A zeolite-coated NiIn hydrogenation catalyst with water conduction channels, its preparation method and application
By constructing water conduction channels by alternately coating the outside of the NiIn catalyst with hydrophilic and hydrophobic zeolite layers, the problem of water's influence on the catalyst in the CO2 hydrogenation reaction was solved, thereby improving the catalyst's stability and CO2 conversion efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING TECH UNIV
- Filing Date
- 2024-03-25
- Publication Date
- 2026-07-03
AI Technical Summary
CO2 activation and efficient conversion in hydrogenation reactions are difficult. The competitive adsorption of water on the catalyst surface with CO2 and H2 adsorption sites affects the activity and stability of the catalyst. Water byproducts cause oxidation and corrosion to the catalyst surface.
Alternating hydrophilic and hydrophobic zeolite layers are coated on the outside of the NiIn catalyst core to construct a hydrophobic-hydrophilic-hydrophobic water conduction channel. Water is removed in situ through the water conduction channel, which improves the catalyst stability and promotes CO2 conversion.
By designing a water conduction channel, the thermodynamic limitations of the CO2 hydrogenation reaction were broken, improving the stability of the catalyst and the yield of the target product, thus promoting the efficient conversion of CO2.
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Figure CN118122372B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of CO2 hydrogenation catalyst preparation technology, specifically relating to a zeolite-coated NiIn hydrogenation catalyst with water conduction channels, its preparation method, and its application. Background Technology
[0002] The direct conversion of H2 and CO2 produced from clean energy into high-value-added chemicals (such as methanol, methane, and low-carbon olefins) is an important way to utilize the greenhouse gas CO2 as a resource, and it can also play a role in reducing CO2 emissions, which is of great strategic significance.
[0003] Because CO2 is a relatively inert molecule thermodynamically, achieving its activation and efficient conversion presents significant difficulties and challenges. Furthermore, the hydrogenation reaction of CO2 is often accompanied by the generation of water as a byproduct. The competitive adsorption of water on the catalyst surface against CO2 and H2 adsorption sites, as well as the oxidation, corrosion, and structural alterations caused by water on the catalyst surface, all significantly impact the catalyst's activity and stability. Summary of the Invention
[0004] To address the aforementioned problems, this invention proposes a zeolite-coated NiIn hydrogenation catalyst with water conduction channels, its preparation method, and its applications. By alternately coating the core of the zeolite-coated NiIn hydrogenation catalyst with hydrophilic and hydrophobic shells, a water conduction channel with a hydrophobic-hydrophilic-hydrophobic structure is constructed on the catalyst surface. The in-situ removal of water through these channels enhances the stability of the CO2 hydrogenation catalyst, promotes efficient CO2 conversion, increases the yield of the target product, and provides a solution for the development of efficient CO2 resource utilization.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] A zeolite-coated NiIn hydrogenation catalyst with water conduction channels has a core of NiIn catalytic material, and is coated with a hydrophobic zeolite layer and a hydrophilic zeolite layer from the inside out on the outside. A hydrophobic material is grafted onto the surface of the hydrophilic zeolite layer.
[0007] The hydrophobic material mentioned is a siloxane.
[0008] The siloxane is selected from one or more of KH570, PDVB, PDMS, and MTMS.
[0009] The preparation method of the above-mentioned zeolite-coated NiIn hydrogenation catalyst with water conduction channels includes the following steps:
[0010] S1. Preparation of a hydrophobic zeolite-coated NiIn hydrogenation catalyst core
[0011] ① Mix the silicon source, stencil agent, and water, stir, and age for a certain period of time;
[0012] ② Mix and stir nickel nitrate, indium nitrate, and a complexing agent to prepare a nickel-indium complex.
[0013] ③ Add the nickel-indium complex from step ② dropwise to the material obtained in step ① and stir for a certain period of time.
[0014] ④ Transfer the mixture obtained in step ③ to a high-pressure reactor with a polytetrafluoroethylene liner and hydrothermally treat it at a certain temperature for a certain time.
[0015] ⑤ The solid obtained in step ④ is washed, dried and calcined to obtain the hydrophobic zeolite layer coated NiIn hydrogenation catalyst core.
[0016] S2, Constructing the outer shell of the water transmission channel
[0017] ① A catalyst hydrophilic layer precursor solution is prepared by mixing and stirring silicon source, aluminum source, template agent and anhydrous ethanol and aging for a certain period of time.
[0018] ② The zeolite-coated NiIn hydrogenation catalyst core in S1 is immersed in the zeolite-coated NiIn hydrogenation catalyst core obtained in ① above.
[0019] ③ The zeolite-coated NiIn hydrogenation catalyst core coated with the hydrophilic precursor in step ② above is transferred to a high-pressure reactor with a polytetrafluoroethylene liner and subjected to steam-assisted crystallization for a certain period of time.
[0020] ④ The solid in ③ is washed, dried and calcined to obtain a zeolite-coated NiIn hydrogenation catalyst core with a hydrophilic shell.
[0021] ⑤ By modifying the zeolite-coated NiIn hydrogenation catalyst core with a hydrophilic shell obtained in ④ through hydrophobic modification with siloxane, a zeolite-coated NiIn hydrogenation catalyst with a water transport channel consisting of a hydrophobic-hydrophilic-hydrophobic channel is obtained.
[0022] The silicon source mentioned in ① of S1 is any one of tetraethyl orthosilicate, silicon hydrate, or sodium silicate.
[0023] The template agent mentioned in ① of S1 is either tetrapropylammonium hydroxide or tetrapropylammonium bromide.
[0024] The aging time mentioned in ① of S1 is 6-12 hours.
[0025] The complexing agent mentioned in ② of S1 is any one of ethylenediamine, ethylenediaminetetraacetic acid, and catechol.
[0026] The molar ratio of silicon source, stencil agent, nickel nitrate, and indium nitrate is 1:0.5-1.5:0.001-0.01:0.001-0.01.
[0027] The stirring time in step ③ of S1 is 1-3 hours.
[0028] The hydrothermal treatment temperature in section ④ of S1 is 170-190℃.
[0029] The hydrothermal treatment time for S1 in section ④ is 72-96 hours.
[0030] The calcination temperature of S1 in step ⑤ is 500-700℃, and the calcination time is 2-6h.
[0031] The silicon source mentioned in ① of S2 is any one of tetraethyl orthosilicate, silicon hydrate, or sodium silicate.
[0032] The aluminum source mentioned in ① of S2 is any one of sodium aluminate, boehmite, or aluminum isopropoxide.
[0033] The template agent mentioned in ① of S2 is either tetrapropylammonium hydroxide or tetrapropylammonium bromide.
[0034] In S2, the molar ratio of silicon source, aluminum source, template agent, and anhydrous ethanol is 1:0.01-0.1:0.5-1.5:0.1-1.
[0035] The aging time mentioned in ① of S2 is 1-3 hours.
[0036] The steam-assisted crystallization treatment time described in ③ of S2 is 24-48h.
[0037] The calcination temperature described in section ④ of S2 is 500-700℃, and the calcination time is 2-6h.
[0038] The siloxane mentioned in S2 ⑤ is any one of KH570, PDVB, PDMS, and MTMS.
[0039] The above-mentioned catalysts are used in the catalytic reaction of H2 and CO2 to prepare low-carbon olefins.
[0040] Beneficial effects
[0041] This invention proposes a zeolite-coated NiIn hydrogenation catalyst with water conduction channels, its preparation method, and its application. By alternately coating the core of the zeolite-coated NiIn hydrogenation catalyst with hydrophilic and hydrophobic shells, a water conduction channel with a hydrophobic-hydrophilic-hydrophobic structure is constructed on the catalyst surface. The in-situ removal of water through these channels breaks the thermodynamic limitations of the CO2 hydrogenation reaction, improves the stability of the CO2 hydrogenation catalyst, promotes efficient CO2 conversion, and increases the yield of the target product, providing a solution for the development of efficient CO2 resource utilization. According to Le Chatelier's principle, removing the product breaks the thermodynamic limitations of the reaction, causing the reaction to shift in the direction of increased product yield. By constructing hydrophobic channels on the catalyst surface to remove the water generated in the CO2 hydrogenation reaction, not only is the catalyst's performance stabilized, but the selectivity and yield of the target product are also increased. Attached Figure Description
[0042] Figure 1 A schematic diagram of a catalyst evaluation device provided in an embodiment of the present invention.
[0043] Figure 2 These are experimental data obtained from specific implementation cases.
[0044] Figure 3 A is a schematic diagram of the contact angle of a hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell; B is a schematic diagram of the contact angle of a siloxane-modified hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell.
[0045] Figure 4 This is a schematic diagram of a catalyst.
[0046] Figure 5 This is a schematic diagram of the XRD characterization of the catalyst in Example 1.
[0047] Figure 1 The components corresponding to each number are: 1-pressure reducing valve, 2-mass flow controller, 3-reactor, 4-back pressure valve. Detailed Implementation
[0048] Comparative Example 1
[0049] Hydrophobic S-1 coated NiIn catalyst for CO2 hydrogenation to methanol
[0050] ① Add 13g of tetrapropylammonium hydroxide to 25mL of deionized water and stir. Then add 8.32g of tetraethyl orthosilicate dropwise and age at room temperature for 6h.
[0051] ② Add 0.905g of nickel nitrate hexahydrate and 0.847g of indium nitrate hydrate to 6mL of ethylenediamine aqueous solution to prepare a nickel-indium complex.
[0052] ③ Add the nickel-indium complex from ② to ① dropwise and stir for 1 hour.
[0053] ④ Transfer the mixture from ③ to a high-pressure reactor with a polytetrafluoroethylene liner and hydrothermally treat it at 170°C for 96 hours.
[0054] ⑤ The solid obtained in ④ was washed, dried at 80℃ overnight, and calcined at 550℃ for 4 hours to obtain the hydrophobic S-1 coated NiIn catalyst.
[0055] The prepared S-1 coated NiIn catalyst was mixed with quartz sand and then packed into a container. Figure 1 The catalyst evaluation device shown is used to evaluate the performance of the catalyst.
[0056] The catalyst evaluation conditions were CO2 / H2 / N2 = 72 / 24 / 4, the total flow rate of the feed gas was 50 mL / min, the reaction temperature was 250℃, and the reaction pressure was 5 MPa. The composition of the reactor outlet gas was analyzed by gas chromatography.
[0057] Comparative Example 2
[0058] Hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell is used for CO2 hydrogenation to methanol.
[0059] S1. Preparation of hydrophobic S-1-coated NiIn hydrogenation catalyst core
[0060] ① Add 13g of tetrapropylammonium hydroxide to 25mL of deionized water and stir. Then add 8.32g of tetraethyl orthosilicate dropwise and age at room temperature for 6h.
[0061] ② Add 0.905g of nickel nitrate hexahydrate and 0.847g of indium nitrate hydrate to 6mL of ethylenediamine aqueous solution to prepare a nickel-indium complex.
[0062] ③ Add the nickel-indium complex from ② to ① dropwise and stir for 1 hour.
[0063] ④ Transfer the mixture from ③ to a high-pressure reactor with a polytetrafluoroethylene liner and hydrothermally treat it at 170°C for 96 hours.
[0064] ⑤ The solid obtained in ④ is washed, dried at 80℃ overnight, and calcined at 550℃ for 4 hours to obtain the hydrophobic S-1 coated NiIn catalyst.
[0065] S2. Preparation of hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell.
[0066] ① Add 13g tetrapropylammonium hydroxide, 1.37g sodium aluminate, and 8.32g tetraethyl orthosilicate to 20mL of anhydrous ethanol, stir, and age at room temperature for 2h.
[0067] ②Immerse the hydrophobic S-1 coated NiIn catalyst core into the above ① to obtain a zeolite-coated NiIn hydrogenation catalyst with a hydrophilic precursor.
[0068] ③ The hydrophobic S-1-coated NiIn catalyst coated with the hydrophilic precursor in step ② above was transferred to a high-pressure reactor with a polytetrafluoroethylene liner and subjected to steam-assisted crystallization for 24 hours.
[0069] ④ The solid from ③ was washed, dried at 80°C overnight, and calcined at 550°C for 4 hours to obtain a hydrophobic S-1 coated NiIn catalyst with a hydrophilic shell.
[0070] The prepared hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell was mixed with quartz sand and then packed into a container. Figure 1 The catalyst evaluation device shown is used to evaluate the performance of the catalyst.
[0071] The catalyst evaluation conditions were CO2 / H2 / N2 = 72 / 24 / 4, the total flow rate of the feed gas was 50 mL / min, the reaction temperature was 250℃, and the reaction pressure was 5 MPa. The composition of the reactor outlet gas was analyzed by gas chromatography.
[0072] Example 1
[0073] Zeolite-coated NiIn catalysts with water conduction channels are used for CO2 hydrogenation to methanol.
[0074] S1. Preparation of hydrophobic S-1-coated NiIn hydrogenation catalyst core
[0075] ① Add 13g of tetrapropylammonium hydroxide to 25mL of deionized water and stir. Then add 8.32g of tetraethyl orthosilicate dropwise and age at room temperature for 6h.
[0076] ② Add 0.905g of nickel nitrate hexahydrate and 0.847g of indium nitrate hydrate to 6mL of ethylenediamine aqueous solution to prepare a nickel-indium complex.
[0077] ③ Add the nickel-indium complex from ② to ① dropwise and stir for 1 hour.
[0078] ④ Transfer the mixture from ③ to a high-pressure reactor with a polytetrafluoroethylene liner and hydrothermally treat it at 170°C for 96 hours.
[0079] ⑤ The solid obtained in ④ is washed, dried at 80℃ overnight, and calcined at 550℃ for 4 hours to obtain the hydrophobic S-1 coated NiIn catalyst.
[0080] S2. Preparation of hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell.
[0081] ① Add 13g tetrapropylammonium hydroxide, 1.37g sodium aluminate, and 8.32g tetraethyl orthosilicate to 20mL of anhydrous ethanol, stir, and age at room temperature for 2h.
[0082] ②Immerse the hydrophobic S-1 coated NiIn catalyst core prepared in S1 into the above ① to obtain a hydrophobic S-1 coated NiIn hydrogenation catalyst coated with a hydrophilic precursor.
[0083] ③ The hydrophobic S-1-coated NiIn catalyst coated with the hydrophilic precursor in step ② above was transferred to a high-pressure reactor with a polytetrafluoroethylene liner and subjected to steam-assisted crystallization for 24 hours.
[0084] ④ The solid from ③ was washed, dried at 80°C overnight, and calcined at 550°C for 4 hours to obtain a hydrophobic S-1 coated NiIn catalyst with a hydrophilic shell.
[0085] S3, siloxane-modified hydrophobic S-1-coated NiIn catalyst with a hydrophilic shell.
[0086] The hydrophobic S-1 coated NiIn catalyst with a hydrophilic shell prepared in S2 was modified with PDVB hydrophobic modification. The core of the zeolite-coated NiIn hydrogenation catalyst was alternately coated with hydrophilic and hydrophobic shells. This process was used to construct water conduction channels with a hydrophobic-hydrophilic-hydrophobic structure on the catalyst surface, thus obtaining the zeolite-coated NiIn catalyst with water conduction channels.
[0087] The prepared zeolite-coated NiIn catalyst with water conduction channels was mixed with quartz sand and then packed into a container. Figure 1 The catalyst evaluation device shown is used to evaluate the performance of the catalyst.
[0088] The catalyst evaluation conditions were CO2 / H2 / N2 = 72 / 24 / 4, the total flow rate of the feed gas was 50 mL / min, the reaction temperature was 250℃, and the reaction pressure was 5 MPa. The composition of the reactor outlet gas was analyzed by gas chromatography.
[0089] Depend on Figure 2 It can be seen that the construction of water conduction channels on the catalyst surface facilitates the in-situ removal of water by-products, promotes CO2 conversion, and increases methanol production.
Claims
1. A zeolite-coated NiIn hydrogenation catalyst having water-conducting channels, characterized in that, Its core is a NiIn catalyst material, and its outer side is coated with a hydrophobic zeolite layer and a hydrophilic zeolite layer from the inside out. Siloxane is grafted onto the surface of the hydrophilic zeolite layer. The siloxane is selected from any one or more of KH570, PDMS, and MTMS; The preparation method of the zeolite-coated NiIn hydrogenation catalyst with water conduction channels includes the following steps: S1. Preparation of a hydrophobic zeolite-coated NiIn hydrogenation catalyst core ① Mix the silicon source, template agent, and water, stir, and age for a certain period of time; ② Mix and stir nickel nitrate, indium nitrate, and a complexing agent to prepare a nickel-indium complex; ③ Add the nickel-indium complex from step ② dropwise to the material obtained in step ① and stir for a certain period of time; ④ Transfer the mixture obtained in step ③ to a high-pressure reactor and hydrothermally treat it at a certain temperature for a certain time; ⑤ The solid obtained in step ④ is washed, dried and calcined to obtain the hydrophobic zeolite layer coated NiIn hydrogenation catalyst core; S2, Constructing the outer shell of the water conduction channel ① A catalyst hydrophilic layer precursor solution is prepared by mixing and stirring silicon source, aluminum source, template agent, and anhydrous ethanol and aging for a certain period of time; ② The hydrophobic zeolite layer-coated NiIn hydrogenation catalyst core obtained in S1 is immersed in the catalyst hydrophilic layer precursor solution in step ①; ③ Transfer the material obtained in step ② above to a high-pressure reactor for steam-assisted crystallization treatment for a certain period of time; ④ The solid obtained in ③ is washed, dried and calcined to obtain a zeolite-coated NiIn hydrogenation catalyst core with a hydrophilic shell; ⑤ The zeolite-coated NiIn hydrogenation catalyst core with a hydrophilic shell obtained in ④ is modified by hydrophobic modification with siloxane to obtain a zeolite-coated NiIn hydrogenation catalyst with a water conduction channel consisting of a hydrophobic-hydrophilic-hydrophobic channel.
2. The zeolite-coated NiIn hydrogenation catalyst with water-conducting channels according to claim 1, characterized in that, The silicon source mentioned in S1 ① is any one of tetraethyl orthosilicate, silicon hydrate, or sodium silicate; the template agent mentioned in S1 ① is any one of tetrapropylammonium hydroxide or tetrapropylammonium bromide; the aging time mentioned in S1 ① is 6-12 h.
3. The zeolite-coated NiIn hydrogenation catalyst with water conduction channels according to claim 1, characterized in that, The complexing agent mentioned in ② of S1 is any one of ethylenediamine, ethylenediaminetetraacetic acid, and catechol; the molar ratio of silicon source, template agent, nickel nitrate, and indium nitrate in S1 is 1:0.5-1.5:0.001-0.01:0.001-0.01; the stirring time in ③ of S1 is 1-3 h.
4. The zeolite-coated NiIn hydrogenation catalyst with water conduction channels according to claim 1, characterized in that, The hydrothermal treatment temperature in step ④ of S1 is 170-190 ℃; the hydrothermal treatment time in step ④ of S1 is 72-96 h; the calcination temperature in step ⑤ of S1 is 500-700 ℃, and the calcination time is 2-6 h.
5. The zeolite-coated NiIn hydrogenation catalyst with water conduction channels according to claim 1, characterized in that, The silicon source mentioned in S2 ① is any one of tetraethyl orthosilicate, silicon hydrate, or sodium silicate; the aluminum source mentioned in S2 ① is any one of sodium aluminate, boehmite, or aluminum isopropoxide; the template agent mentioned in S2 ① is any one of tetrapropylammonium hydroxide or tetrapropylammonium bromide; the molar ratio of silicon source, aluminum source, template agent, and anhydrous ethanol in S2 ① is 1:0.01-0.1:0.5-1.5:0.1-1; the aging time mentioned in S2 ① is 1-3 h.
6. The zeolite-coated NiIn hydrogenation catalyst with water conduction channels according to claim 1, characterized in that, The steam-assisted crystallization treatment time described in ③ of S2 is 24-48 h; the calcination temperature described in ④ of S2 is 500-700 ℃, and the calcination time is 2-6 h.
7. The zeolite-coated NiIn hydrogenation catalyst with water conduction channels according to claim 1, characterized in that, The siloxane mentioned in S2 ⑤ is any one of KH570, PDMS, and MTMS.
8. The application of the zeolite-coated NiIn hydrogenation catalyst with water conduction channels as described in claim 1 in the catalytic reaction of H2 and CO2 to prepare low-carbon olefins.