Catalyst for olefin esterification and preparation method and application thereof

Abstract

The invention provides a catalyst for olefin esterification and a preparation method and application thereof. The catalyst takes silicon dioxide as a carrier to load active components of solid superacid and heteropoly acid, and through the synergistic effect of providing high-strength acid sites by the solid superacid and providing uniformly distributed active acid sites by the heteropoly acid, the catalytic efficiency of the addition-esterification reaction of olefin and organic acid is remarkably improved, and the catalytic efficiency of the addition-esterification reaction of olefin and organic acid is improved. The catalyst is especially suitable for the reaction of C5 component olefin and acetic acid in a high-temperature Fischer-Tropsch synthesis product. The preparation method is simple in process, the catalyst is excellent in thermal stability and hydrothermal stability, the target product is high in selectivity, and the catalyst is suitable for fixed bed reactors and has wide industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical catalysis, and in particular to a catalyst for olefin esterification reaction and a preparation method thereof, as well as application of the catalyst in addition-esterification reaction of olefin and organic acid, and is particularly suitable for the reaction of C5 component olefin in high-temperature Fischer-Tropsch synthesis product with acetic acid. Background Art

[0002] The resource characteristics of rich coal, less oil and poor gas have led to the rapid development of my country's coal-to-liquid industry. At present, the coal-to-liquid projects built are mainly based on indirect coal liquefaction. The core of indirect coal liquefaction is Fischer-Tropsch synthesis technology, which is divided into low-temperature and high-temperature Fischer-Tropsch synthesis. Compared with low-temperature Fischer-Tropsch, the olefin content in the high-temperature Fischer-Tropsch synthesis product is richer, with a content of more than 50%. If this part of olefins can be used for high value, it will be of great significance to promote the development and deep processing of the Fischer-Tropsch synthesis industry.

[0003] As a fine chemical product, sec-amyl acetate has a fruity aroma. Due to its slow volatility and gradual decomposition when exposed to moisture, it is mainly used as a solvent for nitrocellulose lacquer in the coating industry to improve leveling and whitening properties.

[0004] The synthesis methods of secondary amyl acetate mainly include acid-alcohol esterification and acid-ene addition-esterification. Water is generated as a byproduct during the acid-alcohol esterification process, which not only causes catalyst deactivation but also increases post-processing costs. Compared with the acid-alcohol esterification method, the acid-ene method for synthesizing acetate is a green chemical process with an atomic utilization rate of 100%.

[0005] In the synthesis of acetate, supported heteropoly acid catalysts are favored by many researchers. Patent CN100553778C uses Hβ zeolite supported phosphotungstic acid catalyst to synthesize n-butyl acetate through the esterification reaction of acetic acid and n-butanol. Patent CN103586057A uses silica supported phosphotungstic acid as a catalyst to synthesize ethyl acetate. Yang Lei et al. used SBA-15 as a carrier to prepare a supported heteropoly acid catalyst (H4SiW 12 O 40 / SBA-15), and further applied it to the reaction of preparing cyclohexyl acrylate from cyclohexene (Yang Lei, Ai Shenglan, Guangdong Chemical Industry, 2015, 42, 21.). However, the disadvantage of the directly supported heteropolyacid catalyst is that its acid strength is limited, which makes it difficult to 5+ The catalytic activity in the addition-esterification reaction of α-olefins with acetic acid is relatively low. This is mainly due to the fact that compared with low-carbon olefins below C4 and cyclohexene, C 5+ The reactivity of α-olefins is low, and olefin isomerization will inevitably occur during the reaction to produce corresponding isomeric esters.

[0006] Therefore, in the reaction of producing secondary amyl acetate from C5 component olefins, how to overcome the disadvantage of low acid strength of supported heteropolyacid catalysts is an important issue that needs to be solved urgently. Summary of the invention

[0007] The present invention provides a catalyst for olefin esterification and a preparation method thereof, and relates to the application of the catalyst in the addition-esterification reaction of olefins and organic acids. The catalyst of the present invention uses silicon dioxide as a carrier, loads active components of solid superacids and heteropolyacids, and significantly improves the catalytic performance through the synergistic effect of the two types of acids, thereby solving the problem of low conversion rate and target product selectivity of existing catalysts in the reaction of C5 component olefins and acetic acid in high-temperature Fischer-Tropsch synthesis products. The preparation method of the present invention has a simple process and controllable conditions. The prepared catalyst is suitable for efficiently catalyzing the addition-esterification reaction of olefins and organic acids in a fixed bed reactor, providing an efficient solution for fine chemicals and high-value utilization of resources.

[0008] According to a first aspect of the present invention, a catalyst for olefin esterification is provided, the catalyst comprising active components of a solid superacid and a heteropolyacid supported on a silica carrier, wherein the solid superacid is used to provide high-strength acid sites, and the heteropolyacid is used to provide uniformly distributed active acid sites.

[0009] In some technical solutions, the solid superacid is composed of metal-modified zirconium dioxide-sulfate.

[0010] In some technical solutions, the metal is one of aluminum, magnesium, zinc, tin or cerium.

[0011] In some technical solutions, the heteropoly acid is one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid or germanotungstic acid.

[0012] According to a second aspect of the present invention, there is further provided a method for preparing a catalyst for olefin esterification, comprising the following steps:

[0013] The metal salt and zirconium oxychloride octahydrate are dissolved in water, a silica carrier is added, the pH value of the solution is adjusted to an alkaline range, and after standing and aging, the solution is filtered and dried to obtain a precursor;

[0014] After the precursor is immersed in an acid solution, it is calcined at a suitable temperature to obtain a solid super acid;

[0015] The solid superacid is mixed with a heteropolyacid solution, and subjected to uniform dispersion treatment, static aging and drying to obtain the above-mentioned catalyst for olefin esterification.

[0016] As a preferred embodiment, during the preparation of the precursor,

[0017] The metal salt is one of aluminum nitrate, magnesium chloride, zinc nitrate, tin chloride or cerium nitrate, and the amount thereof is 0.1% to 5% by mass relative to zirconium oxychloride octahydrate;

[0018] The pH value of the solution is 9.0-10.0.

[0019] As a preferred embodiment, during the preparation of the solid superacid,

[0020] The acidic solution is a 1.0-1.5M sulfuric acid solution;

[0021] The calcination temperature is 450-600°C.

[0022] As a preferred embodiment, during the preparation of the catalyst for olefin esterification,

[0023] The heteropoly acid is one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid or germanotungstic acid;

[0024] The drying temperature is 60-120°C.

[0025] According to a third aspect of the present invention, there is further provided an application of a catalyst for olefin esterification, which is used to catalyze the addition-esterification reaction of olefins and organic acids, wherein:

[0026] The olefins are C5 component olefins in the high-temperature Fischer-Tropsch synthesis product, and the C5 component olefins include 1-pentene, C5 isomeric olefins, oxygen-containing compounds and aromatic hydrocarbons;

[0027] The organic acid is acetic acid.

[0028] As a preferred embodiment, the addition-esterification reaction is carried out in a fixed bed reactor, and the reaction conditions are a reaction temperature of 80 to 120° C. and an acid-olefin molar ratio of 0.5 to 4.0.

[0029] The present invention adopts the above technical solution to have at least the following beneficial effects:

[0030] 1. ZrO2-M / SO4 in the catalyst of the present invention 2- As a solid superacid active component, it provides high-strength acid sites, which can effectively overcome the problem of low reaction activity caused by insufficient acid strength of traditional catalysts, so that C5 component olefins in high-temperature Fischer-Tropsch synthesis products can fully participate in the addition-esterification reaction. 2- The strong acidity can significantly reduce the inhibitory effect of impurities on the reaction and improve the reaction efficiency.

[0031] 2. The heteropoly acid (such as phosphotungstic acid, silicotungstic acid, etc.) of the present invention is used as the second active component, and by providing evenly distributed acid sites, it synergizes with the solid superacid, effectively avoiding the problem of decreased catalytic activity due to low acid density. This synergistic effect not only improves the overall acid strength, but also enhances the selectivity and stability of the catalyst.

[0032] 3. The silica of the present invention has the characteristics of high specific surface area as a carrier, providing a uniformly distributed carrier platform for the active components, which makes the active sites of the catalyst fully exposed, thereby improving the catalytic efficiency. Compared with the traditional supported heteropolyacid catalyst, the catalyst of the present invention can overcome the defects of low acid strength and poor activity, and show better catalytic performance in olefin addition-esterification reaction.

[0033] 4. The C5 component olefins in the high-temperature Fischer-Tropsch synthesis product are a complex mixture, including 1-pentene, C5 isoolefins, oxygen-containing compounds and aromatics. Unlike the traditional acid-olefin method, which mainly focuses on the research of low-carbon olefins below C4 and cyclohexene, the present invention develops a high-efficiency catalyst for the C5 component olefins, and realizes the high-efficiency addition-esterification reaction of low-activity olefins in this complex component with acetic acid, which not only improves the selectivity of the target ester, but also effectively utilizes oxygen-containing compounds and other impurity components.

[0034] 5. The catalyst of the present invention is suitable for fixed bed reactors and exhibits excellent catalytic activity and target product selectivity under mild reaction conditions (80-120°C). Its thermal stability and hydrothermal stability enable the catalyst to maintain high catalytic performance for a long time. At the same time, the preparation process is simple, the cost is low, and it is easy to achieve industrial scale production.

[0035] 6. The current acid-olefin process for synthesizing acetate mainly focuses on low-carbon olefins, while the C5 component olefins in the high-temperature Fischer-Tropsch synthesis product have not been fully studied. The present invention not only effectively catalyzes the reaction of C5 component olefins and acetic acid through the design of the catalyst and the optimization of reaction conditions, but also fills the technical gap in the high-value utilization of the C5 component in the relevant field, and provides a new idea for the deep processing of high-temperature Fischer-Tropsch synthesis products. DETAILED DESCRIPTION

[0036] The following will be combined with specific embodiments to clearly and completely describe the technical solutions in the present invention. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0037] According to an embodiment provided by the present invention, a catalyst for olefin esterification comprises the following steps:

[0038] Example 1

[0039] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, then dry in an oven at 120°C. The resulting precursor is labeled as ZrO2-Al / SiO2.

[0040] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- / SiO2.

[0041] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was marked as HPW / ZrO2-Al.

[0042] HPW / ZrO2-Al was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0043] Example 2

[0044] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of magnesium chloride in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, then dry in an oven at 120°C, and the resulting precursor is ZrO2-Mg / SiO2.

[0045] (2) ZrO2-Mg / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Mg / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Mg / SO4 2- / SiO2.

[0046] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Mg / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was marked as HPW / ZrO2-Mg.

[0047] HPW / ZrO2-Mg was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0048] Example 3

[0049] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of zinc nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, and then dry it in an oven at 120°C. The resulting precursor is ZrO2-Zn / SiO2.

[0050] (2) ZrO2-Zn / SiO2 was sulfonated by an equal volume impregnation method. A certain amount of ZrO2-Zn / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Zn / SO4 2- / SiO2.

[0051] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Zn / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was marked as HPW / ZrO2-Zn.

[0052] HPW / ZrO2-Zn was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0053] Example 4

[0054] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of cerium nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, and then dry it in an oven at 120°C. The resulting precursor is ZrO2-Ce / SiO2.

[0055] (2) ZrO2-Ce / SiO2 was sulfonated by an equal volume impregnation method. A certain amount of ZrO2-Ce / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Ce / SO4 2- / SiO2.

[0056] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Ce / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was marked as HPW / ZrO2-Ce.

[0057] HPW / ZrO2-Ce was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0058] Example 5

[0059] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, and then dry it in an oven at 120°C. The resulting precursor is ZrO2-Al / SiO2.

[0060] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.0 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- (1.0) / SiO2.

[0061] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al / SO4 2- (1.0) / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was labeled HPW / ZrO2-Al H .

[0062] HPW / ZrO2-Al H The reaction was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0063] Example 6

[0064] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, and then dry it in an oven at 120°C. The resulting precursor is ZrO2-Al / SiO2.

[0065] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 500 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4. 2- / SiO2 / 500.

[0066] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al / SO4 2- / SiO2 / 500, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was labeled HPW / ZrO2-Al T .

[0067] HPW / ZrO2-Al T The reaction was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0068] Example 7

[0069] (1) Dissolve 12.37g of zirconium oxychloride octahydrate and 0.1237g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water until the pH value is 9.5, stir for 20 minutes and then age at room temperature for 24 hours. Filter until there is no chloride ion in the filtrate, then dry it in an oven at 120°C. The resulting precursor is ZrO2-Al P / SiO2.

[0070] (2) ZrO2-Al P / SiO2 is sulfonated to form a certain amount of ZrO2-Al P / SiO2 was placed in a 1.5M H2SO4 solution, treated with ultrasound for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al P / SO4 2- / SiO2.

[0071] (3) Dissolve 2.0 g of phosphotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al P / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was labeled HPW / ZrO2-Al P .

[0072] HPW / ZrO2-Al P The reaction was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0073] Example 8

[0074] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, then dry in an oven at 120°C. The resulting precursor is labeled as ZrO2-Al / SiO2.

[0075] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- / SiO2.

[0076] (3) Dissolve 2.0 g of silicotungstic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was marked as HSiW / ZrO2-Al.

[0077] HSiW / ZrO2-Al was applied to the reaction of C5 component olefins in high-temperature Fischer-Tropsch synthesis products with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0078] Example 9

[0079] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, then dry in an oven at 120°C. The resulting precursor is labeled as ZrO2-Al / SiO2.

[0080] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- / SiO2.

[0081] (3) Dissolve 2.0 g of phosphomolybdic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The resulting catalyst was marked as HPMo / ZrO2-Al.

[0082] HPMo / ZrO2-Al was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0083] Example 10

[0084] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, then dry in an oven at 120°C. The resulting precursor is labeled as ZrO2-Al / SiO2.

[0085] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- / SiO2.

[0086] (3) Dissolve 2.0 g of silicomolybdic acid in 2.0 mL of water, then add 2.0 g of the above ZrO2-Al / SO4 2- / SiO2, ultrasonically treated for 30 min, left to stand for 12 h, and finally dried at 60 °C for 24 h. The obtained catalyst was marked as HSiMo / ZrO2-Al.

[0087] HSiMo / ZrO2-Al was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0088] Comparative Example 1

[0089] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add ammonia water until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, then dry in an oven at 120°C, and the resulting precursor is ZrO2-Al.

[0090] (2) ZrO2-Al was sulfonated by an equal volume impregnation method. A certain amount of ZrO2-Al was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- .

[0091] Comparative Example 2

[0092] (1) Dissolve 12.37 g of zirconium oxychloride octahydrate and 0.1237 g of aluminum nitrate in a certain amount of water and stir evenly, then add a certain amount of SiO2, add ammonia water dropwise until the pH value is 9.0, stir for 20 min, and then age at room temperature for 24 h. Filter until there is no chloride ion in the filtrate, and then dry it in an oven at 120°C. The resulting precursor is ZrO2-Al / SiO2.

[0093] (2) ZrO2-Al / SiO2 was sulfonated by isovolumetric impregnation. A certain amount of ZrO2-Al / SiO2 was placed in a 1.5 M H2SO4 solution, ultrasonically treated for 30 min, left to stand for 12 h, and finally calcined at 550 °C for 3 h. The resulting catalyst was labeled ZrO2-Al / SO4 2- / SiO2.

[0094] ZrO2-Al / SO4 2- / SiO2 is applied to the reaction of C5 component olefins in high-temperature Fischer-Tropsch synthesis products with acetic acid. The reaction is carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0095] Comparative Example 3

[0096] Take 2.0 g of phosphotungstic acid and dissolve it in 3.0 mL of water, then add 2.0 g of the above SiO2, ultrasonically treat for 30 min, let it stand for 12 h, and finally dry it at 60°C for 24 h. The obtained catalyst is marked as HPW / SiO2.

[0097] HPW / SiO2 was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0098] Comparative Example 4

[0099] Take 2.0 ml of silicotungstic acid and dissolve it in 3.0 ml of water, then add 2.0 g of the above SiO2, treat it with ultrasound for 30 min, let it stand for 12 h, and finally dry it at 60 °C for 24 h. The obtained catalyst is marked as HSiW / SiO2.

[0100] HSiW / SiO2 was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0101] Comparative Example 5

[0102] Take 2.0 mL of phosphomolybdic acid and dissolve it in 3.0 mL of water, then add 2.0 g of the above SiO2, ultrasonically treat for 30 min, let it stand for 12 h, and finally dry it at 60°C for 24 h. The obtained catalyst is marked as HPMo / SiO2.

[0103] HPMo / SiO2 was applied to the reaction of C5 component olefins in the high-temperature Fischer-Tropsch synthesis product with acetic acid. The reaction was carried out in a fixed bed reactor. The reaction conditions and results are listed in Table 1.

[0104] Table 1 Catalyst performance test results

[0105]

[0106] It can be seen from the data in Table 1 that compared with traditional supported heteropoly acid catalysts and solid superacid catalysts, the solid superacid and heteropolyacid catalysts simultaneously supported by silica have better catalytic activity, which is mainly due to the significant improvement in the acid strength and acid content of the catalyst prepared by this method. Among a series of catalysts, HPW / ZrO2-Al has the best catalytic activity, and the 1-pentene conversion rate and secondary amyl acetate selectivity are 92% and 51%, respectively.

[0107] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A catalyst for olefin esterification, characterized in that: The catalyst comprises active components of solid superacid and heteropolyacid supported by silicon dioxide as a carrier, wherein the solid superacid is used to provide high-strength acid sites, and the heteropolyacid is used to provide uniformly distributed active acid sites.

2. The catalyst according to claim 1, characterized in that The solid super acid is composed of metal-modified zirconium dioxide-sulfate.

3. The catalyst according to claim 2, characterized in that The metal is one of aluminum, magnesium, zinc, tin or cerium.

4. The catalyst according to claim 1, characterized in that The heteropoly acid is one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid or germanotungstic acid.

5. A method for preparing a catalyst for olefin esterification, characterized in that: The following steps are involved: The metal salt and zirconium oxychloride octahydrate are dissolved in water, a silica carrier is added, the pH value of the solution is adjusted to an alkaline range, and after standing and aging, the solution is filtered and dried to obtain a precursor; After the precursor is immersed in an acid solution, it is calcined at a suitable temperature to obtain a solid super acid; The solid superacid is mixed with a heteropolyacid solution, subjected to uniform dispersion treatment, static aging and drying, to obtain the catalyst for olefin esterification as claimed in any one of claims 1 to 4.

6. The preparation method according to claim 5, characterized in that: During the preparation of the precursor, The metal salt is one of aluminum nitrate, magnesium chloride, zinc nitrate, tin chloride or cerium nitrate, and the amount thereof is 0.1% to 5% by mass relative to zirconium oxychloride octahydrate; The pH value of the solution is 9.0-10.

0.

7. The preparation method according to claim 5, characterized in that: During the preparation of the solid superacid, The acidic solution is a 1.0-1.5M sulfuric acid solution; The calcination temperature is 450-600°C.

8. The preparation method according to claim 5, characterized in that: In the preparation process of the catalyst for olefin esterification, The heteropoly acid is one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid or germanotungstic acid; The drying temperature is 60-120°C.

9. An application of a catalyst for olefin esterification, characterized in that: The catalyst is prepared according to any one of claims 1 to 4, or according to any one of claims 5 to 8, and is used to catalyze the addition-esterification reaction of olefins and organic acids, wherein: The olefins are C5 component olefins in the high-temperature Fischer-Tropsch synthesis product, and the C5 component olefins include 1-pentene, C5 isomeric olefins, oxygen-containing compounds and aromatic hydrocarbons; The organic acid is acetic acid.

10. The use according to claim 9, characterized in that: The addition-esterification reaction is carried out in a fixed bed reactor under the following reaction conditions: reaction temperature of 80-120° C. and acid-olefin molar ratio of 0.5-4.0.

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