Catalyst applied to liquid-phase hydrogenation of octenal and preparation method of catalyst

Abstract

The invention relates to the field of catalysts, in particular to a catalyst applied to liquid-phase hydrogenation of octenal and a preparation method of the catalyst. The invention relates to a catalyst for liquid-phase hydrogenation of octenal, which is in copper-nickel continuous gradient distribution in the radial direction and simultaneously meets the following requirements: (i) a 0-30nm outer layer is an inlaid self-reduction active shell; (ii) the molar ratio of Cu to Ni in a 30-80nm gradient transition region is continuously reduced from 10: 1 to 1: 2; (iii) a self-repairing region with a core of 80-200 nm being Ni-NiO coupled oxygen vacancies; (iv) a conformal coverage thickness lt of the entire particle surface; the invention relates to a phenylsilane hydrophobic monomolecular network with the diameter of 2nm. The catalyst provided by the invention can convert the octane by-product 1t; the copper loss is 1t; 0.1 ppm, and the activity of gt is maintained for 1000 hours; the synergistic beneficial effects of being free of pre-reduction, long in service life, high in selectivity and resistant to inactivation are achieved.

Description

Technical Field

[0001] This application relates to the field of catalyst technology, and in particular to a catalyst for the liquid-phase hydrogenation of octenal and a method for its preparation. Background Technology

[0002] Octenal liquid-phase hydrogenation is a core unit in the production of the plasticizer alcohol 2-ethylhexanol. Currently, Cu / Zn / Al oxide catalysts are commonly used for octenal liquid-phase hydrogenation, and various additives are often added to improve performance.

[0003] However, it has the following common problems: it requires high-temperature (200-250℃) pure hydrogen pre-reduction before starting, which consumes a lot of energy and poses a risk of combustion and explosion; the water content in the reaction system is as high as 5-10wt%, which leads to the dissolution of the active copper phase and deactivation by sintering; copper grains grow very easily under liquid phase conditions of 100-200℃, and the activity decreases by more than 20% after 1000h; the selectivity of by-products octane and octene is more than 3%, which reduces the yield per unit.

[0004] Existing literature has attempted to introduce additives such as Ni, Co, and Mn, but these all follow the "homogeneous co-precipitation" approach and cannot resolve the "activity-selectivity-lifetime" triangle contradiction. Therefore, developing a long-lifetime, highly selective octenal hydrogenation catalyst has become a pain point in the industry. Summary of the Invention

[0005] To improve catalyst selectivity and extend catalyst lifetime, this application provides a catalyst for the liquid-phase hydrogenation of octenal and its preparation method.

[0006] In the first aspect, this application provides a catalyst for the liquid-phase hydrogenation of octenal, employing the following technical solution.

[0007] A catalyst for the liquid-phase hydrogenation of octenal, wherein the catalyst exhibits a continuous copper-nickel gradient distribution in the radial direction and simultaneously satisfies:

[0008] (i) 0-30nm outer layer is mosaic The self-reducing active shell;

[0009] (ii) The Cu:Ni molar ratio in the 30-80nm gradient transition region continuously decreases from 10:1 to 1:2;

[0010] (iii) The 80-200nm core is Ni-NiO coupled. Self-repair zone of oxygen vacancies;

[0011] (iv) The entire particle surface is conformally covered with a phenylsilane hydrophobic monomolecular network with a thickness of <2 nm.

[0012] By adopting the above technical solution, the catalyst of this application achieves a synergistic improvement in catalytic activity, selectivity, and stability through a radial copper-nickel continuous gradient distribution and precise design of multilayer functional regions. Its beneficial effects can be comprehensively reflected in three aspects: reaction efficiency, product regulation, and long-term service life. The outer 0-30nm layer... mosaic Self-reducing active shells allow for the rapid construction of highly active Cu-based active sites without additional pretreatment, and The oxygen vacancies enhance the adsorption and activation of the aldehyde group in octenal, significantly increasing the hydrogenation reaction rate. The continuous gradual change in the Cu:Ni molar ratio (10:1 to 1:2) in the 30-80 nm gradient transition region allows for precise control of the reaction pathway through the synergistic effect of the copper and nickel active components. This retains the high selectivity of copper-based catalysts for aldehyde hydrogenation (inhibiting excessive hydrogenation of olefin double bonds) while optimizing reaction kinetics with the auxiliary activity of nickel, balancing activity and selectivity. The Ni-NiO coupling in the 80-200 nm core... Oxygen vacancy self-repair zone, can be through The oxygen vacancy migration and Ni-NiO redox cycle replenish the active sites and oxygen species that may be lost from the outer active shell during the reaction, significantly extending the catalyst's lifespan. Meanwhile, the <2nm phenylsilane hydrophobic monolayer network on the entire particle surface effectively isolates water and polar impurities in the liquid-phase reaction system, preventing active components from being deactivated by hydration or poisoned by impurities. It also reduces catalyst particle aggregation, further ensuring the stability and repeatability of catalytic performance. In summary, through the complementary functions of its multilayer structure, this catalyst simultaneously achieves high hydrogenation activity, high target product selectivity, and long-term catalytic stability in the liquid-phase hydrogenation reaction of octenal. It maintains octane byproducts <0.5%, copper loss <0.1 ppm, and activity retention >97% after 1000 h, achieving a synergistic effect of no pre-reduction, long lifespan, high selectivity, and resistance to deactivation.

[0013] Furthermore, the aforementioned and The oxygen vacancy concentration is ≥8%, and the oxygen vacancy concentration is determined by the peak area ratio of XPSOα / (Oα+Oβ).

[0014] By adopting the above technical solution, firstly, the hyperoxia vacancy concentration of ≥8% was significantly increased. The adsorption and activation capacity of the active shell for octenal molecules—Oxygen vacancies, as electron-rich sites, can efficiently capture oxygen atoms in the aldehyde group, lowering the activation energy barrier for hydrogenation of the C=O bond, and simultaneously promoting… exist Dissociation and spillover at active sites significantly increase the hydrogenation reaction rate of catalysts with low oxygen vacancy concentrations; secondly, high oxygen vacancy concentrations allow for precise control of reaction selectivity. The abundant oxygen vacancies in the core can inhibit the excessive adsorption of the C=C double bond in octenal by Ni sites through electronic interactions with Ni-NiO, thus avoiding the formation of byproducts (such as octane). The high oxygen vacancies in the active shell can stabilize The valence state of the active site ensures preferential catalysis of aldehyde hydrogenation, further enhancing the selectivity of the target product (octanol); finally, a high oxygen vacancy concentration endows the catalyst with superior self-healing ability—in long-term liquid-phase reactions, slight oxidation or carbon deposition at the active site can lead to temporary consumption of oxygen vacancies, while an initial high oxygen vacancy concentration of ≥8% can mitigate this. , The redox cycle rapidly replenishes lost oxygen vacancies and promotes the dynamic reconstruction of Ni-NiO, effectively inhibiting the sintering and deactivation of active components, and significantly extending the number of catalyst cycles and service life.

[0015] Actual measurements show that when the vacancy concentration increases from 3.2% to 9.1%, the conversion rate over 1000 h increases from 90.1% to 97.8%, the byproduct octane decreases from 1.8% to 0.35%, and copper loss decreases by another order of magnitude.

[0016] Furthermore, its chemical composition by mass percentage includes: CuO 25-35%, NiO 8-15%. -3%, -3%, ZnO5-10% 10-20%, margin.

[0017] By adopting the above technical solution, the overall chemical composition is locked at CuO 25-35%, NiO 8-15%. -3% -3%, ZnO 5-10%, 10-20% Within the narrow window of the margin, on the one hand, it ensures that the total Cu-Ni amount is sufficient to form a continuous gradient of 30-80 nm, avoiding insufficient surface active sites due to excessively low Cu or deep hydrogenation due to excessively high Ni; on the other hand, trace amounts of Ce-Zr can provide ≥8% oxygen vacancies, and ZnO and Cooperatively stabilize gradient skeleton and promote dispersion, The remaining portion serves as a carrier for oriented nanotubes, providing high specific surface area and pore orientation. Endpoint measurements show that the conversion rates after 1000 h are still 97.2% and 98.0% for the lower limit of 25% CuO-8% NiO and the upper limit of 35% CuO-15% NiO, respectively, with octanol selectivity ≥98.2%. Byproducts and copper loss are both below the thresholds in the claims, demonstrating that this composition range covers the tolerance for process fluctuations.

[0018] Furthermore, the hydrophobic monomolecular network is one or more combinations of phenyltrimethoxysilane, trifluoropropyltriethoxysilane, or octyltriethoxysilane.

[0019] By employing the above technical solution, the hydrophobic monolayer is confined to phenyltrimethoxysilane, trifluoropropyltriethoxysilane, or octyltriethoxysilane and combinations thereof. On the one hand, the Si-O-Si covalent network generated after silane hydrolysis can form a dense hydrophobic film of <2 nm on the 0-30 nm active shell surface, instantly increasing the contact angle to 108-115°. This significantly reduces the adsorption coverage of water molecules on the catalyst surface, blocking the flow of water into the liquid phase. The hydrolysis-dissolution pathway is observed; on the other hand, the organic side chains of the three silanes (phenyl, trifluoropropyl, and octyl) have different polarities and steric hindrances, which can selectively repel polar additives or plasticizers that may be present in the charging pile cable during operation, further reducing the interfacial dielectric constant and reducing energy loss during hydrogen overflow. Actual measurements show that each of the three silanes, used individually, can control copper loss to 0.07-0.08 ppm, and when used in combination, the contact angle can reach 112°, with a performance difference of <0.2%. This demonstrates that this combination range provides both process formulation flexibility and ensures bottom-line performance against water, by-products, and deactivation.

[0020] Furthermore, the catalyst support is vertically oriented. Nanotube arrays with a cavity diameter of 10-50 nm and a length of 100-300 nm.

[0021] By adopting the above technical solution, a vertical orientation with a lumen size of 10-50 nm and a length of 100-300 nm is achieved. Nanotube arrays serve as a carrier, utilizing their radially through-holes as... , Pulsed electrodeposition provides electric field guidance, enabling the metal precursor to be deposited directionally along the tube wall, naturally forming a continuous gradient of 30-80 nm. On the other hand, the vertical walls and open ports of the nanotubes significantly increase the specific surface area and active site exposure, while reducing diffusion resistance caused by tortuous channels. This makes it easier for octenal molecules to reach the outer active shell, shortening the hydrogen overflow path to <100 nm and increasing the reaction rate. Furthermore, It is inert and has abundant surface hydroxyl groups, which can interact with Forming Si-O-Zr bonds to anchor the nucleus Oxygen vacancies prevent Zr loss in high-temperature aqueous phases; experimental results show that, under the same elemental composition, the copper loss of oriented nanotube carriers is lower than that of disordered mesopores. A further 20% reduction would increase the conversion rate by 2.3 percentage points over 1000 hours.

[0022] Furthermore, the Cu:Ni gradient exhibits a linear or exponential continuous change within the 30-80 nm range, and the gradient slope is... .

[0023] By adopting the above technical solution, the Cu:Ni molar ratio in the 30-80 nm transition region is limited to a linear or exponential continuous change with a slope. On the one hand, it utilizes the chemical potential difference generated by the concentration gradient at the nanoscale to drive During thermal diffusion, a seamless interface is formed, avoiding the uneven distribution of active sites caused by the "metal cluster jump" that occurs in traditional co-precipitation; on the other hand... The slope ensures that the Cu:Ni ratio smoothly decreases from 10:1 to 1:2 within a thickness of about 50 nm, with an average decrease of 0.18 molar ratio units per nanometer. This slope is steep enough to block the diffusion of the outer high Cu region to the core, thereby suppressing the formation of deep hydrogenation byproducts (octane, octene).

[0024] Secondly, a method for preparing a catalyst is provided, employing the following technical solution.

[0025] A method for preparing a catalyst includes the following steps:

[0026] S1. Pulse electrodeposition of Cu-Ce precursor;

[0027] S2. Vacuum impregnation with Ni salt followed by thermal diffusion forms a Cu-Ni gradient;

[0028] S3. Introduce separately and ;

[0029] S4. Vapor-phase silanization growth of hydrophobic monolayers.

[0030] By adopting the above technical solution, a four-step method of "pulse electrodeposition - vacuum thermal diffusion - zoned additives - vapor-phase silanization" is used to prepare the catalyst. First, Cu-Ce is directionally deposited on the inner wall of a 10-50 nm tube using a pulsed electric field. A concentration pre-distribution is formed radially; followed by vacuum impregnation. And in Thermal diffusion at 450 ℃ is driven by concentration gradient and temperature field, enabling... outward, Inward interdiffusion, Cu:Ni molar ratio in the 30-80 nm range The slope decreases continuously, avoiding the abrupt interface of traditional co-precipitation. Ce is sprayed onto the outer layer, and Zr is vacuum-sealed in the core, ensuring... Enriched on the surface, Anchored to the core, oxygen vacancy channels are formed throughout the particles; finally, vapor-phase silanization grows a phenylsilane monolayer at a scale of <2 nm, requiring no solvent and without clogging the pores, achieving conformal hydrophobicity in one step. This route does not require high-temperature pure hydrogen pre-reduction and can spontaneously complete the CuO→… reaction at a reaction temperature of 120-160 °C. After activation, the conversion rate remained >97% for 1000 h, with octane byproducts <0.5% and copper loss <0.1 ppm.

[0031] Thirdly, this application provides the use of a catalyst in the liquid-phase hydrogenation of octenal, using the following technical solution.

[0032] The application of a catalyst in the liquid-phase hydrogenation of octenal, wherein the reaction is carried out in a fixed bed, slurry bed, or trickle bed at a temperature of 120-160℃, a hydrogen pressure of 2-4 MPa, and a liquid hourly space velocity of 0.5- Furthermore, no hydrogen pre-reduction is required during the start-up phase.

[0033] By employing the above technical solution, the catalyst is used for the liquid-phase hydrogenation of octenal in a fixed bed, slurry bed, or trickle bed at 120-160℃, 2-4 MPa, and a liquid hourly space velocity of 0.5- Under these operating conditions, no pure hydrogen pre-reduction is required at startup; direct feeding allows for spontaneous completion of CuO→ in less than 30 minutes. After activation, the conversion rate remains >97% for 1000 hours, the octanol selectivity is >98%, the byproduct octane is <0.5%, and the copper loss is <0.1ppm. The pre-reduction process eliminates the need for a high-temperature hydrogen section, saving hydrogen costs and eliminating the risk of combustion and explosion during furnace start-up.

[0034] In summary, this application has the following beneficial effects:

[0035] The catalyst in this application is obtained through the "outer layer" - Self-reducing shell, 30-80 nm Cu:Ni continuous gradient, 80-200 nm Ni-NiO- The self-healing core is coupled in four regions, forming a continuous "activity-buffering-stabilization" channel from the surface to the interior: the outer layer rapidly dissociates hydrogen and initiates hydrogenation at a high Cu / Ni ratio; the gradient region smoothly transitions and suppresses excessive hydrogenation byproducts; and the core utilizes the Ni-NiO interface and... Oxygen vacancies continuously capture migrating copper and prevent grain sintering; further supplemented by a <2nm phenylsilane hydrophobic network to block water... It dissolves and reduces the thickness of the interfacial water film, resulting in octane byproducts of <0.5%, copper loss of <0.1 ppm, and activity retention of >97% after 1000 h, achieving synergistic benefits of no pre-reduction, long lifespan, high selectivity, and resistance to deactivation. Detailed Implementation

[0036] The present application will be further described in detail below with reference to the embodiments.

[0037] Example of raw material and intermediate preparation

[0038] raw material

[0039] It should be noted that: unless otherwise specified, the following examples shall be carried out under conventional conditions or conditions recommended by the manufacturer, and the raw materials used in the following examples shall be commercially available unless otherwise specified.

[0040] Example

[0041] Example 1

[0042] A catalyst for the liquid-phase hydrogenation of octenal, the preparation method of which is as follows:

[0043] S1. Carrier

[0044] Vertical orientation Nanotubes (20 nm lumen, 200 nm length) were mixed with boehmite in a ratio of 70:30, rolled into 100 µm microspheres, and calcined at 550 °C for 4 h to obtain a composite carrier.

[0045] S2. Pulse electrodeposition

[0046] electrolyte Cu / Ce = 10:1, current density Duty cycle 1:4, 20 min; vacuum drying at 80℃ for 2 h;

[0047] S3. Thermal diffusion

[0048] Vacuum impregnation After drying at 120℃ 450℃ for 2 hours; EPMA linear scanning showed that the Cu:Ni ratio in the 30-80nm region linearly decreased from 10:1 to 1:2, with a gradient slope of ;

[0049] S4. Dual-Auxiliary Agent

[0050] outer spray ; kernel vacuum XPSOα / (Oα+Oβ)=9.1%, oxygen vacancy concentration 9.1%;

[0051] S5. Drainage mesh

[0052] Phenylacetyltrimethoxysilane vapor at 80℃ for 3 hours had a contact angle of 110° and a thickness of 1.6 nm.

[0053] The final catalyst Cat-1 composition is: CuO 30.2%, NiO 11.8%. , ZnO 7.9%, 14.5%, Balance; PMA surface distribution shows that the enrichment coefficients of Ni and Zr signals in the 80-200nm region are 0.90 and 0.95, respectively, and the calculated Ni:Zr molar ratio is 8.8:1.

[0054] Example 2

[0055] A catalyst for the liquid-phase hydrogenation of octenal, the preparation method of which is as follows:

[0056] S1. Carrier

[0057] Same as Example 1;

[0058] S2. Pulse electrodeposition

[0059] electrolyte (Total metal concentration reduced to 0.0504 M), current density Duty cycle 1:4, 20 min; vacuum drying at 80℃ for 2 h;

[0060] S3. Thermal diffusion

[0061] Vacuum impregnation , EPMA measurements showed that the Cu:Ni ratio linearly decreased from 10:1 to 1:2 in the 30-80 nm region, with a gradient slope of... ;

[0062] S4. Dual-Auxiliary Agent

[0063] outer spray 400℃ for 2 hours; core vacuum 350℃ for 2 hours; XPSOα / (Oα+Oβ) = 8.2%, oxygen vacancies 8.2%;

[0064] S5. Drainage mesh

[0065] Phenylacetyltrimethoxysilane vapor at 80℃ for 3 hours had a contact angle of 109° and a thickness of 1.5 nm.

[0066] The final catalyst Cat-2 composition (ICP): CuO 25.0%, NiO 8.0%, 0.0%, 0.0%, ZnO 5.0%, 20.0%, Balance; PMA surface distribution shows that the enrichment coefficients of Ni and Zr signals in the 80-200nm region are 0.90 and 0.95, respectively, and the calculated Ni:Zr molar ratio in the core is 7.9:1.

[0067] Example 3

[0068] A catalyst for the liquid-phase hydrogenation of octenal, the preparation method of which is as follows:

[0069] S1. Carrier

[0070] Same as Example 1;

[0071] S2. Pulse electrodeposition

[0072] electrolyte (Total metal concentration 0.0696 M), current density Duty cycle 1:4, 20 min; vacuum drying at 80℃ for 2 h;

[0073] S3. Thermal diffusion

[0074] Vacuum impregnation 450℃ for 2 hours; EPMA measurements showed that the Cu:Ni ratio in the 30-80 nm region linearly decreased from 10:1 to 1:2, with a gradient slope of... ;

[0075] S4. Dual-Auxiliary Agent

[0076] outer spray 400℃ for 2 hours; core vacuum 350℃ for 2 hours; Oxygen vacancies were 10.3%;

[0077] S5. Drainage mesh

[0078] Phenylacetyltrimethoxysilane vapor at 80℃ for 3 hours had a contact angle of 111° and a thickness of 1.7 nm.

[0079] The final catalyst Cat-3 composition (ICP): CuO 35.0%, NiO 15.0%, 3.0%, ZnO 10.0%, 10.0%, Balance; PMA surface distribution shows that the enrichment coefficients of Ni and Zr signals in the 80-200nm region are 0.90 and 0.95, respectively, and the calculated Ni:Zr molar ratio is 9.5:1.

[0080] Example 4

[0081] Unlike Example 1, Example 4 S5 was treated with trifluoropropyltriethoxysilane vapor at a contact angle of 115°.

[0082] Example 5

[0083] Unlike Example 1, Example 5 S5 was treated with octyltriethoxysilane vapor at a contact angle of 108°.

[0084] Example 6

[0085] Unlike Example 1, Example 6 S5 used a mixed silane (phenyl + trifluoropropyl molar ratio 1:1), steam treatment, and a contact angle of 112°.

[0086] Example 7

[0087] Unlike Example 1, Example 7S1 uses an equal amount of disordered mesopores. - (pore size 15 nm, specific surface area) )replace Nanotubes.

[0088] Comparative Example

[0089] Comparative Example 1

[0090] A catalyst for the liquid-phase hydrogenation of octenal, the preparation method of which is as follows:

[0091] S1. Carrier

[0092] Same as Example 1;

[0093] S2. Uniform impregnation

[0094] The carrier is immersed in an equal volume at one time. The mixture was left to stand at 25 °C for 2 h and then dried at 80 °C for 12 h; no pulse electrodeposition or thermal diffusion was observed.

[0095] S3. Roasting

[0096] Same as in Example 1 (550 °C for 4 h), a Cu / Ni / Ce uniformly dispersed precursor was obtained;

[0097] S4. Dual-Auxiliary Agent

[0098] Same as Example 1 (outer layer Ce, inner layer Zr);

[0099] The final sample Ref-1 had the same overall elemental content as Example 1, but EPMA line scan showed that the Cu:Ni molar ratio was constant at 2.5:1 throughout the particles, with no gradient.

[0100] Comparative Example 2

[0101] Unlike Example 1, step S4 is omitted in Comparative Example 2.

[0102] Comparative Example 3

[0103] A catalyst for the liquid-phase hydrogenation of octenal, the preparation method of which is as follows:

[0104] Unlike Example 1, step S4 does not involve any vacancy-filled additives:

[0105] Outer layer: stoichiometry Nanopowder (commercially available, specific surface area) Prepare a 0.1 M slurry, and physically spray impregnate 5 wt% in air at 400 ℃ for 2 h;

[0106] Core: Stoichiometry Nanoparticles were prepared into a 0.1 M slurry, and 5 wt% was vacuum impregnated at 350 °C for 2 hours; the entire process was carried out without a reducing atmosphere or any other harmful substances. source;

[0107] The overall elemental content of the final product is the same as that of Example 1 (ICP verification), but XPS Oα / (Oα+Oβ)=3.2%, and the oxygen vacancy concentration≈0.

[0108] Performance testing

[0109] The catalysts obtained in the examples and comparative examples were subjected to the following performance tests, and the test results are shown in Table 1:

[0110] Oxygen vacancy concentration: XPS Oα / (Oα+Oβ) peak area ratio;

[0111] Gradient slope: EPMA linear scan Cu / Ni molar ratio slope;

[0112] Hydrophobic properties: contact angle + elliptic thickness measurement;

[0113] Catalytic performance: fixed bed, 140 ℃, 3 MPa, liquid space velocity Octenal / water = 90:10, no pre-reduction required, steady-state conversion rate over 1000 h, octanol selectivity, and total amount of byproducts octane + octene;

[0114] Water loss resistance: Immersion at 23 ℃ and 80 %RH for 24 h, ICP test ;

[0115] Regeneration performance: 160 ℃ After processing for 2 hours, the material was cooled and then re-fed, and the conversion rate recovered.

[0116] Table 1 Performance Test Results

[0117] Combining Example 1 and Comparative Example 1, and referring to Table 1, it can be seen that under 1000 hours of continuous steady-state operation, the octane byproduct mass selectivity of Example 1 was only 0.35%, while that of Comparative Example 1 reached 3.2%, with byproducts being suppressed by more than 9 times; copper loss decreased from 1.2 ppm to 0.08 ppm, and the anti-dissolution ability improved by 15 times; the octenal conversion rate rebounded from 81.3% to 97.8%, and the activity retention rate improved by about 16 percentage points. These three sets of data collectively demonstrate that only when the "Cu-Ni gradient + ≥8% oxygen vacancies + hydrophobic network" are present simultaneously can low byproducts, low loss, and high steady-state activity be achieved; the absence of any one of these factors leads to a sharp deterioration in performance.

[0118] Combining Example 1 and Comparative Example 2, and referring to Table 1, it can be seen that even with the gradient and vacancies retained, removing only the hydrophobic silane layer still causes copper loss to rise from 0.08 ppm to 0.8 ppm, and octane selectivity to increase from 0.35% to 0.50%. The hydrophobic mesh alone can further reduce loss by an order of magnitude and compress the excessive hydrogenation side reaction by 30%. Therefore, the conformal silane membrane is not only a waterproof barrier but also a chemical gate that inhibits deep hydrogenation.

[0119] Combining Example 1 and Comparative Example 3, and referring to Table 1, it can be seen that when the Ce and Zr sources were changed to stoichiometric oxides and air calcined, the XPS oxygen vacancy rate dropped from 9.1% to 3.2%, the 1000-hour conversion rate decreased from 97.8% to 90.1%, and the octane byproduct rate jumped from 0.35% to 1.8%, with both lifetime and selectivity declining simultaneously. The data indicate that ≥8% oxygen vacancy is the minimum threshold for maintaining the self-reduction-self-repair cycle; insufficient vacancy will cause a five-fold increase in byproducts.

[0120] Combining Embodiment 1 and Embodiment 7, and referring to Table 1, it can be seen that Embodiment 7 will directional Nanotubes replaced with disordered mesopores - Under otherwise identical conditions, copper loss increased from 0.08 ppm to 0.10 ppm, still within the range of <0.1 ppm, but the loss amount increased by another 20%.

[0121] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A catalyst for the liquid-phase hydrogenation of octenal, characterized in that, The catalyst exhibits a continuous copper-nickel gradient distribution in the radial direction and simultaneously satisfies: (i) 0-30nm outer layer is mosaic The self-reducing active shell; (ii) The Cu:Ni molar ratio in the 30-80nm gradient transition region continuously decreases from 10:1 to 1:2; (iii) The 80-200nm core is Ni-NiO coupled. Self-repair zone of oxygen vacancies; (iv) The entire particle surface is conformally covered with a phenylsilane hydrophobic monomolecular network with a thickness of <2 nm.

2. The catalyst for liquid-phase hydrogenation of octenal according to claim 1, characterized in that, The and The oxygen vacancy concentration is ≥8%, and the oxygen vacancy concentration is determined by the peak area ratio of XPSOα / (Oα+Oβ).

3. The catalyst for liquid-phase hydrogenation of octenal according to claim 1, characterized in that, Its chemical composition by mass percentage includes: CuO 25-35%, NiO 8-15%. -3%, -3%, -10%, -20%, margin.

4. The catalyst for liquid-phase hydrogenation of octenal according to claim 1, characterized in that, The hydrophobic unimolecular network is one or more combinations of phenyltrimethoxysilane, trifluoropropyltriethoxysilane, or octyltriethoxysilane.

5. The catalyst for liquid-phase hydrogenation of octenal according to claim 1, characterized in that, The catalyst support is vertically oriented. Nanotube arrays with a cavity diameter of 10-50 nm and a length of 100-300 nm.

6. The catalyst for liquid-phase hydrogenation of octenal according to claim 1, characterized in that, The Cu:Ni gradient exhibits a linear or exponential continuous change within the 30-80 nm range, and the gradient slope is ≥ .

7. The catalyst for liquid-phase hydrogenation of octenal according to claim 1, characterized in that, The Ni-NiO coupling In the core, the molar ratio of Ni to Zr is 3:1 to 10:

1.

8. A method for preparing a catalyst as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Pulse electrodeposition of Cu-Ce precursor; S2. Vacuum impregnation with Ni salt followed by thermal diffusion forms a Cu-Ni gradient; S3. Introduce separately and ; S4. Vapor-phase silanization growth of hydrophobic monolayers.

9. Use of the catalyst according to any one of claims 1-7 in the liquid-phase hydrogenation of octenal, characterized in that, The reaction is carried out in a fixed bed, slurry bed, or trickle bed at a temperature of 120-160℃, a hydrogen pressure of 2-4 MPa, and a liquid hourly space velocity (LHSV). Furthermore, no hydrogen pre-reduction is required during the start-up phase.

Images