Catalyst for selectively catalyzing hydrogenation of phenol compounds and preparation method thereof

Abstract

The invention provides a catalyst for selectively catalyzing hydrogenation of phenol compounds and a preparation method of the catalyst, and belongs to the field of catalysts. The catalyst is composed of an oxide carrier and palladium nanoparticles, wherein the oxide carrier comprises at least one of Al2O3, SiO2, MgO, CeO2, TiO2 and ZrO2; an interface formed by palladium metal, oxygen in the oxide carrier and metal in the oxide carrier exists between the oxide carrier and the palladium nanoparticles, the palladium metal and the oxygen in the oxide carrier are connected through chemical bonds, and the oxygen in the oxide carrier and the metal in the oxide carrier are connected through chemical bonds. The catalyst can be used for catalysis at normal temperature and normal pressure, is high in activity and high in activity stability, and can be repeatedly utilized for multiple times.

Description

Technical Field

[0001] The invention relates to the field of catalysts, and in particular to a catalyst for selectively catalyzing the hydrogenation of phenol compounds and a preparation method thereof. Background Art

[0002] Selectivity is crucial for chemical transformations, especially when a chemical reaction involves multiple reactive groups and only one specific group needs to be converted while avoiding other conversions. One important example is the selective catalytic hydrogenation of phenol to produce cyclohexanone. In this reaction, the aromatic ring of the reactant phenol has a low hydrogenation activity, while the carbonyl group of the product cyclohexanone has a high hydrogenation activity, which makes it difficult to prohibit the conversion of cyclohexanone to cyclohexanol under hydrogenation conditions that ensure the rapid conversion of phenol to cyclohexanone. Therefore, it is challenging to construct a catalytic system that achieves both high phenol conversion (>80%) and high cyclohexanone selectivity (>95%).

[0003] Cyclohexanone is an important chemical that is widely used in the production of nylon 6, nylon 66, drugs and polyester. In industrial production, cyclohexanone is mainly produced by the Asahi process, cyclohexane oxidation and phenol hydrogenation, the latter of which includes a two-step process and a one-step process. The first three processes all involve high temperature and high pressure processes. The harsh reaction conditions will lead to low yields and high energy consumption. In contrast, the one-step phenol hydrogenation process, known as phenol selective catalytic hydrogenation, can be carried out under mild conditions. It has the advantages of high hydrogen utilization, few by-products and easy product separation, which is more in line with the requirements of green chemistry and has received widespread attention and research in recent years. However, research on efficient catalysts is still lacking, and there are still challenges in how to achieve high activity, high selectivity and high stability of catalysts at room temperature and atmospheric pressure. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a catalyst and method for selectively catalyzing the hydrogenation of phenol compounds to prepare cyclohexanone compounds, comprising: using the catalyst provided by the present invention as a catalyst, hydrogen as a hydrogen source, and oxygen as a promoter, and selectively catalyzing the hydrogenation of biphenol compounds to prepare cyclohexanone compounds; the reaction conditions are mild, at room temperature and pressure, with oxygen as an auxiliary agent, and the method has the advantages of being able to achieve high conversion rate of phenol, high conversion rate, high selectivity and high stability.

[0005] In a first aspect, the present invention provides a catalyst.

[0006] A catalyst, the catalyst is composed of an oxide carrier and palladium nanoparticles, the oxide carrier includes at least one of Al2O3, SiO2, MgO, CeO2, TiO2 and ZrO2, preferably Al2O3, more preferably γ-Al2O3; there is an interface between the oxide carrier and the palladium nanoparticles composed of palladium metal and oxygen in the oxide carrier and metal in the oxide carrier, the palladium metal and oxygen in the oxide carrier, as well as oxygen in the oxide carrier and metal in the oxide carrier, respectively, are connected by chemical bonds.

[0007] In some embodiments, the loading amount of the palladium nanoparticles on the oxide support in the catalyst is 0.1wt%-10wt%. In some embodiments, the loading amount of the palladium nanoparticles on the oxide support in the catalyst is 0.5wt%-5wt%. In some embodiments, the loading amount of the palladium nanoparticles on the oxide support in the catalyst is 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt% or 10wt%.

[0008] In some embodiments, the palladium nanoparticles include zero-valent palladium element and positive-valent palladium element.

[0009] In some embodiments, the positive-valent palladium element is a +2-valent palladium element and / or a +1-valent palladium element.

[0010] In some embodiments, in the X-ray photoelectron spectroscopy of the catalyst, the zero-valent palladium element Pd3d 5 / 2 The binding energy of the catalyst is 334eV-336eV. In some embodiments, in the X-ray photoelectron spectrum of the catalyst, the Pd 3d 5 / 2 The binding energy of is 335.4 eV.

[0011] In some embodiments, the zero-valent palladium element Pd 3d 3 / 2 The binding energy of the zero-valent palladium element is 339 eV-342 eV. 3 / 2 The binding energy is 340.8 eV.

[0012] In some embodiments, in the X-ray photoelectron spectroscopy of the catalyst, the Pd3d 5 / 2 The binding energy of the catalyst is 336eV-339eV. In some embodiments, in the X-ray photoelectron spectrum of the catalyst, the Pd 3d5 / 2 The binding energy is 336.8 eV.

[0013] In some embodiments, the positive-valent palladium element Pd 3d 3 / 2 The binding energy of the palladium element is 341eV-344eV. 3 / 2 The binding energy of is 342.4 eV.

[0014] In some embodiments, the particle size of the palladium nanoparticles is less than or equal to 5 nm.

[0015] In some embodiments, the oxide carrier is γ-Al2O3, the loading amount of the palladium nanoparticles in the catalyst is 1wt%, and the powder X-ray diffraction spectrum of the catalyst is as follows: Figure 2 shown.

[0016] In some embodiments, the oxide carrier is γ-Al2O3, the loading amount of the palladium nanoparticles in the catalyst is 1wt%, and the in-situ CO adsorption infrared spectrum of the catalyst is as follows: Figure 3 shown.

[0017] In a second aspect, the present invention provides a method for preparing the catalyst described in the first aspect.

[0018] A method for preparing the catalyst described in the first aspect comprises: mixing an oxide carrier and a palladium precursor in a solvent, stirring, centrifuging or filtering to obtain a solid, washing the solid with water, drying, calcining, and then reducing it in a hydrogen-argon mixed gas to obtain the catalyst.

[0019] In some embodiments, the solvent is water.

[0020] In some embodiments, the stirring time is 1 h to 10 h. In some embodiments, the stirring time is 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0021] In some embodiments, the calcination temperature is 300° C.-600° C. In some embodiments, the calcination temperature is 300° C., 350° C., 400° C., 450° C., 500° C., 550° C. or 600° C.

[0022] In some embodiments, the reduction temperature is 200° C. to 400° C. In some embodiments, the reduction temperature is 200° C., 250° C., 300° C., 350° C. or 400° C.

[0023] In some embodiments, the volume percentage of hydrogen in the hydrogen-argon mixture is 1 vol%-10 vol%. In some embodiments, the volume percentage of hydrogen in the hydrogen-argon mixture is 1 vol%, 2 vol%, 3 vol%, 4 vol%, 5 vol%, 6 vol%, 7 vol%, 8 vol%, 9 vol% or 10 vol%. In some embodiments, the volume percentage of hydrogen in the hydrogen-argon mixture is 5 vol%.

[0024] In some embodiments, the reduction time is 1 h-10 h. In some embodiments, the reduction time is 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0025] In some embodiments, the palladium precursor is at least one of sodium chloropalladate, chloropalladic acid, palladium acetate, palladium acetylacetonate, palladium nitrate, and diacetonitrile palladium chloride.

[0026] In some embodiments, the mass ratio of palladium in the palladium precursor to the oxide support is 0.1:100-10:100. In some embodiments, the mass ratio of palladium in the palladium precursor to the oxide support is 0.1:100, 0.5:100, 1:100, 1.5:100, 2:100, 2.5:100, 3:100, 3.5:100, 4:100, 4:100, 4.5:100, 5:100, 6:100, 7:100, 8:100, 9:100 or 10:100.

[0027] In a third aspect, the present invention provides use of the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect.

[0028] A use of the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect in selectively catalyzing the preparation of cyclohexanone compounds from phenol compounds.

[0029] In a fourth aspect, the present invention provides a method for preparing cyclohexanone compounds.

[0030] A method for preparing cyclohexanone compounds, comprising: mixing the catalyst described in the first aspect or the catalyst obtained by the preparation method described in the second aspect, a phenol compound and a reaction solvent, and reacting them in the presence of hydrogen and a second gas to obtain cyclohexanone compounds, wherein the second gas is a gas containing oxygen.

[0031] In some embodiments, the structure of the phenol compound is:

[0032]

[0033] The structure of the cyclohexanone compound is:

[0034]

[0035] in,

[0036] (R2)m means that the m H groups on the ring are independently replaced by m identical or different R2 substituents,

[0037] m is 0, 1, 2, 3, 4 or 5;

[0038] (R3)n means that n H groups on the ring are independently replaced by n R3 substituents, wherein R3 is a hydroxyl group;

[0039] (R4)n means that 2n (i.e., 2 times n) H on the ring are independently replaced by n R4; wherein R4 is =O;

[0040] n is 0, 1, 2, 3, 4 or 5;

[0041] And 0≤m+n≤5;

[0042] Each R2 is independently alkyl, alkoxy, halogen, aldehyde or -COR1;

[0043] Wherein R1 is alkyl, hydroxyl, alkoxy or halogen (halogen such as: F, Cl, Br, I).

[0044] In some embodiments, the reaction solvent is at least one of water, methanol, ethanol, acetonitrile, toluene, tetrahydrofuran, GBL (γ-butyrolactone), chlorobenzene, DMF (N,N-dimethylformamide), NMP (N-methylpyrrolidone), DMC (dimethyl carbonate) and dioxane.

[0045] In some embodiments, the reaction temperature of the reaction is 0° C.-70° C. In some embodiments, the reaction temperature of the reaction is 0° C., 5° C., 10° C., 15° C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., or 70° C.

[0046] In some embodiments, the reaction time of the reaction is 0.5h-50h. In some embodiments, the reaction time of the reaction is 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 15h, 20h, 24h, 25h, 30h, 35h, 40h, 45h or 50h.

[0047] In some embodiments, the volume ratio of the hydrogen to the second gas is 1:20-20: 1. In some embodiments, the volume ratio of the hydrogen to the second gas is 1:10-10: 1. In some embodiments, the volume ratio of the hydrogen to the second gas is 1:20, 1:15, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1 or 20:1.

[0048] In some embodiments, the total gas pressure of the hydrogen and the second gas is 0.1 MPa-1.0 MPa. In some embodiments, the total gas pressure of the hydrogen and the second gas is 0.11 MPa-0.7 MPa. In some embodiments, the total gas pressure of the hydrogen and the second gas is 0.1 MPa, 0.11 MPa, 0.15 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1.0 MPa.

[0049] In some embodiments, the molar ratio of palladium in the catalyst to the phenolic compound is 1:50-1:5000. In some embodiments, the molar ratio of palladium in the catalyst to the phenolic compound is 1:50-1:2000. In some embodiments, the molar ratio of palladium in the catalyst to the phenolic compound is 1:50-1:1000. In some embodiments, the molar ratio of palladium in the catalyst to the phenolic compound is 1:50, 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:1500 or 1:2000.

[0050] In some embodiments, the second gas is at least one of oxygen, air, an oxygen-argon mixture, or an oxygen-nitrogen mixture.

[0051] In some embodiments, the phenol compound is selected from at least one of p-methylphenol, o-methylphenol, m-methylphenol, p-ethylphenol, p-tert-butylphenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, p-ethoxyphenol, p-fluorophenol, p-chlorophenol, p-bromophenol, p-hydroxybenzaldehyde and p-hydroxyacetophenone.

[0052] In some embodiments, the cyclohexanone compound is selected from at least one of p-methylcyclohexanone, o-methylcyclohexanone, m-methylcyclohexanone, p-ethylcyclohexanone, p-tert-butylcyclohexanone, 1,4-cyclohexanedione, 1,2-cyclohexanedione, 1,3-cyclohexanedione, p-methoxycyclohexanone, p-ethoxycyclohexanone, p-fluorocyclohexanone, p-chlorocyclohexanone, p-bromocyclohexanone, cyclohexanone-4-carboxaldehyde and 4-acetylcyclohexanone.

[0053] In some embodiments, the phenol compound and the cyclohexanone compound are selected from the following corresponding phenol compounds and cyclohexanone compounds, respectively:

[0054] Phenol compounds Cyclohexanone compounds p-Toluene p-Methylcyclohexanone o-Cresol o-Methylcyclohexanone m-Cresol m-Methylcyclohexanone p-Ethylphenol 4-Ethylcyclohexanone 4-tert-Butylphenol 4-tert-Butylcyclohexanone Hydroquinone 1,4-Cyclohexanedione Catechol 1,2-Cyclohexanedione Resorcinol 1,3-Cyclohexanedione p-Methoxyphenol p-Methoxycyclohexanone p-Ethoxyphenol 4-Ethoxycyclohexanone p-Fluorophenol 4-Fluorocyclohexanone p-Chlorophenol 4-Chlorocyclohexanone p-Bromophenol 4-Bromocyclohexanone p-Hydroxybenzaldehyde Cyclohexanone-4-carboxaldehyde p-Hydroxyacetophenone 4-Acetylcyclohexanone

[0055] Beneficial Effects

[0056] Compared with the prior art, a certain embodiment provided by the present invention has at least one of the following beneficial effects:

[0057] (1) The catalyst provided by the present invention can maintain a cyclic test of 5 hours per reaction for at least 10 times, has significant stability, and is conducive to reducing reaction costs and promoting the industrialization of products.

[0058] (2) Compared with catalysts prepared using other active metals or other types of carriers, the Pd / Al2O3, Pd / SiO2, Pd / MgO, Pd / CeO2, Pd / TiO2 and Pd / ZrO2 catalysts provided by the present invention can selectively catalyze the hydrogenation of phenol to cyclohexanone, with a conversion rate greater than 99.9% and a selectivity for cyclohexanone compounds greater than 99.9%, and have excellent catalytic activity.

[0059] (3) The catalyst of the present invention uses a mixed gas of a second gas containing oxygen (such as oxygen or air) and a small amount of hydrogen as an atmosphere to catalyze hydrogenation to prepare cyclohexanone, which is beneficial to reducing costs and facilitating industrial development.

[0060] (4) The catalyst provided by the present invention still has significant activity in catalytic hydrogenation of phenol compounds to cyclohexanone compounds even when a small amount of the catalyst is used (the molar ratio of the Pd element in the catalyst to the reaction substrate phenol compound can be at least as low as 1:2000). The catalyst provided by the present invention has good activity in catalytic hydrogenation of phenol compounds to cyclohexanone compounds.

[0061] (5) The catalyst provided by the present invention has a wide range of reaction substrates. Any of p-methylphenol, o-methylphenol, m-methylphenol, p-ethylphenol, p-tert-butylphenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, p-ethoxyphenol, p-fluorophenol, p-chlorophenol, p-bromophenol, p-hydroxybenzaldehyde and p-hydroxyacetophenone can be selectively catalytically hydrogenated to the corresponding cyclohexanone compounds with good conversion rate and selectivity for cyclohexanone compounds.

[0062] (6) In the preparation of the catalyst of the present invention, by calcining at a specific temperature (300°C-600°C) and reducing at a specific temperature (200°C-400°C), the catalytic reaction conversion rate, cyclohexanone compound selectivity, activity and stability of the obtained catalyst are greatly improved, and an unexpected technical effect is achieved.

[0063] (7) The catalyst provided by the present invention can carry out efficient catalytic reaction under conditions of normal temperature and pressure or normal temperature and near normal pressure, with high conversion rate and selectivity for cyclohexanone compounds, good activity, which is conducive to reducing the difficulty of operation and facilitating industrial development.

[0064] (8) The catalytic reaction rate of the catalyst provided by the present invention is high. When the Pd metal loading is 1 wt% and the Pd / Al2O3 catalyst is used in a phenol compound feed molar ratio of 1:1000, the conversion rate is greater than 99.9% within 5 hours, and the cyclohexanone selectivity is greater than 99.9%; when the Pd metal loading is 1 wt% and the Pd / Al2O3 catalyst is used in a phenol compound feed molar ratio of 1:50, the conversion rate is greater than 99.9% within 2 hours, and the cyclohexanone selectivity is greater than 99.9%. The use of the catalyst provided by the present invention is conducive to accelerating the reaction efficiency.

[0065] Definition of terms

[0066] The term "room temperature" refers to ambient temperature, which in some embodiments is 15°C-40°C, in some embodiments is 20°C-35°C, and in some embodiments is 25°C-30°C.

[0067] The term "loading amount" refers to the percentage of the mass of active metal to the mass of the support (the oxide support in the present invention).

[0068] In the above text of the present invention, regardless of whether the words "about" or "approximately" are used, all the numbers disclosed herein are approximate values. Based on the disclosed numbers, the value of each number may vary by less than ±10% or reasonable differences considered by those skilled in the art, such as ±1%, ±2%, ±3%, ±4% or ±5%.

[0069] The terms "above", "below", "within" and the like are understood to include the number itself, for example, more than two means ≥ two.

[0070] The term "and / or" should be understood to mean any one of the optional items or a combination of any two or more of the optional items.

[0071] The term "wt%" means percent by mass.

[0072] The terms "vol %" or "% vol" mean volume percentage.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 This is a transmission electron microscope (TEM) characterization image of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1.

[0075] Figure 2 This is a powder X-ray diffraction (XRD) characterization diagram of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1.

[0076] Figure 3 This is the in-situ CO adsorption infrared spectrum characterization diagram of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1.

[0077] Figure 4 It is a representative scanning transmission electron microscopy (STEM, scale bar, 100 nm) and STEM-EDS element distribution characterization diagram of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1.

[0078] Figure 5 This is the X-ray photoelectron spectroscopy characterization diagram of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1.

[0079] Figure 6This is a statistical diagram of the catalytic performance of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1 for selective catalytic hydrogenation of phenol.

[0080] Figure 7 This is a statistical diagram of the reaction kinetics of selective catalytic hydrogenation of phenol by the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1, which is pseudo-first-order kinetics.

[0081] Figure 8 This is the transmission electron microscopy (TEM) characterization image of Pd NPs catalyst.

[0082] Fig. 9 This is a graph showing the catalytic performance of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1 for selective catalytic hydrogenation of phenol under anaerobic conditions.

[0083] Fig.10 This is a graph showing the catalytic performance of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1 for selective catalytic hydrogenation of phenol under hydrogen-free conditions.

[0084] Fig.11 This is the X-ray near-edge absorption structure (XANES) characterization diagram of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1, the Pd metal foil and palladium oxide.

[0085] Fig.12 This is an X-ray extended edge absorption structure (EXAFS) characterization diagram of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% obtained in Example 1, Pd metal foil and palladium oxide. DETAILED DESCRIPTION

[0086] In order to enable those skilled in the art to better understand the technical solution of the present invention, some non-limiting embodiments are further disclosed below to further illustrate the present invention in detail.

[0087] The reagents used in the present invention can be purchased from the market or prepared by the method described in the present invention.

[0088] The Al2O3 described in the following examples is γ-Al2O3.

[0089] Example 1: Preparation of Pd / Al2O3 Catalyst with 1 wt% Pd Metal Loading

[0090] Preparation of catalyst: 1gAl2O3 (oxide carrier) was dispersed in 100mL water in a 250mL round-bottom flask, and then 10ml aqueous solution containing 27.8mg Na2PdCl4 (precursor) (Pd is an active metal) was added under stirring, and stirring was continued for 2h. The product was separated by centrifugation to obtain a precipitate, which was washed with water. The washed precipitate was dried at 60°C for 12h. The dried precipitate was placed in a crucible, and then the crucible was placed in a muffle furnace, the heating rate was set to 2°C / min, the temperature was raised to 600°C and roasted for 4h, and then naturally cooled to room temperature. The crucible was then placed in a tubular furnace, and a hydrogen-argon mixed gas containing 5vol% hydrogen was introduced, the gas flow rate was set to 50mL / min, the air replacement time was 20min, the heating rate was set to 2°C / min, the temperature was raised to 300°C for reduction reaction for 2h, and then naturally cooled to room temperature, and the gas was turned off to obtain a Pd / Al2O3 catalyst with a Pd metal loading of 1wt%.

[0091] Catalyst characterization: The above catalysts were characterized. Figure 1 It is a transmission electron microscopy photograph of Pd / Al2O3 catalyst. The results show that Pd NPs are uniformly dispersed on the surface of Al2O3 carrier, there are no large-sized particles, and the particle size is very small (<5nm). Representative nanoparticles are marked with white dotted circles in the figure. Figure 2 is the powder X-ray diffraction spectrum of Pd / Al2O3 catalyst. Figure 2 It can be seen that the powder X-ray diffraction spectrum of the catalyst can only show the diffraction peak of Al2O3 material, but no diffraction peak of Pd NPs, indicating that the nanoparticles are all small in size and no large particles exist. Figure 3 This is the in situ CO adsorption infrared spectrum (CO-FTIR) of Pd / Al2O3 catalyst, showing the typical CO adsorption pattern exhibited by Pd NPs. Figure 4 The scanning transmission electron microscopy (STEM) image and energy dispersive spectroscopy (EDS) elemental distribution characterization of the Pd / Al2O3 catalyst show that the Pd NPs are well dispersed on the Al2O3 surface and there are no large-sized Pd NPs. The in situ X-ray photoelectron spectroscopy (XPS) of the Pd / Al2O3 catalyst is shown in Figure 5 , Figure 5 It is proved that Pd NPs contain zero-valent and positive-valent Pd elements, indicating that the Pd in ​​the Pd / Al2O3 catalyst is in a mixed valence state and has abundant interfaces (Pd-O-Al). The mixed valence state of the Pd element and the abundant interfaces (Pd-O-Al) are further characterized by synchrotron X-ray absorption fine structure spectroscopy, see Fig.11 and Fig.12First, from the white edge position of the Pd K-edge X-ray near-edge absorption structure (XANES), it can be seen that Pd is between 0 and +2 valence states, indicating that Pd is in a mixed valence state, including zero-valent and positive-valent Pd elements ( Fig.11 ). In addition, from the X-ray extended edge absorption structure (EXAFS) of the Pd K edge, it can be seen that pure Pd metal only has Pd-Pd bonds, PdO only has Pd-O bonds, and Pd / Al2O3 catalysts have both Pd-Pd bonds and Pd-O bonds, indicating that there are Pd-Pd bonds between Pd elements, and the Pd elements in contact with the support are bonded to alumina through Pd-O bonds, that is, there is a Pd-O-Al interface, and the interface is rich ( Fig.12 ).

[0092] Selective catalytic preparation of cyclohexanone from phenol: 10.6 mg of the Pd / Al2O3 catalyst (containing 1 μmol Pd) with a Pd metal loading of 1 wt% prepared in Example 1 was dispersed in 5 mL of water, and then 94 mg of phenol (1 mmol) was added under stirring at 30°C. Next, 0.1 MPa of H2 (i.e., hydrogen and air in a volume ratio of 1:1, with a total gas pressure of 0.2 MPa) was refilled into the container while 0.1 MPa of air was contained in the container. At different times during the reaction, 100 μL of the reaction solution was taken out and analyzed by gas chromatography. Note: After each sampling, 0.1 MPa of air was used to purge for 10 s to remove residual H2, and then 0.1 MPa of H2 (i.e., hydrogen and air in a volume ratio of 1:1, with a total gas pressure of 0.2 MPa) was refilled into the container while 0.1 MPa of air was contained in the container for further reaction. Figure 6 As shown in the figure, phenol was completely converted into cyclohexanone within 5 hours at 30°C without the formation of cyclohexanol as a by-product. Figure 7 As shown, the reaction proceeds according to standard first-order kinetics, indicating that the reaction rate is proportional to the first power of phenol concentration and the catalyst has good stability.

[0093] Investigation of the stability of the catalytic activity of the catalyst: 10.6 mg of the Pd / Al2O3 catalyst prepared in Example 1 with a Pd metal loading of 1 wt% was tested 10 times in a cycle according to the above-mentioned method for selectively catalyzing phenol to prepare cyclohexanone, with each reaction lasting 5 hours. The conversion rate and selectivity of cyclohexanone were tested for each reaction. The results are shown in Table 1. The catalyst showed no deactivation in the 10 cycle tests, further confirming its high stability.

[0094] result:

[0095] Table 1: Investigation results of catalyst catalytic activity stability

[0096] Cycle Test Conversion rate Cyclohexanone selectivity 1st time ＞99.9％ ＞99.9％ 2nd ＞99.9％ ＞99.9％ 3rd ＞99.9％ ＞99.9％ 4th ＞99.9％ ＞99.9％ 5th ＞99.9％ ＞99.9％ 6th ＞99.9％ ＞99.9％ 7th ＞99.9％ ＞99.9％ 8th ＞99.9％ ＞99.9％ 9th ＞99.9％ ＞99.9％ 10th ＞99.9％ ＞99.9％

[0097] Conclusion: The catalyst provided by the present invention can maintain a cyclic test of 5 hours per reaction for at least 10 times, has significant stability, is beneficial to reducing reaction costs and promoting the industrialization of products.

[0098] Example 2: Investigation of oxide supports and active metals

[0099] The preparation method of the catalyst of Example 1 is referred to and the oxide carrier is adjusted to be one of SiO2, MgO, CeO2, TiO2, ZrO2, ZnO, AlN, Al(OH)3, C3N4 and XC-72, respectively. The feed mass of the adjusted oxide carrier is the same as the feed mass of the oxide carrier of Example 1. Except for the oxide carrier, the other conditions and operations are the same as those of "Preparation of Catalyst" in Example 1, and Pd / SiO2, Pd / MgO, Pd / CeO2, Pd / TiO2, ... O2, Pd / ZrO2, Pd / ZnO, Pd / AlN, Pd / Al(OH)3, Pd / C3N4 and Pd / XC-72 catalysts, and the obtained Pd / SiO2, Pd / MgO, Pd / CeO2, Pd / TiO2, Pd / ZrO2, Pd / ZnO, Pd / AlN, Pd / Al(OH)3, Pd / C3N4 and Pd / XC-72 catalysts were investigated according to the method of "selective catalysis of phenol to prepare cyclohexanone" described in Example 1, and the reaction was carried out for 5 hours.

[0100] Refer to the preparation method of the catalyst in Example 1 and adjust the precursors to chlororuthenic acid, nickel nitrate, chloroplatinic acid, and chlororhodic acid (active metals are Ru, Ni, Pt, and Rh, respectively). The mass of the active metal in the adjusted precursor is the same as the mass of the active metal in Example 1. Except for the precursor, the other conditions and operations are the same as those in the "Preparation of Catalyst" in Example 1, and Ru / γ-Al2O3, Ni / γ-Al2O3, Pt / γ-Al2O3 and Rh / γ-Al2O3 catalysts are obtained respectively. The obtained Ru / γ-Al2O3, Ni / γ-Al2O3, Pt / γ-Al2O3 and Rh / γ-Al2O3 catalysts are taken and investigated according to the "Selective Catalysis of Phenol to Prepare Cyclohexanone" method described in Example 1, and the reaction is carried out for 5 hours.

[0101] Results: See Table 2.

[0102] Table 2: Investigation of different oxide supports and active metals

[0103]

[0104]

[0105] Conclusion: Compared with catalysts prepared by using other active metals or other types of carriers, the Pd / Al2O3, Pd / SiO2, Pd / MgO, Pd / CeO2, Pd / TiO2 and Pd / ZrO2 catalysts provided by the present invention can selectively catalyze the hydrogenation of phenol to cyclohexanone, with a conversion rate greater than 99.9% and a selectivity greater than 99.9%, and have excellent catalytic activity.

[0106] Example 3: Investigation of Pd metal loading

[0107] Referring to the preparation method of the catalyst in Example 1, the feeding amount of Na2PdCl4 was adjusted to prepare Pd / Al2O3 catalysts with Pd metal loadings of 0.1wt%, 0.5wt%, 2wt%, 4wt%, 6wt%, 8wt% and 10wt%, respectively. Then, the catalysts with different Pd metal loadings were taken for investigation according to the method of "selective catalysis of phenol to prepare cyclohexanone" described in Example 1. The investigation time of the catalytic reaction of the catalyst with a loading of less than 1wt% was extended to 10h.

[0108] Results: See Table 3.

[0109] Table 3: Investigation of different Pd metal loadings

[0110]

[0111] Conclusion: The obtained catalysts with different Pd metal loadings can all catalyze the selective hydrogenation of phenol to cyclohexanone, with a conversion rate greater than 99.9% and a selectivity greater than 99.9%.

[0112] Example 4: Investigation of reaction solvents in catalytic reactions

[0113] 10.6 mg of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% prepared in Example 1 was tested according to the method for selectively catalyzing phenol to prepare cyclohexanone and reacted for 5 hours. The only difference from Example 1 was the different solvents used in the selective catalytic reaction of phenol to prepare cyclohexanone. The solvents used were methanol, ethanol, acetonitrile, toluene and one of dioxane.

[0114] Results: See Table 4.

[0115] Table 4: Investigation of different reaction solvents for catalytic reactions

[0116]

[0117] Conclusion: In the above solvents, phenol can be selectively catalytically hydrogenated to cyclohexanone, with a conversion rate greater than 99.9% and a cyclohexanone selectivity greater than 99.9%.

[0118] Example 5: Temperature investigation of catalytic reaction

[0119] 10.6 mg of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% prepared in Example 1 was tested according to the method for selectively catalyzing phenol to prepare cyclohexanone. The reaction was carried out for 5 hours. The only difference from Example 1 was the reaction temperature in the selective catalytic reaction of phenol to prepare cyclohexanone. The reaction temperatures used were 0°C, 10°C, 20°C, 50°C and 70°C, respectively.

[0120] Results: See Table 5.

[0121] Table 5: Investigation of different reaction temperatures in the selective catalytic reaction of phenol to cyclohexanone

[0122]

[0123]

[0124] Conclusion: At the reaction temperature in the above selective catalytic reaction of preparing cyclohexanone from phenol, phenol can be selectively catalytically hydrogenated to cyclohexanone, with a conversion rate of more than 99.9% and a cyclohexanone selectivity of more than 99.9%.

[0125] Example 6: Investigation of Hydrogen Pressure in Catalytic Reaction

[0126] 10.6 mg of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% prepared in Example 1 was taken and tested according to the method for selective catalytic preparation of cyclohexanone from phenol. The reaction was carried out for 5 hours. The only difference from Example 1 was the different hydrogen pressures in the catalytic reaction. The pressures of the hydrogen used were 0.01 MPa, 0.05 MPa, 0.2 MPa, 0.4 MPa and 0.6 MPa, respectively (i.e., the volume ratios of hydrogen to air were 1:10, 1:2, 2:1, 4:1, 6:1, respectively, and the total gas pressures were 0.11 MPa, 0.15 MPa, 0.3 MPa, 0.5 MPa, .7 MPa, respectively).

[0127] Results: See Table 6.

[0128] Table 6: Investigation of hydrogen pressure

[0129]

[0130] Conclusion: Under the above hydrogen pressure, phenol can be selectively catalytically hydrogenated to cyclohexanone using the catalyst provided by the present invention, with a conversion rate greater than 99.9% and a cyclohexanone selectivity greater than 99.9%.

[0131] The catalyst of the present invention uses a mixed gas of a second gas containing oxygen (such as oxygen or air) and a small amount of hydrogen as an atmosphere condition to catalyze hydrogenation to prepare cyclohexanone, which is beneficial to reducing costs and facilitating industrial development.

[0132] Example 7: Investigation of oxygen pressure in catalytic reaction

[0133] 10.6 mg of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% prepared in Example 1 was taken and tested according to the method for selectively catalyzing phenol to prepare cyclohexanone. The reaction was carried out for 5 hours. The only difference from Example 1 was that the air was replaced by oxygen, and the pressures of the oxygen used were 0.01 MPa, 0.05 MPa, 0.2 MPa, 0.4 MPa and 0.6 MPa, respectively (i.e., the volume ratios of oxygen to hydrogen were 1:10, 1:2, 2:1, 4:1 and 6:1, respectively, and the total gas pressures were 0.11 MPa, 0.15 MPa, 0.3 MPa, 0.5 MPa and 0.7 MPa, respectively).

[0134] result:

[0135] See Table 7.

[0136] Table 7: Investigation of oxygen pressure

[0137]

[0138] Conclusion: Under the above oxygen pressure, phenol can be selectively catalytically hydrogenated to cyclohexanone using the catalyst provided by the present invention, with a conversion rate greater than 99.9% and a cyclohexanone selectivity greater than 99.9%.

[0139] Comparative Example 8: Investigation of Catalyst

[0140] Al2O3, SiO2, MgO, CeO2, TiO2, ZrO2, Pd nanoparticles ( Figure 8 ) and a physical mixture of Al2O3 and Pd nanoparticles were used as catalysts, respectively, and the method for selectively catalyzing phenol to prepare cyclohexanone described in Example 1 was investigated and the reaction was carried out for 5 hours.

[0141] Results: See Table 8.

[0142] Table 8: Investigation of different catalysts

[0143]

[0144] Conclusion: The conversion rate of the reaction using the above catalysts is no more than 5%.

[0145] Comparative Example 9: Investigation of Catalytic Reaction Conditions (without Oxygen)

[0146] 10.6 mg of the Pd / Al2O3 catalyst prepared in Example 1 with a Pd metal loading of 1 wt% was dispersed in 5 mL of water, and then 94 mg of phenol (1 mmol) was added under stirring at 30° C. Next, 0.1 MPa of hydrogen was introduced into the container and air was excluded. The reaction was carried out for different time periods, and 100 μL of the reaction solution was taken out and analyzed by gas chromatography.

[0147] 10.6 mg of the Pd / Al2O3 catalyst prepared in Example 1 with a Pd metal loading of 1 wt% was dispersed in 5 mL of water, and then 94 mg of phenol (1 mmol) was added under stirring at 30° C. Next, 0.2 MPa of hydrogen was introduced into the container and air was excluded. The reaction was carried out for different time periods, and 100 μL of the reaction solution was taken out and analyzed by gas chromatography.

[0148] Results: See Table 9 and Fig. 9 .

[0149] Table 9: Catalytic reactions under oxygen-free conditions

[0150]

[0151]

[0152] Conclusion: In the absence of oxygen, the catalyst provided by the present invention is difficult to fully catalyze the selective hydrogenation of phenol to cyclohexanone, and the conversion rate is less than 4%. Fig. 9 shown.

[0153] Comparative Example 10: Investigation of catalytic reaction conditions (without hydrogen)

[0154] 10.6 mg of the Pd / Al2O3 catalyst prepared in Example 1 with a Pd metal loading of 1 wt% was dispersed in 5 mL of water, and then 94 mg of phenol (1 mmol) was added under stirring at 30° C. Next, 0.1 MPa of air was introduced into the container. The reaction was carried out for different time periods, and 100 μL of the reaction solution was taken out and analyzed by gas chromatography.

[0155] 10.6 mg of the Pd / Al2O3 (1 μmol Pd) catalyst prepared in Example 1 was dispersed in 5 mL of water, and then 94 mg of phenol (1 mmol) was added under stirring at 30° C. Next, 0.2 MPa of air was introduced into the container. The reaction was carried out for different time periods, and 100 μL of the reaction solution was taken out and analyzed by gas chromatography.

[0156] result:

[0157] See Table 10 and Fig.10 .

[0158] Table 10: Catalytic reactions without hydrogen

[0159]

[0160]

[0161] Conclusion: In the absence of hydrogen, the catalyst provided by the present invention is difficult to selectively catalyze the hydrogenation of phenol to cyclohexanone, and the conversion rate is almost 0%. Fig.10 shown.

[0162] Example 11: Investigation of Catalyst Feeding Amount in Catalytic Reaction

[0163] 10.6 mg of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% prepared in Example 1 was taken and examined with reference to the method for selectively catalyzing phenol to prepare cyclohexanone. The differences from Example 1 are the different feeding molar ratios of the Pd element to the reaction substrate phenol in the catalyst and the different catalytic reaction time. The feeding molar ratios of the Pd element to the reaction substrate phenol in the catalyst are 1:50, 1:100, 1:200, and 1:2000, respectively, and the reaction time of the catalytic reaction is carried out according to Table 11.

[0164] Results: See Table 11.

[0165] Table 11: Investigation of catalyst dosage in catalytic reaction

[0166]

[0167] Conclusion: At least within the range of the molar ratio of the Pd element to the reaction substrate phenol in the above catalyst, phenol can be selectively catalytically hydrogenated to cyclohexanone, with a conversion rate greater than 99.9% and a cyclohexanone selectivity greater than 99.9%, indicating that a small amount of the catalyst provided by the present invention still has significant activity in catalytically hydrogenating phenol compounds to cyclohexanone compounds, and the catalyst provided by the present invention has good activity in catalytically hydrogenating phenol compounds to cyclohexanone compounds.

[0168] Example 12: Investigation of reaction substrates for catalytic reactions

[0169] 10.6 mg of the Pd / Al2O3 catalyst with a Pd metal loading of 1 wt% prepared in Example 1 was taken and examined with reference to the method for selectively catalyzing phenol to prepare cyclohexanone. The reaction was carried out for 5 hours. The only difference from Example 1 was the difference in the reaction substrates, which were respectively p-methylphenol, o-methylphenol, m-methylphenol, p-ethylphenol, p-tert-butylphenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, p-ethoxyphenol, p-fluorophenol, p-chlorophenol, p-bromophenol, p-hydroxybenzaldehyde and one of p-hydroxyacetophenone; the adjusted molar amount of the reaction substrate was the same as that in Example 1.

[0170] Results: See Table 12.

[0171] Table 12: Investigation of different reaction substrates

[0172] Reaction substrate Conversion rate product Cyclohexanone compounds selectivity p-Toluene ＞99.9％ p-Methylcyclohexanone ＞99.9％ o-Cresol ＞99.9％ o-Methylcyclohexanone ＞99.9％ m-Cresol ＞99.9％ m-Methylcyclohexanone ＞99.9％ p-Ethylphenol ＞99.9％ 4-Ethylcyclohexanone ＞99.9％ 4-tert-Butylphenol ＞99.9％ 4-tert-Butylcyclohexanone ＞99.9％ Hydroquinone ＞99.9％ 1,4-Cyclohexanedione ＞99.9％ Catechol ＞99.9％ 1,2-Cyclohexanedione ＞99.9％ Resorcinol ＞99.9％ 1,3-Cyclohexanedione ＞99.9％ p-Methoxyphenol ＞99.9％ p-Methoxycyclohexanone ＞99.9％ p-Ethoxyphenol ＞99.9％ 4-Ethoxycyclohexanone ＞99.9％ p-Fluorophenol ＞99.9％ 4-Fluorocyclohexanone ＞99.9％ p-Chlorophenol ＞99.9％ 4-Chlorocyclohexanone ＞99.9％ p-Bromophenol ＞99.9％ 4-Bromocyclohexanone ＞99.9％ p-Hydroxybenzaldehyde ＞99.9％ Cyclohexanone-4-carboxaldehyde ＞99.9％ p-Hydroxyacetophenone ＞99.9％ 4-Acetylcyclohexanone ＞99.9％

[0173] Conclusion: Any of the substrates, including p-methylphenol, o-methylphenol, m-methylphenol, p-ethylphenol, p-tert-butylphenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, p-ethoxyphenol, p-fluorophenol, p-chlorophenol, p-bromophenol, p-hydroxybenzaldehyde and p-hydroxyacetophenone, can be selectively catalytically hydrogenated to the corresponding cyclohexanone compounds, with a conversion rate greater than 99.9% and a cyclohexanone compound selectivity greater than 99.9%.

[0174] Example 13: Investigation of Calcination Temperature in Catalyst Preparation

[0175] The preparation method of the catalyst of Example 1 was referred to and the calcination temperature in the muffle furnace was adjusted to one of 50° C., 100° C., 200° C., 300° C., 400° C., 500° C., 600° C., 700° C., 800° C., 900° C. and 1000° C. The catalysts obtained at each calcination temperature were investigated according to the method for selectively catalyzing phenol to prepare cyclohexanone as described in Example 1, and the reaction was carried out for 5 hours.

[0176] Results: See Table 13.

[0177] Table 13: Results of investigation on calcination temperature in catalyst preparation

[0178]

[0179]

[0180] Conclusion: The Pd / Al2O3 catalysts obtained by calcining at 300℃, 400℃, 500℃ and 600℃ in the catalyst preparation process can selectively catalyze the hydrogenation of phenol to cyclohexanone, and the phenol conversion rate is greater than 99.9% and the cyclohexanone selectivity is greater than 99.9% after 5h.

[0181] Example 14: Investigation of reduction temperature in catalyst preparation

[0182] The catalyst preparation method of Example 1 was referred to and the temperature of the reduction reaction was adjusted to one of 50° C., 100° C., 150° C., 200° C., 400° C., 500° C., 600° C., 700° C., 800° C., 900° C. and 1000° C. The catalysts obtained at each calcination temperature were investigated according to the method for selectively catalyzing phenol to prepare cyclohexanone as described in Example 1, and the reaction was carried out for 5 hours.

[0183] Results: See Table 14.

[0184] Table 14: Results of investigation on reduction temperature in catalyst preparation

[0185] Reduction temperature in catalyst preparation Conversion rate Cyclohexanone selectivity 50℃ ＜50％ ＞99.9％ 100℃ ＜50％ ＞99.9％ 150℃ ＜50％ ＞99.9％ 200℃ ＞99.9％ ＞99.9％ 400℃ ＞99.9％ ＞99.9％ 500℃ ＜90％ ＞99.9％ 600℃ ＜70％ ＞99.9％ 700℃ ＜50％ ＞99.9％ 800℃ ＜50％ ＞99.9％ 900℃ ＜50％ ＞99.9％ 1000℃ ＜50％ ＞99.9％

[0186] Conclusion: The Pd / Al2O3 catalyst obtained when the reduction reaction temperature in the catalyst preparation is 200℃-400℃ can selectively catalyze the hydrogenation of phenol to cyclohexanone. After 5h, the phenol conversion rate is greater than 95% and the cyclohexanone selectivity is greater than 99.9%.

[0187] The method of the present invention has been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein within the content, spirit and scope of the present invention to implement and apply the technology of the present invention. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention.

Claims

1. A catalyst, characterized in that The catalyst is composed of an oxide support and palladium nanoparticles, wherein the oxide support includes at least one of Al2O3, SiO2, MgO, CeO2, TiO2 and ZrO2, preferably Al2O3, and more preferably γ-Al2O3; there is an interface between the oxide support and the palladium nanoparticles composed of palladium metal, oxygen in the oxide support and metal in the oxide support, and the palladium metal and oxygen in the oxide support, as well as oxygen in the oxide support and metal in the oxide support, are connected by chemical bonds respectively.

2. The catalyst according to claim 1, wherein the loading amount of the palladium nanoparticles on the oxide carrier in the catalyst is 0.1wt%-10wt% or 0.5wt%-5wt%, or 1wt%; and / or The palladium nanoparticles include zero-valent palladium element and positive-valent palladium element; and / or The positive-valent palladium element is a +2-valent palladium element and / or a +1-valent palladium element; and / or In the X-ray photoelectron spectroscopy of the catalyst, the Pd 3d 5 / 2 The binding energy of the zero-valent palladium element Pd 3d 3 / 2 The binding energy is 339eV-342eV, preferably 340.8eV; and / or In the X-ray photoelectron spectrum of the catalyst, the Pd 3d 5 / 2 The binding energy of the positive palladium element Pd 3d 3 / 2 The binding energy is 341eV-344eV, preferably 342.4eV; and / or The particle size of the palladium nanoparticles is less than or equal to 5 nm.

3. The catalyst according to any one of claims 1 to 2, wherein the oxide carrier is γ-Al2O3, the loading amount of the palladium nanoparticles in the catalyst is 1wt%, and the powder X-ray diffraction spectrum of the catalyst is shown in FIG2; and / or The oxide carrier is γ-Al2O3, the loading amount of the palladium nanoparticles in the catalyst is 1 wt%, and the in-situ CO adsorption infrared spectrum of the catalyst is shown in FIG3 .

4. A method for preparing the catalyst according to any one of claims 1 to 3, characterized in that: include: The oxide carrier and the palladium precursor are mixed in a solvent, stirred, centrifuged or filtered to obtain a solid, which is then washed with water, dried, calcined, and reduced in a hydrogen-argon mixed gas to obtain the catalyst.

5. The preparation method according to claim 4, wherein the solvent is water; and / or The stirring time is 1h-10h or 2h; and / or The calcination temperature is 300°C-600°C; and / or The reduction temperature is 200°C-400°C; and / or The volume percentage of hydrogen in the hydrogen-argon mixed gas is 1 vol%-10 vol%, preferably 5 vol%; and / or The reduction time is 1h-10h; and / or The palladium precursor is at least one of sodium chloropalladate, chloropalladic acid, palladium acetate, palladium acetylacetonate, palladium nitrate, and diacetonitrile palladium chloride; and / or The mass ratio of palladium in the palladium precursor to the oxide carrier is 0.1:100-10:

100.

6. Use of the catalyst according to any one of claims 1 to 3 or the catalyst obtained by the preparation method according to any one of claims 4 to 5 in the selective catalytic preparation of cyclohexanone compounds from phenol compounds.

7. A method for preparing cyclohexanone compounds, comprising: The catalyst according to any one of claims 1 to 3 or the catalyst obtained by the preparation method according to any one of claims 4 to 5, a phenol compound and a reaction solvent are mixed, and reacted in the presence of hydrogen and a second gas to obtain a cyclohexanone compound, wherein the second gas is a gas containing oxygen.

8. The method according to claim 7, wherein the structure of the phenol compound is: The structure of the cyclohexanone compound is: in, (R2)m means that the m H groups on the ring are independently replaced by m identical or different R2 substituents, m is 0, 1, 2, 3, 4 or 5; (R3)n means that n H groups on the ring are independently replaced by n R3 substituents, wherein R3 is a hydroxyl group; (R4)n means that 2n H atoms on the ring are independently replaced by n R4 atoms; wherein R4 is =O; n is 0, 1, 2, 3, 4 or 5; And 0≤m+n≤5; Each R2 is independently alkyl, alkoxy, halogen, aldehyde or -COR1; Wherein R1 is alkyl, hydroxy, alkoxy or halogen.

9. The method according to any one of claims 7-8, wherein the reaction solvent is at least one of water, methanol, ethanol, acetonitrile, toluene, tetrahydrofuran, GBL (γ-butyrolactone), chlorobenzene, DMF (N,N-dimethylformamide), NMP (N-methylpyrrolidone), DMC (dimethyl carbonate) and dioxane; and / or The reaction temperature of the reaction is 0°C-70°C; and / or The reaction time of the reaction is 0.5h-50h; and / or The volume ratio of the hydrogen to the second gas is 1:20-20:1 or 1:10-10:1; and / or The total gas pressure of the hydrogen and the second gas is 0.1MPa-1.0MPa or 0.11MPa-0.7MPa; and / or The molar ratio of palladium element in the catalyst to the phenol compound is 1:50-1:5000 or 1:50-1:2000 or 1:50-1:1000; and / or The second gas is at least one of oxygen, air, an oxygen-argon mixed gas, or an oxygen-nitrogen mixed gas.

10. The method according to any one of claims 7 to 8, wherein the phenol compound is selected from at least one of p-methylphenol, o-methylphenol, m-methylphenol, p-ethylphenol, p-tert-butylphenol, hydroquinone, catechol, resorcinol, p-methoxyphenol, p-ethoxyphenol, p-fluorophenol, p-chlorophenol, p-bromophenol, p-hydroxybenzaldehyde and p-hydroxyacetophenone; The cyclohexanone compound is selected from at least one of p-methylcyclohexanone, o-methylcyclohexanone, m-methylcyclohexanone, p-ethylcyclohexanone, p-tert-butylcyclohexanone, 1,4-cyclohexanedione, 1,2-cyclohexanedione, 1,3-cyclohexanedione, p-methoxycyclohexanone, p-ethoxycyclohexanone, p-fluorocyclohexanone, p-chlorocyclohexanone, p-bromocyclohexanone, cyclohexanone-4-carboxaldehyde and 4-acetylcyclohexanone.

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