High-enol-selectivity alkynol hydrogenation catalyst as well as preparation method and application thereof
By loading precious metals on mesoporous molecular sieves and combining them with ZIF-8 composite catalysts, the environmental pollution and high energy consumption problems of traditional catalysts were solved, and the effect of producing 1,4-butenediol with high selectivity and stability was achieved.
Patent Information
- Application Number
- CN202510823263.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-19
- Publication Date
- 2025-09-23
AI Technical Summary
In the existing technology, the traditional lead-Kilndra catalyst has environmental pollution and product separation problems in the hydrogenation reaction of 1,4-butynediol, and has high energy consumption, making it difficult to achieve high selectivity and stability in the production of 1,4-butenediol.
A noble metal catalyst supported by a mesoporous molecular sieve is composited with the metal-organic framework material ZIF-8. The catalyst is constructed by in situ growth on the surface. The synergistic effect of the microporous structure and the organic framework is combined to regulate the catalyst activity and limit the formation of isomerized by-products.
The high selectivity and stability of 1,4-butenediol production in the 1,4-butynediol hydrogenation reaction were achieved, which reduced the reaction energy consumption, solved the environmental pollution problem, and improved the product separation efficiency.
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Figure CN120679603A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydrogen catalysts, and in particular to a high ene-selective alkynol hydrogenation catalyst, a preparation method and an application thereof. Background Art
[0002] The selective hydrogenation of carbon-carbon triple bonds to form carbon-carbon double bonds is of great significance for the production of both commodity chemicals and the synthesis of fine and specialty chemicals. 1,4-Butynediol (BED), a partially hydrogenated product of 1,4-butynediol (BYD), is an important intermediate in the production of substances such as endosulfan, vitamin A, and vitamin B, and is also an additive in resin manufacturing.
[0003] During the partial hydrogenation of BYD, a common approach is to add a suitable inhibitor to traditional precious metal hydrogenation catalysts to prevent the complete hydrogenation of carbon-carbon triple bonds to carbon-carbon single bonds. This reduces the catalytic activity and improves enol selectivity. For example, the Lindela catalyst, which uses lead as a dopant, can enhance BYD selectivity, reducing it to cis-BED. Furthermore, basic compounds such as quinoline are often added during the reaction to slow the subsequent hydrogenation of BED to 1,4-butanediol (BDO). However, the use of Lindela catalysts for BED production inevitably involves the use of toxic lead compounds and other soluble additives, which are detrimental to environmental protection and product separation. Therefore, it is necessary to develop a green and stable alternative to Lindela catalysts to achieve efficient BED production. Summary of the Invention
[0004] In light of this, the present invention provides a high enol-selective alkynol hydrogenation catalyst, its preparation method, and its application. The catalyst of the present invention is composed of a mesoporous molecular sieve-supported noble metal catalyst and a metal-organic framework (MOF). Through the synergistic effect of the two, the catalyst's hydrogenation activity is rationally regulated while the formation of isomeric byproducts is limited, resulting in extremely high BED selectivity and good stability in the BYD hydrogenation reaction.
[0005] The first aspect of the present invention is to provide a method for preparing a high alkene alcohol selectivity alkynol hydrogenation catalyst, comprising the following steps:
[0006] S1. Dissolve a soluble salt of Pd and KBr in deionized water to obtain solution A;
[0007] S2, dissolving polyvinylpyrrolidone (PVP) and ascorbic acid in deionized water to obtain solution B;
[0008] S3, mixing solution A and solution B, adding Al2O3, heating and stirring to load Pd onto Al2O3, and obtaining a mixture containing PVP-Pd / Al2O3;
[0009] S4. After cooling the mixture containing PVP-Pd / Al2O3 to room temperature, 2-methylimidazole is added and stirred. Zinc nitrate hexahydrate is added to react so that ZIF-8 is generated on the surface of PVP-Pd / Al2O3. The mixture is centrifuged, washed, and dried to obtain a PVP-Pd / Al2O3@ZIF-8 high eneol-selective alkynol hydrogenation catalyst.
[0010] Preferably, in S1, the soluble salt of Pd is PdCl2; in solution A, the content of palladium chloride is 0.2 wt.%, and the content of KBr is 3 wt.%.
[0011] Preferably, in S2, in the solution B, the content of PVP is 2 wt.%, the content of ascorbic acid is 2 wt.%, and the mass volume ratio of Al2O3 to solution A is 1 g:10 mL.
[0012] Preferably, in S3, the volume ratio of solution A to solution B is 2:1; the heating and stirring temperature is 110° C., and the heating and stirring time is 3 h.
[0013] Preferably, in S4, the amount of zinc nitrate hexahydrate is 3%-20% of the mass of Al2O3, the mass ratio of 2-methylimidazole to zinc nitrate hexahydrate is 15:1; the reaction time is 2h; the drying temperature is 100°C, and the drying time is 10h.
[0014] The second aspect of the present invention is to provide a high ene alcohol selectivity alkynol hydrogenation catalyst prepared according to the above method.
[0015] The third aspect of the present invention is to provide an application of a high ene alcohol selectivity alkynol hydrogenation catalyst, the method is as follows:
[0016] PVP-Pd / Al2O3@ZIF-8, BYD and deionized water were mixed and stirred under H2 atmosphere to obtain a BYD partial hydrogenation product containing 1,4-butenediol.
[0017] Preferably, the ratio of PVP-Pd / Al2O3@ZIF-8, BYD, and deionized water is 0.05 g:0.568 g:10 mL; the H2 pressure is 3 MPa, the stirring speed is 500 r / min, the reaction temperature is 50°C, and the reaction time is 1 h.
[0018] Preferably, the high ene-selective alkynol hydrogenation catalyst needs to be pretreated before use to remove the surface passivation layer. The specific method is as follows: the high ene-selective alkynol hydrogenation catalyst is heat-treated under H2 atmosphere; the heat treatment temperature is 200°C and the heat treatment time is 2h.
[0019] Compared with the prior art, the present invention has the following beneficial technical effects:
[0020] The high ene-selective alkynol hydrogenation catalyst of the present invention exhibits extremely high BED selectivity and stability in the BYD hydrogenation reaction, solves the environmental pollution and product separation problems of traditional lead kilindral catalysts, reduces reaction energy consumption, and has good conversion and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will be further described below with reference to the accompanying drawings.
[0022] Figure 1 SEM images of 1% PVP-Pd / Al2O3@ZIF-8 and ZIF-8 in Test Example 1;
[0023] Figure 2 These are the BYD conversion and BED selectivity test results of 1% PVP-Pd / Al2O3@ZIF-8 and 1% PVP-Pd / Al2O3 in Test Example 2. DETAILED DESCRIPTION
[0024] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0025] The first aspect of the present invention is to provide a method for preparing a high alkene alcohol selectivity alkynol hydrogenation catalyst, comprising the following steps:
[0026] S1. Dissolve a soluble salt of Pd and KBr in deionized water to obtain solution A;
[0027] S2, dissolving polyvinylpyrrolidone (PVP) and ascorbic acid in deionized water to obtain solution B;
[0028] S3, mixing solution A and solution B, adding Al2O3, heating and stirring to load Pd onto Al2O3, and obtaining a mixture containing PVP-Pd / Al2O3;
[0029] S4. After cooling the mixture containing PVP-Pd / Al2O3 to room temperature, 2-methylimidazole is added and stirred. Zinc nitrate hexahydrate is added to react so that ZIF-8 is generated on the surface of PVP-Pd / Al2O3. The mixture is centrifuged, washed, and dried to obtain a PVP-Pd / Al2O3@ZIF-8 high eneol-selective alkynol hydrogenation catalyst.
[0030] In the S1 of the present invention, the soluble salt of Pd is PdCl2; in the solution A, the content of palladium chloride is 0.2wt.%, and the content of KBr is 3wt.%; in the S2, in the solution B, the content of PVP is 2wt.%, and the content of ascorbic acid is 2wt.%; in the S3, the volume ratio of solution A to solution B is 2:1; the heating and stirring temperature is 110°C, and the heating and stirring time is 3h; in the S4, the amount of zinc nitrate hexahydrate is 3%-20% of the mass of Al2O3, and the mass ratio of 2-methylimidazole to zinc nitrate hexahydrate is 15:1; the reaction time is 2h; the drying temperature is 100°C, and the drying time is 10h.
[0031] The second aspect of the present invention is to provide a high ene alcohol selectivity alkynol hydrogenation catalyst prepared according to the above method.
[0032] The third aspect of the present invention is to provide an application of a high ene alcohol selectivity alkynol hydrogenation catalyst, the method is as follows:
[0033] PVP-Pd / Al2O3@ZIF-8, BYD and deionized water were mixed and stirred under H2 atmosphere to obtain a BYD partial hydrogenation product containing 1,4-butenediol.
[0034] The ratio of PVP-Pd / Al2O3@ZIF-8, BYD and deionized water in the present invention is 0.05g:0.568g:10mL; the H2 pressure is 3MPa, the stirring speed is 500r / min, the reaction temperature is 50°C, and the reaction time is 1h.
[0035] In some specific embodiments of the present invention, the high ene-selective alkynol hydrogenation catalyst needs to be pretreated before use to remove the surface passivation layer. The specific method is as follows: the high ene-selective alkynol hydrogenation catalyst is heat-treated under a H2 atmosphere; the heat treatment temperature is 200°C and the heat treatment time is 2h.
[0036] The present invention uses mesoporous Al2O3-supported palladium nanoparticles as the core and constructs a catalyst with a composite structure by in situ growth of ZIF-8 metal-organic framework materials on the surface. At the same time, a one-pot method using a water solvent system is used to introduce a MOFs material with a microporous structure into the mesoporous molecular sieve-supported precious metal catalyst. Among them, the microporous structure of ZIF-8 provides a steric hindrance effect, and its organic framework provides a similar effect as an organic inhibitor. The synergistic effect of the two can not only rationally regulate the catalyst hydrogenation activity, but also limit the formation of isomerized by-products, thereby showing extremely high BED selectivity in the BYD hydrogenation reaction. At the same time, the ZIF-8 coating layer can also give the catalytic material good stability, thereby achieving efficient preparation of BED.
[0037] Unless otherwise specified, all experiments were repeated three times and the results were expressed as the mean value.
[0038] Example 1 A method for preparing a high ene alcohol selectivity alkynol hydrogenation catalyst, comprising the following steps:
[0039] S1. Dissolve 0.02 g of PdCl2 and 0.3 g of KBr in 10 mL of deionized water to obtain solution A.
[0040] S2. Dissolve 0.1 g of PVP in 5 mL of deionized water and add 0.1 g of ascorbic acid to obtain solution B.
[0041] S3: Solution A and Solution B were mixed in a reaction vessel and 1 g of Al2O3 was immediately added. The reaction vessel was then heated to 110°C and stirred at 400 rpm for 3 h to form a mixture containing PVP-Pd / Al2O3.
[0042] S4. After the above reaction is completed, there is no need to isolate the PVP-Pd / Al2O3 intermediate product. After the reaction system is cooled to room temperature, 0.6 g of 2-methylimidazole is added and stirred for 30 minutes. Then, 0.04 g of zinc nitrate hexahydrate is added and stirred for 2 hours. The mixture is centrifuged, washed with deionized water three times, and dried at 100°C for 10 hours to obtain a 1% PVP-Pd / Al2O3@ZIF-8 high eneol-selective alkynol hydrogenation catalyst.
[0043] The preparation method of comparative example 11% PVP-Pd / Al2O3 is as follows:
[0044] S1. Dissolve 0.02 g of PdCl2 and 0.3 g of KBr in 10 mL of deionized water to obtain solution A.
[0045] S2. Dissolve 0.1 g of PVP in 5 mL of deionized water and add 0.1 g of ascorbic acid to obtain solution B.
[0046] S3: Solution A and solution B were mixed in a reaction vessel and 1 g of Al2O3 was immediately added. The reaction vessel was then heated to 110°C and stirred continuously at 400 r / min for 3 h (stirring rate 300-500 r / min) to form a mixture containing PVP-Pd / Al2O3. After the reaction system was cooled to room temperature, it was centrifuged, washed with deionized water three times, and dried at 100°C for 10 h to obtain a 1% PVP-Pd / Al2O3 catalyst.
[0047] The preparation method of comparative example 21% PVP-Pd@ZIF-8 is as follows:
[0048] S1. Dissolve 0.02 g of PdCl2 and 0.3 g of KBr in 10 mL of deionized water to obtain solution A.
[0049] S2. Dissolve 0.1 g of PVP in 5 mL of deionized water and add 0.1 g of ascorbic acid to obtain solution B.
[0050] S3: Solution A and solution B were heated to 110°C in a reaction vessel and stirred continuously at 400 rpm for 3 h to form PVP-Pd;
[0051] S4 After the reaction system is cooled to room temperature, 0.6 g of 2-methylimidazole is added and stirred for 30 minutes, and then 0.04 g of zinc nitrate hexahydrate is added and stirred for 2 hours. The mixture is centrifuged and washed with deionized water three times, and dried at 100°C for 10 hours to obtain a 1% PVP-Pd@ZIF-8 catalyst.
[0052] Test Example 1 SEM Characterization
[0053] The PVP-Pd / Al2O3@ZIF-8 high ene-selective alkynol hydrogenation catalyst obtained in Example 1 was characterized by SEM. Figure 1 shown.
[0054] Depend on Figure 1 It can be seen that ZIF-8 particles are evenly distributed on the surface of PVP-Pd / Al2O3 catalyst.
[0055] Test Example 2 Catalytic Performance Determination
[0056] The catalytic performance test was carried out in a high-pressure reactor. Before the reaction, the catalyst was heated to 200°C in a H2 atmosphere and maintained for 2 hours to remove the surface passivation layer.
[0057] Typical reaction conditions are as follows: 0.05 g of catalyst, 0.568 g of BYD, 10 mL of deionized water as solvent, 3 MPa of H₂ pressure in the reactor, 50°C temperature, and 500 rpm stirring. Reaction products were analyzed by gas chromatography.
[0058] The catalytic reaction results of the 1% PVP-Pd / Al2O3@ZIF-8 sample of Example 1 of the present invention and the reference samples 1% PVP-Pd / Al2O3 and 1% PVP-Pd@ZIF-8 are shown in Tables 1 and Figure 2 shown.
[0059] Table 1 BYD conversion and BED selectivity detection results
[0060]
[0061]
[0062] From Table 1 and Figure 2It can be seen that the 1% PVP-Pd / Al2O3@ZIF-8 prepared in the present invention and the 1% PVP-Pd / Al2O3 reference sample have almost the same reactivity, and both can completely convert BYD within 0.5 h.
[0063] The 1% PVP-Pd / Al2O3@ZIF-8 prepared in this paper exhibits significant selectivity for BED, achieving a BED selectivity of 99.5% at a reaction time of 0.5 h. As the reaction time increases, BED is no longer further converted to BDO and other byproducts, and after 4 hours, the BED selectivity remains as high as 97%. The reference sample, 1% PVP-Pd@ZIF-8, while also exhibiting high BED selectivity, exhibits lower reactivity, requiring 3-4 hours to fully convert BYD.
[0064] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.
Claims
1. A method for preparing a high ene alcohol selectivity alkynol hydrogenation catalyst, characterized in that: The following steps are involved: S1. Dissolve a soluble salt of Pd and KBr in deionized water to obtain solution A; S2, dissolving polyvinylpyrrolidone (PVP) and ascorbic acid in deionized water to obtain solution B; S3, mixing solution A and solution B, adding Al2O3, heating and stirring to load Pd onto Al2O3, and obtaining a mixture containing PVP-Pd / Al2O3; S4. After cooling the mixture containing PVP-Pd / Al2O3 to room temperature, 2-methylimidazole is added and stirred. Zinc nitrate hexahydrate is added to react so that ZIF-8 is generated on the surface of PVP-Pd / Al2O3. The mixture is centrifuged, washed, and dried to obtain a PVP-Pd / Al2O3@ZIF-8 high eneol-selective alkynol hydrogenation catalyst.
2. The preparation method according to claim 1, characterized in that In the S1, the soluble salt of Pd is PdCl2.
3. The preparation method according to claim 1, characterized in that In the solution A, the content of palladium chloride is 0.2 wt.%, and the content of KBr is 3 wt.%.
4. The preparation method according to claim 1, characterized in that In the S2, the content of PVP in the solution B is 2 wt.%, and the content of ascorbic acid is 2 wt.%.
5. The preparation method according to claim 1, characterized in that In S3, the volume ratio of solution A to solution B is 2:1, and the mass volume ratio of Al2O3 to solution A is 1 g:10 mL.
6. The preparation method according to claim 1, characterized in that In S3, the heating and stirring temperature is 110° C., and the heating and stirring time is 3 h.
7. The preparation method according to claim 1, characterized in that In S4, the amount of zinc nitrate hexahydrate is 3%-20% of the mass of Al2O3, the mass ratio of 2-methylimidazole to zinc nitrate hexahydrate is 15:1; and the reaction time is 2 hours.
8. The preparation method according to claim 1, characterized in that The drying temperature is 100° C. and the drying time is 10 h.
9. A high ene alcohol selectivity alkynol hydrogenation catalyst, characterized in that Prepared by the method according to any one of claims 1 to 8.
10. An application of a high ene-selective alkynol hydrogenation catalyst, characterized in that: Here’s how: PVP-Pd / Al2O3@ZIF-8, 1,4-butynediol, and deionized water were mixed and stirred under H2 atmosphere for reaction; The PVP-Pd / Al2O3@ZIF-8 is PVP-Pd / Al2O3@ZIF-8 prepared by the method according to any one of claims 1 to 8 or the PVP-Pd / Al2O3@ZIF-8 according to claim 9.