Dual-pore-forming pickling HCP phase Ni-based nano-catalyst and preparation method and application thereof
By constructing a hierarchical porous structure and removing sodium residues from the HCP-phase Ni-based nanocatalyst through double-pore acid washing, the problem of insufficient conversion and selectivity in the low-temperature aqueous ethanol condensation reaction was solved, and efficient carbon alcohol production was achieved.
Patent Information
- Application Number
- CN202511178097.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-21
- Publication Date
- 2025-11-07
AI Technical Summary
Existing catalysts struggle to achieve both high conversion rates and carbon alcohol selectivity in low-temperature aqueous ethanol condensation reactions, and also suffer from problems such as high solvent toxicity and harsh reaction conditions.
A dual-pore acid-washed HCP phase Ni-based nanocatalyst was developed, which constructed a hierarchical porous structure through the synergistic effect of NaHCO3 and NaCl. Combined with HCl acid washing treatment, sodium residue was removed and the size of metal particles was reduced, thus protecting the active sites.
Highly efficient catalytic upgrading of ethanol and aqueous solutions was achieved under mild conditions, improving the yield and selectivity of C4+, C6+, and C8+ alcohols and reducing the formation of byproducts.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of catalysts, and particularly relates to a double-pore-creating pickling HCP phase Ni-based nanometer catalyst. BACKGROUND
[0002] With the continuous growth of global demand for sustainable energy and green chemical industry, the use of renewable biomass resources to produce fuels and high-value chemicals has become an important development direction. Among them, bio-fermentation ethanol as a typical renewable bio-fuel and chemical raw material, its large-scale application has important significance to reduce the dependence on fossil resources. However, the fermentation product is usually a dilute aqueous solution with an ethanol mass fraction of about 5%-15%, and it is difficult to separate by conventional distillation due to the strong hydrogen bond interaction between ethanol and water molecules to form azeotrope; and the energy consumption of the subsequent distillation and dehydration process accounts for a high proportion, which greatly limits its economy and large-scale application. Therefore, the development of technology for directly upgrading fermentation ethanol aqueous solution under mild conditions is of great importance to improve the utilization efficiency of biomass resources.
[0003] On the other hand, alcohol condensation reaction is the core path to prepare high-value higher alcohols, which can be synthesized by short-chain alcohol condensation-hydrogenation to branched higher alcohols. Such higher alcohols have great application potential in plasticizers, surfactants, clean fuel blending and other fields. The condensation route using renewable ethanol as raw material is more in line with the demand of green chemistry. Traditional alcohol condensation mostly uses organic solvents or pure alcohol phase systems, but there are problems such as high solvent toxicity and harsh reaction conditions. In recent years, water medium has become a new research direction due to its economic, environmental friendly, safety and other advantages, but its negative impact on catalysts is significant-the strong polarity of water easily covers the active sites of the catalyst, the hydrogen bond interaction between alcohol and water will inhibit the generation of condensation intermediates, and some catalysts are easy to hydrolyze and deactivate, resulting in insufficient efficiency and stability of water-phase condensation reaction. Especially under low temperature conditions, existing catalysts are difficult to balance the improvement of ethanol conversion rate and the control of carbon alcohol selectivity, which becomes a key bottleneck restricting the practical application of water-phase alcohol condensation. SUMMARY
[0004] In view of the deficiency of harsh reaction conditions in the existing technology of ethanol low-temperature water-phase coupling to prepare carbon alcohol, the application provides a double-pore-creating pickling HCP phase Ni-based nanometer catalyst, which constructs a high specific surface area multi-level pore structure through the synergistic effect of double pore-creating agents, effectively enhances the mass transfer efficiency in the reaction process, and has high catalytic efficiency and strong selectivity.
[0005] The second object of the present application is to provide a preparation method of the dual-pore acid-washed HCP phase Ni-based nanometer catalyst, which is prepared by a one-pot method, is simple and easy to implement, and can completely remove sodium residues by HCl acid washing treatment, thereby avoiding the poisoning effect of alkaline sites on active centers; meanwhile, the acid washing process etches the surface of the carbon carrier, effectively reducing the particle size of the metal active component.
[0006] The third object of the present application is to provide a dual-pore acid-washed HCP phase Ni-based nanometer catalyst for catalyzing the preparation of carbon alcohol from ethanol and water, which has mild reaction conditions and can achieve high conversion rate and high selectivity at a lower temperature.
[0007] To this end, the first technical solution provided by the present application is as follows:
[0008] A dual-pore acid-washed HCP phase Ni-based nanometer catalyst, which is composed of a nanometer carbon carrier with a hierarchical pore structure and an active component of Ni in an HCP crystal phase distributed on the surface and inside the pores of the carrier; the active metal Ni loading amount is 10-20%.
[0009] Further, the average particle size of the active component Ni in the above-mentioned dual-pore acid-washed HCP phase Ni-based nanometer catalyst is 10-20 nm.
[0010] The second technical solution provided by the present application is a preparation method of the above-mentioned dual-pore acid-washed HCP phase Ni-based nanometer catalyst, which sequentially comprises the following steps:
[0011] S1: polyethyleneimine and polyvinylpyrrolidone are added to an ethanol aqueous solution to completely dissolve, then sodium bicarbonate and sodium chloride are added, and an HCl solution is added to adjust the pH of the system to 7, then nickel acetylacetonate is added, and HCl is continuously added to adjust the pH of the system to 5-6, so as to ensure that the nickel is completely dissolved, then the solution is dried to obtain a Ni nanometer catalyst precursor;
[0012] S2: the Ni nanometer catalyst precursor obtained in S1 is calcined at 300-500 DEG C for 10-20 min in an inert gas, and the carbonization product is subjected to acid washing with an HCl solution for 6-12 h, and then the dual-pore acid-washed HCP phase Ni-based nanometer catalyst is obtained by suction filtration and normal temperature drying;
[0013] The mass ratio of the polyethyleneimine, polyvinylpyrrolidone, sodium bicarbonate, and sodium chloride is (1-1.2):(2-2.5):(4-5):(5-4).
[0014] In the application, after the multi-level porous carbon carrier constructed by the NaHCO3 / NaCl double pore-forming agent and acid washing etching, the HCP phase metal Ni is dispersed on the surface and in the pores of the carrier, effectively protecting the metal active center, so that the catalyst reduces the reaction barrier and reduces the generation of by-products under mild conditions, realizes the catalytic upgrading of low-temperature high-water-content ethanol aqueous solution.
[0015] If only sodium bicarbonate is added, the lack of template support can easily cause the collapse of the pore, leading to the embedding of active metal, the reduction of active sites and the reduction of catalytic activity; if only sodium chloride is added, the catalyst is short of micropores, the active sites are less, and the acid washing cannot reach the dense area, which can easily lead to Na + residual poisoning, reduced catalytic activity and low carbon alcohol yield.
[0016] In the application, the addition amount of sodium bicarbonate and sodium chloride, the hydrochloric acid for adjusting the pH of the solution, and the carbonization temperature, carbonization time and acid washing time have an influence on the metal particle size, metal content and metal nickel crystal phase, and further have an important influence on the catalytic performance of the catalyst, thereby affecting the yield of C4+ alcohol, C6+ alcohol and C8+ alcohol.
[0017] Further, the preparation method of the above-mentioned double-pore acid-washing HCP phase Ni-based nanocatalyst comprises the following steps in sequence:
[0018] S1: polyethyleneimine and polyvinylpyrrolidone are added to an ethanol aqueous solution to completely dissolve, sodium bicarbonate and sodium chloride are added, hydrochloric acid is added to adjust the pH to 7, and nickel acetylacetonate is added in portions, the pH is adjusted to 5-6 with hydrochloric acid after each addition of nickel acetylacetonate to ensure complete dissolution of the metal, and then the solution is dried to obtain a Ni nanocatalyst precursor;
[0019] S2: the Ni nanocatalyst precursor obtained in S1 is calcined at 400 DEG C for 15 min in an inert gas, and the carbonization product is acid-washed at room temperature with 0.5 mol / L HCl, and after suction filtration and room temperature drying, the double-pore acid-washing HCP phase Ni-based nanocatalyst is obtained.
[0020] Further, in the above-mentioned preparation method of the double-pore acid-washing HCP phase Ni-based nanocatalyst, the concentration of the HCl solution is 0.5-1 mol / L.
[0021] In the application, if the concentration of the hydrochloric acid for adjusting the pH of the solution is too high, the polymer will be degraded and the chloride ion will be poisoned, and the strong acid etching of the carbon skeleton will lead to imbalance of the pore size; if the concentration is too low, the nickel acetylacetonate will not be completely dissolved, the nickel particles will be aggregated, the dispersion degree will be reduced, and the catalytic activity will be attenuated.
[0022] Further, the preparation method of the double-pore pickling HCP phase Ni-based nanometer catalyst, the inert atmosphere is one or more of nitrogen, helium and argon.
[0023] Further, the preparation method of the double-pore pickling HCP phase Ni-based nanometer catalyst, the pickling temperature is room temperature.
[0024] The application also provides a double-pore pickling HCP phase Ni-based nanometer catalyst for catalyzing the reaction of preparing middle carbon alcohol from high water content ethanol at low temperature.
[0025] A method for preparing middle carbon alcohol from ethanol at low temperature, the double-pore pickling HCP phase Ni-based nanometer catalyst is used as the catalyst, water and ethanol are used as the reaction substrates to prepare middle carbon alcohol in an alkaline environment.
[0026] Further, the method for preparing middle carbon alcohol from ethanol at low temperature, the double-pore pickling HCP phase Ni-based nanometer catalyst is used as the catalyst, water and ethanol are used as the reaction substrates to prepare middle carbon alcohol in an alkaline environment, the reaction is carried out at 50-100 DEG C, the initial pressure is 0 MPa, the reaction is carried out for 48-96 h, the reaction kettle is cooled to room temperature after the reaction is completed, and then centrifugation and filtration are carried out, and then the liquid and the solid are collected respectively, the liquid mainly contains C4+ alcohol, C6+ alcohol and C8+ alcohol.
[0027] The mass ratio of the water, the ethanol and the double-pore pickling HCP phase Ni-based nanometer catalyst is 2.4-3.2:2.4-3:0.6-1.
[0028] Compared with the prior art, the technical scheme provided by the application has the following technical advantages:
[0029] 1. The double-pore pickling catalyst provided by the application, NaHCO3 is decomposed by heat in the carbonization process, gas is released to form microporous-mesoporous structure; NaCl is removed by pickling to leave macroporous structure, and the macroporous structure forms a hierarchical pore network with the pores generated by the decomposition of NaHCO3; the particle size of the metal active component is 10-20 nm; the double-pore forming agent cooperatively forms a high specific surface area hierarchical pore structure to strengthen the reaction mass transfer.
[0030] 2. The technical scheme provided by the application, HCl pickling completely removes sodium residues, etches the surface of the carbon carrier and can effectively reduce the particle size of the metal active component, effectively protects the metal active center, avoids the poisoning of the active center by the alkaline site, reduces the reaction barrier and reduces the generation of by-products, and realizes the preparation of C4+ alcohol, C6+ alcohol and C8+ alcohol from ethanol and water below 100 DEG C. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1XRD pattern of the nanocatalyst prepared for the present application Example 7, Comparative Examples 13, 14 and 15.
[0032] Figure 2 XRD pattern of the nanocatalyst prepared for the present application Comparative Examples 6 and 9
[0033] Figure 3 XRD pattern of the nanocatalyst prepared for the present application Example 1, 5, Comparative Example 6, 16.
[0034] Figure 4 Transmission electron microscope pattern of the nanocatalyst prepared for the present application Example 1.
[0035] Figure 5 Transmission electron microscope pattern of the nanocatalyst prepared for the present application Example 1.
[0036] Figure 6 Scanning electron microscope pattern of the nanocatalyst prepared for the present application Example 1. DETAILED DESCRIPTION
[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.
[0038] In the following examples, the raw materials used are commercially available or self-made.
[0039] Example 1
[0040] The present embodiment provides a double-pore-forming pickling HCP phase Ni-based nanocatalyst, and a preparation method thereof, which comprises the following steps.
[0041] S1: 0.83 g of polyethyleneimine (molecular weight: 600) and 2.16 g of polyvinylpyrrolidone (molecular weight: 26000) are added to 200 ml of 50% mass fraction ethanol aqueous solution, heated to complete dissolution (about 1 minute) on a magnetic stirrer at 95℃, to obtain solution A, 5 g of sodium bicarbonate and 5 g of sodium chloride are added to solution A, and the system pH is adjusted to 7 with 0.5 mol / L HCl solution, after the sodium bicarbonate and sodium chloride are completely dissolved, 2.5 g of acetylacetone nickel is added in five times, 0.5 mol / L HCl solution is added dropwise to adjust the system pH to 5-6 after each addition of 0.5 g of acetylacetone nickel, and then the next acetylacetone nickel addition is performed, the acidic condition ensures the complete dissolution of acetylacetone nickel, and the finally obtained solution is dried at 80℃ for 12 hours to obtain a Ni nanocatalyst precursor;
[0042] S2: The Ni nanocatalyst precursor obtained in S1 was calcined at 400℃ for 15 min in a nitrogen atmosphere, and the calcined product was acid washed in 0.5 mol / L HCl at room temperature for 12 h. After suction filtration, the product was dried at room temperature to obtain a double-pore acid-washed Ni-based nanocatalyst in the HCP phase.
[0043] Example 2
[0044] The double-pore acid-washed Ni-based nanocatalyst in the HCP phase provided in this example differs from that of Example 1 in that the amount of the double-pore agent added in step S1 is replaced by 4 g of sodium bicarbonate and 4 g of NaCl.
[0045] Example 3
[0046] The double-pore acid-washed Ni-based nanocatalyst in the HCP phase provided in this example differs from that of Example 1 in that the amount of the double-pore agent added in step S1 is replaced by 5 g of sodium bicarbonate and 4 g of NaCl.
[0047] Example 4
[0048] The double-pore acid-washed Ni-based nanocatalyst in the HCP phase provided in this example differs from that of Example 1 in that the concentration of HCl in step S1 is replaced by 1 mol / L.
[0049] Example 5
[0050] The double-pore acid-washed Ni-based nanocatalyst in the HCP phase provided in this example differs from that of Example 1 in that the acid washing time in step S2 is replaced by 6 h.
[0051] Example 6
[0052] The double-pore acid-washed Ni-based nanocatalyst in the FCC / HCP phase provided in this example differs from that of Example 4 in that the acid washing time in step S2 is replaced by 6 h.
[0053] Example 7
[0054] The double-pore acid-washed Ni-based nanocatalyst in the HCP phase provided in this example differs from that of Example 4 in that the acid washing time in step S2 is replaced by 9 h.
[0055] Comparative Example 1
[0056] The double-pore acid-washed Ni-based nanocatalyst provided in this comparative example differs from that of Example 1 in that the amount of the double-pore agent added in step S1 is replaced by 3 g of sodium bicarbonate and 3 g of NaCl.
[0057] Comparative Example 2
[0058] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 6 g of sodium bicarbonate and 6 g of NaCl.
[0059] Comparative Example 3
[0060] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0061] Comparative Example 4
[0062] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0063] Comparative Example 5
[0064] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0065] Comparative Example 6
[0066] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0067] Comparative Example 7
[0068] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0069] Comparative Example 8
[0070] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0071] Comparative Example 9
[0072] The dual-pore pickling HCP phase Ni-based nanocatalyst provided by the present comparative example has a preparation method different from that of Example 1 in that the amount of the dual-pore agent in step S1 is replaced by 5 g of sodium bicarbonate and 3 g of NaCl.
[0073] Comparative Example 10
[0074] The comparative example provides a single-pore-forming pickling HCP phase Ni-based nanometer catalyst, and the difference between the preparation method thereof and that of Example 6 is that the double pore-forming agent in step S1 is replaced by only adding 5 g of NaHCO3.
[0075] Comparative Example 11
[0076] The comparative example provides a single-pore-forming pickling HCP phase Ni-based nanometer catalyst, and the difference between the preparation method thereof and that of Example 6 is that the double pore-forming agent in step S1 is replaced by only adding 5 g of NaHCO3.
[0077] Comparative Example 12
[0078] The comparative example provides a single-pore-forming pickling HCP phase Ni-based nanometer catalyst, and the difference between the preparation method thereof and that of Example 6 is that the double pore-forming agent in step S1 is replaced by only adding 5 g of NaHCO3.
[0079] Comparative Example 13
[0080] The comparative example provides a single-pore-forming pickling HCP phase Ni-based nanometer catalyst, and the difference between the preparation method thereof and that of Example 7 is that the double pore-forming agent in step S1 is replaced by only adding 5 g of NaHCO3.
[0081] Comparative Example 14
[0082] The comparative example provides a single-pore-forming pickling HCP phase Ni-based nanometer catalyst, and the difference between the preparation method thereof and that of Example 7 is that the double pore-forming agent in step S1 is replaced by only adding 5 g of NaHCO3.
[0083] Comparative Example 15
[0084] The comparative example provides a single-pore-forming pickling HCP phase Ni-based nanometer catalyst, and the difference between the preparation method thereof and that of Example 7 is that the double pore-forming agent in step S1 is replaced by only adding 5 g of NaHCO3.
[0085] Comparative Example 16
[0086] The comparative example provides a double-pore-forming catalyst, and the difference between the preparation method thereof and that of Example 1 is that step S2 is not performed. The specific parameters for preparing the catalysts in Examples 1-7 and Comparative Examples 1-16 are shown in Table 1.
[0087] Table 1
[0088]
[0089]
[0090] The structures of the catalysts prepared in Examples 1-7 and Comparative Examples 1-16 are as follows:
[0091] (1) XRD
[0092] Figure 1 XRD patterns of the nanocatalysts prepared in Example 7, Comparative Examples 13, 14 and 15 of the present application were obtained. By analyzing the patterns, it was found that different pore-forming agents had a significant influence on the grain size of the nickel element: when a single pore-forming agent (such as NaHC03, KHCO3 or K2CO3) was used, the nickel particles were coarsened due to the disorder of the gas release process, the residual template agent and the difficulty in completely removing the potassium impurities, resulting in a grain size of the nickel particles greater than 20 nm; when NaHC03 and NaCl were used as the double pore-forming agents for pore-forming, the NaCl template could construct a through-hole macroporous structure, effectively ensuring the depth and uniformity of the pickling process, thereby completely removing the residual sodium ions and promoting the real dispersion of the nickel particles, and finally the particle size of the nickel particles could be controlled at about 10 nm, which significantly reduced the metal particle size and was beneficial to improving the accessibility of the catalytic active sites.
[0093] Figure 2 XRD patterns of the nanocatalysts prepared in Comparative Examples 6 and 9 of the present application were obtained. The patterns showed that different concentrations of hydrochloric acid had a key influence on the phase transition of the nickel metal: when the concentration of hydrochloric acid was 0.5 mol / L, the nickel metal showed a single HCP phase; when the concentration of hydrochloric acid was increased to 1 mol / L, the nickel metal was converted into a mixed FCC / HCP phase. The mechanism was that in 0.5 mol / L hydrochloric acid, hydrogen atoms could uniformly penetrate the nickel lattice, causing lattice expansion and completing the stable phase transition from FCC to HCP; in 1 mol / L high-concentration hydrochloric acid, excessive H + would dissolve the protective oxide film on the surface of the nickel, leading to a dominant corrosion reaction, and part of the FCC phase could not be completely converted and remained, while excessive hydrogen atoms were precipitated to form bubbles, which destroyed the integrity of the lattice, and finally formed a mixed phase structure.
[0094] Figure 3 XRD patterns of the nanocatalysts prepared in Example 1 and 5, Comparative Examples 6 and 16 of the present application were obtained. By comparing the patterns of the catalysts before and after acid washing, it was found that the double-pore-forming catalyst without acid washing had a large number of impurity peaks, the HCP phase characteristic peak of the nickel metal was not clearly shown, and the actual loading amount of the nickel metal was low due to the impurities introduced by the pore-forming agent; after acid washing, the HCP phase characteristic peak of the nickel metal was significantly exposed, indicating that the acid washing process effectively removed the impurities and promoted the exposure of the active sites. Further analysis of the influence of the acid washing time on the catalysts found that as the acid washing time was prolonged, the loading amount of the nickel metal decreased slightly, but the anchoring effect of the mesoporous structure on the impurities was significantly enhanced, which was more conducive to improving the catalytic performance.
[0095] (2) Catalyst morphology
[0096] Figure 4 、 Figure 5 The transmission electron microscopy (TEM) image of the nanocatalyst prepared in Example 1 of the present application was obtained. As shown in the image,Figure 4 It can be seen that the metal nanoparticles in the catalyst have a particle size of about 15 nm and are uniformly distributed on the surface of the carbon carrier. Figure 5 Further, the clear spherical nickel particles are closely intertwined with the light-colored carbon skeleton structure, confirming that the acid washing process effectively removes sodium salt residues, and the nickel metal is not completely wrapped by the layered nanocarbon but is fully exposed on the surface of the carrier. This structural design significantly increases the contact area of the nickel active sites with the reactants, which is beneficial to improving the catalytic activity.
[0097] Figure 6 A scanning electron microscope image of the nanocatalyst prepared in Example 1 is shown in the figure. It can be seen that the pore structure formed by the synergistic effect of the two pore-forming agents is mainly mesoporous and macroporous, and the etching effect of the acid washing process on the surface of the catalyst effectively controls the pore structure and surface morphology of the catalyst. The above structural characteristics provide more optimal mass transfer channels and adsorption sites for ethanol molecules, thereby promoting the efficient conversion of ethanol.
[0098] Example 8
[0099] The present example provides a method for preparing carbon alcohol at low temperature by coupling high water content ethanol, which comprises adding 0.8 g of the dual-pore-forming acid-washed HCP phase Ni-based nanocatalyst prepared in Example 1, 3 g of water, 3 g of ethanol, and 0.52 g of sodium hydroxide into a 25 ml steel magnetic stirring reaction kettle, and carrying out the reaction at a reaction temperature of 100°C and an initial pressure of 0 MPa for 72 h. After the reaction, the reaction kettle is cooled to room temperature, and then centrifugation and filtration are performed to obtain liquid and catalyst solid phases. The solid and liquid phase products are collected, and the liquid phase product is detected and analyzed by gas chromatography. It is found that the main product of the liquid phase product is C4+ alcohol, C6+ alcohol, and a small amount of C8+ alcohol. The results are shown in Table 2 below.
[0100] Example 9
[0101] The present example provides a method for preparing carbon alcohol at low temperature by coupling high water content ethanol, which has the same preparation process and parameters as Example 8, except that the catalyst provided in Example 2 is used. The experimental results are shown in Table 2 below.
[0102] Example 10
[0103] The present example provides a method for preparing carbon alcohol at low temperature by coupling high water content ethanol, which has the same preparation process and parameters as Example 8, except that the catalyst provided in Example 3 is used. The experimental results are shown in Table 2 below.
[0104] Example 11
[0105] The present example provides a method for preparing carbon alcohol at low temperature by coupling high water content ethanol, which has the same preparation process and parameters as Example 8, except that the catalyst provided in Example 4 is used. The experimental results are shown in Table 2 below.
[0106] Example 12
[0107] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Example 5 is used. The experimental results are shown in Table 2 below.
[0108] Example 13
[0109] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Example 6 is used. The experimental results are shown in Table 2 below.
[0110] Example 14
[0111] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Example 7 is used. The experimental results are shown in Table 2 below.
[0112] Comparative Example 16
[0113] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Comparative Example 1 is used. The experimental results are shown in Table 2 below.
[0114] Comparative Example 17
[0115] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Comparative Example 2 is used. The experimental results are shown in Table 2 below.
[0116] Comparative Example 18
[0117] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Comparative Example 3 is used. The experimental results are shown in Table 2 below.
[0118] Comparative Example 19
[0119] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as those of Example 8, except that the catalyst provided in Comparative Example 4 is used. The experimental results are shown in Table 2 below.
[0120] Comparative Example 20
[0121] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 5 is used, and the experimental results are shown in Table 2 below.
[0122] Comparative Example 21
[0123] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 6 is used, and the experimental results are shown in Table 2 below.
[0124] Comparative Example 22
[0125] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 7 is used, and the experimental results are shown in Table 2 below.
[0126] Comparative Example 23
[0127] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 8 is used, and the experimental results are shown in Table 2 below.
[0128] Comparative Example 24
[0129] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 9 is used, and the experimental results are shown in Table 2 below.
[0130] Comparative Example 25
[0131] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 10 is used, and the experimental results are shown in Table 2 below.
[0132] Comparative Example 26
[0133] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 11 is used, and the experimental results are shown in Table 2 below.
[0134] Comparative Example 27
[0135] The present example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, the preparation process and parameters thereof are the same as those of Example 8, the difference lies in that the catalyst provided in Comparative Example 12 is used, and the experimental results are shown in Table 2 below.
[0136] Comparative Example 28
[0137] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as Example 8, except that the catalyst provided in Comparative Example 13 is used. The experimental results are shown in Table 2 below.
[0138] Comparative Example 29
[0139] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as Example 8, except that the catalyst provided in Comparative Example 14 is used. The experimental results are shown in Table 2 below.
[0140] Comparative Example 30
[0141] This example provides a method for preparing carbon alcohol by low-temperature coupling of high water content ethanol, which has the same preparation process and parameters as Example 8, except that the catalyst provided in Comparative Example 15 is used. The experimental results are shown in Table 2 below.
[0142] Table 2 Catalytic activity results of products prepared in Examples 8-14 and Comparative Examples 16-30
[0143]
[0144] As can be seen from the experimental data in Table 2, the catalyst in the present application has a significant effect on the conversion rate of ethanol, the selectivity of C4+, C6+, and C8+. The comparison results of Example 6 and Comparative Examples 10, 11, and 12 show that, under the premise that other conditions remain unchanged, the synergistic pore-forming effect of the dual pore-forming agent is significantly better than that of the single pore-forming agent. Specifically, the gas generated by the decomposition of NaHCO3 can form irregular mesoporous structures, and NaCl acts as a hard template to occupy space. After acid washing to remove the NaCl template, the original occupied pores are completely exposed, and the residual sodium salt impurities in the pore-forming process are effectively removed, avoiding the poisoning of the active sites by basic sites, which ultimately greatly improves the ethanol conversion rate compared to the single pore-forming agent system.
[0145] The comparison of Example 1 with Examples 2, 3, and Comparative Examples 1 and 2 shows that, under the premise that other conditions remain unchanged, the addition ratio of the dual pore-forming agent has a key influence on the catalytic performance. When the addition amount of the dual pore-forming agent is too low, the amount of gas released is insufficient and the support effect of the template is weakened, resulting in incomplete mesoporous structures. When the addition amount is too high, the excess pore-forming agent will form weak areas inside the carbon skeleton, which can easily cause the collapse of the pore wall after acid washing, and the residual sodium will poison the active sites, ultimately leading to a decrease in the ethanol conversion rate.
[0146] The comparison between Example 1 and Example 4 further verifies the importance of the concentration of hydrochloric acid for adjusting the pH of the solution. When the concentration of hydrochloric acid for adjusting the pH of the solution is too high, although H + The nickel lattice can be etched more efficiently to reduce the particle size, but excessive H + will destroy the pore structure of the carbon carrier, resulting in some active sites being covered by the carbon skeleton, thereby reducing the catalytic efficiency.
[0147] The comparison between Example 1 and Comparative Examples 4 and 5 shows that the selection of the washing solvent has a non-negligible influence on the performance of the catalyst. Although the dual-pore catalyst washed with ultrapure water and ethanol has a similar particle size to the nickel particles washed with hydrochloric acid, ultrapure water and ethanol cannot effectively remove residual sodium ions, resulting in continuous poisoning of the active center by sodium residues; acid washing can completely remove sodium impurities, significantly improving the catalytic activity and C8+ alcohol selectivity.
[0148] The comparison between Example 1 and Example 5, Comparative Examples 6 and 7 reveals the regulation of acid washing time on the catalytic performance. When the acid washing time is too short, the sodium salt of the pore-forming agent cannot be completely removed, resulting in partial poisoning of the active sites; when the acid washing time is too long, the carbon skeleton will be excessively eroded by the acid solution, causing the collapse of the pores and the generation of a large amount of residual chloride ions, which not only reduces the specific surface area of the catalyst, but also causes secondary poisoning of the active sites due to the adsorption of chloride ions, ultimately leading to a decrease in the selectivity of carbon alcohol.
[0149] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or modifications can be made by those of ordinary skill in the art. Here, it is not necessary or possible to exhaust all embodiments. Any modification, equivalent replacement and improvement made within the spirit and principles of the present application shall be included in the protection scope of the claims of the present application.
Claims
1. A dual-pore hole acid-washed HCP phase Ni-based nanocatalyst, characterized in that, The active component is Ni with HCP crystal phase, and the nano-carbon with multi-level pore structure is used as the carrier and the active component is distributed on the surface and inside the pores of the carrier.
2. The double-pore pickling HCP phase Ni-based nanometer catalyst according to claim 1, wherein the average particle size of the active component Ni is 10-20 nm.
3. The method of making a dual pore-acid washed HCP phase Ni-based nanocatalyst of claim 1, characterized by, The preparation method comprises the following steps in sequence: S1: polyethyleneimine and polyvinylpyrrolidone are added into an aqueous ethanol solution to be completely dissolved, then sodium bicarbonate and sodium chloride are added, and an HCl solution is added to adjust the pH of the system to 7, then nickel acetylacetonate is added, and HCl is continuously added to adjust the pH of the system to 5-6, so as to ensure that the nickel is completely dissolved, and then the solution is dried to obtain a Ni nanometer catalyst precursor; S2: the Ni nanometer catalyst precursor obtained in S1 is calcined at 300-500°C for 10-20 min in an inert gas, and the carbonization product is pickled with an HCl solution for 6-12 h, and then the double-pore pickling HCP phase Ni-based nanometer catalyst is obtained through suction filtration and drying at room temperature; The mass ratio of the polyethyleneimine, polyvinylpyrrolidone, sodium bicarbonate and sodium chloride is (1-1.2):(2-2.5):(4-5):(5-4).
4. The method of claim 3, wherein the method is characterized by: The concentration of the HCl solution is 0.5-1 mol / L.
5. The method of claim 3, wherein the method is characterized by: The inert atmosphere is one or more of nitrogen, helium and argon.
6. The method of claim 3, wherein the method is characterized by: The pickling temperature is room temperature.
7. The dual pore creating acid washed HCP phase Ni-based nanocatalyst of claim 1, wherein, The double-pore pickling HCP phase Ni-based nanometer catalyst is prepared by the preparation method.
8. The double-pore pickling HCP phase Ni-based nanometer catalyst according to claim 1 is used for catalyzing the reaction of preparing carbon alcohol from high water content ethanol at low temperature.
9. A process for the low temperature coupling of ethanol to produce carbinols, characterized by, The double-pore pickling HCP phase Ni-based nanometer catalyst according to claim 1 is used as a catalyst to prepare carbon alcohol by using water and ethanol as reaction substrates in an alkaline environment.
10. The process for the low-temperature coupling preparation of carbonols from ethanol according to claim 9, characterized in that, The double-pore pickling HCP phase Ni-based nanometer catalyst according to claim 1 is used as a catalyst to prepare carbon alcohol by using water and ethanol as reaction substrates in an alkaline environment, The reaction is carried out at 50-100°C and an initial pressure of 0 MPa for 48-96 h, and after the reaction is completed, the reaction kettle is cooled to room temperature, and then centrifugation and filtration are carried out, and then the liquid and the solid are collected, and the liquid mainly contains C4+ alcohol, C6+ alcohol and C8+ alcohol; The mass ratio of the water, ethanol and double-pore pickling HCP phase Ni-based nanometer catalyst is 2.4-3.2:2.4-3:0.6-1.