Application of non-noble metal supported catalyst in catalytic hydrogenation reaction and method for catalyzing 5-methyl-3-hexene-2-ketone hydrogenation by using non-noble metal supported catalyst to obtain methyl isopentanone

Abstract

The invention belongs to the technical field of catalysts, and particularly relates to application of a non-noble metal supported catalyst in catalytic hydrogenation reaction and a method for catalyzing 5-methyl-3-hexene-2-ketone hydrogenation by using the non-noble metal supported catalyst to obtain methyl isopentanone. The invention provides application of a non-noble metal supported catalyst in catalytic hydrogenation reaction. The non-noble metal supported catalyst comprises a composite carrier and an active component supported in the composite carrier, the composite carrier is aluminum oxide and lanthanum oxide, and the active component comprises iron, cobalt, copper or nickel. The non-noble metal supported catalyst provided by the invention can provide catalytic active site density and electron transfer efficiency which are equivalent to or even better than those of a noble metal catalyst under interaction of an active center structure, electronic characteristics and a carrier; meanwhile, the unique d electron orbital characteristic is beneficial to stabilization of a reaction intermediate and reduction of transition state activation energy, so that the catalyst cost is remarkably reduced while the selectivity of catalytic hydrogenation is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and specifically relates to the application of a non-noble metal supported catalyst in catalytic hydrogenation reactions and a method for using the same to catalyze the hydrogenation of 5-methyl-3-hexen-2-one to obtain methyl isoamyl ketone. Background Art

[0002] Methyl isoamyl ketone (abbreviated as MIAK), chemically named 5-methyl-2-hexanone, is a colorless transparent liquid with a light aroma. It is mainly used as a solvent for cellulose acetate, acrylic resin, polyvinyl formal resin, etc., and has broad application prospects. MIAK is also the main raw material for preparing rubber antioxidants 7PPD, 77PD, and TMPPD of p-phenylenediamine type. At present, the industrial synthesis method of methyl isoamyl ketone is mainly the one-step synthesis of methyl isoamyl ketone by condensation and hydrogenation of isobutyraldehyde and acetone. Specifically, isobutyraldehyde and acetone undergo an aldol condensation reaction under the catalysis of a base or an acid to form 4-hydroxy-5-methyl-2-hexanone, which is then dehydrated to form two isomers, 5-methyl-3-hexen-2-one and 5-methyl-4-hexen-2-one, and then both are hydrogenated to obtain the target product methyl isoamyl ketone.

[0003] In the existing process of hydrogenating 5-methyl-3-hexen-2-one to produce methyl isoamyl ketone, noble metal catalysts such as platinum and palladium are mostly used. However, the high cost of these catalysts limits their large-scale application. Summary of the Invention

[0004] In view of this, the present invention provides the application of a non-noble metal supported catalyst in catalytic hydrogenation reactions and a method for using the same to catalyze the hydrogenation of 5-methyl-3-hexen-2-one to obtain methyl isoamyl ketone. The use of a non-noble metal supported catalyst to catalyze the hydrogenation reaction of 5-methyl-3-hexen-2-one can improve the selectivity of catalytic hydrogenation while significantly reducing the catalyst cost.

[0005] To solve the above technical problems, the present invention provides the application of a non-noble metal supported catalyst in catalytic hydrogenation reactions. The non-noble metal supported catalyst includes a composite support and an active component supported on the composite support;

[0006] The composite support is alumina and lanthanum oxide, and the active component includes iron, cobalt, copper, or nickel.

[0007] Preferably, the catalytic hydrogenation reaction is the reaction of catalytically hydrogenating 5-methyl-3-hexen-2-one to produce methyl isoamyl ketone.

[0008] Preferably, the loading amount of the active component in the non-noble metal supported catalyst is 0.1 - 20 wt%.

[0009] The molar ratio of aluminum element to lanthanum element in the composite support is 2 to 8:1.

[0010] Preferably, the preparation method of the non-noble metal supported catalyst comprises the following steps:

[0011] Mix alumina, lanthanum oxide, a precursor and water to obtain a primary catalyst;

[0012] Subject the primary catalyst to calcination and reduction treatments in sequence to obtain the non-noble metal supported catalyst.

[0013] Preferably, the mixing is carried out under stirring, and the stirring time is 6 to 12 h.

[0014] Preferably, the calcination temperature is 300 to 500 °C, and the heat preservation time for calcination is 1 to 5 h.

[0015] Preferably, the reducing agent for the reduction treatment is hydrogen, the reduction treatment temperature is 300 to 600 °C, and the reduction treatment time is 1 to 3 h.

[0016] The present invention also provides a preparation method for catalytic hydrogenation of 5-methyl-3-hexen-2-one to obtain methyl isopentyl ketone by using a non-noble metal supported catalyst, comprising the following steps:

[0017] Mix 5-methyl-3-hexen-2-one and the non-noble metal supported catalyst to obtain a mixed system;

[0018] Introduce hydrogen into the mixed system for catalytic hydrogenation to obtain methyl isopentyl ketone;

[0019] The non-noble metal supported catalyst comprises a composite support and an active component supported on the composite support;

[0020] The composite support is alumina and lanthanum oxide, and the active component comprises iron, cobalt, copper or nickel.

[0021] Preferably, the mixing is carried out in a reaction kettle;

[0022] The mass ratio of 5-methyl-3-hexen-2-one to the non-noble metal supported catalyst is 5 to 500:1;

[0023] The temperature for catalytic hydrogenation is 90 to 150 °C, the pressure for catalytic hydrogenation is 0.5 to 6 MPa, and the time for catalytic hydrogenation is 2 to 6 h.

[0024] Preferably, after the catalytic hydrogenation, it further comprises:

[0025] Centrifuge the system after catalytic hydrogenation to obtain methyl isopentyl ketone and a recovered catalyst respectively.

[0026] The present invention provides an application of a non-noble metal supported catalyst in a catalytic hydrogenation reaction. The non-noble metal supported catalyst includes a composite support and an active component supported on the composite support; the composite support is alumina and lanthanum oxide, and the active component includes iron, cobalt, copper or nickel. The present invention effectively reduces the use of precious metal resources by using a non-noble metal catalyst instead of a traditional precious metal catalyst in the catalytic hydrogenation reaction. The non-noble metal supported catalyst provided by the present invention can provide a catalytic active site density and an electron transfer efficiency equivalent to or even better than those of a precious metal catalyst under the action of the active center structure, electronic characteristics and support interaction. At the same time, the unique d-electron orbital characteristics of the non-noble metal supported catalyst are beneficial to the stabilization of reaction intermediates and the reduction of the activation energy of the transition state, thereby significantly reducing the catalyst cost while maintaining or improving the catalytic efficiency (significantly improving the selectivity of catalytic hydrogenation). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the principle of catalytic hydrogenation of 5-methyl-3-hexen-2-one with the non-noble metal supported catalyst in the present invention;

[0028] Figure 2 It is a gas chromatogram of methyl isopentanone prepared in Example 12. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention provides an application of a non-noble metal supported catalyst in a catalytic hydrogenation reaction. The non-noble metal supported catalyst includes a composite support and an active component supported on the composite support;

[0030] The composite support is alumina and lanthanum oxide, and the active component includes iron, cobalt, copper or nickel.

[0031] As a specific embodiment of the present invention, the catalytic hydrogenation reaction can be a reaction of catalytic hydrogenation of 5-methyl-3-hexen-2-one to produce methyl isopentanone.

[0032] As a specific embodiment of the present invention, the loading amount of the active component in the non-noble metal supported catalyst can be 0.1-20 wt%, can also be 1-15 wt%, and can further be 5-10 wt%; the molar ratio of aluminum element to lanthanum element in the composite support can be 2-8:1, and can specifically be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1 or 8:1. As a specific embodiment of the present invention, the specific surface area of the composite support can be 115-120 m 2 / g, and can specifically be 117.08 m 2 / g; The composite support has a pore structure, and the average pore diameter of the pore structure can be 9 - 10 nm, specifically 9.06 nm. In the present invention, the surface of the composite support is rich in active sites, which is beneficial to the progress of catalytic or adsorption reactions. At the same time, the pore structure in the composite support belongs to the mesoporous structure, and the mesopores help to improve the mass transfer efficiency. The combination of a high specific surface area and a suitable mesoporous structure improves the performance of the composite support as a catalyst support.

[0033] As a specific embodiment of the present invention, the preparation method of the non-noble metal supported catalyst may include the following steps:

[0034] Mix alumina, lanthanum oxide, a precursor, and water to obtain a primary catalyst;

[0035] Subject the primary catalyst to calcination and reduction treatments in sequence to obtain the non-noble metal supported catalyst.

[0036] As a specific embodiment of the present invention, the average particle size of the alumina can be 20 - 25 nm, specifically 20.1 nm; the average particle size of the lanthanum oxide can be 35 - 40 nm, specifically 38.5 nm. As a specific embodiment of the present invention, the precursor can be a soluble salt of the active component, specifically a soluble iron salt, a soluble cobalt salt, a soluble copper salt, or a soluble nickel salt. The soluble iron salt can be iron nitrate, the soluble cobalt salt can be cobalt nitrate, the soluble copper salt can be copper nitrate, and the soluble nickel salt can be nickel nitrate, nickel sulfate, or nickel chloride. As a specific embodiment of the present invention, the water can be deionized water. The present invention has no special limitation on the dosage of the precursor, as long as it can meet the loading amount of the active component in the non-noble metal supported catalyst.

[0037] As a specific embodiment of the present invention, the mixing can be carried out under stirring, and the stirring time can be 6 - 12 h, or 8 - 10 h. The present invention has no special limitation on the stirring speed, as long as the mixture can be evenly mixed. In the mixing process of the present invention, alumina and lanthanum oxide form a composite support through physical mixing. At the same time, the precursor can uniformly penetrate into the pores of the support and form a tight bond with the support surface.

[0038] As a specific embodiment of the present invention, after mixing, it may further include: separating the solid and liquid in the mixed system, and allowing the solid obtained by the solid-liquid separation to stand to obtain a primary catalyst. The present invention has no special requirements for the solid-liquid separation, and conventional methods in the art can be used. As a specific embodiment of the present invention, the standing time can be 10 - 14 h, specifically 12 h. Allowing the solid obtained by the solid-liquid separation to stand in the present invention can further solidify the precursor on the support to form a stable structure.

[0039] As a specific embodiment of the present invention, the calcination temperature can be 300-500°C, or can also be 350-450°C; the heat preservation time of the calcination can be 1-5 h, and can specifically be 1 h, 2 h, 3 h, 4 h or 5 h. Calcining within the above range in the present invention can remove volatile components in the precursor, and at the same time promote the conversion of the precursor into metal oxide, forming a stable catalyst structure. The calcination process not only helps to improve the thermal stability of the catalyst, but also enhances its catalytic activity.

[0040] As a specific embodiment of the present invention, the reducing agent for the reduction treatment can be hydrogen, the temperature of the reduction treatment can be 300-600°C, or can also be 350-450°C; the time of the reduction treatment can be 1-3 h, and can specifically be 1 h, 2 h or 3 h. The present invention uses hydrogen to reduce metal oxide to metal, thereby activating the catalytic activity of the catalyst.

[0041] In the present invention, the non-noble metal supported catalyst has good activity and stability in the reaction of catalytic hydrogenation of 5-methyl-3-hexen-2-one to methyl isopentanone; by introducing the modified oxide La2O3, the present invention significantly increases the specific surface area of the catalyst and forms a mesoporous structure, which helps the reactants to enter the catalyst pores and improves the reaction efficiency. In addition, the present invention uses lanthanum oxide to modify alumina to increase the acidic sites on the catalyst surface, which helps the adsorption and activation of reactants, and at the same time enhances the stability of the catalyst and reduces the formation of carbon deposition. There is a strong interaction between the active components (iron, cobalt, copper or nickel) and the modified support metal (such as Al, La), and even alloys (such as Ni-La, Ni-Al) may be formed, which further enhances the activity and stability of the catalyst.

[0042] The present invention also provides a preparation method for catalytic hydrogenation of 5-methyl-3-hexen-2-one to obtain methyl isopentanone by using a non-noble metal supported catalyst, including the following steps:

[0043] Mix 5-methyl-3-hexen-2-one and a non-noble metal supported catalyst to obtain a mixed system;

[0044] Introduce hydrogen into the mixed system for catalytic hydrogenation to obtain methyl isopentanone.

[0045] The present invention mixes 5-methyl-3-hexen-2-one and a non-precious metal supported catalyst to obtain a mixed system. As a specific embodiment of the present invention, the mass ratio of the 5-methyl-3-hexen-2-one to the non-precious metal supported catalyst can be 5 to 500:1, specifically 5:1, 10:1, 50:1, 100:1, 200:1, 300:1, 400:1 or 500:1. As a specific embodiment of the present invention, the mixing can be carried out in a reaction kettle.

[0046] After obtaining the mixed system, the present invention introduces hydrogen into the mixed system for catalytic hydrogenation to obtain methyl isopentanone. As a specific embodiment of the present invention, before introducing hydrogen into the mixed system, it may further include: introducing nitrogen into the mixed system to displace the air in the mixed system to ensure the purity of the reaction environment.

[0047] As a specific embodiment of the present invention, the temperature of the catalytic hydrogenation can be 90 to 150 °C, specifically 90 °C, 100 °C, 120 °C, 130 °C, 140 °C, or 150 °C; the pressure of the catalytic hydrogenation can be 0.5 to 6 MPa, specifically 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa or 6 MPa; the time of the catalytic hydrogenation can be 2 to 6 h, specifically 2 h, 3 h, 4 h, 5 h or 6 h.

[0048] As a specific embodiment of the present invention, the catalytic hydrogenation can be accompanied by stirring.

[0049] In the present invention, the equation for catalytic hydrogenation of 5-methyl-3-hexen-2-one to obtain methyl isopentanone using the non-precious metal supported catalyst is shown in Equation 1:

[0050]

[0051] The preparation method provided by the present invention does not require the addition of a solvent. Compared with the traditional catalytic hydrogenation reaction that requires the addition of a solvent, it not only reduces the production cost, but also reduces the environmental pollution problem and optimizes the existing production process. By adjusting the reaction system, the present invention successfully conducts the hydrogenation reaction of 5-methyl-3-hexen-2-one in a solvent-free environment, avoiding the use of a solvent, thereby reducing environmental pollution. At the same time, it also simplifies the subsequent product separation and purification steps, improving the economy and environmental friendliness of the overall process.

[0052] As a specific embodiment of the present invention, after the catalytic hydrogenation, it may further include: performing solid-liquid separation on the system after the catalytic hydrogenation to obtain methyl isopentanone and a recovered catalyst respectively.

[0053] As a specific embodiment of the present invention, the solid-liquid separation may include centrifugation or magnetic separation. The present invention has no special requirements for the centrifugation or magnetic separation, as long as the solid-liquid separation can be achieved. The recovered catalyst obtained by centrifugation in the present invention can be directly recycled, and the recycled catalyst still has good catalytic performance; the number of times of recycling can be more than 5 times.

[0054] In the present invention, the C═C double bond and the C═O double bond in 5-methyl-3-hexen-2-one exist conjugately. This conjugation effect causes the electron clouds of the two double bonds to overlap, thereby enhancing the stability of the molecule. In a non-conjugated system, due to the relatively high energy of the π bond of the C═C double bond, compared with the C═O double bond, it is more likely to undergo a hydrogenation reaction. However, in the conjugated system of 5-methyl-3-hexen-2-one, the conjugation effect significantly improves the hydrogenation reduction activity of the C═O double bond, resulting in the possibility that both the C═O double bond and the C═C double bond may participate in the reaction during the hydrogenation reduction reaction, thereby affecting the selectivity of the target product.

[0055] The present invention uses an Al2O3-La2O3 composite support to optimize the catalytic system. By introducing the modified oxide La2O3 into the catalyst, the specific surface area of the catalyst is significantly increased, and a mesoporous structure conducive to the penetration and diffusion of reactants is formed. This structural characteristic not only accelerates the reaction process and improves the reaction efficiency, but also increases the acidic sites on the catalyst surface, thereby promoting the effective adsorption and activation of the C═C double bond of the reactants. There is a strong interaction between the active component and the support metals Al and La, and Ni-La and Ni-Al alloy phases may be further formed. This interaction greatly improves the activity and stability of the catalyst, effectively reduces the formation of carbon deposition, and extends the service life of the catalyst. The non-precious metal supported catalyst system realizes the precise control of the selectivity of the target product by adjusting the hydrogenation activity of the C═O double bond and the C═C double bond. Specifically, the non-precious metal supported catalyst has a relatively weak adsorption capacity for the C═O bond and mainly relies on oxygen electron vacancies. However, due to the near saturation of the oxygen electron vacancies in the 5-methyl-3-hexen-2-one molecule, it is difficult to be further adsorbed; on the contrary, the C═C bond is more easily stretched and exposed under the action of the catalyst, facilitating subsequent activation and hydrogenation reactions. In addition, the methyl group near the carbon-oxygen double bond in the 5-methyl-3-hexen-2-one molecule produces a significant steric hindrance effect, hindering the attack of hydrogen atoms on the carbon-oxygen double bond; while the space near the carbon-carbon double bond is relatively open, and hydrogen atoms are more likely to approach and undergo a hydrogenation reaction. Combining with the reaction schematic diagram ( Figure 1)It can be seen that in the process of hydrogenating 5-methyl-3-hexen-2-one with the non-noble metal supported catalyst of the present invention, the reaction mainly proceeds along Path 1 (the main product is methyl isopentanone), effectively controlling the formation of by-products in Path 2 and inhibiting Path 3 of the over-hydrogenation of methyl isopentanone. Compared with noble metal catalysts, although the non-noble metal supported catalyst used in the present invention may be slightly insufficient in hydrogenation activity, it shows significant advantages in controlling side reactions, giving full play to the characteristics of non-noble metal catalysts such as rich resources, low cost, simple preparation, and easy industrial production. At the same time, the non-noble metal supported catalyst provided by the present invention also has excellent anti-poisoning ability, can maintain stable catalytic performance during long-term use, thereby reducing the occurrence of side reactions and improving economic benefits.

[0056] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below in conjunction with examples, but they cannot be understood as limiting the protection scope of the present invention.

[0057] Example 1

[0058] 0.04 mol of alumina with an average particle size of 20.1 nm, 0.005 mol of lanthanum oxide with an average particle size of 38.5 nm, 3.14 g of nickel nitrate precursor, and 50 g of deionized water were mixed under stirring for 10 h and then solid-liquid separated. The solid obtained by solid-liquid separation was allowed to stand for 12 h to obtain a primary catalyst;

[0059] The primary catalyst was calcined in a muffle furnace at 400 °C for 3 h and then reduced at 400 °C in a hydrogen atmosphere for 3 h to obtain a non-noble metal supported catalyst, denoted as Ni / Al2O3-La2O3;

[0060] The nickel loading in Ni / Al2O3-La2O3 is 10 wt%, and the molar ratio of aluminum element to lanthanum element in the composite support (Al2O3-La2O3) is 8:1.

[0061] Using 5-methyl-3-hexen-2-one as the raw material and Ni / Al2O3-La2O3 as the catalyst, according to the mass ratio of 5-methyl-3-hexen-2-one to Ni / Al2O3-La2O3 of 50:1, the Ni / Al2O3-La2O3 catalyst and 5-methyl-3-hexen-2-one were added to a 100 mL high-pressure reactor;

[0062] The air in the high-pressure reactor was replaced 5 times with nitrogen and then hydrogen was filled. Catalytic hydrogenation (with stirring) was carried out at a temperature of 90 °C and a pressure of 1 MPa for 5 h; after centrifugation, methyl isopentanone was obtained.

[0063] Example 2

[0064] The non-noble metal supported catalyst was prepared according to the method of Example 1, except that the nickel nitrate precursor was replaced with an iron nitrate precursor, and the obtained non-noble metal supported catalyst was denoted as Fe / Al2O3-La2O3; the iron loading in Fe / Al2O3-La2O3 was 10 wt%.

[0065] 5-Methyl-3-hexen-2-one was catalytically hydrogenated using Fe / Al2O3-La2O3 as the catalyst according to the method of Example 1 to obtain methyl isopentyl ketone.

[0066] Example 3

[0067] The non-noble metal supported catalyst was prepared according to the method of Example 1, except that the nickel nitrate precursor was replaced with a cobalt nitrate precursor, and the obtained non-noble metal supported catalyst was denoted as Co / Al2O3-La2O3; the cobalt loading in Co / Al2O3-La2O3 was 10 wt%.

[0068] 5-Methyl-3-hexen-2-one was catalytically hydrogenated using Co / Al2O3-La2O3 as the catalyst according to the method of Example 1 to obtain methyl isopentyl ketone.

[0069] Example 4

[0070] The non-noble metal supported catalyst was prepared according to the method of Example 1, except that the nickel nitrate precursor was replaced with a copper nitrate precursor, and the obtained non-noble metal supported catalyst was denoted as Cu / Al2O3-La2O3; the copper loading in Cu / Al2O3-La2O3 was 10 wt%.

[0071] 5-Methyl-3-hexen-2-one was catalytically hydrogenated using Cu / Al2O3-La2O3 as the catalyst according to the method of Example 1 to obtain methyl isopentyl ketone.

[0072] Comparative Example 1

[0073] 5-Methyl-3-hexen-2-one was catalytically hydrogenated to obtain methyl isopentyl ketone according to the method of Example 1, except that Pd / C (Adamas-beta CAS: 7440-05-3) with a palladium loading of 5% was used as the catalyst.

[0074] Comparative Example 2

[0075] 5-Methyl-3-hexen-2-one was catalytically hydrogenated to obtain methyl isopentyl ketone according to the method of Example 1, except that Ru / C (Adamas-beta CAS: 7440-18-8) with a ruthenium loading of 5% was used as the catalyst.

[0076] Comparative Example 3

[0077] The catalytic hydrogenation of 5-methyl-3-hexen-2-one was carried out according to the method of Example 1 to obtain methyl isopentyl ketone, except that Pt / C (Adamas-beta CAS: 7440-06-4) with a platinum loading of 5% was used as the catalyst.

[0078] The purity of the methyl isopentyl ketone products prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was detected using a high-performance gas chromatograph, and the conversion rate and selectivity were calculated. The results are listed in Table 1.

[0079] Table 1 Conditions for catalytic hydrogenation in Examples 1 to 4 and results of conversion rate and selectivity

[0080]

[0081]

[0082] As can be seen from Table 1, although the conversion rate of non-precious metal supported catalysts such as Fe, Co, Cu, and Ni is slightly lower than that of precious metal catalysts (such as Pd / C, Ru / C, Pt / C), the non-precious metal supported catalysts show significant advantages in terms of reaction selectivity. The selectivity of the Ni / Al2O3-La2O3 catalyst is as high as 95.9%, while the selectivity of precious metal catalysts is generally low (50.4% for Pd / C, 61.3% for Ru / C, and 56.7% for Pt / C). This indicates that although the reaction activity of non-precious metal catalysts is slightly inferior to that of precious metals, their excellent selectivity can effectively inhibit the formation of by-products. In addition, the non-precious metal supported catalysts have a lower cost and rich resources, further enhancing their large-scale application in industrial catalysis. Considering catalytic activity, selectivity, and economy comprehensively, Fe, Co, Cu, and Ni non-precious metal supported catalysts show great potential in controlling the formation of by-products and improving reaction efficiency.

[0083] Examples 5 to 11

[0084] The non-precious metal supported catalyst Ni / Al2O3-La2O3 was prepared according to the method of Example 1.

[0085] The catalytic hydrogenation of 5-methyl-3-hexen-2-one was carried out using Ni / Al2O3-La2O3 as the catalyst according to the method of Example 1 to obtain methyl isopentyl ketone, except that different feed ratios (mass ratio of 5-methyl-3-hexen-2-one to Ni / Al2O3-La2O3 catalyst) were used. The specific parameters are shown in Table 2.

[0086] The purity of the methyl isopentyl ketone products prepared in Example 1 and Examples 5 to 11 was detected using a high-performance gas chromatograph, and the conversion rate and selectivity were calculated. The results are listed in Table 2.

[0087] Table 2 Conversion rates and selectivities at different feed ratios in Examples 1, 5 - 11

[0088]

[0089]

[0090] As can be seen from Table 2, within the range of the mass ratio of 5 - methyl - 3 - hexen - 2 - one to the Ni / Al2O3 - La2O3 catalyst being 5 - 500:1, the catalytic hydrogenation reaction can still maintain good catalytic efficiency and product selectivity. Catalytic hydrogenation of 5 - methyl - 3 - hexen - 2 - one with the Ni / Al2O3 - La2O3 catalyst has great flexibility, and the feed ratio can be adjusted according to actual needs to achieve the best economic benefits.

[0091] It should be noted that from the perspective of industrial production economy, when the feed ratio is 500:1, although the conversion rate is low, its extremely high selectivity (99.7%) and significantly reduced catalyst dosage have significantly reduced the production cost. By optimizing the reaction conditions (such as raising the reaction temperature to 130°C), the conversion rate at a feed ratio of 500:1 can be further increased, thereby achieving higher economic benefits while ensuring high selectivity. Therefore, considering the catalyst consumption, product yield, and post - treatment cost comprehensively, a feed ratio of 500:1 is determined as the optimal condition. In summary, this example not only verifies the excellent performance of the Ni / Al2O3 - La2O3 catalyst within a wide range of feed ratios but also provides a method to achieve the dual goals of high selectivity and economy by optimizing the reaction conditions.

[0092] Examples 12 - 15

[0093] Prepare the non - noble metal - supported catalyst Ni / Al2O3 - La2O3 according to the method of Example 1.

[0094] Catalytically hydrogenate 5 - methyl - 3 - hexen - 2 - one with Ni / Al2O3 - La2O3 as the catalyst at different temperatures according to the method of Example 1 to obtain methyl isopentanone. The specific parameters are shown in Table 3.

[0095] Use a high - performance gas chromatograph to detect the purity of the methyl isopentanone products prepared in Examples 12 - 15, and calculate the conversion rate and selectivity. The results are listed in Table 3; Figure 2 The chromatogram of the methyl isopentanone prepared in Example 12.

[0096] Table 3 Conversion rates and selectivities at different temperatures in Examples 12 - 15

[0097]

[0098]

[0099] As can be seen from Table 3, under the condition of a high feed ratio, the reactant molecules need longer time or higher energy to diffuse to the catalyst surface and react. When the reaction temperature is in the range of 130-140 °C, the conversion rate is greatly improved. It can achieve a high conversion rate (>97%) while maintaining a high selectivity (>95%), ensuring the economy of the reaction and the quality of the product. By precisely controlling the temperature of the selective hydrogenation reaction within the range of 120-150 °C, the present invention can effectively reduce the generation of by-products, thereby improving the purity of the target product, methyl isopentanone.

[0100] From Figure 2 it can be seen that the Ni / Al2O3-La2O3 catalyst exhibits excellent catalytic performance and can efficiently convert 5-methyl-3-hexen-2-one into the target product, methyl isopentanone. The peak area of the target product in the chromatogram is significant, and the peak area of the by-products is small, indicating that the catalyst has a high selectivity for the target product while efficiently converting the reactants.

[0101] Example 16

[0102] Prepare the non-noble metal supported catalyst Ni / Al2O3-La2O3 according to the method of Example 1.

[0103] Carry out catalytic hydrogenation of 5-methyl-3-hexen-2-one using Ni / Al2O3-La2O3 as the catalyst according to the method of Example 12, and then centrifuge to obtain methyl isopentanone and the recovered Ni / Al2O3-La2O3 catalyst respectively;

[0104] Use the recovered Ni / Al2O3-La2O3 catalyst to carry out 5 cycles of catalytic hydrogenation of 5-methyl-3-hexen-2-one; Use high-performance gas chromatography to detect the purity of the methyl isopentanone products prepared by 5 cycles of catalytic hydrogenation, and calculate the conversion rate and selectivity. The results are listed in Table 4.

[0105] Table 4 Conversion rate and selectivity of cyclic catalytic hydrogenation in Example 16

[0106]

[0107]

[0108] As can be seen from Table 4, after multiple cycles of use, the catalyst still maintains high activity, demonstrating its good cyclic use performance in the hydrogenation reaction.

[0109] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, rather than all embodiments. People can also obtain other embodiments based on this embodiment without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. Application of a non-precious metal supported catalyst in a catalytic hydrogenation reaction, characterized in that: The non-precious metal supported catalyst comprises a composite support and an active component supported in the composite support; The composite carrier is aluminum oxide and lanthanum oxide, and the active component includes iron, cobalt, copper or nickel.

2. The application according to claim 1, characterized in that: The catalytic hydrogenation reaction is a reaction in which 5-methyl-3-hexen-2-one is catalytically hydrogenated to generate methyl isoamyl ketone.

3. The application according to claim 1, characterized in that: The loading amount of the active component in the non-precious metal supported catalyst is 0.1 to 20 wt %; The molar ratio of aluminum element to lanthanum element in the composite carrier is 2 to 8:

1.

4. The use according to claim 1 or 3, characterized in that: The preparation method of the non-precious metal supported catalyst comprises the following steps: mixing aluminum oxide, lanthanum oxide, a precursor and water to obtain a primary catalyst; The primary catalyst is sequentially subjected to calcination and reduction treatment to obtain the non-precious metal supported catalyst.

5. The application according to claim 4, characterized in that: The mixing is carried out under stirring conditions, and the stirring time is 6 to 12 hours.

6. The use according to claim 4, characterized in that: The calcination temperature is 300-500° C., and the calcination insulation time is 1-5 hours.

7. The use according to claim 4, characterized in that: The reducing agent for the reduction treatment is hydrogen, the temperature of the reduction treatment is 300 to 600° C., and the time of the reduction treatment is 1 to 3 hours.

8. A method for preparing methyl isoamyl ketone by hydrogenating 5-methyl-3-hexene-2-one using a non-precious metal supported catalyst, characterized in that: The following steps are involved: Mixing 5-methyl-3-hexen-2-one and a non-precious metal supported catalyst to obtain a mixed system; introducing hydrogen into the mixed system for catalytic hydrogenation to obtain methyl isoamyl ketone; The non-precious metal supported catalyst comprises a composite support and an active component supported in the composite support; The composite carrier is aluminum oxide and lanthanum oxide, and the active component includes iron, cobalt, copper or nickel.

9. The preparation method according to claim 8, characterized in that: The mixing is carried out in a reaction kettle; The mass ratio of the 5-methyl-3-hexene-2-one to the non-precious metal supported catalyst is 5 to 500:1; The temperature of the catalytic hydrogenation is 90-150° C., the pressure of the catalytic hydrogenation is 0.5-6 MPa, and the time of the catalytic hydrogenation is 2-6 hours.

10. The preparation method according to claim 8 or 9, characterized in that: The catalytic hydrogenation further comprises: The system after catalytic hydrogenation is centrifuged to obtain methyl isoamyl ketone and recovered catalyst respectively.

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