Catalyst for preparing gamma-butyrolactone through liquid-phase dehydrogenation of 1, 4-butanediol as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for preparing gamma-butyrolactone through liquid phase dehydrogenation of 1, 4-butanediol as well as a preparation method and application of the catalyst. Belongs to the technical field of catalyst preparation. The catalyst is composed of a carrier, CuO and MOx, the CuO and the MOx are loaded on the carrier, Cu accounts for 10-50% of the total mass of the catalyst, M accounts for 1-25% of the total mass of the catalyst, M is one of Mn, Zn, Co, Ni, Fe, Cr, Ce, Nb, Ru, Pt, Ir and Pd, and the carrier is one of silicon oxide, aluminum oxide, magnesium oxide, lanthanum oxide, hydroxyapatite and magnesium-aluminum hydrotalcite. An oxide-oxide interface is formed between CuO and MOx through roasting and reduction, and relatively strong electron interaction exists between highly dispersed Cu nanoparticles and the oxide-oxide interface, so that the stability of the catalyst can be enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst preparation, and more specifically, relates to a catalyst for preparing gamma-butyrolactone by liquid-phase dehydrogenation of 1,4-butanediol, and a preparation method and application thereof. Background Art

[0002] Copper-based catalysts are widely used in the gas-phase dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone. Copper catalysts are very prone to sintering under high temperature and hydrogen conditions, which causes the copper particles to grow continuously and gradually deactivate the catalyst, thus affecting the life of the catalyst. Therefore, improving the dispersion and stability of copper particles is the key to improving the life of copper catalysts (Chemical Engineering Journal 489 (2024) 151366). Compared with the gas-phase dehydrogenation reaction, the liquid-phase dehydrogenation reaction of 1,4-butanediol is more efficient, and the contact between the catalyst and the liquid 1,4-butanediol is more complete, but the catalyst needs to have higher stability. Therefore, it is urgent to research and develop a dehydrogenation catalyst with high copper particle dispersion and good stability. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a catalyst for preparing γ-butyrolactone by liquid-phase dehydrogenation of 1,4-butanediol, which has a simple preparation process, high copper particle dispersion and very excellent stability, as well as a preparation method and application thereof. Applying the catalyst to prepare γ-butyrolactone by liquid-phase dehydrogenation of 1,4-butanediol can achieve the effects of high reactivity and high stability at the same time.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The invention provides a catalyst for preparing gamma-butyrolactone by liquid phase dehydrogenation of 1,4-butanediol, comprising a carrier and CuO, MO loaded on the carrier. x The catalyst composition comprises: Cu accounts for 10-50% of the total mass of the catalyst, M accounts for 1-25% of the total mass of the catalyst, M is one of Mn, Zn, Co, Ni, Fe, Cr, Ce, Nb, Ru, Pt, Ir and Pd, and the carrier is one of silicon oxide, aluminum oxide, magnesium oxide, lanthanum oxide, hydroxyapatite and magnesium aluminum hydrotalcite.

[0006] Based on the above technical solution, further, Cu accounts for 1-20% of the total mass of the catalyst, preferably 2-10%, and M accounts for 1-10% of the total mass of the catalyst, preferably 1-7%.

[0007] Based on the above technical solution, further, the molar ratio of Cu to M is 2:1 to 6:1.

[0008] Another aspect of the present invention provides a method for preparing the above-mentioned catalyst, comprising the following steps:

[0009] 1) The metal salt solution containing M is loaded onto the carrier by an impregnation method, dried, and calcined at 400-700° C. for 2-12 hours to obtain a solid sample;

[0010] 2) The copper salt solution is loaded onto the solid sample obtained in step 1) by an impregnation method, dried, and calcined at 400-800° C. for 2-12 hours to obtain a catalyst.

[0011] Based on the above technical solution, further, the M metal salt described in step 1) is at least one of M's nitrate, acetate, sulfate, chloride and hydrates thereof.

[0012] Based on the above technical solution, further, the impregnation method described in step 1) includes an equal volume impregnation method and an excess impregnation method.

[0013] Based on the above technical solution, further, in step 1), the drying temperature is 70-120° C., the roasting temperature is 400-600° C., and the roasting time is 3-10 hours.

[0014] Based on the above technical solution, further, the copper salt described in step 2) is at least one of copper nitrate, acetate, sulfate, chloride and hydrates thereof.

[0015] Based on the above technical solution, further, the impregnation method described in step 2) includes an equal volume impregnation method and an excess impregnation method.

[0016] Based on the above technical solution, further, in step 2), the drying temperature is 70-120° C., the roasting temperature is 400-600° C., and the roasting time is 3-10 hours.

[0017] The present invention also provides application of the above catalyst in catalyzing the reaction of preparing γ-butyrolactone by liquid phase dehydrogenation of 1,4-butanediol.

[0018] Based on the above technical scheme, further, the reaction is carried out in a fixed bed reactor, the catalyst is loaded in the fixed bed reactor, the catalyst is first reduced at 200-400° C. for 1-12 hours under a hydrogen atmosphere, and then 1,4-butanediol liquid is introduced, the liquid hourly space velocity of 1,4-butanediol is 0.2-3 g / h·g catalyst, and γ-butyrolactone is prepared under the conditions of 180-220° C. and a reaction pressure of 1-3 atmospheres.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) The present invention first prepares highly dispersed MO by high temperature calcination. xOn the carrier, the copper salt is then loaded on the above solid and calcined at high temperature to obtain highly dispersed CuO, CuO and MO x Both are highly dispersed on the carrier, and the two easily form an oxide-oxide interface. Under hydrogen reduction conditions, the oxide-oxide interface can effectively inhibit the growth of Cu particles and is the source of high Cu particle dispersion (see Figure 1 ), thereby improving the dehydrogenation reaction activity.

[0021] 2) Hydrogen reduction leads to a strong electronic interaction between Cu particles and the oxide-oxide interface, which can enhance the stability of the catalyst. Therefore, the electronic interaction between the oxide-oxide interface can be used to develop a copper-based dehydrogenation catalyst with high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 10CuO prepared in Example 1 x -5MnO y / Al 2 O 3 Transmission electron microscopy image of the catalyst.

[0023] Figure 2 10CuO prepared in Example 1 x -5MnO y / Al 2 O 3 Catalyst stability test results. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative labor all fall within the protection scope of the present invention.

[0025] Comparative Example 1

[0026] 10CuO x / Al 2 O 3 Catalyst synthesis: An aqueous solution containing 2.41 g of copper nitrate trihydrate (10 mmol) was loaded onto 10 g of Al 2 O 3 , stirred for 2 h, aged for 10 h, dried at 100 °C, and calcined in a muffle furnace at 500 °C for 5 h to obtain 10CuO x -5MnO y / Al 2 O 3 .

[0027] The catalyst (5g) was pressed into tablets (20-40 mesh), placed in a fixed bed reactor with an inner diameter of 10mm, reduced at 300℃ for 6 hours under a hydrogen atmosphere, and then cooled to room temperature. 1,4-butanediol liquid dried by 4A molecular sieve was introduced, the liquid hourly space velocity was 0.6 g / h·g catalyst, the reaction pressure was 1.5 atmospheres, the reaction temperature was 200℃, and γ-butyrolactone was produced. The reaction started and stabilized for 3h, and the reactants were collected and analyzed by gas chromatography. The calculated reaction conversion rate of 1,4-butanediol was 56.2%, and the selectivity of γ-butyrolactone was 45.1%.

[0028] Example 1

[0029] 10CuO x -5MnO y / Al 2 O 3 Catalyst synthesis: An aqueous solution containing 1.13 g of manganese nitrate trihydrate (5 mmol) was loaded onto 10 g of Al 2 O 3 The mixture was stirred for 2 h, aged for 10 h, dried at 100 °C, and calcined in a muffle furnace at 500 °C for 5 h to obtain 5MnO y / Al 2 O 3 ; Using equal volume impregnation method, 2.41g copper nitrate trihydrate (10mmol) aqueous solution was loaded into the above 5MnO y / Al 2 O 3 , stirred for 2 h, aged for 10 h, dried at 100 °C, and calcined in a muffle furnace at 500 °C for 5 h to obtain 10CuO x -5MnO y / La 2 O 3 .

[0030] The catalyst (5g) was pressed into tablets (20-40 mesh), placed in a fixed bed reactor with an inner diameter of 10mm, reduced at 300℃ for 6 hours under a hydrogen atmosphere, and then cooled to room temperature. 1,4-butanediol liquid dried over 4A molecular sieve was introduced, the liquid hourly space velocity was 0.6 g / h·g catalyst, the reaction pressure was 1.5 atmospheres, the reaction temperature was 200℃, and γ-butyrolactone was produced. The reaction started and stabilized for 3h, and the reactants were collected and analyzed by gas chromatography. The calculated reaction conversion rate of 1,4-butanediol was 88.6%, and the selectivity of γ-butyrolactone was 99.4%.

[0031] Example 2

[0032] 20CuO x -5MnO y / Al 2 O 3Catalyst synthesis: The preparation process and catalytic reaction were similar to those in Example 1, except that the mass of copper nitrate trihydrate was increased to 4.83 g (20 mmol).

[0033] The reaction conversion rate of 1,4-butanediol was calculated to be 93.1%, and the selectivity of γ-butyrolactone was 89.2%.

[0034] Example 3

[0035] 30CuO x -5MnO y / Al 2 O 3 Catalyst synthesis: The preparation process and catalytic reaction were similar to those in Example 1, except that the mass of copper nitrate trihydrate was increased to 7.23 g (30 mmol).

[0036] The reaction conversion rate of 1,4-butanediol was calculated to be 97.8%, and the selectivity of γ-butyrolactone was 69.1%.

[0037] Example 4

[0038] 10CuO x -2MnO y / Al 2 O 3 Catalyst synthesis: The preparation process and catalytic reaction were similar to those in Example 1, except that the mass of manganese nitrate trihydrate was reduced to 0.452 g (2.5 mmol).

[0039] The reaction conversion rate of 1,4-butanediol was calculated to be 74.5%, and the selectivity of γ-butyrolactone was 90.1%.

[0040] Example 5

[0041] 10CuO x -0.5MnO y / Al 2 O 3 Catalyst synthesis: The preparation process and catalytic reaction were similar to those in Example 1, except that the mass of manganese nitrate trihydrate was reduced to 0.09 g (0.5 mmol).

[0042] The calculated reaction conversion rate of 1,4-butanediol was 60.2%, and the selectivity of γ-butyrolactone was 59.8%.

[0043] Example 6

[0044] 10CuO x -5MnO y / Al 2 O 3Stability test: The catalytic reaction was the same as in Example 1. During the 500-hour operation, the reactants were collected at irregular intervals and analyzed by gas chromatography. According to calculations, the reaction conversion rate of 1,4-butanediol remained above 92%, and the selectivity of γ-butyrolactone remained above 99%. The data on the reaction conversion rate of 1,4-butanediol and the selectivity of γ-butyrolactone are shown in Figure 2 .

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for preparing γ-butyrolactone by liquid phase dehydrogenation of 1,4-butanediol, characterized in that: The catalyst is composed of a carrier and CuO, MO loaded on the carrier. x The catalyst composition comprises: Cu accounts for 10-50% of the total mass of the catalyst, M accounts for 1-25% of the total mass of the catalyst, M is one of Mn, Zn, Co, Ni, Fe, Cr, Ce, Nb, Ru, Pt, Ir and Pd, and the carrier is one of silicon oxide, aluminum oxide, magnesium oxide, lanthanum oxide, hydroxyapatite and magnesium aluminum hydrotalcite.

2. The catalyst according to claim 1, characterized in that Cu accounts for 1-20% of the total mass of the catalyst, preferably 2-10%, and M accounts for 1-10% of the total mass of the catalyst, preferably 1-7%.

3. The catalyst according to claim 1 or 2, characterized in that The molar ratio of Cu to M is 2:1 to 6:

1.

4. The method for preparing the catalyst according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) The metal salt solution containing M is loaded onto the carrier by an impregnation method, dried, and calcined at 400-700° C. for 2-12 hours to obtain a solid sample; 2) The copper salt solution is loaded onto the solid sample obtained in step 1) by an impregnation method, dried, and calcined at 400-800° C. for 2-12 hours to obtain a catalyst.

5. The preparation method according to claim 4, characterized in that: The M metal salt described in step 1) is at least one of the nitrate, acetate, sulfate, chloride and hydrate of M; the impregnation method includes an equal volume impregnation method and an excess impregnation method; the drying temperature is 70-120° C., the roasting temperature is 400-600° C., and the roasting time is 3-10 hours.

6. The preparation method according to claim 4, characterized in that: The copper salt described in step 2) is at least one of copper nitrate, acetate, sulfate, chloride and hydrate thereof; the impregnation method includes an equal volume impregnation method and an excess impregnation method; the drying temperature is 70-120° C., the roasting temperature is 400-600° C., and the roasting time is 3-10 hours.

7. Use of the catalyst according to any one of claims 1 to 3 in catalyzing the liquid phase dehydrogenation of 1,4-butanediol to prepare γ-butyrolactone.

8. The use according to claim 7, characterized in that: The reaction is carried out in a fixed bed reactor. The catalyst is loaded in the fixed bed reactor. The catalyst is first reduced at 200-400° C. for 1-12 hours in a hydrogen atmosphere, and then 1,4-butanediol liquid is introduced. The liquid hourly space velocity of 1,4-butanediol is 0.2-3 g / h·g catalyst. γ-butyrolactone is prepared under the conditions of 180-220° C. and a reaction pressure of 1-3 atmospheres.

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