A supported catalyst for the synthesis of 2-butyl-2-ethyl-1,3-propanediol and a process for its preparation

Abstract

The application belongs to the technical field of catalyst catalytic hydrogenation, and particularly relates to a supported catalyst for synthesizing 2-butyl-2-ethyl-1,3-propanediol (BEPD) and a preparation method thereof. The catalyst is prepared by modifying a non-conductive Al2O3 carrier through a low-pressure pulse electric field induction method, and loading multi-metal alloy particles prepared by the method onto the modified Al2O3 carrier, and has the characteristics of strong resistance to formaldehyde and coexistence of double crystal phase structures. The catalyst can realize continuous reaction of the intermediate 2-ethyl-2-hydroxymethylhexanal (EHMH) generated by the reaction of 2-ethylhexanal and formaldehyde on a fixed bed reactor to prepare BEPD through catalytic hydrogenation. In the catalytic hydrogenation process, the catalyst activity is not affected even if the formaldehyde content in the reaction raw material reaches 10.0%, the EHMH conversion rate is greater than or equal to 99.8%, the BEPD selectivity is greater than or equal to 99.6%, and the catalyst can be stably operated for more than 3000 hours. The catalyst can be applied to the industrial production of BEPD.

Description

Technical Field

[0001] This invention belongs to the field of catalyst hydrogenation technology, specifically relating to a supported catalyst for the synthesis of 2-butyl-2-ethyl-1,3-propanediol (BEPD) and its preparation method. Background Technology

[0002] BEPD is an important diol widely used in polyester resins, powder coatings, coil coatings, and other fields. It possesses excellent hydrolysis resistance, flexibility, and low water absorption, effectively resolving the traditional dilemma of balancing "high hardness" and "high flexibility," and "high strength" and "ease of processing," making it an ideal choice for developing subsequent high-performance polymer materials.

[0003] The main synthetic route for BEPD is as follows: using 2-ethylhexanal and formaldehyde as raw materials, an aldol condensation reaction is carried out under certain conditions to generate the intermediate 2-ethyl-2-hydroxymethylhexanal (EHMH), which is then obtained by cross-cannizzaro reaction or catalytic hydrogenation. Patent US 6369281B1 uses a mixture of 2-ethylhexanal and formaldehyde as raw materials, adding hydroxide compounds stepwise and incrementally to the reaction system, reacting at 50-70°C for 6 hours, achieving a BEPD yield of 95%. However, during the reaction, formaldehyde itself is oxidized to formic acid, which is ultimately discharged as formate. This leads to significant waste of raw materials and a heavy burden on subsequent waste treatment. Furthermore, to ensure the complete conversion of the intermediate, an excessive amount of formaldehyde is required, resulting in increased byproducts and increased difficulty in subsequent purification.

[0004] The catalytic hydrogenation reaction uses H2 as a reducing agent, producing only water after the reaction. Unreacted 2-ethylhexanal and tertiary amine catalyst can be efficiently recovered and recycled through unit operations such as distillation. This method offers high atom economy, low environmental impact, and high product purity. Patent EP 0599883B1 describes a reaction involving a mixture of 2-ethylhexanal, formaldehyde aqueous solution, and tertiary amine. The resulting purified organic phase is then separated by extractive distillation. Catalytic hydrogenation of this purified organic phase using 50% Ni / Al2O3 achieves a final BEPD purity of over 99%. However, the formaldehyde concentration in the organic phase must be controlled below 1.7 wt% before catalytic hydrogenation; otherwise, the catalyst is prone to deactivation.

[0005] In the catalytic hydrogenation synthesis of BEPD, improving catalyst lifetime and reducing the severity of reaction conditions and pretreatment costs remain challenges that need to be addressed. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a multi-metal alloy particle-supported catalyst and its preparation method. This catalyst features strong formaldehyde resistance, coexistence of bicrystalline phases, and long lifespan. It can enable the continuous production of BEPD by catalytic hydrogenation of the organic phase after reaction and treatment with 2-ethylhexanol and formaldehyde in a fixed-bed reactor.

[0007] This invention is achieved through the following technical solution:

[0008] The catalyst is composed of a support and an active component on the support. The support is modified alumina, and the active component is a Ni-M alloy. The second metal M is selected from Cu, Mn, and Zn.

[0009] Specifically, the steps include the following:

[0010] (1) Pretreatment of the support: γ-Al2O3 was immersed in alkali metal and / or alkaline earth metal salt solution and stirred for 0.5~1.5h. During the treatment, a low-voltage pulse electric field induction method was used. After the treatment, the support was filtered, washed with deionized water until neutral, dried and calcined to obtain modified Al2O3 support.

[0011] (2) Preparation of metal alloy particles: Weigh the alkaline mixture and amino polycarboxylic acid chelate into the reaction vessel, heat and dissolve them in a magnetic stirrer. After they are completely dissolved, add different metal precursors to the reaction vessel in batches within a fixed temperature range, heat and stir for 1 hour. After they are completely dissolved, adjust the pH of the solution to 11-12 with 0.5-1.0 mol / L Na2CO3 solution, then heat to 80℃ and reflux for 3 hours. At the same time, use the low-pressure pulse electric field induction method to assist the treatment and obtain the metal alloy particle reaction solution.

[0012] (3) Loading of metal alloy particles: The modified Al2O3 support was added to the above reaction solution and stirred and kept at a constant temperature. The stirring speed was 500 r / min. The loading was carried out in two stages using the low-pressure pulse electric field induction method. After the loading was completed, the reaction solution was filtered under reduced pressure, washed until neutral, dried and calcined to obtain alumina catalyst supported by multi-metal alloy particles.

[0013] Further, the alkali metal and / or alkaline earth metal salt mentioned in step (1) is one or more of NaNO3, KNO3, and Ca(NO3)2; the content of the alkali metal and / or alkaline earth metal salt accounts for 0.5 to 3.0% of the total weight of the catalyst.

[0014] Furthermore, the pulsed electric fields described in steps (1) and (3) are applied using a parallel plate electrode system or a ring electrode system, and are each applied independently in two segments. The parameters for the first segment are: 5-20V, pulse frequency 10-500Hz, duty cycle 40-50%, and processing time 30-60min; the parameters for the second segment are: 5-20V, pulse frequency 1000-2000Hz, duty cycle 40-50%, and processing time 5-30min.

[0015] The drying process described in steps (1) and (3) is to run at 120°C for 6 hours;

[0016] The roasting process was as follows: the temperature was increased from room temperature to 550-600℃ at a rate of 5℃ / min, and the process was run for 5 hours.

[0017] Further, the alkaline mixture mentioned in step (2) is an aqueous solution of Na2CO3 and NaHCO3, with a molar ratio of 1:1-2 and a concentration of 0.1-0.5 mol / L.

[0018] Further, the aminopolycarboxylic acid chelate in step (2) is a chain polyamine polycarboxylic acid with 2-4 nitrogen atoms, and the concentration of aminopolycarboxylic acid in the mixed solution is 3.0-5.0 wt%.

[0019] Further, in step (2), the active metal component in the metal alloy particles is a Ni-M alloy, the second metal M is selected from Cu, Mn, and Zn, and the content of the active metal component accounts for 20-30 wt% of the total weight of the catalyst; the metal precursor used is Ni(NO3)2·6H2O and one of Mn(NO3)2·4H2O, Cu(NO3)2·3H2O, and Zn(NO3)2·6H2O.

[0020] The temperature of the mixed solution before adding the metal precursor is set to 40-50℃.

[0021] Furthermore, the low-voltage pulsed electric field induction process described in step (2) is carried out in two stages. The parameters of the first stage are: 5-20V, pulse frequency 10-500Hz, duty cycle 40-50%, and processing time 1.5-2h. The parameters of the second stage are: 5-20V, pulse frequency 1000-2000Hz, duty cycle 40-50%, and processing time 1-1.5h.

[0022] Furthermore, during the loading process in step (3), the temperature for stirring and constant temperature is set to 50-60℃.

[0023] Furthermore, the catalyst has an amorphous-nanocrystalline dual-phase coexistence structure, and the average particle size of the alloy particles is 5-10 nm.

[0024] A method for synthesizing 2-butyl-2-ethyl-1,3-propanediol using a catalyst prepared by the aforementioned method, wherein the catalytic hydrogenation synthesis of BEPD is carried out in a fixed-bed reactor, using 2-ethylhexanal and a 40% formaldehyde aqueous solution as raw materials, which are mixed with triethylamine and subjected to aldol condensation reaction at 100-120℃ and 0.2MPa to obtain a crude organic phase containing the intermediate 2-ethyl-2-hydroxymethylhexanal (EHMH). The crude organic phase is extracted and distilled to obtain a purified organic phase. After the catalyst is pre-activated with H2 at 300℃ for 2h, the purified organic phase is catalytically hydrogenated at 150-160℃ and 2.0-2.5MPa to synthesize the BEPD product.

[0025] In the above reaction, the molar ratio of 2-ethylhexanal to formaldehyde is (1.3-1.6):1, and the mass ratio of triethylamine to 2-ethylhexanal is (0.3-0.5):1; the purified organic phase contains ≥89wt% EHMH and 0.5-10.0wt% formaldehyde.

[0026] The catalyst of this invention showed no significant decrease in activity after operating in a continuous reaction system for 2000 hours. EHMH conversion was ≥99.8%, and BEPD selectivity was ≥99.6%.

[0027] The present invention has the following advantages over the prior art:

[0028] 1) The catalyst has strong formaldehyde resistance during catalytic hydrogenation, which reduces the severity of reaction conditions.

[0029] 2) The amorphous-nanocrystalline dual-phase structure has a small average particle size and significantly improved catalytic activity.

[0030] 3) Improve metal utilization efficiency, reduce production costs, and minimize environmental pollution. Detailed Implementation

[0031] The embodiments listed in this invention will be described in detail below through specific examples, but the scope of protection of this invention is not limited to the following examples.

[0032] Example 1

[0033] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0034] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0035] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0036] Example 2

[0037] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 5V, pulse frequency 10Hz, duty cycle 50%, treatment for 30 min; then voltage 5V, pulse frequency 2000Hz, duty cycle 50%, treatment for 30 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0038] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0039] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0040] Example 3

[0041] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0042] A measured amount of 0.3 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 50 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0043] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0044] Example 4

[0045] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0046] A measured amount of 0.3 mol / L alkaline mixture was weighed and poured into a reaction vessel. 5.0 wt% ethylenediaminetetraacetic acid was added, and the mixture was stirred and dissolved at 40°C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 50°C and heated and stirred for 1 hour. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field induced a two-stage treatment process: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; the second stage parameters were: voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, ultimately yielding a metal alloy particle reaction solution.

[0047] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0048] Example 5

[0049] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0050] A measured amount of 0.3 mol / L alkaline mixture was weighed and poured into a reaction vessel. 3.0 wt% diethylenetriaminepentaacetic acid was added, and the mixture was stirred and dissolved at 40°C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Mn(NO3)2·4H2O were added to a three-necked flask at 50°C and heated with stirring for 1 hour. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field-induced process was used, divided into two stages: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; the second stage parameters were: voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, finally yielding a metal alloy particle reaction solution.

[0051] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Mn supported catalyst.

[0052] Example 6

[0053] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0054] A measured amount of 0.3 mol / L alkaline mixture was weighed and poured into a reaction vessel. 3.0 wt% diethylenetriaminepentaacetic acid was added, and the mixture was stirred and dissolved at 40°C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Zn(NO3)2·6H2O were added to a three-necked flask at 50°C and heated and stirred for 1 hour. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field induced a two-stage treatment process: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; the second stage parameters were: voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, ultimately yielding a metal alloy particle reaction solution.

[0055] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 15% Ni-15% Zn supported catalyst.

[0056] Example 7

[0057] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0058] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0059] After the reaction solution cooled to 50°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0060] Example 8

[0061] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0062] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0063] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 5V, pulse frequency 10Hz, duty cycle 50%, for 60 min; then voltage 5V, pulse frequency 1000Hz, duty cycle 50%, for 5 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0064] Example 9

[0065] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 60 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0066] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0067] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 2000Hz, duty cycle 50%, for another 30 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0068] Example 10

[0069] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 60 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0070] A measured amount of 0.4 mol / L alkaline mixture was weighed and poured into a reaction vessel. 3.0 wt% diethylenetriaminepentaacetic acid was added, and the mixture was stirred and dissolved at 40°C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 45°C, and the mixture was heated and stirred for 1 hour. After complete dissolution, 1.0 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field induced a two-stage treatment process: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; the second stage parameters were: voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, ultimately yielding a metal alloy particle reaction solution.

[0071] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 40%, for 30 min; then voltage 20V, pulse frequency 2000Hz, duty cycle 40%, for another 30 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0072] Example 11

[0073] γ-Al₂O₃ was immersed in Ca(NO₃)₂ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 60 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0074] A measured amount of 0.4 mol / L alkaline mixture was weighed and poured into a reaction vessel. 3.0 wt% diethylenetriaminepentaacetic acid was added, and the mixture was stirred and dissolved at 40°C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 45°C, and the mixture was heated and stirred for 1 hour. After complete dissolution, 1.0 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field induced a two-stage treatment process: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; the second stage parameters were: voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, ultimately yielding a metal alloy particle reaction solution.

[0075] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 40%, for 30 min; then voltage 20V, pulse frequency 2000Hz, duty cycle 40%, for another 30 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0076] Comparative Example 1

[0077] γ-Al₂O₃ was immersed in NaNO₃ solution and stirred at 60°C for 1 hour. After immersion, the solution was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0078] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0079] After the reaction solution cooled to 60°C, the modified Al2O3 support was added to the reaction solution and impregnated and stirred at a constant temperature of 500 r / min for 2 h. After loading was completed, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0080] Comparative Example 2

[0081] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at room temperature for 1 hour, during which a low-voltage pulsed electric field was used for induction assistance: voltage 20V, pulse frequency 1000Hz, duty cycle 100%, treatment for 30 minutes; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, treatment for 10 minutes. After the treatment, the solution was filtered, washed with deionized water until neutral, and placed in an oven. The temperature was increased from room temperature to 60℃ at 10℃ / min and held for 1 hour; then increased to 100℃ at 10℃ / min and held for 1 hour; then increased to 120℃ at 10℃ / min and held for 4 hours. After calcination, the modified Al₂O₃ support was obtained.

[0082] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0083] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0084] Comparative Example 3

[0085] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0086] A measured amount of 0.3 mol / L alkaline mixture was poured into a reaction vessel, and 2.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 50 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0087] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0088] Comparative Example 4

[0089] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0090] A measured amount of 0.3 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% nitric acid triacetic acid was added. The mixture was stirred at 40°C until dissolved. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 50°C and heated and stirred for 1 hour. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field induction process was used, which was divided into two stages: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; then the voltage was 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, finally yielding a metal alloy particle reaction solution.

[0091] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0092] Comparative Example 5

[0093] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0094] A measured amount of 0.3 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 30 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0095] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 15% Ni-25% Cu supported catalyst.

[0096] Comparative Example 6

[0097] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0098] A measured amount of 0.3 mol / L alkaline mixture was weighed and poured into a reaction vessel. 3.0 wt% diethylenetriaminepentaacetic acid was added, and the mixture was stirred and dissolved at 40°C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Mg(NO3)2·6H2O were added to a three-necked flask at 50°C, and the mixture was heated and stirred for 1 hour. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80°C and refluxed for 3 hours. During this period, a low-voltage pulsed electric field induction process was used, divided into two stages: the first stage parameters were: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 2 hours; then the second stage parameters were: voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 1 hour, finally yielding a metal alloy particle reaction solution.

[0099] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 15% Ni-15% Mg supported catalyst.

[0100] Comparative Example 7

[0101] γ-Al₂O₃ was immersed in a metal salt solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0102] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0103] After the reaction solution cooled to 40°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0104] Comparative Example 8

[0105] γ-Al₂O₃ was immersed in a metal salt solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0106] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0107] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 1000Hz, duty cycle 100%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0108] Comparative Example 9

[0109] γ-Al₂O₃ was immersed in a metal salt solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0110] A measured amount of 0.1 mol / L alkaline mixture was poured into a reaction vessel, and 3.0 wt% diethylenetriaminepentaacetic acid was added. The mixture was stirred and dissolved at 40 °C. After complete dissolution, measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O were added to a three-necked flask at 40 °C and heated and stirred for 1 h. After complete dissolution, 0.5 mol / L Na2CO3 solution was added dropwise until the pH reached 11-12. The mixture was then heated to 80 °C and refluxed for 3 h. During this process, a low-voltage pulsed electric field induced a two-stage treatment: the first stage parameters were: voltage 20 V, pulse frequency 500 Hz, duty cycle 50%, for 2 h; the second stage parameters were: voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, for 1 h. The final product was a metal alloy particle reaction solution.

[0111] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 1000Hz, duty cycle 100%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0112] Comparative Example 10

[0113] γ-Al₂O₃ was immersed in NaNO₃ solution and treated with stirring at 60°C for 0.5 h, during which a low-voltage pulsed electric field was used for induction and assistance: voltage 20 V, pulse frequency 1000 Hz, duty cycle 100%, treatment for 30 min; then voltage 20 V, pulse frequency 1000 Hz, duty cycle 50%, treatment for 10 min. After the treatment, the mixture was filtered, washed with deionized water until neutral, dried, and calcined to obtain the modified Al₂O₃ support.

[0114] Weigh a measured amount of 0.1 mol / L alkaline mixture and pour it into a reaction vessel. Add 3.0 wt% diethylenetriaminepentaacetic acid and stir to dissolve at 40 °C. After complete dissolution, pour measured amounts of Ni(NO3)2·6H2O and Cu(NO3)2·3H2O into a three-necked flask at 40 °C and heat and stir for 1 h. After complete dissolution, add 0.5 mol / L Na2CO3 solution dropwise until the pH reaches 11-12, then reflux at 80 °C for 3 h.

[0115] After the reaction solution cooled to 60°C, the modified Al₂O₃ support was added to the reaction solution and stirred at a constant temperature of 500 r / min. Loading was performed using a low-voltage pulsed electric field induction method: voltage 20V, pulse frequency 500Hz, duty cycle 50%, for 30 min; then voltage 20V, pulse frequency 1000Hz, duty cycle 50%, for 10 min. After loading, the reaction solution was filtered under reduced pressure, washed until neutral, and dried in an oven. Then, it was calcined in a muffle furnace from room temperature to 600°C at a rate of 5°C / min for 5 h to obtain a 10% Ni-10% Cu supported catalyst.

[0116] The catalytic performance of the catalysts in Examples 1-11 and Comparative Examples 1-10 was tested.

[0117] The test results are shown in Table 1 below.

[0118] Table 1 Catalytic performance of catalysts in the examples and proportions

[0119] Example 1 150 2.0 0.5 99.8 99.6 Example 2 150 2.0 2.0 99.8 99.7 Example 3 150 2.0 6.0 99.9 99.7 Example 4 150 2.0 8.0 99.9 99.8 Example 5 150 2.0 10.0 99.9 99.8 Example 6 160 2.0 10.0 99.8 99.8 Example 7 160 2.0 10.0 99.8 99.8 Example 8 160 2.0 10.0 99.8 99.6 Example 9 160 2.5 10.0 99.8 99.6 Example 10 160 2.5 10.0 99.9 99.8 Example 11 160 2.5 10.0 99.9 99.7 Comparative Example 1 160 2.5 1.0 50.2 77.2 Comparative Example 2 160 2.5 1.0 94.2 65.8 Comparative Example 3 160 2.5 2.0 90.2 91.5 Comparative Example 4 160 2.5 3.0 94.1 90.2 Comparative Example 5 160 2.5 5.0 90.2 95.2 Comparative Example 6 160 2.5 5.0 85.8 40.5 Comparative Example 7 160 2.5 0.5 82.8 62.5 Comparative Example 8 160 2.5 0.5 88.1 66.8 Comparative Example 9 160 2.5 0.5 84.4 80.2 Comparative Example 10 160 2.5 1.0 95.0 70.2

[0120] As can be seen from Table 1 above, the catalyst prepared by the method of the present invention can realize the continuous reaction of 2-ethyl-2-hydroxymethylhexanol (EHMH), the intermediate generated by the reaction of 2-ethylhexanol and formaldehyde, to BEPD in a fixed-bed reactor. During the catalytic hydrogenation process, the catalyst activity is not affected even when the formaldehyde content in the reaction feed reaches 10.0%, the EHMH conversion rate is ≥99.8%, and the BEPD selectivity is ≥99.6%. The catalyst of the present invention can be applied to the industrial production of BEPD.

[0121] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a supported catalyst for the synthesis of 2-butyl-2-ethyl-1,3-propanediol, characterized in that, The catalyst synthesis includes the following steps: (1) Pretreatment of the support: γ-Al2O3 was immersed in alkali metal and / or alkaline earth metal salt solution and treated by low-voltage pulse electric field induction method. After the treatment, the modified Al2O3 support was obtained by filtration, drying and calcination. (2) Preparation of metal alloy particles: Weigh the alkaline mixture and amino polycarboxylic acid chelate into the reaction vessel. After they are completely dissolved, add different metal precursors in batches. After they are completely dissolved, adjust the pH of the solution to 11-12, then heat and reflux. At the same time, use the low-pressure pulse electric field induction method to assist the treatment and obtain the metal alloy particle reaction solution. (3) Loading of metal alloy particles: The modified Al2O3 support was added to the above reaction solution and stirred and kept at a constant temperature. The loading was carried out in two stages using a low-voltage pulse electric field induction method. After the loading was completed, the reaction solution was filtered, washed, dried and calcined to obtain alumina catalyst supported by multi-metal alloy particles.

2. The preparation method according to claim 1, characterized in that, The alkali metal and / or alkaline earth metal salts mentioned in step (1) are one or more of NaNO3, KNO3, and Ca(NO3)2.

3. The preparation method according to claim 1, characterized in that, In steps (1) and (3), the pulsed electric field is applied using a parallel plate electrode system or a ring electrode system, and each is performed independently in two segments. The parameters for the first segment are: 5-20V, pulse frequency 10-500Hz, duty cycle 40-50%, and processing time 30-60min; the parameters for the second segment are: 5-20V, pulse frequency 1000-2000Hz, duty cycle 40-50%, and processing time 5-30min.

4. The preparation method according to claim 1, characterized in that, The alkaline mixture mentioned in step (2) is an aqueous solution of Na2CO3 and NaHCO3 with a molar ratio of 1:1-2 and a concentration of 0.1-0.5 mol / L.

5. The preparation method according to claim 1, characterized in that, The amino polycarboxylic acid chelate mentioned in step (2) is a chain polyamine polycarboxylic acid with 2-4 nitrogen atoms, and the concentration of amino polycarboxylic acid in the mixed solution is 3.0-5.0 wt%.

6. The preparation method according to claim 1, characterized in that, The active metal component in the metal alloy particles described in step (2) is a Ni-M alloy, and the second metal M is selected from Cu, Mn, and Zn; the metal precursor used is Ni(NO3)2·6H2O and a corresponding one selected from Mn(NO3)2·4H2O, Cu(NO3)2·3H2O, and Zn(NO3)2·6H2O.

7. The preparation method according to claim 1, characterized in that, The low-voltage pulse electric field induction process described in step (2) is carried out in two stages. The parameters of the first stage are: 5-20V, pulse frequency 10-500Hz, duty cycle 40-50%, and processing time 1.5-2h. The parameters of the second stage are: 5-20V, pulse frequency 1000-2000Hz, duty cycle 40-50%, and processing time 1-1.5h.

8. The preparation method according to claim 1, characterized in that, During the loading process in step (3), the temperature for stirring and constant temperature is set to 50-60℃.

9. The preparation method according to claim 1, characterized in that, The catalyst has an amorphous-nanocrystalline dual-phase coexistence structure, and the average particle size of the alloy particles is 5-10 nm.

10. A method for synthesizing 2-butyl-2-ethyl-1,3-propanediol using a catalyst prepared according to any one of claims 1 to 9, characterized in that, The catalytic hydrogenation synthesis of BEPD is carried out in a fixed-bed reactor. Using 2-ethylhexanal and formaldehyde aqueous solution as raw materials, the mixture is combined with triethylamine and subjected to aldol condensation to obtain a crude organic phase containing the intermediate 2-ethyl-2-hydroxymethylhexanal. The crude organic phase is then extracted and distilled to obtain a purified organic phase. After pre-activating the catalyst with H2 at 300℃ for 2 hours, the purified organic phase is catalytically hydrogenated at 150-160℃ and 2.0-2.5 MPa to synthesize the BEPD product.