Catalyst for preparing 1-phenethyl alcohol through acetophenone hydrogenation as well as preparation method and application of catalyst

Abstract

The invention relates to a CuZn / Silicalite-1 catalyst for preparing 1-phenethyl alcohol through direct hydrogenation of acetophenone as well as a preparation method and application of the CuZn / Silicalite-1 catalyst. The catalyst comprises copper oxide, zinc oxide and a molecular sieve Silicalite-1. The preparation method comprises the following steps: carrying out parallel flow precipitation on a copper salt and zinc salt mixed solution and an alkali solution, aging, filtering, washing and drying to obtain an oxide precursor; the preparation method comprises the following steps: uniformly mixing a template agent tetrapropylammonium hydroxide aqueous solution, tetraethoxysilane and deionized water, crystallizing, centrifuging, washing and drying to obtain molecular sieve raw powder; mixing, ball-milling and roasting the oxide precursor and molecular sieve raw powder; and uniformly mixing the roasted catalyst with an auxiliary agent, tabletting and forming to obtain the formed catalyst. The catalyst prepared by the method disclosed by the invention has the advantages of high dispersity of the active component Cu, difficulty in sintering and the like, and is high in activity and selectivity.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic hydrogenation, and particularly relates to a catalyst for preparing 1-phenylethanol by liquid-phase hydrogenation of acetophenone, and a preparation method and application thereof. Background Art

[0002] 1-Phenylethanol is an important chemical product, which is widely used in the pharmaceutical industry and the fragrance manufacturing industry. Among the various routes for synthesizing 1-phenylethanol, the catalytic hydrogenation of acetophenone has attracted wide attention because it is the most atom-economical.

[0003] There are multiple side reactions in the hydrogenation of acetophenone to produce 1-phenylethanol. The development of highly active and highly selective acetophenone hydrogenation catalysts is a research focus. The catalysts used for acetophenone hydrogenation mainly include precious metal catalysts such as Pt, Pd, and Rh and non-precious metal catalysts such as Ni-based and Cu-based. Among them, precious metal catalysts are expensive and Ni-based catalysts have low selectivity for 1-phenylethanol. In comparison, Cu-based catalysts have the advantages of high activity, high selectivity, and low price for acetophenone hydrogenation reactions.

[0004] Cu-based acetophenone hydrogenation catalysts have been reported in literature and patents, and researchers have done a lot of work to optimize catalyst performance. Lv et al. optimized the preparation method and prepared SiO2-supported nano-Cu catalysts using urea uniform precipitation method, which improved the acetophenone conversion rate and reaction stability (Applied Organometallic Chemistry. 2019, 33(8), e5000; Catalysis Letters. 2020, 150(1), 56-64).

[0005] Patent CN 112221508A discloses a heterogeneous shaped SiO2-supported CuZn@C catalyst, which reduces the amount of Cu and the use of co-catalysts.

[0006] Patents CN 115445629 A, CN 111346638 A, and CN108043414 A respectively disclose Cu-based acetophenone hydrogenation catalysts of different combinations and structures, and improve the catalyst performance by adding additives, adjusting the catalyst structure, etc.

[0007] The hydrogenation process of acetophenone is prone to the side reaction of 1-phenylethanol hydrogenolysis / dehydration to produce ethylbenzene / styrene. In order to obtain an efficient acetophenone hydrogenation catalyst, not only is it necessary for the active component Cu to have high dispersion to improve the acetophenone conversion rate, but also the catalyst needs to have fewer strong acid sites to reduce the by-product selectivity. At the same time, the active component Cu needs to have strong anti-sintering ability to improve the catalyst stability.

[0008] Therefore, in view of the problems of low dispersion of the active component Cu, strong catalyst acidity, weak interaction between the carrier and the active component, etc. in the Cu-based catalysts used in the hydrogenation of acetophenone to prepare 1-phenylethanol, how to improve the dispersion and stability of the active component Cu and regulate the acidity of the catalyst by a simple preparation method through the regulation of additives and carriers is of great significance for the preparation of high-performance acetophenone hydrogenation catalysts. Summary of the invention

[0009] According to a first aspect of the present invention, a catalyst for hydrogenating acetophenone to produce 1-phenylethanol is provided, which has the advantages of high dispersion of active component Cu and low sintering, and has high catalyst activity and good selectivity.

[0010] The CuZn / Silicalite-1 catalyst for preparing 1-phenylethanol by hydrogenation of acetophenone of the present invention comprises, based on the weight of the catalyst, 16-35wt% of copper oxide, 24%-45wt% of zinc oxide, and 25-60wt% of Silicalite-1 molecular sieve.

[0011] According to a second aspect of the present invention, there is provided a method for preparing the above-mentioned catalyst for hydrogenating acetophenone to 1-phenylethanol, the method comprising the following steps: (1) mixing a mixed solution containing copper salt and zinc salt with an alkaline solution for precipitation, aging, filtering, washing, and drying to obtain an oxide precursor; (2) uniformly mixing a template agent tetrapropylammonium hydroxide aqueous solution, ethyl orthosilicate and deionized water, and sequentially crystallizing, centrifuging, washing and drying the mixture to obtain a molecular sieve raw powder; (3) mixing the oxide precursor and the molecular sieve raw powder and subjecting them to ball milling treatment, and calcining the ball milled sample to obtain a catalyst; (4) The calcined catalyst and the additive are mixed evenly and formed into tablets to obtain a shaped catalyst.

[0012] The copper salt is selected from one or both of copper nitrate and copper acetate, and the zinc salt is selected from one or both of zinc nitrate and zinc acetate. The total molar concentration of metal ions in the copper-zinc mixed salt solution is 0.5-2 mol / L, preferably 0.8-1.2 mol / L.

[0013] The alkaline solution is selected from an aqueous solution of at least one of sodium carbonate and sodium bicarbonate, and the molar concentration of the alkaline molecules in the alkaline solution is 0.5-2 mol / L, preferably 0.8-1.2 mol / L.

[0014] The total molar concentration of the metal ions in the mixed solution and the molar concentration of the alkali molecules in the alkali solution may be the same or different, but are preferably the same or substantially the same.

[0015] The mixed precipitation in step (1) specifically includes the following conditions: The mixed sedimentation method is co-current sedimentation; The precipitation temperature is 50-70°C; The precipitation pH value is 6.0-9.0; preferably 6.5-8.2; Aging temperature is 55-75℃; The aging time is 20-50 min; preferably 25-35 min.

[0016] The crystallization process described in step (2) specifically includes the following conditions: The molar ratio of the template agent tetrapropylammonium hydroxide and ethyl orthosilicate is 4:1; The molar ratio of deionized water to tetraethyl orthosilicate is (8.5-100):1; preferably (8.5-50):1; The crystallization temperature is 130-180°C; preferably 150-180°C; The crystallization time is 24-72h.

[0017] The ball milling process described in step (3) is specifically as follows: the ball milling is carried out in a ball mill, the diameter of the grinding balls in the ball mill is 5-20 mm, the rotation speed of the grinding balls is 400-500 r / min, and the ball milling time is 12-24 h.

[0018] The drying temperatures in step (1) and step (2) may be the same or different, and the drying times may be the same or different, wherein the drying temperatures are both within the range of 100-120° C., and the drying times are both within the range of 12-24 h; The calcination temperature in step (3) is in the range of 350-550°C and the calcination time is 2-6h.

[0019] In a specific embodiment, the method for preparing the catalyst comprises the following steps: (1) Weigh an appropriate amount of soluble copper salt and zinc salt and dissolve them in deionized water to prepare a mixed salt solution; weigh an appropriate amount of alkali and dissolve it in deionized water to prepare an alkali solution; (2) The two aqueous solutions are precipitated in parallel at a certain temperature and pH, and then aged, filtered, and dried to obtain an oxide precursor; (3) Weighing appropriate amounts of tetrapropylammonium hydroxide, ethyl orthosilicate and deionized water to prepare a mixed solution, mixing them evenly, adding them into a high-pressure reactor, crystallizing them at a certain temperature for a certain period of time, centrifuging, washing and drying to obtain molecular sieve raw powder; (4) Weighing an appropriate amount of oxide precursor and molecular sieve raw powder, mixing them and subjecting them to ball milling treatment, and calcining the sample after ball milling treatment to obtain a catalyst; (5) The calcined catalyst and the additive are mixed evenly and formed into tablets to obtain a shaped catalyst.

[0020] Optionally, the soluble copper salt and zinc salt are selected from one or both of metal nitrates and acetates; and the alkaline solution is selected from an aqueous solution of at least one of sodium carbonate or sodium bicarbonate.

[0021] Optionally, during the preparation of the salt solution and the alkaline solution, the molar concentration of total metal ions in the salt solution is kept substantially the same as that of the alkaline solution, within the range of 0.5-2 mol / L, preferably 0.8-1.2 mol / L.

[0022] Optionally, the precipitation process is carried out in a water bath, and the pH value in the precipitation process is controlled by adjusting the flow rate of the salt solution and the alkaline solution under stirring conditions with a stirring paddle. Specifically, the water bath temperature is 50-70°C; the pH value is 6.0-9.0, preferably the pH value is 6.5-8.2; the aging temperature is 55-75°C; and the aging time is 20-50 minutes, preferably 25-35 minutes.

[0023] Optionally, the drying process refers to drying the obtained solid at 100-120° C. for 12-24 hours.

[0024] Optionally, the crystallization process is carried out in a high-pressure reactor, and the prepared mixed solution is added to the high-pressure reactor and placed in an oven. Specifically, the crystallization temperature is 130-180° C., preferably 150-180° C.; and the crystallization time is 24-72 hours.

[0025] Optionally, the ball milling process is carried out in a ball mill, the oxide precursor and the molecular sieve raw powder are mixed and added to a ball milling tank, and grinding balls are added for ball milling. Specifically, the grinding ball speed is 400-500r / min, and the ball milling time is 12-24h.

[0026] Optionally, the calcination process refers to calcining the dried solid at 350-550°C; specifically, first heating to 150°C at a heating rate of 2°C / min, keeping warm for 2h, and then continuing to heat to 350-550°C at a heating rate of 2°C / min, keeping warm for 2-6h.

[0027] Optionally, the tableting process is carried out on a tableting machine, and the specifications of the shaped catalyst are selected according to needs.

[0028] According to a third aspect of the present invention, a method for preparing 1-phenylethanol by hydrogenating acetophenone is provided, wherein a solution containing acetophenone and hydrogen are mixed and passed through a reactor, and contacted with at least one of the catalysts described in any one of the above items and the catalysts prepared by any one of the above methods to produce 1-phenylethanol.

[0029] In a specific embodiment, a method for preparing 1-phenylethanol by hydrogenating acetophenone comprises: The catalyst was reduced and activated by first raising the reactor temperature to 170°C under a nitrogen atmosphere and maintaining a nitrogen volume space velocity of 300-600 h -1 , keep the temperature constant for 1-2h to remove the physical water adsorbed by the catalyst. Pass a mixture of hydrogen and nitrogen to reduce the catalyst, and maintain the mixed gas volume space velocity at 300-600h -1 , the hydrogen gas volume fraction does not exceed 10%; after reduction for at least 1 hour, gradually increase the hydrogen concentration to volume fractions of 10%, 20%, 30%, 50%, and 100%, and control the hot spot temperature of the catalyst bed during the reduction process not to exceed 230°C; raise the temperature to 200-230°C and reduce in a full hydrogen atmosphere for 2-4 hours to obtain an activated catalyst.

[0030] Optionally, the specific conditions of the contact reaction include: The reaction temperature is 80-130°C; The reaction pressure is 1.5-2.6MPa; The molar ratio of H2 / acetophenone is (3-20): 1; The hourly space velocity of acetophenone liquid is 0.4-0.6g·g cat -1 ·h -1 .

[0031] The beneficial effects of this application include but are not limited to: (1) The present invention provides a catalyst for hydrogenating acetophenone to produce 1-phenylethanol. The catalyst has the characteristics of high dispersion of active component Cu and low sintering of active component, so that the catalyst has the advantages of high reaction activity and high catalyst stability.

[0032] (2) The present invention provides a catalyst for hydrogenating acetophenone to produce 1-phenylethanol. During the preparation process, Zn and Cu in the oxide precursor undergo isomorphous substitution, which can effectively promote the dispersion of the active component Cu and provide the final catalyst with a rich copper-zinc oxide interface.

[0033] (3) The present invention provides a catalyst for hydrogenating acetophenone to produce 1-phenylethanol. The addition of a carrier, Silicalite-1, interacts with metal species through the carrier's hydroxyl holes, which not only makes the active components highly dispersed, but also stabilizes the active components during the reaction by anchoring them.

[0034] (4) The present invention provides a catalyst for hydrogenating acetophenone to produce 1-phenylethanol. By first ball-milling the oxide precursor and the molecular sieve raw powder and then calcining them, the metal components can be evenly dispersed in the molecular sieve and fully contact with the hydroxyl nests of the carrier.

[0035] (5) The catalyst of the present invention is applied to the hydrogenation of acetophenone to produce 1-phenylethanol, which not only ensures a high product yield, but also has a wide range of adjustable reaction process conditions, making the present invention universal and having a very wide range of industrial applications. Implementation

[0036] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0037] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0038] The raw material acetophenone and the hydrogenation reaction product were detected by Agilent 7890A gas chromatograph using Agilent's DB-Waxer capillary column.

[0039] In the examples of this application, the conversion rate and selectivity are calculated as follows: Acetophenone conversion rate = (number of moles of acetophenone in the feed - number of moles of acetophenone in the output) ÷ number of moles of acetophenone in the feed × 100% 1-Phenylethanol selectivity = moles of 1-phenylethanol in the output / (moles of acetophenone in the feed - moles of acetophenone in the output) × 100% Example 1

[0040] Weigh 198.9g of zinc nitrate and 131.3g of copper nitrate, dissolve them in 1750mL of deionized water to obtain aqueous solution I; weigh 185.5g of ammonium carbonate and dissolve it in 1750mL of deionized water to obtain aqueous solution II; co-precipitate aqueous solution I and aqueous solution II in a 70°C water bath with stirring paddles, and control the pH value to be 6.2-6.4 during precipitation. After co-precipitation, age at 75°C for 30min, wash and dry at 100°C for 12h to obtain an oxide precursor.

[0041] Weigh 203.4 g of tetrapropylammonium hydroxide aqueous solution (25 wt%), 208.3 g of ethyl orthosilicate, and 747.5 g of deionized water, mix and stir for 4 hours to obtain solution III. Add solution III into a high-pressure reactor, crystallize at 180°C for 72 hours, centrifuge and wash, and dry at 100°C for 12 hours to obtain molecular sieve raw powder.

[0042] Weigh 194.4g of oxide precursor and 70.6g of molecular sieve powder, place them in the ball mill of the ball mill, add grinding balls, adjust the speed of the grinding balls to 500r / min, and ball mill for 12h. The ball-milled sample is calcined at 500℃ for 3h to obtain a catalyst. The calcined catalyst is evenly mixed with the additives and formed into tablets to obtain a formed catalyst. Example 2

[0043] Weigh 198.9g of zinc nitrate and 131.3g of copper nitrate, dissolve them in 1750mL of deionized water to obtain aqueous solution I; weigh 222.6g of ammonium carbonate and dissolve them in 2100mL of deionized water to obtain aqueous solution II; co-precipitate aqueous solution I and aqueous solution II in a 65°C water bath with stirring paddles, and control the pH value to be 6.9-7.1 during precipitation. After co-precipitation, age at 70°C for 30min, wash and dry at 100°C for 12h to obtain an oxide precursor.

[0044] Weigh 203.4 g of tetrapropylammonium hydroxide aqueous solution (25 wt%) and 208.3 g of ethyl orthosilicate, mix and stir for 4 h to obtain solution III. Add solution III into a high-pressure reactor, crystallize at 170°C for 24 h, centrifuge and wash, and dry at 100°C for 12 h to obtain molecular sieve raw powder.

[0045] The subsequent preparation procedures were consistent with those in Example 1. Example 3

[0046] Weigh 181.8g of zinc nitrate and 150.1g of copper nitrate, dissolve them in 1750mL of deionized water to obtain aqueous solution I; weigh 264.6g of ammonium carbonate and dissolve them in 2650mL of deionized water to obtain aqueous solution II; co-precipitate aqueous solution I and aqueous solution II in a 60°C water bath with stirring paddles, and control the pH value to 7.6-7.8 during precipitation. After co-precipitation, age at 65°C for 30min, wash, and dry at 100°C for 12h to obtain an oxide precursor.

[0047] Except that the calcination temperature was changed to 400° C., the subsequent preparation procedures were consistent with those of Example 2. Example 4

[0048] Weigh 99.5g of zinc nitrate and 65.7g of copper nitrate, dissolve them in 875mL of deionized water to obtain aqueous solution I; weigh 141.8g of ammonium carbonate and dissolve it in 1400mL of deionized water to obtain aqueous solution II; co-precipitate aqueous solution I and aqueous solution II in a 60°C water bath with stirring paddles, and control the pH value to 8.0-8.2 during precipitation. After co-precipitation, age at 65°C for 30min, wash and dry at 100°C for 12h to obtain an oxide precursor.

[0049] Weigh 244.0 g of tetrapropylammonium hydroxide aqueous solution (25 wt%), 250.0 g of ethyl orthosilicate, and 465.0 g of deionized water, mix and stir for 4 hours to obtain solution III. Add solution III into a high-pressure reactor, crystallize at 170°C for 72 hours, centrifuge and wash, and dry at 100°C for 12 hours to obtain molecular sieve raw powder.

[0050] Weigh 92.1g of oxide precursor and 86.0g of molecular sieve powder, place them in the ball mill of the ball mill, add grinding balls, adjust the speed of the grinding balls to 400r / min, and ball mill for 16h. The ball-milled sample is calcined at 550℃ for 4h to obtain a catalyst. The calcined catalyst is evenly mixed with the additives and formed into tablets to obtain a formed catalyst. Example 5

[0051] Weigh 157.8g of zinc nitrate and 187.6g of copper nitrate, dissolve them in 1800mL of deionized water to obtain aqueous solution I; weigh 233.2g of ammonium carbonate and dissolve them in 2300mL of deionized water to obtain aqueous solution II; co-precipitate aqueous solution I and aqueous solution II in a 60°C water bath with stirring paddles, and control the pH value to be 6.9-7.1 during precipitation. After co-precipitation, age at 65°C for 30min, wash and dry at 100°C for 12h to obtain an oxide precursor.

[0052] Weigh 269.5 g of tetrapropylammonium hydroxide aqueous solution (25 wt%) and 173.6 g of ethyl orthosilicate, mix and stir for 4 h to obtain solution III. Add solution III into a high-pressure reactor, crystallize at 170° C. for 48 h, centrifuge and wash, and dry at 100° C. for 12 h to obtain molecular sieve raw powder.

[0053] Weigh 192.9g of oxide precursor and 60.0g of molecular sieve powder, place them in the ball mill of the ball mill, add grinding balls, adjust the speed of the grinding balls to 450r / min, and ball mill for 12h. The ball-milled sample is calcined at 350℃ for 4h to obtain a catalyst. The calcined catalyst is evenly mixed with the additives and formed into tablets to obtain a formed catalyst. Example 6

[0054] Weigh 84.4g of zinc nitrate and 85.2g of copper nitrate, dissolve them in 900mL of deionized water to obtain aqueous solution I; weigh 115.0g of ammonium carbonate and dissolve it in 1200mL of deionized water to obtain aqueous solution II; co-precipitate aqueous solution I and aqueous solution II in a 60°C water bath with stirring paddles, and control the pH value to 7.4-7.5 during precipitation. After co-precipitation, age at 65°C for 30min, wash and dry at 100°C for 12h to obtain an oxide precursor.

[0055] Weigh 292.8g of tetrapropylammonium hydroxide aqueous solution (25wt%), 300.0g of ethyl orthosilicate, and 298.9g of deionized water, mix and stir for 4h to obtain solution III. Add solution III into a high-pressure reactor, crystallize at 170°C for 72h, centrifuge and wash, and dry at 100°C for 12h to obtain molecular sieve raw powder.

[0056] Weigh 72.9g of oxide precursor and 102.0g of molecular sieve powder, place them in the ball mill of the ball mill, add grinding balls, adjust the speed of the grinding balls to 500r / min, and ball mill for 12h. The ball-milled sample is calcined at 450℃ for 4h to obtain a catalyst. The calcined catalyst is evenly mixed with the additives and formed into tablets to obtain a formed catalyst. Example 7

[0057] The reaction performance of the catalysts in the above Examples 1-6 was examined under the following conditions.

[0058] Catalyst reduction activation: The formed catalyst was loaded into a fixed bed reactor with a catalyst loading of 50 mL. First, the reactor temperature was raised to 170°C under a nitrogen atmosphere, and the nitrogen volume space velocity was maintained at 480 h -1 , and keep the temperature constant for 2 hours to remove the physical water adsorbed by the catalyst. Then, a mixed gas of hydrogen and nitrogen is introduced to reduce the catalyst, with a hydrogen gas volume fraction of 2%. After reduction for at least 1 hour, the hydrogen concentration is gradually increased to a volume fraction of 5%, 10%, 20%, 50%, and 100%, and the hot spot temperature of the catalyst bed is controlled not to exceed 230°C during the reduction process; finally, the temperature is raised to 230°C and reduced for 2 hours in a full hydrogen atmosphere to obtain an activated catalyst.

[0059] Reaction evaluation: After the catalyst was reduced and activated, an ethylbenzene solution with a mass fraction of 15% acetophenone was used as the reaction raw material at a reaction temperature of 90°C and a reaction pressure of 2.3 MPa. The mass space velocity of the acetophenone liquid was controlled to be 0.4 g·g cat -1 ·h -1 , H2 / acetophenone molar ratio is 15: 1. Under these conditions, acetophenone hydrogenation reaction was carried out to obtain a reaction product. The reaction results are shown in the following table.

[0060]

[0061] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Any technical personnel familiar with the profession, without departing from the scope of the technical solution of the present application, making slight changes or modifications using the technical contents disclosed above are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A catalyst for preparing 1-phenylethanol by hydrogenation of acetophenone, characterized in that: Based on the weight of the catalyst, the catalyst comprises: 16-35wt% of copper oxide, 24%-45wt% of zinc oxide, and 25-60wt% of Silicalite-1 molecular sieve.

2. The method for preparing the catalyst for preparing 1-phenylethanol by hydrogenation of acetophenone according to claim 1, characterized in that: The method comprises the following steps: (1) mixing a mixed solution containing copper salt and zinc salt with an alkaline solution for precipitation, aging, filtering, washing, and drying to obtain an oxide precursor; (2) uniformly mixing a template agent tetrapropylammonium hydroxide aqueous solution, ethyl orthosilicate and deionized water, and sequentially crystallizing, centrifuging, washing and drying the mixture to obtain a molecular sieve raw powder; (3) mixing the oxide precursor and the molecular sieve raw powder and subjecting them to ball milling treatment, and calcining the ball milled sample to obtain a catalyst; (4) The calcined catalyst and the additive are mixed evenly and formed into tablets to obtain a shaped CuZn / Silicalite-1 catalyst.

3. The method for preparing a catalyst according to claim 2, characterized in that: The copper salt and zinc salt are selected from one or both of nitrates or acetates of corresponding metals.

4. The method for preparing a catalyst according to claim 2, characterized in that: The alkaline solution is selected from an aqueous solution of at least one of sodium carbonate or sodium bicarbonate.

5. The method for preparing a catalyst according to claim 2, characterized in that: The mixed precipitation in step (1) specifically includes the following conditions: the mixed precipitation method is co-current precipitation; the precipitation temperature is 50-70° C.; the precipitation pH value is 6.0-9.0; the aging temperature is 55-75° C.; and the aging time is 20-50 min.

6. The method for preparing a catalyst according to claim 2, characterized in that: In the crystallization process described in step (2), the raw material composition conditions include: the molar ratio of the template agent tetrapropylammonium hydroxide to tetraethyl orthosilicate is 4:1; the molar ratio of deionized water to tetraethyl orthosilicate is (8.5-100):

1.

7. The method for preparing a catalyst according to claim 2, characterized in that: In the crystallization process described in step (2), the crystallization conditions include: a crystallization temperature of 130-180° C.; and a crystallization time of 24-72 h.

8. The method for preparing a catalyst according to claim 2, characterized in that: The ball milling process described in step (3) is specifically as follows: the ball milling is carried out in a ball mill, the diameter of the grinding balls in the ball mill is 5-20 mm, the rotation speed of the grinding balls is 400-500 r / min, and the ball milling time is 12-24 h.

9. The method for preparing a catalyst according to claim 2, characterized in that: The drying temperatures in step (1) and step (2) are both 100-120° C., and the drying time is both 12-24 hours; the roasting temperature in step (3) is 350-550° C., and the roasting time is 2-6 hours.

10. A method for preparing 1-phenylethanol by hydrogenating acetophenone, characterized in that: A solution containing acetophenone and hydrogen are mixed and passed through a reactor to react with at least one of the catalyst according to claim 1 and the catalyst prepared by the method according to any one of claims 2 to 9 to generate 1-phenylethanol.

11. The method according to claim 10, characterized in that The specific conditions of the contact reaction include: reaction temperature of 80-130°C; reaction pressure of 1.5-2.6MPa; H2 / acetophenone molar ratio of (3-20):1; acetophenone liquid hourly space velocity of 0.4-0.6g·g cat -1 ·h -1 .

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