Preparation method and use method of SiO2-packaged bimetallic core-shell structure catalyst for preparing BDO through BYD hydrogenation
By using a bimetallic core-shell structure catalyst encapsulated with SiO2, the problems of insufficient selectivity and stability of traditional catalysts in the BYD hydrogenation reaction were solved, achieving high selectivity and high stability in BDO preparation.
Patent Information
- Application Number
- CN202511746562.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-02-17
AI Technical Summary
The traditional acetylacetonate method for preparing BDO has problems such as difficulty in separating and purifying the product and high exothermic temperature. In addition, traditional catalysts have insufficient selectivity and stability in the BYD hydrogenation reaction.
A bimetallic core-shell structure catalyst encapsulated in SiO2 was prepared by co-precipitation of Ni-X/Al2O3 as the catalyst core, and then a porous SiO2 shell was wrapped with it by structure-directed method to form a Si-O-Ni structure, which improved the catalytic activity and inhibited the aggregation and deactivation of active metal.
The preparation of BDO by the hydrogenation of BYD with high selectivity and high stability was achieved. The catalyst maintained more than 95% BDO selectivity within 48 hours, which significantly improved the activity and lifespan of the catalyst.
Smart Images
Figure FT_1 
Figure SMS_1
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of chemical synthesis, and particularly relates to a preparation method and use method of a SiO2-encapsulated bimetallic core-shell structure catalyst for preparing BDO by BYD hydrogenation. BACKGROUND
[0002] In recent years, the state has become increasingly strict in plastic pollution control. With the implementation of the "plastic restriction order", the demand for degradable plastics continues to grow, and the market demand for BDO as a monomer raw material for degradable plastics shows a high growth trend. The selective hydrogenation of 1,4-butyne diol (BYD) is the main way to produce 1,4-butanediol (BDO) in industry at present. The acetylene aldehyde process route is mature, the catalyst is cheap, and the product yield is high, which has a significant advantage in the industrial production of BDO. BYD hydrogenation is an important process of the acetylene aldehyde method, but the traditional acetylene aldehyde method for preparing BDO has the problems of difficult separation and purification of products and high heat release temperature, so it is crucial to develop and design a catalyst with high selectivity and high heat resistance.
[0003] The core-shell structure has a good effect on improving the reaction activity and stability of the catalyst. The advantages of the core-shell structure catalyst mainly lie in two aspects. On the one hand, due to the isolation and limitation of the shell layer, the inner core has high dispersity and high selectivity. On the other hand, through the close contact (even forming chemical bonds) on the interface, strong interaction is generated between the core and the shell. Among them, the metal and metal oxide nanoparticles coated by the silicon dioxide shell layer have been widely studied as catalysts.
[0004] Ni is widely used in the reaction catalyst for preparing BDO by BYD hydrogenation due to its low cost and more excellent selectivity for generating BDO. The research on traditional supported nickel catalysts shows that Al2O3 as a carrier can achieve better catalytic effect, and SiO2 as a commonly used shell layer of core-shell catalyst can inhibit the aggregation and sintering of active metals through anchoring effect, thereby improving the stability of the catalyst.
[0005] In summary, it is of great significance to develop a SiO2-encapsulated bimetallic core-shell structure catalyst with high catalytic activity and high selectivity for preparing BDO by BYD hydrogenation. SUMMARY
[0006] The purpose of this invention is to provide a method for preparing and using a SiO2-encapsulated bimetallic core-shell structure catalyst for the hydrogenation of BYD to BDO. The catalyst of this invention consists of a bimetallic core and an Al2O3 support, with a porous SiO2 shell encapsulated by a structure-directed method to form a core-shell structure. The bimetallic core and the Al2O3 support work together to enhance catalytic activity. The catalyst shell forms a Si-O-Ni structure with Ni, further improving catalytic activity and anchoring the active metal in the core, inhibiting metal aggregation and deactivation, and improving catalytic stability. This results in the prepared Ni-X / Al2O3@SiO2 exhibiting high catalytic activity and stability.
[0007] The technical solution provided by this invention is as follows:
[0008] A method for preparing a SiO2-encapsulated bimetallic core-shell structure catalyst, characterized by comprising the following steps:
[0009] S1. Dissolve the soluble salts of Ni, X, and Al in deionized water to obtain solution A;
[0010] S2. Dissolve NaOH in deionized water to obtain solution B;
[0011] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to produce a precipitate. After stirring continuously for 12-16 hours, wash the precipitate, dry it in an oven at 100-120℃ for 8-12 hours, and calcine it at 500-550℃ for 4-6 hours to obtain Ni-X / Al2O3.
[0012] S4. The template agent CTAB, ammonia, ethanol, and deionized water are mixed and ultrasonically dispersed in a ratio of 1~1.2:10~12:100~120:200~240. Ni-X / Al2O3 is dispersed in the solution, and tetraethyl orthosilicate is added dropwise while stirring at 50~70℃ for 3h. The precipitate is washed, dried in an oven at 100~120℃ for 8~12h, and calcined at 500~550℃ for 4~6h to obtain the Ni-X / Al2O3@SiO2 core-shell structure catalyst.
[0013] Furthermore, the soluble salt of Ni is selected from Ni(NO3)2·6H2O, the soluble salt of X is selected from at least one of Ce(NO3)3·6H2O, La(NO3)3·6H2O or Mn(NO3)2·4H2O, and the soluble salt of Al is selected from Al(NO3)3·9H2O.
[0014] Furthermore, in the prepared Ni-X / Al2O3@SiO2, the Ni content accounts for 10-30 wt% of the total catalyst mass, the Al2O3 content accounts for 60-80 wt% of the total catalyst mass, X is an active metal promoter selected from at least one of Ce, La, and Mn, and the X content (measured in oxidation state) accounts for 5-10 wt% of the total catalyst mass.
[0015] Furthermore, the pH adjustment is set to 8.0~9.0.
[0016] Furthermore, the calcination heating rate is 2°C / min.
[0017] The present invention also provides the application of the above catalyst in the selective hydrogenation of BYD to prepare BDO reaction, wherein the catalyst is placed in a fixed bed reactor and high-purity hydrogen is used to replace the gas in the reaction tube.
[0018] Furthermore, the reaction solvent is water, and the mass ratio of BYD to water is 3:7.
[0019] Furthermore, the reaction conditions are as follows: reaction temperature 50~70℃, reaction pressure 5~6MPa, catalyst loading 10ml, gas flow rate 10~20ml / min, liquid flow rate 0.1~0.2ml / min.
[0020] Beneficial technical effects of the present invention:
[0021] This invention synthesizes a bimetallic Ni-X / Al2O3 catalyst core via co-precipitation and encapsulates porous SiO2 as the catalyst shell using a structure-directed method. The bimetallic catalyst and the Al2O3 support work together to improve the catalyst's activity and selectivity. The introduction of the porous SiO2 shell and Ni forms a Si-O-Ni structure, which enhances the catalytic activity. At the same time, the anchoring effect restricts the aggregation, sintering, and deactivation of the active metal, thus improving the catalytic stability. This invention has promising application prospects. Attached Figure Description
[0022] Figure 1 Schematic diagram of TPR characterization data results Detailed Implementation
[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024]
Example 1
[0025] For ease of comparison, the experimental results are listed in Table 1.
[0026] This embodiment provides a Ni-Ce / Al2O3@SiO2 core-shell structured catalyst, including the following steps:
[0027] S1. Dissolve 9.91g Ni(NO3)2·6H2O, 1.55g Ce(NO3)3·6H2O and 55.19g Al(NO3)3·9H2O in deionized water to obtain solution A;
[0028] S2. Dissolve NaOH in deionized water to obtain solution B;
[0029] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to 8 to produce a precipitate. After stirring continuously for 16 hours, wash the precipitate, dry it in an oven at 100℃ for 10 hours, and calcine it at 550℃ for 6 hours to obtain Ni-Ce / Al2O3.
[0030] S4. The template agent CTAB, ammonia, ethanol, and deionized water were mixed and ultrasonically dispersed in a ratio of 1:10:100:200. Ni-Ce / Al2O3 was dispersed into the solution, and 20 ml of tetraethyl orthosilicate was added dropwise while stirring at 60 °C for 3 h. The precipitate was washed, dried in an oven at 100 °C for 10 h, and calcined at 550 °C for 6 h to obtain the Ni-Ce / Al2O3@SiO2 core-shell structure catalyst.
[0031]
Example 2
[0032] For ease of comparison, the experimental results are listed in Table 1.
[0033] This embodiment provides a Ni-La / Al2O3@SiO2 core-shell structured catalyst, including the following steps:
[0034] S1. Dissolve 9.91g Ni(NO3)2·6H2O, 1.56g La(NO3)3·6H2O and 55.19g Al(NO3)3·9H2O in deionized water to obtain solution A;
[0035] S2. Dissolve NaOH in deionized water to obtain solution B;
[0036] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to 8 to produce a precipitate. After stirring continuously for 16 hours, wash the precipitate, dry it in an oven at 100℃ for 10 hours, and calcine it at 550℃ for 6 hours to obtain Ni-La / Al2O3.
[0037] S2. Dissolve NaOH in deionized water to obtain solution B;
[0038] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to 8 to produce a precipitate. After stirring continuously for 16 hours, wash the precipitate, dry it in an oven at 100℃ for 10 hours, and calcine it at 550℃ for 6 hours to obtain Ni-La / Al2O3.
[0039] S4. The template agent CTAB, ammonia, ethanol, and deionized water were mixed and ultrasonically dispersed in a ratio of 1:10:100:200. Ni-La / Al2O3 was dispersed into the solution, and 20 ml of tetraethyl orthosilicate was added dropwise. The mixture was stirred at 60 °C for 3 h, the precipitate was washed, dried in an oven at 100 °C for 10 h, and calcined at 550 °C for 6 h to obtain the Ni-La / Al2O3@SiO2 core-shell structure catalyst.
[0040]
Example 3
[0041] For ease of comparison, the experimental results are listed in Table 1.
[0042] This embodiment provides a Ni-Mn / Al2O3@SiO2 core-shell structured catalyst, including the following steps:
[0043] S1. Dissolve 9.91g Ni(NO3)2·6H2O, 2.28g Mn(NO3)2·4H2O and 55.19g Al(NO3)3·9H2O in deionized water to obtain solution A;
[0044] S2. Dissolve NaOH in deionized water to obtain solution B;
[0045] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to 8 to produce a precipitate. After stirring continuously for 16 hours, wash the precipitate, dry it in an oven at 100℃ for 10 hours, and calcine it at 550℃ for 6 hours to obtain Ni-Mn / Al2O3.
[0046] S4. The template agent CTAB, ammonia, ethanol, and deionized water were mixed and ultrasonically dispersed in a ratio of 1:10:100:200. Ni-Mn / Al2O3 was dispersed into the solution, and 20 ml of tetraethyl orthosilicate was added dropwise. The mixture was stirred at 60 °C for 3 h, the precipitate was washed, dried in an oven at 100 °C for 10 h, and calcined at 550 °C for 6 h to obtain the Ni-Mn / Al2O3@SiO2 core-shell structure catalyst.
[0047] Comparative Example 1
[0048] For ease of comparison, the experimental results are listed in Table 1.
[0049] This embodiment provides a metal-free Ni / Al2O3@SiO2 catalyst, including the following steps:
[0050] S1. Dissolve 9.91g Ni(NO3)2·6H2O and 55.19g Al(NO3)3·9H2O in deionized water to obtain solution A;
[0051] S2. Dissolve NaOH in deionized water to obtain solution B;
[0052] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to 8 to produce a precipitate. After stirring continuously for 16 hours, wash the precipitate, dry it in an oven at 100°C for 10 hours, and calcine it at 550°C for 6 hours to obtain the Ni / Al2O3 catalyst.
[0053] S4. The template agent CTAB, ammonia, ethanol, and deionized water were mixed and ultrasonically dispersed in a ratio of 1:10:100:200. Ni / Al2O3 was dispersed into the solution, and 20 ml of tetraethyl orthosilicate was added dropwise while stirring at 60 °C for 3 h. The precipitate was washed, dried in an oven at 100 °C for 10 h, and calcined at 550 °C for 6 h to obtain a metal-free Ni / Al2O3@SiO2 core-shell structure catalyst.
[0054] Comparative Example 2
[0055] For ease of comparison, the experimental results are listed in Table 1.
[0056] This embodiment provides a shell-less Ni-Ce / Al2O3 catalyst, including the following steps:
[0057] S1. Dissolve 9.91g Ni(NO3)2·6H2O, 1.55g Ce(NO3)2·4H2O and 55.19g Al(NO3)3·9H2O in deionized water to obtain solution A;
[0058] S2. Dissolve NaOH in deionized water to obtain solution B;
[0059] S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to 8 to produce a precipitate. After stirring continuously for 16 hours, wash the precipitate, dry it in an oven at 100℃ for 12 hours, and calcine it at 550℃ for 6 hours to obtain a shell-less Ni-Ce / Al2O3 catalyst.
[0060] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
[0061] Table 1 Results of BYD conversion rate and BDO selectivity detection
[0062]
[0063] As shown in Table 1, the catalysts prepared by the present invention with SiO2 shells introduced via the structure-directed method all exhibit high catalytic activity and stability. In particular, in terms of stability, the Ni-Ce / Al2O3 catalyst without a shell in Comparative Example 2 showed a decrease in BDO selectivity to 80% within 48 hours, while the catalyst with the SiO2 shell still maintained a high BDO selectivity of 95% after 48 hours. This is because the introduction of the porous SiO2 shell forms a Si-O-Ni structure with Ni, which not only improves the catalytic activity but also anchors the active metal, limiting its aggregation, sintering, and deactivation, thus improving catalytic stability. In Comparative Example 1, the BDO selectivity of the Ni / Al2O3@SiO2 core-shell catalyst without metal promoters decreased from approximately 93% to approximately 90%, while the initial BDO selectivity of the Ni-Ce / Al2O3@SiO2 core-shell catalyst with metal promoters remained above 95% after 48 hours, even though the initial BDO selectivity was around 97%. This is because the addition of metal promoters makes the bonding between different metal components more robust and compact. The introduction of metal Ce changes the electron cloud density on the surface of Ni particles. This electron modulation forms new acidic sites, which more effectively stabilize the electron cloud of unsaturated bonds, inhibit structural changes in intermediates, avoid the formation of byproducts such as 2-hydroxytetrahydrofuran, and improve the selectivity for BDO.
[0064] Furthermore, different catalyst compositions require different reduction temperatures, such as... Figure 1The TPR characterization results for three different catalysts are shown. It can be seen that for all three catalysts, hydrogen consumption begins at around 350℃ during the reduction process. For the Ni / Al2O3@SiO2 catalyst without metal promoters, the peak hydrogen consumption occurs at around 490℃. For the Ni-Ce / Al2O3 catalyst without a SiO2 shell, the peak hydrogen consumption occurs at around 500℃. However, for the Ni-Ce / Al2O3@SiO2 catalyst with both metal promoters and a SiO2 shell, the peak hydrogen consumption occurs at around 580℃, and its hydrogen consumption intensity is significantly higher than that of the other two catalyst compositions. For these three catalysts, the reduction temperature is set to the temperature at which the corresponding hydrogen consumption peaks in the TPR results. The Ni-Ce / Al2O3@SiO2 catalyst exhibits the highest peak hydrogen consumption. This is because when both a metal promoter and a SiO2 shell are introduced into the catalyst, the addition of the metal promoter strengthens the bond between different metal components, requiring more hydrogen for complete reduction. Higher reduction temperatures indicate stronger interactions between the support and the active metal in the catalyst system. With the addition of the metal promoter, the interaction between the support and the active metal intensifies. The introduction of the SiO2 shell forms a Si-O-Ni structure with Ni, simultaneously enveloping the catalyst surface. This requires even more hydrogen for complete reduction, and the structure exhibits better stability, necessitating higher temperatures. The combined effect of the metal promoter and the attached SiO2 shell further enhances the catalyst's stability, resulting in a longer lifespan under the harsh reaction conditions of a fixed bed.
[0065] Among the catalysts mentioned above, the Ni-Ce / Al2O3@SiO2 catalyst in Example 1 stands out the most. It achieves almost 100% BYD conversion within 4 hours, with an initial maximum BDO selectivity of 97.3% and a selectivity that remains above 95% for 48 hours. Compared with the Ni / Al2O3@SiO2 catalyst in Comparative Example 1 and the Ni-Ce / Al2O3 catalyst in Comparative Example 2, it has significantly better catalytic activity and stability.
Claims
1. A method for preparing a SiO2-encapsulated bimetallic core-shell structure catalyst for the selective hydrogenation of BYD to BDO, characterized in that, Includes the following steps: S1. Dissolve the soluble salts of Ni, X, and Al in deionized water to obtain solution A; S2. Dissolve NaOH in deionized water to obtain solution B; S3. Slowly add solution A and solution B dropwise to a three-necked flask to mix them and control the pH to produce a precipitate. After stirring continuously for 12-16 hours, wash the precipitate, dry it in an oven at 100-120℃ for 8-12 hours, and calcine it at 500-550℃ for 4-6 hours to obtain Ni-X / Al2O3. S4. The template agent CTAB, ammonia, ethanol, and deionized water are mixed and ultrasonically dispersed in a ratio of 1~1.2:10~12:100~120:200~240. Ni-X / Al2O3 is dispersed in the solution, and tetraethyl orthosilicate is added dropwise and stirred at 50~70℃ for 3h. The precipitate is washed, dried in an oven at 100~120℃ for 8~12h, and calcined at 500~550℃ for 4~6h to obtain the Ni-X / Al2O3@SiO2 core-shell structure catalyst.
2. The preparation method according to claim 1, characterized in that, In S1, the soluble salt of Ni is selected from Ni(NO3)2·6H2O, the soluble salt of X is selected from at least one of Ce(NO3)3·6H2O, La(NO3)3·6H2O or Mn(NO3)2·4H2O, and the soluble salt of Al is selected from Al(NO3)3·9H2O.
3. The preparation method according to claim 1, characterized in that, In S3 and S4, the solution pH is adjusted to 8.0~9.0, the calcination heating rate is 2℃ / min, and the content of Ni in the prepared catalyst accounts for 10~30wt% of the total mass of the catalyst, the content of Al2O3 accounts for 60~80wt% of the total mass of the catalyst, and X is an active metal promoter selected from at least one of Ce, La, and Mn, and the content of X (measured in oxidation state) accounts for 5~10wt% of the total mass of the catalyst.
4. A SiO2-encapsulated bimetallic core-shell catalyst for the selective hydrogenation of BYD to BDO, characterized in that, Prepared by the method described in any one of claims 1-3.
5. An application of a SiO2-encapsulated bimetallic core-shell structure catalyst for the selective hydrogenation of BYD to BDO, characterized in that, The catalyst was placed in a fixed-bed reactor, and the gas in the reaction tube was replaced with high-purity hydrogen. The reaction solvent was water, and the mass ratio of BYD to water in the raw materials was 3:
7. The reaction conditions were as follows: reaction temperature 50~70℃, reaction pressure 5~6MPa, catalyst loading 10ml, gas flow rate 10~20ml / min, and liquid flow rate 0.1~0.2ml / min.