Preparation method and application of carbide nanocomposite molecular sieve catalyst

Abstract

The application discloses a preparation method of a carbide nano-composite molecular sieve catalyst. The catalyst is represented by a formula M2-C / M1-C@ZSM-5, active metal M1 is first encapsulated in a molecular sieve ZSM-5, then active metal M2 is impregnated and loaded on the surface of the M1@ZSM-5 molecular sieve, and the M2-C / M1-C@ZSM-5 molecular sieve catalyst is obtained through calcination and carbonization treatment. The active metals M1 and M2 are selected from one or two of Rh, Co, Os, Au, Ir, Ru, Pt, Pd, Ni and Cu. The molecular sieve catalyst provided by the application has good performance in an internal olefin isomerization hydroformylation reaction, the active metal M1 in the carbonized catalyst promotes mild internal olefin isomerization conditions, realizes internal olefin isomerization and hydroformylation reaction coupling, and reduces the generation of by-products such as alkanes and alcohols. The carbonized supported metal M2 can effectively adjust the selectivity of normal aldehyde and isomerized aldehyde in the product. The internal and external distribution characteristics of M1 and M2 ensure the efficiency of the hydroformylation reaction of the internal olefin isomerization into terminal olefins.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of M2-C / M1-C@ZSM-5 carbide nanocomposite molecular sieve catalyst and its application, more particularly to a kind of internal olefin isomerization hydroformylation catalyst and its application. BACKGROUND

[0002] Olefin hydroformylation reaction is 100% atom economy reaction, product aldehyde is very useful intermediate, can be used to produce alcohol, acid, ester and amine and other compounds. At present, global hydroformylation capacity reaches 1200 million tons / year, and olefin hydroformylation reaction in industry is mainly homogeneous catalytic process, and the catalyst used is mainly homogeneous Rh and Co metal phosphine ligand complex, which faces various problems such as metal and ligand loss, complex operation. Therefore, it is urgent to develop green and environmentally friendly heterogeneous process and catalyst.

[0003] Internal olefin is a relatively common olefin in industry, such as product olefin produced by alkane dehydrogenation process is mainly internal olefin, but internal olefin hydroformylation has always been a difficulty in the field of hydroformylation research, mainly because the activity of internal olefin is low and it is difficult to convert. At present, there is no special heterogeneous catalyst and process for internal olefin hydroformylation reaction in industry. The catalytic activity of some commonly used commercial homogeneous catalysts for internal olefin cannot meet the production demand. In industry, the reaction activity of internal olefin hydroformylation is often improved by increasing the reaction temperature, but it brings high by-product selectivity, high energy consumption and high safety risk, and degradation and deterioration of the catalyst used in the reaction. SUMMARY

[0004] In view of the above shortcomings or defects, the purpose of the present application is to provide a heterogeneous catalytic system for catalyzing internal olefin hydroformylation to prepare aldehyde, which can effectively solve the problems of poor catalyst activity, poor product selectivity, low recycling rate and poor stability in the existing internal olefin hydroformylation reaction.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A kind of M2-C / M1-C@ZSM-5 molecular sieve catalyst, the preparation method comprises: first, active metal M1 is encapsulated in molecular sieve ZSM-5 to obtain M1@ZSM-5 molecular sieve, then active metal M2 is impregnated and loaded on the surface of M1@ZSM-5 molecular sieve, and finally M2-C / M1-C@ZSM-5 molecular sieve catalyst is obtained by calcination and carbonization treatment.

[0007] In a specific embodiment, the preparation method of the above-mentioned M2-C / M1-C@ZSM-5 molecular sieve catalyst comprises the following steps:

[0008] 1) Synthesis of M1@ZSM-5 molecular sieve

[0009] Silicon and aluminum sources were added to water and mixed to form a mixed gel. A deionized aqueous solution containing compound M1 was added to the mixed gel, followed by the addition of an organic template agent and a crystallization reaction. After filtration, washing, drying and calcination, molecular sieve M1@ZSM-5 was obtained.

[0010] Furthermore, the synthesis of M1@ZSM-5 molecular sieve in step 1) includes the following steps:

[0011] (a) Weigh a certain amount of silicon source and aluminum source and add them to water. The molar ratio of silicon source to aluminum source is 1:0.05-0.4, preferably 1:0.1-0.2. Stir at room temperature for 1-10 hours to form a mixed gel.

[0012] (b) Add an appropriate amount of the M1-containing compound to the mixed gel described in step (a), wherein the molar ratio of M1 to the silicon source is 10. -6 -10 -1 :1, and stir at room temperature for 0.5-1h; M1 is selected from one or more of Rh, Co, Os, Au, Ir, Ru, Pt, Pd, Ni, Cu and Fe.

[0013] (c) Add an appropriate amount of organic template agent to the mixed solution of step (b), wherein the molar ratio of template agent to silicon source is 0.1-1:1, and stir at room temperature for 0.5-3 hours;

[0014] (d) The mixed gel described in step (c) is transferred to a hydrothermal synthesis reactor and grown at high temperature to obtain a coarse molecular sieve;

[0015] (e) The coarse molecular sieve obtained in step (d) is filtered, washed, dried and calcined to obtain molecular sieve M1@ZSM-5.

[0016] Furthermore, the aluminum source is selected from at least one of boehmite, aluminum oxide, sodium aluminate, diaspore, gibbsite, aluminum isopropoxide, aluminum nitrate, and metallic aluminum solution; the silicon source is selected from at least one of silica gel, silica sol, and organosilicates.

[0017] Further, the M1-containing compound is selected from at least one of rhodium nitrate, rhodium chloride, rhodium acetylacetonate, cobalt nitrate, cobalt chloride, cobalt acetate, sodium hexachloroosmium tetroxide, chloroauric acid, iridium chloride, carbonyl iridium, iridium fluoride, hexachloroiridic acid, ruthenium nitrate, ruthenium chloride, chloroplatinic acid, palladium nitrate, palladium iodide, palladium chloride, palladium bromide, nickel nitrate, nickel chloride, copper nitrate, copper chloride, and ferric chloride.

[0018] Furthermore, the organic template agent is selected from at least one of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and di-n-propylamine;

[0019] Furthermore, the high-temperature crystallization temperature in step (d) is 80-200℃, and the time is 2-6 days.

[0020] Further, the drying conditions described in step (e) are: air drying, temperature 50-150℃, time 12-48h. The calcination conditions described in step (e) are: air calcination, temperature 200-800℃, time 6-48h.

[0021] 2) Preparation of M2 / M1@ZSM-5 molecular sieve catalyst

[0022] Add the M2-containing compound to deionized water, then add the M1@ZSM-5 molecular sieve obtained in step 1), add a stabilizer, stir for 0.5-2 hours, let stand for 6-12 hours, dry at 40-100℃ for 6-24 hours, cool to room temperature, grind, and calcine in a muffle furnace at 300-600℃ for 4-24 hours to obtain the M2 / M1@ZSM-5 molecular sieve.

[0023] M2 is selected from one or more of Rh, Co, Os, Au, Ir, Ru, Pt, Pd, Ni, Cu, and Fe.

[0024] Furthermore, in step 2), the stabilizer is one of ethanol and isopropanol, and the mass ratio of the stabilizer to M1@ZSM-5 molecular sieve is 0.1-0.5:1.

[0025] Furthermore, the M2-containing compound is selected from one of the following: rhodium nitrate, rhodium chloride, rhodium acetylacetonate, cobalt nitrate, cobalt chloride, cobalt acetate, sodium hexachloroosmium tetroxide, chloroauric acid, iridium chloride, carbonyl iridium, iridium fluoride, hexachloroiridic acid, ruthenium nitrate, ruthenium chloride, chloroplatinic acid, palladium nitrate, palladium iodide, palladium chloride, palladium bromide, nickel nitrate, nickel chloride, copper nitrate, copper chloride, and ferric chloride.

[0026] Furthermore, the mass ratio of M2 to M1@ZSM-5 molecular sieves is 10. -4 -10 -1 :1.

[0027] 3) Preparation of M2-C / M1-C@ZSM-5 molecular sieve catalysts

[0028] The M2 / M1@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized in a CH4 / H2 mixed gas atmosphere (preferably, V(CH4):V(H2)=50:50) to obtain the M2-C / M1-C@ZSM-5 molecular sieve catalyst.

[0029] Furthermore, the carbonization temperature is 150-1050℃ and the carbonization time is 0.5-10h. Preferably, the carbonization temperature is 650-850℃ and the carbonization time is 6-8h.

[0030] This invention also relates to the application of the M2-C / M1-C@ZSM-5 molecular sieve catalyst as described above for the synthesis of aldehydes via the hydroformylation reaction of internal olefin isomerization.

[0031] A method for preparing aldehydes by isomerization and hydroformylation of internal olefins includes the following steps: adding internal olefins, M2-C / M1-C@ZSM-5 molecular sieve catalysts and organic solvents into a high-pressure reactor; introducing carbon monoxide and hydrogen into the high-pressure reactor; reacting the reactor at 60-200℃ for 2-48 hours; setting the stirring rate to 100-1000 rpm; and isomerizing and hydroformylating the internal olefins to generate aldehyde compounds.

[0032] Further, the internal olefin includes one or more C4-C20 internal olefin compounds, and the molar ratio of the internal olefin to M1 in the M2-C / M1-C@ZSM-5 molecular sieve catalyst is 10. 1 -10 4 .

[0033] Furthermore, the organic solvent includes one or more of toluene, tetrahydrofuran, and ethyl acetate.

[0034] Furthermore, the total pressure of the carbon monoxide and hydrogen is 0.5-10 MPa, and the hydrogen-to-carbon ratio (pressure ratio of hydrogen to carbon monoxide) is 0.2-5.

[0035] The beneficial effects of this invention are:

[0036] The heterogeneous catalyst provided by this invention has excellent performance in the hydroformylation reaction of internal olefins. After M1 coordinates with the olefin in the catalyst body, it promotes the isomerization of the internal olefin to the terminal olefin. M2 catalyzes the terminal olefin to generate the product aldehyde. The selectivity of the n-aldehyde in the hydroformylation product is high, the ratio of n-aldehyde to iso-aldehyde is greater than 3, and the alkane content in the product is less than 1%.

[0037] Compared to traditional homogeneous catalysts with phosphine ligands, these heterogeneous catalysts are easier to separate and exhibit higher catalytic activity. They also demonstrate greater stability against air and moisture, requiring less stringent operating conditions. This effectively reduces the production cost of high-carbon aldehydes and provides a new industrial technology for the hydroformylation of internal olefins. Detailed Implementation

[0038] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0039] Unless otherwise specified, all raw materials used in the following specific embodiments of the present invention are obtained through commercial purchase.

[0040] Unless otherwise specified, in this invention, the term "room temperature" refers to 20°C-40°C.

[0041] Example 1

[0042] The Rh-C / Pd-C@ZSM-5 molecular sieve catalyst in this embodiment was prepared by the following steps:

[0043] 1) Synthesis of Pd@ZSM-5 molecular sieve

[0044] (a) Weigh 8.4 g of tetraethyl orthosilicate and 0.4 g of boehmite (molecular weight 71) and add them to 30 g of water. Stir for 2 h to form a mixed gel.

[0045] (b) Weigh 4.7 mg of palladium nitrate and add it to 5 mL of deionized water. Add the palladium nitrate aqueous solution to the mixed solution described in step (a) and stir at room temperature for 0.5-1 h.

[0046] (c) Add 4.5 g of the organic template agent tetraethylammonium hydroxide to the mixed gel described in step (b) and stir at room temperature for 1 h;

[0047] (d) The mixed solution described in step (c) was transferred to a 100 mL hydrothermal synthesis reactor and crystallized at 180 °C for 72 h; the autoclave was then cooled to room temperature to obtain a coarse molecular sieve.

[0048] (e) The coarse molecular sieve obtained in step (d) was filtered and washed to obtain a white solid, which was then dried in an oven at 100°C for 12 hours. The sample was then placed in a muffle furnace and heated to 550°C for 6 hours to obtain molecular sieve Pd@ZSM-5.

[0049] 2) Synthesis of Rh / Pd@ZSM-5 molecular sieve catalyst

[0050] Add 2.6 mg of rhodium trichloride trihydrate to 5 mL of deionized water, then add 1.0 g of the prepared Pd@ZSM-5 molecular sieve and 0.3 g of ethanol as a stabilizer. Stir for 2 h, let stand for 6 h, dry the sample in an oven at 100 °C for 12 h, cool to room temperature, grind into powder, and calcine in a muffle furnace at 550 °C for 6 h to obtain the Rh / Pd@ZSM-5 molecular sieve catalyst.

[0051] 3) Preparation of Rh-C / Pd-C@ZSM-5 molecular sieve catalysts

[0052] The Rh / Pd@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized at 700°C for 6 hours in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst.

[0053] Example 2

[0054] The Pd-C / Co-C@ZSM-5 molecular sieve catalyst in this embodiment was prepared by the following steps:

[0055] 1) Synthesis of Co@ZSM-5 molecular sieve

[0056] (a) Weigh 8.5g of tetraethyl orthosilicate and 0.42g of boehmite and add them to 30g of water. Stir for 2 hours to form a mixed gel.

[0057] (b) Weigh 8.9 mg of cobalt nitrate and add it to 5 mL of deionized water. Add the cobalt nitrate aqueous solution to the mixed solution described in step (a) and stir at room temperature for 1 h.

[0058] (c) Add 4.8 g of the organic template agent tetraethylammonium hydroxide to the mixed gel described in step (b) and stir at room temperature for 1 h;

[0059] (d) The mixed solution described in step (c) was transferred to a 100 mL hydrothermal synthesis reactor and crystallized at 180 °C for 72 h; the autoclave was then cooled to room temperature to obtain a coarse molecular sieve.

[0060] (e) The coarse molecular sieve obtained in step (d) was filtered and washed to obtain a white solid, which was then dried in an oven at 100°C for 12 hours. The sample was then placed in a muffle furnace and heated to 550°C for 6 hours to obtain molecular sieve Co@ZSM-5.

[0061] 2) Synthesis of Pd / Co@ZSM-5 molecular sieve catalyst

[0062] Add 5.1 mg of palladium nitrate to 5 mL of deionized water, then weigh 1.0 g of the Co@ZSM-5 molecular sieve prepared above, add 0.2 g of stabilizer ethanol, stir for 2 h, let stand for 6 h, put the sample into an oven at 100 °C to dry for 12 h, cool to room temperature, grind into powder, and then calcine in a muffle furnace at 550 °C for 6 h to obtain the Pd / Co@ZSM-5 molecular sieve catalyst.

[0063] 3) Preparation of Pd-C / Co-C@ZSM-5 molecular sieve catalysts

[0064] The Pd / Co@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized at 710°C for 6.5 h in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Pd-C / Co-C@ZSM-5 molecular sieve catalyst.

[0065] Example 3

[0066] The Pd-C / Au-C@ZSM-5 molecular sieve catalyst in this embodiment was prepared by the following steps:

[0067] 1) Synthesis of Au@ZSM-5 molecular sieve

[0068] (a) Weigh 8.4 g of tetraethyl orthosilicate and 0.5 g of boehmite and add them to 30 g of water. Stir for 2 h to form a mixed gel.

[0069] (b) Weigh 3.4 mg of chloroauric acid and add it to 5 mL of deionized water. Add the chloroauric acid aqueous solution to the mixed solution described in step (a) and stir at room temperature for 0.5-1 h.

[0070] (c) Add 5.5 g of the organic template agent tetraethylammonium hydroxide to the mixed gel described in step (b) and stir at room temperature for 1 h;

[0071] (d) The mixed solution described in step (c) was transferred to a 100 mL hydrothermal synthesis reactor and crystallized at 180 °C for 72 h; the autoclave was then cooled to room temperature to obtain a coarse molecular sieve.

[0072] (e) The coarse molecular sieve obtained in step (d) was filtered and washed to obtain a white solid, which was then dried in an oven at 100°C for 12 hours. The sample was then placed in a muffle furnace and heated to 550°C for 6 hours to obtain molecular sieve Au@ZSM-5.

[0073] 2) Synthesis of Pd / Au@ZSM-5 molecular sieve catalyst

[0074] Add 7.6 mg of palladium nitrate to 5 mL of deionized water, then weigh 1.0 g of the Au@ZSM-5 molecular sieve prepared above, add 0.4 g of stabilizer ethanol, stir for 2 h, let stand for 6 h, put the sample into an oven at 100 °C to dry for 12 h, cool to room temperature, grind into powder, and then calcine in a muffle furnace at 550 °C for 6 h to obtain the Pd / Au@ZSM-5 molecular sieve catalyst.

[0075] 3) Preparation of Pd-C / Au-C@ZSM-5 molecular sieve catalysts

[0076] The Pd / Au@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized at 720°C for 5.5 h in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Pd-C / Au-C@ZSM-5 molecular sieve catalyst.

[0077] Example 4

[0078] The Rh-C / Ni-C@ZSM-5 molecular sieve catalyst in this embodiment was prepared by the following steps:

[0079] 1) Synthesis of Ni@ZSM-5 molecular sieve

[0080] (a) Weigh 8.4 g of tetraethyl orthosilicate and 0.5 g of boehmite and add them to 30 g of water. Stir for 2 h to form a mixed gel.

[0081] (b) Weigh 8.8 mg of nickel chloride and add it to 5 mL of deionized water. Add the nickel chloride aqueous solution to the mixed solution described in step (a) and stir at room temperature for 0.5 h.

[0082] (c) Add 5.5 g of the organic template agent tetraethylammonium hydroxide to the mixed gel described in step (b) and stir at room temperature for 1 h;

[0083] (d) The mixed solution described in step (c) was transferred to a 100 mL hydrothermal synthesis reactor and crystallized at 180 °C for 72 h; the autoclave was then cooled to room temperature to obtain a coarse molecular sieve.

[0084] (e) The coarse molecular sieve obtained in step (d) was filtered and washed to obtain a white solid, which was then dried in an oven at 100°C for 12 hours. The sample was then placed in a muffle furnace and heated to 550°C for 6 hours to obtain molecular sieve Ni@ZSM-5.

[0085] 2) Synthesis of Rh / Ni@ZSM-5 molecular sieve catalyst

[0086] Add 2.7 mg of rhodium trichloride trihydrate to 5 mL of deionized water, then weigh 1.0 g of the Ni@ZSM-5 molecular sieve prepared above, add 0.3 g of stabilizer ethanol, stir for 2 h, let stand for 6 h, put the sample into an oven at 120 ℃ to dry for 10 h, cool to room temperature, grind into powder, and then calcine in a muffle furnace at 600 ℃ for 6 h to obtain the Rh / Ni@ZSM-5 molecular sieve catalyst;

[0087] 3) Preparation of Rh-C / Ni-C@ZSM-5 molecular sieve catalysts

[0088] The Rh / Ni@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized at 690°C for 7 h in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Rh-C / Ni-C@ZSM-5 molecular sieve catalyst.

[0089] Example 5

[0090] The Rh-C / Cu-C@ZSM-5 molecular sieve catalyst in this embodiment was prepared by the following steps:

[0091] 1) Synthesis of Cu@ZSM-5 molecular sieve

[0092] (a) Weigh 8.5g of tetraethyl orthosilicate and 0.5g of boehmite and add them to 30g of water. Stir for 2 hours to form a mixed gel.

[0093] (b) Weigh 7.2 mg of copper chloride and add it to 5 mL of deionized water. Add copper chloride aqueous solution to the mixed solution described in step (a) and stir at room temperature for 1 h.

[0094] (c) Add 4.5 g of the organic template agent tetraethylammonium hydroxide to the mixed gel described in step (b) and stir at room temperature for 1 h;

[0095] (d) The mixed solution described in step (c) is transferred to a 100 mL hydrothermal synthesis reactor and crystallized at 170 °C for 96 h; the autoclave is then cooled to room temperature to obtain a coarse molecular sieve.

[0096] (e) The coarse molecular sieve obtained in step (d) was filtered and washed to obtain a white solid, which was then dried in an oven at 110°C for 12 hours. The sample was then placed in a muffle furnace and heated to 600°C for 6 hours to obtain molecular sieve Cu@ZSM-5.

[0097] 2) Synthesis of Rh / Cu@ZSM-5 molecular sieve catalyst

[0098] Add 2.6 mg of rhodium trichloride trihydrate to 5 mL of deionized water, then weigh 1.0 g of the Cu@ZSM-5 molecular sieve prepared above, add 0.3 g of stabilizer ethanol, stir for 2 h, let stand for 6 h, put the sample into an oven at 150 ℃ to dry for 12 h, cool to room temperature, grind into powder, and then calcine in a muffle furnace at 600 ℃ for 4 h to obtain the Rh / Cu@ZSM-5 molecular sieve catalyst;

[0099] 3) Preparation of Rh-C / Cu-C@ZSM-5 molecular sieve catalysts

[0100] The Rh / Cu@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized at 700°C for 6 hours in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Rh-C / Cu-C@ZSM-5 molecular sieve catalyst.

[0101] Test Implementation Examples

[0102] Application Example 1

[0103] This application example illustrates the catalytic reaction results of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the hydroformylation reaction of internal olefin isomerization.

[0104] Includes the following steps:

[0105] The isomerization and hydroformylation of internal olefins was carried out in a stainless steel high-pressure reactor with a volume of 100 mL (mechanically stirred). The specific operation procedure was as follows: 50 mg of catalyst and 20 mL of tetrahydrofuran were weighed and added to the reactor, which was then sealed. A mixture of hydrogen and carbon monoxide (H2 / CO) at 0.5 MPa (v:v = 1:1) was introduced into the reactor to fully purge it. 2.0 g of the reactant 2-butene was weighed and added, followed by the introduction of a 2.0 MPa H2 / CO mixture (v:v = 1:1). The stirring rate was set to 500 rpm, the reaction temperature to 110 °C, and the reaction time to 6 h. After the reaction, the reaction products were analyzed and quantified by GC-MS, and the results are shown in Table 1.

[0106] Application Example 2

[0107] This application example provides an application of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Example 1 is that the olefin compound used in Application Example 2 is 2-pentene, which ultimately yields hexanal. A mixture of hydrogen and carbon monoxide (H2 / CO) at 1.0 MPa is introduced, the reaction temperature is 120 °C, and the reaction time is 6 h. Other steps and methods are the same as in Application Example 1, and will not be repeated here. The analytical results are shown in Table 1.

[0108] Application Example 3

[0109] This application example provides an application of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Example 1 is that the olefin compound used in Application Example 3 is 2-hexene, which ultimately yields heptanal. A mixture of hydrogen and carbon monoxide (H2 / CO) at 1.5 MPa is introduced, the reaction temperature is 120 °C, and the reaction time is 8 h. Other steps and methods are the same as in Application Example 1 and will not be repeated here. The analytical results are shown in Table 1.

[0110] Application Example 4

[0111] This application example provides an application of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Example 1 is that the olefin compound used in Example 4 is 2-heptene, which ultimately yields octanal. The mixture of hydrogen and carbon monoxide (H2 / CO) at 2.0 MPa is introduced, the reaction temperature is 125 °C, and the reaction time is 8 h. Other steps and methods are the same as in Example 1 and will not be repeated here. The analysis results are shown in Table 1.

[0112] Application Example 5

[0113] This application example provides an application of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Example 1 is that the olefin compound used in Example 5 is 3-heptene, which ultimately yields octanal. The mixture of hydrogen and carbon monoxide (H2 / CO) at 2.5 MPa is introduced, the reaction temperature is 130 °C, and the reaction time is 10 h. Other steps and methods are the same as in Example 1 and will not be repeated here. The analytical results are shown in Table 1.

[0114] Application Example 6

[0115] This application example provides an application of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Example 1 is that the olefin compound used in Example 6 is 2-octene, which ultimately yields nonanal. A mixture of hydrogen and carbon monoxide (H2 / CO) at 3.0 MPa is introduced, the reaction temperature is 130 °C, and the reaction time is 10 h. Other steps and methods are the same as in Example 1 and will not be repeated here. The analytical results are shown in Table 1.

[0116] Application Example 7

[0117] This application example provides an application of the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared in Example 1 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Example 1 is that the olefin compound used in Example 7 is 3-octene, which ultimately yields nonanal. A mixture of hydrogen and carbon monoxide (H2 / CO) at 4.0 MPa is introduced, the reaction temperature is 130 °C, and the reaction time is 10 h. Other steps and methods are the same as in Example 1 and will not be repeated here. The analytical results are shown in Table 1.

[0118] Application Example 8

[0119] This application example provides an application of the Pd-C / Co-C@ZSM-5 molecular sieve catalyst prepared in Example 2 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Application Example 1 is that the catalyst used in Application Example 8 is the Pd-C / Co-C@ZSM-5 molecular sieve catalyst prepared in Example 2, the reaction temperature is 110℃, the reaction time is 8h, and the other steps and methods are the same as in Application Example 1, which will not be repeated here. The analysis results are shown in Table 1.

[0120] Application Example 9

[0121] This application example provides an application of the Pd-C / Au-C@ZSM-5 molecular sieve catalyst prepared in Example 3 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Application Example 1 is that the catalyst used in Application Example 9 is the Pd-C / Au-C@ZSM-5 molecular sieve catalyst prepared in Example 3, the reaction temperature is 105℃, the reaction time is 7h, and the other steps and methods are the same as in the application example, which will not be repeated here. The analysis results are shown in Table 1.

[0122] Application Example 10

[0123] This application example provides an application of the Rh-C / Ni-C@ZSM-5 molecular sieve catalyst prepared in Example 4 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Application Example 1 is that the catalyst used in Application Example 10 is the Rh-C / Ni-C@ZSM-5 molecular sieve catalyst prepared in Example 4, the reaction temperature is 115℃, the reaction time is 8h, and the other steps and methods are the same as in the application example, which will not be repeated here. The analysis results are shown in Table 1.

[0124] Application Example 11

[0125] This application example provides an application of the Rh-C / Cu-C@ZSM-5 molecular sieve catalyst prepared in Example 5 in the olefin isomerization and hydroformylation reaction. The difference between this application example and Application Example 1 is that the catalyst used in Application Example 11 is the Rh-C / Cu-C@ZSM-5 molecular sieve catalyst prepared in Example 5, the reaction temperature is 135℃, the reaction time is 12h, and the other steps and methods are the same as in the application example, which will not be repeated here. The analysis results are shown in Table 1.

[0126] Comparative Example 1

[0127] This comparative example illustrates the catalytic reaction results of the Rh / Pd@ZSM-5 molecular sieve catalyst prepared in Example 1 in the hydroformylation of olefins. The application in the hydroformylation of olefins differs from Application Example 1 in that the catalyst used is the Rh / Pd@ZSM-5 molecular sieve catalyst prepared in Example 1. Other steps and methods are the same as in Application Example 1 and will not be repeated here. The analytical results are shown in Table 1.

[0128] Comparative Example 2

[0129] This comparative example is used to illustrate the catalytic reaction results of Pd / ZSM-5 molecular sieve catalyst in the hydroformylation reaction of internal olefin isomerization.

[0130] 1) Synthesis of ZSM-5 molecular sieve

[0131] (a) Weigh 8.4 g of tetraethyl orthosilicate and 0.4 g of boehmite and add them to 30 g of water. Stir for 2 h to form a mixed gel.

[0132] (b) Add 7.5 g of the organic template agent tetraethylammonium hydroxide to the mixed gel described in step (a) and stir at room temperature for 1 h;

[0133] (c) The mixed solution described in step (b) is transferred to a 100 mL hydrothermal synthesis reactor and crystallized at 180 °C for 72 h; the autoclave is then cooled to room temperature to obtain a coarse molecular sieve.

[0134] (d) The coarse molecular sieve obtained in step (c) was filtered and washed to obtain a white solid, which was then dried in an oven at 100°C for 12 hours. The sample was then placed in a muffle furnace and heated to 550°C for 6 hours to obtain molecular sieve ZSM-5.

[0135] 2) Synthesis of Pd / ZSM-5 molecular sieve catalysts

[0136] Add 4.7 mg of palladium nitrate to 5 mL of deionized water, then add 2.0 g of ZSM-5 molecular sieve prepared in step 1), and then add 0.5 g of isopropanol as a stabilizer. Stir for 2 h, let stand for 6 h, put the sample into an oven at 100 °C to dry for 12 h, cool to room temperature, grind into powder, and then calcine in a muffle furnace at 550 °C for 6 h. Then reduce in a H2 / Ar mixed gas (V(H2):V(Ar)=5:95) at 400 °C for 6 h to obtain the Pd / ZSM-5 molecular sieve catalyst.

[0137] The application of this method in the olefin isomerization and hydroformylation reaction differs from Application Example 1 in that the catalyst used is a Pd / ZSM-5 molecular sieve catalyst, which ultimately yields pentanal compound. The other steps and methods are the same as in Application Example 1, and will not be repeated here. The analytical results are shown in Table 1.

[0138] Comparative Example 3

[0139] This comparative example illustrates the catalytic reaction results of the Pd@ZSM-5 molecular sieve catalyst in the hydroformylation of internal olefin isomerization. The application in the hydroformylation of olefins differs from Application Example 1 in that the catalyst used is the Pd@ZSM-5 molecular sieve catalyst prepared in Example 1, ultimately yielding pentanal. Other steps and methods are the same as in the Application Example and will not be repeated here. The analytical results are shown in Table 1.

[0140] Comparative Example 4

[0141] This comparative example is used to illustrate the catalytic reaction results of Pd-C / ZSM-5 molecular sieve catalyst in the hydroformylation reaction of internal olefin isomerization.

[0142] The Pd-C / ZSM-5 molecular sieve catalyst of this comparative example was prepared by the following steps:

[0143] Synthesis of Pd-C / ZSM-5 molecular sieves

[0144] The Pd / ZSM-5 molecular sieve prepared in Comparative Example 2 was placed in a tube furnace and carbonized at 700°C for 6 hours in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Pd-C / ZSM-5 molecular sieve catalyst.

[0145] The application of this method in the olefin isomerization and hydroformylation reaction differs from Application Example 1 in that the catalyst used is the Pd-C / ZSM-5 molecular sieve catalyst prepared in Comparative Example 4. The other steps and methods are the same as in the Application Example, and will not be repeated here. The analytical results are shown in Table 1.

[0146] Comparative Example 5

[0147] This comparative example is used to illustrate the catalytic reaction results of Pd-C@ZSM-5 molecular sieve catalyst in the hydroformylation reaction of internal olefin isomerization.

[0148] Synthesis of Pd-C@ZSM-5 molecular sieve

[0149] The Pd@ZSM-5 molecular sieve catalyst prepared in Example 1 was placed in a tube furnace and carbonized at 700°C for 6 hours in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Pd-C@ZSM-5 molecular sieve catalyst.

[0150] The application of this method in the olefin isomerization and hydroformylation reaction differs from Application Example 1 in that the catalyst used is the Pd-C@ZSM-5 molecular sieve catalyst prepared in Comparative Example 5, which ultimately yields pentanal compound. Other steps and methods are the same as in the application example and will not be repeated here. The analytical results are shown in Table 1.

[0151] Comparative Example 6

[0152] This test was conducted to illustrate the catalytic reaction results of the Rh / ZSM-5 molecular sieve catalyst in the hydroformylation of internal olefin isomerization.

[0153] Synthesis of Rh / ZSM-5 molecular sieve catalysts

[0154] Add 2.6 mg of rhodium trichloride trihydrate to 5 mL of deionized water, then add 1.0 g of ZSM-5 molecular sieve prepared in Comparative Example 2 above, stir for 2 h, let stand for 6 h, dry the sample in an oven at 100 °C for 12 h, cool to room temperature, grind into powder, calcine in a muffle furnace at 550 °C for 5 h, and reduce in an H2 / Ar mixed gas (V(H2):V(Ar)=5:95) at 400 °C for 6 h to obtain Rh / ZSM-5 molecular sieve catalyst.

[0155] The application of this method in the olefin isomerization and hydroformylation reaction differs from Application Example 1 in that the catalyst used is the Rh / ZSM-5 molecular sieve catalyst prepared in Comparative Example 6, which ultimately yields pentanal compound. Other steps and methods are the same as in the Application Example, and will not be repeated here. The analytical results are shown in Table 1.

[0156] Comparative Example 7

[0157] This test was conducted to illustrate the catalytic reaction results of the Rh-C / ZSM-5 molecular sieve catalyst in the hydroformylation of internal olefin isomerization.

[0158] Synthesis of Rh-C / ZSM-5 molecular sieve

[0159] The Rh / ZSM-5 molecular sieve prepared in Comparative Example 6 was placed in a tube furnace and carbonized at 710°C for 7 hours in an atmosphere of 50% CH4 / H2 mixed gas (V(CH4):V(H2)=50:50) to obtain the Rh-C / ZSM-5 molecular sieve catalyst.

[0160] The application of olefin isomerization hydroformylation differs from that in Application Example 1 in that the catalyst used in Comparative Example 7 is the Rh-C / ZSM-5 molecular sieve catalyst prepared in Comparative Example 7, which ultimately yields pentanal compound. Other steps and methods are the same as in the Application Example, and will not be repeated here. The analytical results are shown in Table 1.

[0161] Comparative Example 8

[0162] This comparative example provides an application of the ZSM-5 molecular sieve catalyst prepared in Comparative Example 2 in the hydroformylation of olefin isomerization. The difference between this application and Application Example 1 is that the catalyst used is the ZSM-5 molecular sieve catalyst prepared in Comparative Example 2, ultimately yielding pentanal. Other steps and methods are the same as in the Application Example and will not be repeated here. The analytical results are shown in Table 1.

[0163] The reaction products were quantitatively analyzed using an Agilent 6890 gas chromatograph (flame ionization detector, PEG20M capillary column, 50m column length).

[0164] The content of compounds such as alkanes, alkenes, aldehydes, and alcohols after the reaction is calculated using the area normalization method, and the solvent is not included in the integration.

[0165] Table 1. Performance Test Results

[0166]

[0167]

[0168] As can be seen from the results in Table 1, compared with the molecular sieve catalysts in the comparative example, the Rh-C / Pd-C@ZSM-5 molecular sieve catalyst prepared by the method of the present invention has higher catalytic activity and aldehyde selectivity in the hydroformylation reaction of internal olefin isomerization, and the aldehyde product is mainly a normal aldehyde.

[0169] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors.

[0170] Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A method for preparing an M2-C / M1-C@ZSM-5 molecular sieve catalyst, comprising the following steps: Step 1) Synthesis of M1@ZSM-5 molecular sieve (a) Weigh a certain amount of silicon source and aluminum source and add them to water, and stir at room temperature to form a mixed gel; (b) Add an appropriate amount of the M1-containing compound to the mixed gel described in step (a) and stir at room temperature; M1 is selected from one or more of Rh, Co, Os, Au, Ir, Ru, Pt, Pd, Ni, Cu and Fe; (c) Add an appropriate amount of organic template agent to the mixed solution from step (b) and stir at room temperature; (d) The mixed gel from step (c) is transferred to a hydrothermal synthesis reactor and grown at high temperature to obtain a coarse molecular sieve; (e) The coarse molecular sieve obtained in step (d) is filtered, washed, dried and calcined to obtain molecular sieve M1@ZSM-5; Step 2) Preparation of M2 / M1@ZSM-5 molecular sieve catalyst Add the M2-containing compound to deionized water, then add the M1@ZSM-5 molecular sieve obtained in step 1), then add a stabilizer, stir, let stand, dry, and calcine to obtain the M2 / M1@ZSM-5 molecular sieve. M2 is selected from one or more of Rh, Co, Os, Au, Ir, Ru, Pt, Pd, Ni, Cu, and Fe; Step 3) Preparation of M2-C / M1-C@ZSM-5 molecular sieve catalyst The M2 / M1@ZSM-5 molecular sieve obtained in step 2) was placed in a tube furnace and carbonized in a CH4 / H2 mixed atmosphere to obtain the M2-C / M1-C@ZSM-5 molecular sieve catalyst.

2. The preparation method according to claim 1, wherein, In step a, the molar ratio of silicon source to aluminum source is 1:0.05-0.

4.

3. The preparation method according to claim 1 or 2, wherein, In step b, the molar ratio of M1 to the silicon source is 10. -6 -10 -1 :

1.

4. The preparation method according to claim 1 or 2, wherein, In step c, the organic template agent is selected from at least one of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and di-n-propylamine.

5. The preparation method according to claim 4, wherein, In step c, the molar ratio of template agent to silicon source is 0.1-1:

1.

6. The preparation method according to claim 1, wherein, In step d, the high-temperature crystallization temperature is 80-200℃, and the time is 2-6 days.

7. The preparation method according to claim 1, wherein, In step e, the calcination temperature is 200-800℃ and the time is 6-48h.

8. The preparation method according to claim 1, wherein, In step 2), the stabilizer is either ethanol or isopropanol.

9. The preparation method according to claim 8, wherein, In step 2), the mass ratio of stabilizer to M1@ZSM-5 molecular sieve is 0.1-0.5:

1.

10. The preparation method according to claim 1, wherein, In step 2), the mass ratio of M2 to M1@ZSM-5 molecular sieve is 10. -4 -10 -1 :

1.

11. The preparation method according to claim 1, wherein, In step 3), the carbonization temperature is 150-1050℃ and the carbonization time is 0.5-10h.

12. A method for preparing aldehydes via an internal olefin isomerization hydroformylation reaction, comprising the following steps: The internal olefin, the M2-C / M1-C@ZSM-5 molecular sieve catalyst prepared according to any one of claims 1-11, and the organic solvent are added to a high-pressure reactor, which is then filled with carbon monoxide and hydrogen, and the reaction is carried out at 60-200°C. The internal olefins include one or more of C4-C20 internal olefin compounds. The total pressure of carbon monoxide and hydrogen is 0.5-10 MPa, and the hydrogen-to-carbon ratio is 0.2-5.

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