Hydrogenation catalyst, method for preparing and using same, and method for preparing alpha-methylbenzyl alcohol

Abstract

The application relates to the field of catalysts, and discloses a hydrogenation catalyst, a preparation method and application thereof, and a method for preparing alpha-methylbenzyl alcohol, the hydrogenation catalyst comprising a hydrogenation active component and a SiO2 carrier; and the catalyst surface is modified by a siloxane group. The hydrogenation catalyst has the characteristics of high low-temperature hydrogenation activity and long service life. The hydrogenation catalyst is used in a liquid-phase hydrogenation reaction, the hydrogenation catalyst has high catalytic activity, the low-temperature liquid-phase reaction can be better carried out, for example, in the preparation of alpha-methylbenzyl alcohol, the raw material acetophenone can have high conversion rate, the alpha-methylbenzyl alcohol has high selectivity, and the hydrogenation catalyst has long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysts, in particular to a hydrogenation catalyst, a preparation method and application thereof, and a method for preparing alpha-methylbenzene methanol. BACKGROUND

[0002] Acetophenone (AP) is a by-product in the process of preparing propylene oxide (PO) by PO / SM method. After being hydrogenated to prepare 1-phenylethanol (PhE), it is dehydrated to form styrene (SM), thereby improving the utilization rate of raw material ethylbenzene and reducing the unit consumption. The activity of acetophenone hydrogenation is higher than that of aliphatic ketones such as acetone, and the main reason is that the benzene group provides conjugated electrons, which increases the polarity of the C=O bond of acetophenone, making it easy to adsorb on the surface of the catalyst and be activated.

[0003] The selective hydrogenation of acetophenone (ACP) to alpha-methylbenzene methanol (MBA) has been studied on different metals. Common acetophenone hydrogenation catalysts include noble metal catalysts with palladium, platinum, ruthenium, and rhodium as active components, nickel-based catalysts, and copper-based catalysts. Although noble metal catalysts and nickel-based catalysts are used for acetophenone hydrogenation reaction, the selectivity of alpha-methylbenzene methanol is poor [Wang Yuzhen, Qiao Minghua, Hu Huarong, Yan Shirun, Wang Weijiang, Fan Kangnian, Preparation and characterization of Ni-Sn-B / SiO2 amorphous catalyst for high selective hydrogenation of acetophenone, Acta Chimica Sinica, 2004, Vol. 62, No. 14, 1349-1352; Sheng Xudong, Zhang Wei, Lu Mehong, Pd / mesoporous carbon catalytic selective hydrogenation of acetophenone to prepare alpha-phenylethanol. Fine petroleum chemical industry, 2015, 32(2): 58-62.]. Copper-based catalysts have good low-temperature activity, strong C-O bond selectivity, and weak C-C bond formation ability, which can improve the selectivity of phenylethanol.

[0004] Wang Bing (Wang Bing, Master's Thesis of Qingdao University of Science and Technology, 2019) and others of Qingdao University of Science and Technology studied the influence of the preparation method of Cu / SiO2 catalyst on its performance in acetophenone hydrogenation, and found that the Cu / SiO2 catalyst prepared by the urea method has the best performance, but they did not systematically study the influence of silicon source and additives on the Cu / SiO2 catalyst. N.M.Bertero et al. (Applied Catalysis A: General 349 (2008) 100-109) studied the influence of solvent on the performance of acetophenone hydrogenation on Cu / SiO2 catalyst, and found that the activity order of AP hydrogenation corresponding to different solvents is IPA > cyclohexane > toluene > benzene. They also conducted a kinetic study and found that AP is strongly adsorbed on the Cu / SiO2 catalyst, and has a negative order in the reaction, while PhE is weakly adsorbed on the catalyst surface and quickly desorbs from the catalyst surface after the reaction.

[0005] Sumitomo Chemical Company has reported Cu / SiO2 for acetophenone hydrogenation reaction [Oku et al., Sumitomo Chemical Company. US6410806, 2002.; T. Hibi, S. Ito, Sumitomo Chemical Company. US5663458, 1997.], when the copper content is greater than 65%, the selectivity of α-methylbenzyl alcohol is higher. At the same time, the addition of alkali or alkaline earth metal can effectively prevent the occurrence of α-methylbenzyl alcohol hydrogenolysis reaction.

[0006] The catalyst for preparing α-methylbenzyl alcohol from acetophenone belongs to hydrogenation catalyst, and the above reports do not involve the deactivation problem of the catalyst under low temperature reaction condition. SUMMARY

[0007] In hydrogenation reaction, especially in liquid phase hydrogenation reaction, the activity of hydrogenation catalyst is crossed, and the generation of water in the hydrogenation reaction process will cause the deactivation of hydrogenation catalyst. The purpose of the present application is to overcome the problems of poor reaction activity and poor catalyst stability of the existing hydrogenation catalyst in use, especially in liquid phase hydrogenation reaction, to provide a new hydrogenation catalyst and its preparation method and application, and a method for preparing α-methylbenzyl alcohol using the hydrogenation catalyst. The hydrogenation catalyst has the advantages of high low-temperature hydrogenation activity and long service life.

[0008] The first aspect of the present application provides a hydrogenation catalyst, which comprises a hydrogenation active component and a SiO2 carrier; the surface of the catalyst is modified with siloxane group.

[0009] The second aspect of the present application provides a preparation method of hydrogenation catalyst, which comprises: modifying the surface of SiO2 carrier loaded with hydrogenation active component to obtain hydrogenation catalyst.

[0010] The third aspect of the present application provides the application of the hydrogenation catalyst of the present application and / or the hydrogenation catalyst prepared by the preparation method of the hydrogenation catalyst of the present application in liquid phase hydrogenation reaction.

[0011] The fourth aspect of the present application provides a method for preparing α-methylbenzyl alcohol, which comprises: contacting a raw material mixture containing acetophenone with hydrogen in the presence of the hydrogenation catalyst of the present application and / or the hydrogenation catalyst prepared by the preparation method of the hydrogenation catalyst of the present application to carry out liquid phase hydrogenation reaction.

[0012] The beneficial effects that can be obtained by the present invention through the above technical solution include: the hydrogenation catalyst provided by the present invention has high low-temperature liquid phase reaction catalyst activity, which can reduce the possibility of dehydration side reaction during liquid phase reaction and reduce the possibility of water accumulation in the active center of the catalyst, thereby improving the stability of the catalyst during low-temperature reaction. Attached Figure Description

[0013] Figure 1 These are the hydroxyl infrared spectra of hydrogenation catalyst CM-1 and hydrogenation catalyst SCM-1 in Example 1. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] In this invention, to a certain extent, the stability of the hydrogenation catalyst is positively correlated with the single-pass lifetime of the catalyst, wherein the single-pass lifetime refers to a certain active time during which the catalyst can achieve the conversion rate of raw materials and the selectivity of target products.

[0016] The first aspect of the present invention provides a hydrogenation catalyst comprising a hydrogenation active component and a SiO2 support; the catalyst surface is modified with siloxane.

[0017] In this invention, the hydrogenation catalyst provided by this invention has a siloxane-modified surface, which gives it good stability.

[0018] According to a preferred embodiment of the present invention, the support is modified with siloxane. The hydrogenation catalyst of this embodiment can reduce the likelihood of dehydration side reactions and the possibility of water accumulation at the catalyst active sites, thereby improving the stability of the hydrogenation catalyst at low temperatures.

[0019] According to a preferred embodiment of the present invention, the siloxane is provided by a siloxane-containing compound. The hydrogenation catalyst of this embodiment can reduce the likelihood of dehydration side reactions and the possibility of water accumulation at the catalyst active site, thereby improving the stability of the hydrogenation catalyst at low temperatures.

[0020] According to a preferred embodiment of the present invention, the siloxane is provided by a siloxane-containing compound as shown in formula (I).

[0021]

[0022] In formula (I), R1, R2, R3 and R4 are each independently an alkyl group.

[0023] In the present application, the "alkyl group" can be a branched alkyl group or a straight chain alkyl group, and the present application does not have a special limitation in this regard.

[0024] According to a preferred embodiment of the present application, in formula (I), R1, R2, R3 and R4 are each independently a C1-C5 alkyl group, preferably a C1-C2 alkyl group. The hydrogenation catalyst of this embodiment has better low-temperature catalytic activity and stability.

[0025] According to the present application, R1, R2, R3 and R4 can be the same or different, and R1, R2, R3 and R4 are the same based on the consideration of easy availability of raw materials.

[0026] According to a preferred embodiment of the present application, the mass ratio of the siloxane group-containing compound to the carrier is 0.05-0.3:1. The hydrogenation catalyst of this embodiment has better low-temperature catalytic activity and stability.

[0027] In one embodiment, the hydrogenation active component comprises Cu and MO x ; the MO x is at least one selected from the group consisting of an oxide of a Group II B metal, an oxide of a Group VI B metal, an oxide of a Group V II B metal and an oxide of a Group VIII metal. In the hydrogenation catalyst of this embodiment, the Cu and the MO x mutually cooperate to improve the catalytic performance of the hydrogenation catalyst and the stability of the catalyst.

[0028] According to a preferred embodiment of the present application, the MO x is at least one selected from the group consisting of ZnO, MnO, CoO and MoO3.

[0029] According to a preferred embodiment of the present application, the MO x is CoO and / or MoO3.

[0030] According to a preferred embodiment of the present application, the Cu is in terms of an element, and the MO x is in terms of an oxide, and the weight ratio of the Cu to the MO x is 1-20. The hydrogenation catalyst of this embodiment has better catalytic activity and stability.

[0031] According to a preferred embodiment of the present application, the hydrogenation active component accounts for 50-400% by weight, preferably 100-300% by weight, of the weight of the carrier.

[0032] The second aspect of the present application provides a method for preparing a hydrogenation catalyst, which comprises: modifying a SiO2 carrier loaded with a hydrogenation active component with a surface siloxane group to obtain the hydrogenation catalyst.

[0033] In the present application, the hydrogenation active component is loaded on the SiO2 carrier, and the SiO2 carrier loaded with the hydrogenation active component is modified with a surface siloxane group, which can replace the silicon hydroxyl group on the surface of the SiO2 carrier, reduce the possibility of dehydration side reaction and the possibility of water accumulation in the active center of the catalyst, thereby improving the stability of the catalyst in low-temperature reaction.

[0034] According to a preferred embodiment of the present application, the method for modifying the surface with a siloxane group comprises: contacting the SiO2 carrier loaded with the hydrogenation active component with a siloxane group-containing compound in the presence of a solvent, heating to reflux, and then drying the solid product. The hydrogenation catalyst obtained by using this embodiment can reduce the possibility of dehydration side reaction and the possibility of water accumulation in the active center of the catalyst, thereby improving the stability of the catalyst in low-temperature reaction.

[0035] According to the present application, the temperature of heating is only required to promote reflux, which is generally near or greater than the boiling point of the solvent.

[0036] According to a preferred embodiment of the present application, the siloxane group-containing compound has a structural formula shown in formula (I),

[0037]

[0038] In formula (I), R1, R2, R3 and R4 are each independently an alkyl group, preferably a C1-C5 alkyl group, and further preferably a C1-C2 alkyl group.

[0039] According to a preferred embodiment of the present application, the mass ratio of the siloxane group-containing compound to the SiO2 carrier source is 0.05-0.3:1, based on SiO2. The hydrogenation catalyst obtained by using this embodiment can well reduce the possibility of water accumulation in the active center of the catalyst, reduce the occurrence of side reactions in the hydrogenation reaction, and increase the stability of the hydrogenation catalyst.

[0040] According to a preferred embodiment of the present application, the solvent is selected from C6-C8 benzene series, and is preferably at least one of benzene, toluene and xylene.

[0041] According to a preferred embodiment of the present application, the mass ratio of the solvent to the SiO2 carrier source is 5-100:1, based on SiO2.

[0042] According to a preferred embodiment of the present application, the heating refluxing condition comprises a temperature of 80-140℃ and a time of 2-24h.

[0043] According to the present application, after the heating refluxing, the solid product can be obtained by filtering the solid from the liquid. The filter cake can be washed with a corresponding solvent to obtain the solid product.

[0044] According to the present application, the drying condition comprises a drying temperature of 60-150℃ and a drying time of 5-20h.

[0045] According to the present application, the drying of the solid product should be carried out in an oxygen-free condition, for example, by vacuum drying or drying under nitrogen protection.

[0046] According to the present application, the method for obtaining the SiO2 carrier loaded with the hydrogenation active component is not particularly limited as long as the purpose of the present application can be achieved. According to a preferred embodiment of the present application, the method for obtaining the SiO2 carrier loaded with the hydrogenation active component comprises kneading a hydrogenation active source, a SiO2 carrier source, optionally an extrusion aid, and optionally water, optionally shaping, and then drying, calcining, and reducing.

[0047] According to a preferred embodiment of the present application, the hydrogenation active source comprises a copper salt precursor and a precursor of metal M; M is selected from at least one of Group II B metal, Group VI B metal, Group V II B metal, and Group VIII metal. By using this preferred embodiment, MO x Modifying Cu / SiO2 catalyst to obtain Cu-MO x / SiO2, which can improve the activity of the catalyst and enable it to react at a lower temperature. The modification of the siloxane group can replace the silicon hydroxyl group on the surface of the carrier SiO2 with the siloxane group, which can reduce the possibility of dehydration side reaction and the possibility of water gathering at the active center of the catalyst, thereby improving the stability of the catalyst at a low temperature.

[0048] According to a particularly preferred embodiment of the present application, M is selected from at least one of Zn, Mn, Co, and Mo, preferably Co and / or Mo. By using the foregoing embodiment, the obtained hydrogenation catalyst has better low-temperature catalytic activity and stability.

[0049] According to a preferred embodiment of the present application, the hydrogenation active component source accounts for 50-400% by weight of the SiO2 carrier source. By using the foregoing embodiment, the obtained hydrogenation catalyst has better low-temperature catalytic activity and stability.

[0050] In the present application, the kneading method and device can be any method and device in the art, for example, the kneading is carried out in a kneader, and the kneading time can be selected as required, for example, the kneading is carried out for 10-60 min.

[0051] According to the present application, "optionally" means that the feature is used or not used as required; for example, optionally shaping means that shaping is carried out or not carried out as required, preferably shaping is carried out, in particular, the kneaded product obtained by kneading can be extruded into a fine strip of a certain diameter in an extruder, for example, the kneaded product is extruded into a fine strip in a double-screw extruder, the diameter of the fine strip can be 1.0-3.0 mm, and the length can be 2-15 mm.

[0052] According to a preferred embodiment of the present application, the copper salt precursor is selected from at least one of nitrate, hydrochloride and basic carbonate of copper.

[0053] According to a preferred embodiment of the present application, the precursor of the metal M is selected from at least one of nitrate, hydrochloride, metalate and basic carbonate of the metal M.

[0054] According to a preferred embodiment of the present application, the SiO2 carrier source is selected from silica powder and / or silica sol.

[0055] According to a preferred embodiment of the present application, the extrusion aid is selected from at least one of sesbania powder, citric acid and graphite powder.

[0056] According to a preferred embodiment of the present application, the weight ratio of the copper salt precursor to the precursor of the metal M is 1-20, wherein the copper salt precursor is in terms of Cu element, and the precursor of the metal M is in terms of M oxide.

[0057] According to a preferred embodiment of the present application, the amount of the extrusion aid is 1%-20% of the mass of the copper salt precursor.

[0058] According to a preferred embodiment of the present application, the amount of water is 5-150% of the mass of the copper salt precursor.

[0059] According to a preferred embodiment of the present application, when the SiO2 carrier loaded with the hydrogenation active component is obtained, the drying conditions include that the drying temperature is 60-150 ℃, and the drying time is 5-20 h.

[0060] According to a preferred embodiment of the present application, the calcination conditions include that the calcination temperature is 300-500 ℃.

[0061] According to a preferred embodiment of the present application, the calcination conditions include that the calcination time is 2-10 h.

[0062] According to a preferred embodiment of the present application, the reduction conditions include reduction with a reducing gas, preferably hydrogen.

[0063] According to a preferred embodiment of the present application, the reduction conditions include that the pressure of the reducing gas is 0.1-1 MPa.

[0064] According to a preferred embodiment of the present application, the reduction conditions include that the gas hourly space velocity is 200-1000 h-1. -1 a.

[0065] According to a preferred embodiment of the present application, the reduction conditions include that the reduction temperature is 160-270℃.

[0066] According to a preferred embodiment of the present application, the reduction conditions include that the reduction time is 2-10 h.

[0067] The third aspect of the present application provides an application of the hydrogenation catalyst and / or the hydrogenation catalyst prepared by the preparation method of the hydrogenation catalyst in a liquid phase hydrogenation reaction.

[0068] In the present application, the hydrogenation catalyst is used in the liquid phase hydrogenation reaction, and the hydrogenation catalyst has high catalytic activity, so that the low-temperature liquid phase reaction can be better carried out, and the possibility of dehydration side reaction and the possibility of water gathering in the active center of the catalyst can be reduced, thereby improving the stability of the catalyst in the low-temperature reaction.

[0069] According to a preferred embodiment of the present application, the hydrogenation catalyst is used in the liquid phase hydrogenation of arylalkyl ketone. In this embodiment, the arylalkyl ketone has high conversion rate and target product selectivity, and the hydrogenation catalyst can be more stably operated in the liquid phase hydrogenation of arylalkyl ketone.

[0070] The fourth aspect of the present application provides a method for preparing α-methylbenzyl alcohol, which comprises: contacting a raw material mixture containing acetophenone with hydrogen in the presence of the hydrogenation catalyst and / or the hydrogenation catalyst prepared by the preparation method of the hydrogenation catalyst.

[0071] In the present application, the hydrogenation catalyst is used in the preparation of α-methylbenzyl alcohol, wherein the raw material acetophenone has high conversion rate, the target product α-methylbenzyl alcohol has high selectivity, and the liquid phase hydrogenation reaction is stably operated for 3000 h, and the selectivity of the raw material acetophenone and α-methylbenzyl alcohol does not decrease obviously.

[0072] According to the present application, the raw material mixture containing acetophenone refers to a raw material mixture of acetophenone and a solvent. The present application does not have special restrictions on the type of the solvent, for example, the solvent in the raw material mixture can be an alkanol; wherein, preferably, the alkanol is a C1-C5 alkyl alcohol, further, methanol and / or ethanol.

[0073] According to the present application, the concentration of acetophenone in the raw material mixture containing acetophenone does not have special restrictions, for example, the raw material mixture with a concentration of 10-50wt% of acetophenone.

[0074] According to the present application, for the conditions of the hydrogenation reaction, a person skilled in the art can select conditions favorable to the hydrogenation reaction according to the needs, in some embodiments, the conditions of the hydrogenation reaction include: the mass space velocity of acetophenone in the raw material mixture is 0.1-1.0h -1 , preferably 0.3-0.6h -1 , including but not limited to 0.35h -1 , 0.4h -1 , 0.45h -1 , 0.5h -1 , 0.55h -1 , etc.

[0075] According to the present application, in some embodiments, the conditions of the hydrogenation reaction include: the hydrogen pressure is 1.0-5MPa, preferably 1.5-4MPa, including but not limited to 2.0MPa, 2.5MPa, 3.0MPa, 3.5MPa, etc.

[0076] According to the present application, in some embodiments, the conditions of the hydrogenation reaction include: the molar ratio of hydrogen to acetophenone in the feed is 1.0-20, preferably 1.2-15, including but not limited to 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, etc.

[0077] According to the present application, in some embodiments, the reaction temperature is 60-120℃, preferably 65-90℃, including but not limited to 70℃, 75℃, 80℃, 85℃, etc.

[0078] The present application will be described in detail below through examples.

[0079] Example 1

[0080] Preparation of hydrogenation catalyst:

[0081] 103.6 g of basic copper carbonate, 13.7 g of ammonium molybdate, and 30.0 g of SiO2 powder were placed in a kneader, 10 g of citric acid and 5 g of guar gum powder were added, and 100 g of water was added. After kneading for 30 min, the mixture was extruded into thin strips with a diameter of 2 mm in an extruder. The strips were dried at 120 °C for 10 h and calcined at 350 °C for 4 h to obtain the catalyst precursor CMO-1.

[0082] CMO-1 was loaded into a fixed-bed reactor and reduced with hydrogen at a pressure of 0.5 MPa and a volume hourly space velocity (HHSV) of 500 h⁻¹. -1 The reduction temperature was 230℃ and the reduction time was 6 hours, resulting in catalyst CM-1.

[0083] 20 g of CM-1 catalyst was placed in a three-necked flask, and 200 mL of toluene and 5 g of tetramethylsilicate were added. The mixture was refluxed at 110 °C for 4 hours, then filtered, washed five times with 200 mL of toluene each time, and then dried under vacuum at 60 °C for 12 hours. The resulting hydrogenation catalyst was designated SCM-1, with the following weight proportions: Cu 57.5 parts, MoO3 9.6 parts, SiO2 28.8 parts, and silicate 4.0 parts.

[0084] The hydroxyl infrared spectra of hydrogenation catalysts CM-1 and SCM-1 are as follows: Figure 1 As shown, through Figure 1 It can be seen that the concentration of silanol groups on the surface of hydrogenation catalyst SCM-1 is significantly lower than that of hydrogenation catalyst CM-1.

[0085] Example 2

[0086] Preparation of hydrogenation catalysts:

[0087] 151.2 g of copper nitrate trihydrate, 18.3 g of zinc nitrate hexahydrate, 25 g of 40% silica sol AN-40, and 44 g of SiO2 powder were placed in a kneader, 20 g of citric acid and 10 g of guar gum powder were added, and 50 g of water were added. After kneading for 30 min, the mixture was extruded into thin strips with a diameter of 2 mm in an extruder. The strips were dried at 80 °C for 20 h and calcined at 500 °C for 2 h to obtain the catalyst precursor CMO-2.

[0088] CMO-2 was loaded into a fixed-bed reactor and reduced with hydrogen at a pressure of 0.8 MPa and a volume hourly space velocity (HHSV) of 800 h⁻¹. -1 The reduction temperature was 180℃ and the reduction time was 9 hours, resulting in catalyst CM-2.

[0089] The 20 g of CM-2 catalyst was placed in a three-necked flask, 400 mL of benzene and 10 g of tetraethyl silicate were added, refluxed at 100°C for 10 hours, then filtered, washed with benzene for 5 times, 200 mL of benzene was used each time, then dried at 100°C under nitrogen atmosphere for 12 h. The obtained hydrogenation catalyst was recorded as SCM-2. The weight fraction of Cu was 37.8 parts, the weight fraction of ZnO was 4.7 parts, the weight fraction of SiO2 was 50.9 parts, and the weight fraction of silicate was 6.6 parts.

[0090] Example 3

[0091] Preparation of hydrogenation catalyst:

[0092] The 120.9 g of basic copper carbonate, 29.4 g of cobalt nitrate hexahydrate, 30 g of 40% silica sol AN-40, 10.5 g of SiO2 powder were placed in a kneader, 5 g of citric acid and 3 g of mung bean powder were added, 20 g of water was added, kneaded for 20 min, then extruded into fine strips with a diameter of 2 mm in an extruder, dried at 120°C for 10 h, calcined at 300°C for 4 h to obtain the catalyst precursor CMO-3;

[0093] The CMO-3 was loaded into a fixed bed reactor and reduced with hydrogen, the hydrogen pressure was 0.3 MPa, the hydrogen volume space velocity was 800 h-1, the reduction temperature was 200°C, and the reduction time was 5 hours, to obtain the catalyst CM-3. -1

[0094] The 20 g of CM-1 catalyst was placed in a three-necked flask, 200 mL of toluene and 5 g of tetramethyl silicate were added, refluxed at 110°C for 4 hours. Then filtered, washed with toluene for 5 times, 200 mL of toluene was used each time, then dried at 60°C under vacuum for 12 h. The obtained hydrogenation catalyst was recorded as SCM-3, the weight fraction of Cu was 68.1 parts, the weight fraction of CoO was 7.3 parts, the weight fraction of SiO2 was 21.9 parts, and the weight fraction of silicate was 2.6 parts.

[0095] Example 4

[0096] Preparation of hydrogenation catalyst:

[0097] The 120.9 g of basic copper carbonate, 37.8 g of 50% aqueous solution of manganese nitrate, 30 g of 40% silica sol AN-40, 10.5 g of SiO2 powder were placed in a kneader, 5 g of citric acid and 3 g of mung bean powder were added, 20 g of water was added, kneaded for 20 min, then extruded into fine strips with a diameter of 2 mm in an extruder, dried at 120°C for 10 h, calcined at 300°C for 4 h to obtain the catalyst precursor CMO-4;

[0098] The CMO-4 was loaded into a fixed bed reactor and reduced with hydrogen, the hydrogen pressure was 0.3 MPa, the hydrogen volume space velocity was 800 h-1, the reduction temperature was 200°C, and the reduction time was 5 hours, to obtain the catalyst CM-4. -1 ​The reduction temperature is 200°C and the reduction time is 5 hours to obtain a catalyst CM-4;

[0099] 20 g of CM-4 catalyst is placed in a three-necked flask, 200 mL of toluene and 5 g of tetramethyl silicate are added, refluxed at 110°C for 4 hours, then filtered and washed with toluene 5 times, each time with 200 mL of toluene, then dried under vacuum at 60°C for 12 h. The obtained hydrogenation catalyst is noted SCM-4. Its weight fractions are Cu 68.3 parts, MnO 7.3 parts, SiO2 22.0 parts, silicate 2.4 parts.

[0100] Example 5

[0101] The method of example 1 is followed, except that the drying under vacuum at 60°C for 12 h is replaced by drying under air atmosphere at 60°C for 12 h. The obtained catalyst is noted SCM-5.

[0102] Example 6

[0103] The method of example 1 is followed, except that the 5 g of tetramethyl silicate is replaced by 5 g of tetra-n-butyl silicate. The obtained catalyst is noted SCM-6.

[0104] Example 7

[0105] 20 g of SCM-1 catalyst (length 3-6 mm) is loaded in a 12 mm stainless steel reactor, the reaction is carried out at 65°C, the hydrogen pressure is 2.0 MPa, the acetophenone feed is a 30% acetophenone solution in ethanol, the acetophenone space velocity is 0.3 h -1 , the hydrogen to ketone (hydrogen to acetophenone) molar ratio is 2.0, the reaction is carried out for 24 h and the sample is taken, the conversion of acetophenone is 93.5%, the selectivity to a-methylbenzyl alcohol is 99.8% and the selectivity to ethylbenzene is 0.2%.

[0106] Example 8

[0107] The catalyst SCM-2 is evaluated in the same way as example 7, the conversion of acetophenone is 78.3%, the selectivity to a-methylbenzyl alcohol is 98.8% and the selectivity to ethylbenzene is 1.2%.

[0108] Example 9

[0109] The catalyst SCM-3 is evaluated in the same way as example 7, the conversion of acetophenone is 89.3%, the selectivity to a-methylbenzyl alcohol is 99.3% and the selectivity to ethylbenzene is 0.7%.

[0110] Example 10

[0111] Catalyst SCM-4 was evaluated in the same manner as Example 7, and the conversion of acetophenone was 62.8%, the selectivity of α-methylbenzyl alcohol was 99.7%, and the selectivity of ethylbenzene was 0.3%.

[0112] Example 11

[0113] Catalyst SCM-5 was evaluated in the same manner as Example 7, and the conversion of acetophenone was 75.6%, the selectivity of α-methylbenzyl alcohol was 99.2%, and the selectivity of ethylbenzene was 0.8%.

[0114] Example 12

[0115] Catalyst SCM-6 was evaluated in the same manner as Example 7, and the conversion of acetophenone was 53.5%, the selectivity of α-methylbenzyl alcohol was 98.3%, and the selectivity of ethylbenzene was 1.7%.

[0116] Examples 13-16

[0117] Catalyst SCM-1 was evaluated in the same manner as Example 7, except that the reaction conditions were changed, and the results are shown in Table 1.

[0118] Table 1

[0119]

[0120] Example 17

[0121] The life of catalyst SCM-1 was evaluated in the same manner as Example 7, and the results are shown in Table 2.

[0122] Table 2

[0123]

[0124]

[0125] Comparative Example 1

[0126] The life of catalyst CM-1 was evaluated in the same manner as Example 7, and the results are shown in Table 3.

[0127] Table 3

[0128] Reaction time (h) ACP conversion (%) MBA selectivity (%) 500 85.6 99.3 1000 78.3 99.5 1500 70.4 99.0 2000 65.4 98.9 2500 55.4 98.8 3000 45.6 99.4

[0129] Comparative Example 2

[0130] Preparation of hydrogenation catalyst:

[0131] The procedure of Example 3 was followed except that 48.1 g of magnesium nitrate hexahydrate was used in place of 29.4 g of cobalt nitrate hexahydrate to give hydrogenation catalyst cCM-2.

[0132] The hydrogenation catalyst cCM-2 was evaluated in the same manner as Example 7 to give a conversion of acetophenone of 35.6%, a selectivity to 1-phenylethanol of 97.2%, and a selectivity to ethylbenzene of 2.8%.

[0133] The above describes the preferred embodiments of the present application in detail, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosed content of the present application and fall within the protection scope of the present application.

Claims

1. An arylalkyl ketone liquid phase hydrogenation catalyst characterized by, The hydrogenation catalyst comprises a hydrogenation active component and a SiO2 carrier; the surface of the catalyst is provided with siloxane group modification; The hydrogenation-active component comprises Cu and MO x ; the MO x is selected from at least one of ZnO, MnO, CoO and MoO3; The siloxane group is provided by a siloxane group-containing compound; The mass ratio of the siloxane group-containing compound to the carrier is 0.05-0.3:1; The SiO2 carrier loaded with the hydrogenation active component is subjected to surface siloxane group modification to obtain the hydrogenation catalyst.

2. The hydrogenation catalyst according to claim 1, wherein, The siloxane group is provided by a siloxane group-containing compound of formula (I), Formula (I), In formula (I), R1, R2, R3 and R4 are each independently an alkyl group.

3. The hydrogenation catalyst of claim 2, wherein, In formula (I), R1, R2, R3 and R4 are each independently a C1-C5 alkyl group.

4. The hydrogenation catalyst of claim 3, wherein, In formula (I), R1, R2, R3 and R4 are each independently a C1-C2 alkyl group.

5. The hydrogenation catalyst according to claim 1, wherein, The MO x CoO and / or MoO3; and / or Cu in elemental terms, MO x Cu in oxide terms and MO x in a weight ratio of 1-20.

6. The hydrogenation catalyst according to claim 1, wherein, The hydrogenation active component accounts for 50-400% by weight of the weight of the carrier.

7. The hydrogenation catalyst according to claim 6, wherein, The hydrogenation active component accounts for 100-300% by weight of the weight of the carrier.

8. The hydrogenation catalyst according to claim 1, wherein, The method for surface siloxane group modification comprises: contacting the SiO2 carrier loaded with the hydrogenation active component with the siloxane group-containing compound in the presence of a solvent, heating to reflux, and then drying the solid product.

9. The hydrogenation catalyst according to claim 8, wherein, The siloxane group-containing compound has a structural formula of formula (I), Formula (I), In formula (I), R1, R2, R3 and R4 are each independently an alkyl group; and / or The mass ratio of the siloxane group-containing compound to the SiO2 carrier source is 0.05-0.3:1, based on the SiO2; and / or The solvent is selected from C6-C8 benzene series; and / or The mass ratio of the solvent to the SiO2 carrier source is 5-100:1, based on the SiO2; and / or The conditions for heating to reflux include: a temperature of 80-140°C; and / or a time of 2-24h; and / or The conditions for drying include: a drying temperature of 60-150°C and / or a drying time of 5-20h.

10. The hydrogenation catalyst according to claim 9, wherein, In formula (I), R1, R2, R3 and R4 are each independently a C1-C5 alkyl group; and / or The solvent is at least one of benzene, toluene and xylene; and / or The drying is performed under anaerobic conditions.

11. The hydrogenation catalyst of claim 10, wherein, In formula (I), R1, R2, R3 and R4 are each independently a C1-C2 alkyl group.

12. The hydrogenation catalyst according to claim 1, wherein, The method for obtaining the SiO2 carrier loaded with the hydrogenation active component comprises: kneading a hydrogenation active source, a SiO2 carrier source, a co-extrusion agent and water, shaping, and then drying, calcining and reducing.

13. The hydrogenation catalyst of claim 12, wherein, The hydrogenation active source comprises a copper salt precursor and a precursor of metal M, M being at least one selected from group ⅡB, group ⅥB, group VⅡB and group VIII.

14. The hydrogenation catalyst of claim 13, wherein, The copper salt precursor is at least one selected from nitrate, hydrochloride and basic carbonate of copper; and / or The precursor of metal M is at least one selected from nitrate, hydrochloride and basic carbonate of metal M.

15. The hydrogenation catalyst according to claim 12, wherein, The SiO2 carrier source is selected from silica powder and / or silica sol; and / or The extrusion aid is at least one selected from sesbania powder, citric acid and graphite powder; and / or The amount of the extrusion aid is 1-20% of the mass of the copper salt precursor; And / or The amount of the water is 5%-150% of the mass of the copper salt precursor; And / or The drying condition comprises a drying temperature of 60-150℃ and / or a drying time of 5-20h; and / or The calcination condition comprises a calcination temperature of 300-500℃ and / or a calcination time of 2-10h; and / or The conditions of the reduction include: reduction with a reducing gas, and / or the pressure of the reducing gas is 0.1-1 MPa, and / or the gas hourly space velocity is 200-1000 h -1 -1, and / or the reduction temperature is 160-270℃, and / or the reduction time is 2-10 h.

16. The hydrogenation catalyst of claim 15, wherein, The reducing gas is hydrogen.

17. Use of the hydrogenation catalyst according to any one of claims 1-16 in liquid phase hydrogenation of arylalkyl ketone.

18. A process for the preparation of α-methylbenzyl alcohol, characterized in that, The method comprises: contacting a raw material mixture containing acetophenone with hydrogen in the presence of the hydrogenation catalyst according to any one of claims 1-16 to perform liquid phase hydrogenation reaction.

19. The method according to claim 18, wherein, The solvent in the raw material mixture is alkanol; and / or The hydrogenation reaction condition comprises: The mass space velocity of the acetophenone in the raw material mixture is 0.1-1 h -1 ; and / or The hydrogen pressure is 1.0-5MPa; and / or The feed molar ratio of hydrogen to acetophenone is 1.0-20; and / or The reaction temperature is 60-120℃.

20. The method according to claim 19, wherein, The solvent in the raw material mixture is C1-C5 alkyl alcohol; and / or The hydrogenation reaction condition comprises: The mass space velocity of the acetophenone in the raw material mixture is 0.3-0.6 h -1 ; and / or The hydrogen pressure is 1.5-4MPa; and / or The feed molar ratio of hydrogen to acetophenone is 1.2-15; and / or The reaction temperature is 65-90℃.

21. The method of claim 20, wherein, The solvent in the raw material mixture is methanol and / or ethanol.

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