[0033] In some embodiments of the present invention, the molar ratio of hydrogen ions in the acid to aluminum ions in the aluminum source is 0.03-0.1:1, for example 0.03:1, 0.0425:1, 0.048:1, 0.06:1, 0.08:1, 0.1:1, and any value within the range of any two of the above values, preferably 0.0425-0.048:1.

[0034] In some embodiments of the present invention, the pore-forming agent is a carbon-based spherical solid organic and / or inorganic material, preferably selected from at least one of polystyrene spheres, polymethyl methacrylate spheres and carbon spheres, and more preferably polystyrene spheres.

[0035] In some embodiments of the present invention, the amount of the pore-forming agent is 5-30% of the mass of the pseudosol, for example 5%, 10%, 15%, 16%, 20%, 21%, 28%, 30%, and any value within the range of any two of the above values, preferably 15-28%.

[0036] In some embodiments of the present invention, the surfactant is selected from at least one of anionic surfactants, cationic surfactants and nonionic surfactants, preferably selected from at least one of hexadecyltrimethylammonium bromide (CTAB), hexadecyltrimethylammonium chloride (CTAC), polyvinylpyrrolidone (PVP), Tween 80 and sodium dodecyl sulfate (SDS).

[0037] In some embodiments of the present invention, the amount of the surfactant is 0.005-3% of the mass of the pseudosol, for example 0.0075%, 0.0098%, 0.01%, 0.074%, 1.7%, 2%, 3%, and any value within the range of any two of the above values, preferably 0.0075-1.7%.

[0038] In some embodiments of the present invention, the conditions for the ultrasonic treatment in step (2) include: the voltage of the ultrasonic device is set to 12-24V; the ultrasonic time is 0.5-10min.

[0039] In some embodiments of the present invention, the calcination conditions include: a calcination temperature of 550-650°C, preferably 600°C; and a calcination time of 2-4 hours, preferably 3 hours.

[0040] A second aspect of the present invention provides a network porous spherical alumina obtained by the preparation method described in the first aspect.

[0041] In some embodiments of the present invention, the mesh-porous spherical alumina has interconnected mesh channels inside.

[0042] In some embodiments of the present invention, the specific surface area of ​​the mesh-porous spherical alumina is 300-600 m². 2 / g, preferably 320-349m 2 / g.

[0043] In some embodiments of the present invention, the pore volume of the mesh-like porous spherical alumina is 0.60-0.85 mL / g, preferably 0.65-0.73 mL / g.

[0044] In some embodiments of the present invention, the macropore diameter of the mesh porous spherical alumina is mainly distributed in the range of 0.1-1 μm, preferably 150-320 nm.

[0045] The third aspect of this invention provides the application of the network porous spherical alumina described in the second aspect as a catalyst support in petroleum reforming and propane dehydrogenation.

[0046] The present invention will be described in detail below through embodiments.

[0047] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0048] Source of materials: Phobospore: pore volume is 0.64 mL / g, pore size is 10.74 nm; Bismuth trihydrate: purchased from Maclean's; Concentrated nitric acid: mass concentration of 68%; Polymethyl methacrylate balls: purchased from Aladdin, item number P434523-25g; Carbon balls: purchased from Aladdin, product number C196582-100mg; PVP: Purchased from Aladdin, item number KA741044-25g; Polystyrene spheres are prepared by the following method: First, 70 mL of styrene was thoroughly washed sequentially with 20 mL of 10 wt% sodium hydroxide solution and deionized water to remove the stabilizer. Then, 68 mL of the washed styrene was added to a three-necked round-bottom flask containing 500 mL of water containing 1.6 g of PVP. After bubbling with nitrogen for 15 min, the mixture was stirred at 75 °C for 30 min under magnetic stirring. Next, 50 mL of an aqueous solution containing 1 g of K₂S₂O₈ was rapidly added to initiate the polymerization reaction of styrene. After stirring continuously at this temperature for 24 h, the mixture was cooled, and the resulting emulsion product was monodisperse colloidal polystyrene spheres. These were filtered and dried to obtain the polystyrene spheres. The PVP was purchased from Aladdin, catalog number P434441-5g.

[0049] Example 1 This embodiment illustrates the preparation of a network of porous spherical alumina.

[0050] (1) 11g of polystyrene balls were mixed with 30mL of water to obtain a suspension, then 10g of boehmite was added for dispersion, and finally 450μL of concentrated nitric acid and 5mg of CTAB were added. After stirring for 4h, a pseudosol was obtained. The molar ratio of hydrogen ions in concentrated nitric acid to aluminum ions in pseudoboehmite was 0.0425:1; the amount of polystyrene spheres used was 21% of the mass of the pseudosol; and the amount of CTAB used was 0.0098% of the mass of the pseudosol. (2) The pseudo-sol was ultrasonically dispersed for 0.5 min using an ultrasonic device with a voltage of 12V; then it was dropped into an oil-ammonia column (the oil phase was petroleum ether, 6 cm high; the ammonia phase was ammonia water with a mass fraction of 8 wt%, 1 m high) for molding treatment to obtain γ-Al2O3 spherical gel beads. (3) The γ-Al2O3 spherical gel beads were aged in ammonia water for 12 hours, then washed 2-3 times with deionized water to remove excess ammonia water; the washed product was dried at 80°C for 10 hours, and then calcined at 600°C for 3 hours to obtain the network porous spherical alumina with the chemical formula γ-Al2O3 and the morphology of spherical particles, such as... Figure 1 As shown.

[0051] Figure 2For the corresponding XRD pattern, in 2 θ Obvious diffraction peaks were observed at 19.65°, 32.72°, 37.05°, 39.47°, 46.30°, 61.60° and 67.05°, corresponding to the (111), (220), (311), (222), (400), (511) and (440) crystal planes of γ-Al2O3, respectively.

[0052] Figure 3 This is a SEM image of the internal cross-section of the synthesized spherical γ-Al₂O₃. It can be seen that the interior has interconnected network channels, mainly macroporous structures, with some mesoporous structures also present, and the overall pore structure exhibits high uniformity.

[0053] The spherical alumina prepared in this embodiment has multiple pore sizes at 10 nm and 200 nm.

[0054] Example 2 This embodiment illustrates the preparation of a network of porous spherical alumina.

[0055] (1) Mix 10g of polymethyl methacrylate balls with 30mL of water to obtain a suspension, then add 10g of boehmite for dispersion, and finally add 450μL of concentrated nitric acid and 5mg of CTAC. Stir for 4h to obtain a pseudosol. The molar ratio of hydrogen ions in concentrated nitric acid to aluminum ions in pseudoboehmite was 0.0425:1; the amount of polymethyl methacrylate (PMMA) spheres was 20% of the mass of the pseudosol; and the amount of CTAC was 0.01% of the mass of the pseudosol. (2) The pseudo-sol was ultrasonically dispersed for 3 min using an ultrasonic device with a voltage of 12V; then it was dropped into an oil-ammonia column (the oil phase was petroleum ether, 6 cm high; the ammonia phase was ammonia water with a mass fraction of 8 wt%, 1 m high) for molding treatment to obtain γ-Al2O3 spherical gel beads. (3) The γ-Al2O3 spherical gel beads were aged in ammonia water for 12 hours, and then washed with deionized water 2-3 times to remove excess ammonia water. The washed product was dried at 80°C for 10 hours and then calcined at 550°C for 4 hours to obtain the network porous spherical alumina with the chemical formula γ-Al2O3 and the morphology of spherical particles (same as the product in Example 1).

[0056] The spherical alumina prepared in this embodiment has multiple pore sizes at 15 nm and 300 nm.

[0057] Example 3 This embodiment illustrates the preparation of a network of porous spherical alumina.

[0058] (1) 10g of carbon balls were mixed with 46mL of water to obtain a suspension. Then 5g of boehmite and 5g of gibbsite were added for dispersion. Finally, 380μL of concentrated nitric acid and 5mg of PVP were added and stirred for 4h to obtain a pseudosol. The molar ratio of hydrogen ions in concentrated nitric acid to aluminum ions in pseudoboehmite and gibbsite was 0.048:1; the amount of carbon spheres was 15% of the mass of the pseudosol; and the amount of PVP was 0.0075% of the mass of the pseudosol. (2) The pseudo-sol was ultrasonically dispersed for 5 min using an ultrasonic device with a voltage of 12V; then it was dropped into an oil-ammonia column (the oil phase was petroleum ether, 6 cm high; the ammonia phase was ammonia water with a mass fraction of 8 wt%, 1 m high) for molding treatment to obtain γ-Al2O3 spherical gel beads. (3) The γ-Al2O3 spherical gel beads were aged in ammonia water for 12 hours, and then washed with deionized water 2-3 times to remove excess ammonia water. The washed product was dried at 80°C for 10 hours and then calcined at 600°C for 3 hours to obtain the network porous spherical alumina with the chemical formula γ-Al2O3 and the morphology of spherical particles (same as the product in Example 1).

[0059] The spherical alumina prepared in this embodiment has multiple pore sizes at 12 nm and 150 nm.

[0060] Example 4 This embodiment illustrates the preparation of a network of porous spherical alumina.

[0061] (1) 20g of polystyrene balls were mixed with 40mL of water to obtain a suspension, then 10g of boehmite was added for dispersion, and finally 450μL of concentrated nitric acid and 1200mg of Tween 80 were added. After stirring for 4h, a pseudosol was obtained. The molar ratio of hydrogen ions in concentrated nitric acid to aluminum ions in pseudoboehmite was 0.0425:1; the amount of polystyrene spheres used was 28% of the mass of the pseudosol; and the amount of Tween 80 used was 1.7% of the mass of the pseudosol. (2) The pseudo-sol was ultrasonically dispersed for 10 min using an ultrasonic device with a voltage of 12V; then it was dropped into an oil-ammonia column (the oil phase was petroleum ether, 6 cm high; the ammonia phase was ammonia water with a mass fraction of 8 wt%, 1 m high) for molding treatment to obtain γ-Al2O3 spherical gel beads. (3) The γ-Al2O3 spherical gel beads were aged in ammonia water for 12 hours, and then washed with deionized water 2-3 times to remove excess ammonia water. The washed product was dried at 80°C for 10 hours and then calcined at 600°C for 3 hours to obtain the network porous spherical alumina with the chemical formula γ-Al2O3 and the morphology of spherical particles (same as the product in Example 1).

[0062] The spherical alumina prepared in this embodiment has multiple pore sizes at 18 nm and 230 nm.

[0063] Example 5 This embodiment illustrates the preparation of a network of porous spherical alumina.

[0064] (1) 11g of polystyrene balls were mixed with 46mL of water to obtain a suspension, then 10g of boehmite was added for dispersion, and finally 450μL of concentrated nitric acid and 50mg of SDS were added. After stirring for 4h, a pseudosol was obtained. The molar ratio of hydrogen ions in concentrated nitric acid to aluminum ions in pseudoboehmite was 0.0425:1; the amount of polystyrene spheres used was 16% of the mass of the pseudosol; and the amount of SDS used was 0.074% of the mass of the pseudosol. (2) The pseudo-sol was ultrasonically dispersed for 1 min using an ultrasonic device with a voltage of 12V; then it was dropped into an oil-ammonia column (the oil phase was petroleum ether, 6 cm high; the ammonia phase was ammonia water with a mass fraction of 8 wt%, 1 m high) for molding treatment to obtain γ-Al2O3 spherical gel beads. (3) The γ-Al2O3 spherical gel beads were aged in ammonia water for 12 hours, and then washed with deionized water 2-3 times to remove excess ammonia water. The washed product was dried at 80°C for 10 hours and then calcined at 600°C for 3 hours to obtain the network porous spherical alumina with the chemical formula γ-Al2O3 and the morphology of spherical particles (same as the product in Example 1).

[0065] The spherical alumina prepared in this embodiment has multiple pore sizes at 20 nm and 320 nm.

[0066] Comparative Example 1 Spherical alumina was prepared according to the method of Example 1, except that step (1) was adjusted as follows: 40 mL of water and 10 g of boehmite were mixed to obtain a suspension, and then 450 μL of concentrated nitric acid and 50 mg of SDS were added. After stirring for 4 h, a pseudo sol was obtained. The ultrasonic dispersion treatment in step (2) was omitted, and subsequent processing was carried out directly to finally obtain spherical alumina without pore-forming agent doping.

[0067] Figure 4 The results showed that the prepared alumina had obvious alumina diffraction peaks.

[0068] Figure 5 The results showed that no network interconnected pore structure was observed inside, only the pores of the pseudoboehmite itself, and mesopore size distribution was only observed at 10 nm. No macropore structure was observed, and the mesopore channels were uniform.

[0069] Comparative Example 2 Spherical alumina was prepared according to the method of Example 1, except that the ultrasonic dispersion treatment in step (2) was omitted.

[0070] The resulting alumina particles were spherical. However... Figure 6 The results show that there are few internal internet-like structures and the internal pores are unevenly distributed.

[0071] Comparative Example 3 Spherical alumina was prepared according to the method of Example 1, except that 11g of polystyrene spheres in step (1) were replaced with 10g of dodecane, 420μL of concentrated nitric acid was added, and the stirring time was 1h.

[0072] Figure 7 The results showed that large pores of 1-20 micrometers appeared inside, without interconnected mesh-like channels.

[0073] Comparative Example 4 Spherical alumina was prepared according to the method of Example 1, except that 11g of polystyrene spheres in step (1) were replaced with 5g of chitosan, and CTAB was not added, and the amount of concentrated nitric acid added was 410μL.

[0074] Figure 8 The results showed that the interior of alumina exhibited a nanoparticle morphology, with no obvious macroporous structure or interconnected network channels observed.

[0075] Comparative Example 5 Spherical alumina was prepared according to the method of Example 1, except that 11g of polystyrene spheres in step (1) were replaced with 8g of cellulose, and CTAB was not added, and the amount of concentrated nitric acid added was 440μL.

[0076] Figure 9 The results showed that there were no large pores or interconnected network channels inside.

[0077] Comparative Example 6 Spherical alumina was prepared according to the method of Example 1, except that 11g of polystyrene spheres in step (1) were replaced with 6g of sodium stearate, and CTAB was not added, and the amount of concentrated nitric acid added was 430μL.

[0078] Figure 10 The results showed that there were no large pores or interconnected network channels inside.

[0079] Comparative Example 7 Spherical alumina was prepared according to the method of Example 1, except that 11g of polystyrene balls in step (1) were replaced with 5g of starch, and CTAB was not added, and the amount of concentrated nitric acid added was 425μL.

[0080] Figure 11The results showed that the interior exhibited an alumina nanoparticle morphology, without interconnected network channels, no obvious macroporous structure, and a mesoporous structure.

[0081] Test Example 1 The average diameter, bulk density, pore volume, and specific surface area of ​​the spherical alumina obtained in Examples 1-5 and Comparative Examples 1-7 were measured.

[0082] Measurement method: Average diameter: The diameter of the spherical alumina was measured multiple times using vernier calipers, and the average value was taken.

[0083] Bulk density: Weigh an appropriate amount of solid, pour it into a graduated cylinder, record the height of the particles, and the mass removed is the bulk density.

[0084] Pore ​​volume and specific surface area: tested using an N2 adsorption-desorption instrument.

[0085] The results are shown in Table 1.

[0086] Table 1

[0087] As can be seen from the results in Table 1, the bulk density of the spherical alumina prepared in the embodiments of the present invention is slightly higher than that of the spherical alumina prepared in the comparative example, indicating that its pore volume is higher, which can be verified by the pore volume data. A significant difference can be seen from the specific surface area data; the specific surface area of ​​the spherical alumina prepared in the embodiments of the present invention is much larger than that of the spherical alumina prepared in the comparative example, both being approximately 300 μm². 2 / g or more.

[0088] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a network of porous spherical alumina, characterized in that, The method includes the following steps: (1) A pseudo-sol is obtained by mixing aluminum source, acid, pore-forming agent, surfactant and water; (2) The pseudo sol obtained in step (1) was subjected to ultrasonic treatment and oil-ammonia column molding treatment to obtain γ-Al2O3 spherical gel beads; (3) The γ-Al2O3 spherical gel beads obtained in step (2) are aged, washed, dried and calcined to obtain the network porous spherical alumina.

2. The preparation method according to claim 1, wherein, The operation of step (1) includes: first, mixing the pore-forming agent with water to obtain a suspension, then adding an aluminum source for dispersion, and finally adding an acid and a surfactant for mixing to obtain a pseudo sol.

3. The preparation method according to claim 1 or 2, wherein, The aluminum source is selected from at least one of boehmite, boehmite and gibbsite, preferably boehmite; Preferably, the acid is selected from at least one of concentrated nitric acid, acetic acid, and hydrochloric acid, with concentrated nitric acid being the most preferred; Preferably, the molar ratio of hydrogen ions in the acid to aluminum ions in the aluminum source is 0.03-0.1:1, more preferably 0.0425-0.048:

1.

4. The preparation method according to any one of claims 1-3, wherein, The pore-forming agent is a carbon-based spherical solid organic and / or inorganic material, preferably selected from at least one of polystyrene spheres, polymethyl methacrylate spheres and carbon spheres, and more preferably polystyrene spheres; Preferably, the amount of the pore-forming agent is 5-30% of the mass of the pseudosol, and more preferably 15-28%.

5. The preparation method according to any one of claims 1-4, wherein, The surfactant is selected from at least one of anionic surfactants, cationic surfactants and nonionic surfactants, and preferably from at least one of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, polyvinylpyrrolidone, Tween 80 and sodium dodecyl sulfate; Preferably, the amount of surfactant used is 0.005-3% of the mass of the pseudosol, and more preferably 0.0075-1.7%.

6. The preparation method according to any one of claims 1-5, wherein, The conditions for ultrasonic treatment in step (2) include: the voltage of the ultrasonic device is set to 12-24V; the ultrasonic time is 0.5-10min.

7. The preparation method according to any one of claims 1-6, wherein, The calcination conditions include: a calcination temperature of 550-650℃, preferably 600℃; and a calcination time of 2-4 hours, preferably 3 hours.

8. A network porous spherical alumina obtained by the preparation method according to any one of claims 1-7.

9. The mesh-like porous spherical alumina according to claim 8, characterized in that, The mesh-like porous spherical alumina has interconnected mesh-like channels inside; Preferably, the specific surface area of ​​the mesh-like porous spherical alumina is 300-600 m². 2 / g, preferably 320-349m 2 / g; Preferably, the pore volume of the mesh-like porous spherical alumina is 0.60-0.85 mL / g, more preferably 0.65-0.73 mL / g; Preferably, the macropore size of the mesh-like porous spherical alumina is distributed in the range of 0.1-1 μm, and more preferably 150-320 nm.

10. The application of the reticulated porous spherical alumina according to claim 8 or 9 as a catalyst support in petroleum reforming and propane dehydrogenation.

Images