CN107185566B - A kind of catalyst and application of acetone hydrogenation liquid-phase method to synthesize methyl isobutyl ketone - Google Patents

Abstract

A catalyst and application for synthesizing methyl isobutyl ketone by acetone hydrogenation liquid phase method. The catalyst contains fluorine-modified magnesium oxide, titanium dioxide, palladium three effective components and other auxiliary components. The catalyst of the invention is used in the high pressure liquid phase reaction of acetone hydrogenation to synthesize methyl isobutyl ketone, the acetone conversion rate can reach 70.7%, the MIBK selectivity can reach 78.6%, and the corresponding MIBK yield can reach 55.6%. The MIBK yield per unit mass of palladium in the tank reactor was 45.6 mol _MIBK /g _Pd . Compared with similar catalysts, the catalyst has the characteristics of high yield of MIBK, less amount of palladium and simple preparation process.

Description

A kind of catalyst and application of acetone hydrogenation liquid-phase method to synthesize methyl isobutyl ketone

technical field

The invention relates to a catalyst for synthesizing methyl isobutyl ketone by using acetone and hydrogen as raw materials by a high-pressure liquid phase method, and the application of the catalyst.

Background technique

Acetone is a by-product of the phenol production industry as well as the propylene oxide production industry and is currently in excess worldwide. At the same time, acetone is also an important platform compound for the production of chemical raw materials from biomass. How to convert acetone into high value-added chemical products has important economic value.

At present, acetone and hydrogen are mainly mixed at home and abroad, and the polycondensation (base catalysis), dehydration (acid catalysis) and hydrogenation (metal catalysis) processes are completed under the action of multifunctional catalysts to prepare methyl isobutyl ketone (MIBK for short). This is what is referred to in the literature as a one-pot process. MIBK is an excellent medium-boiling organic solvent with stable chemical properties and is widely used in the chemical industry. Due to the advantages of short process and low energy consumption, the one-pot method has gradually become the mainstream of synthesis. A multifunctional catalyst with acid (or acid-base) and metal components at the same time is the key to realize the one-pot synthesis of MIBK. At present, the one-pot catalyst used in industry is a palladium catalyst supported by a strong acid resin (referred to as Pd/resin). Such as patents CN200910008896.7, CN991220519.7, CN98111252.8, US3953517, US4269943. The Pd/resin catalyst has the disadvantage of poor thermal stability. Therefore, the current research on alternative catalysts is still underway.

In addition to Pd/resin catalysts, other catalyst types reported in current literature and patents mainly use metal oxides, composite metal oxides and molecular sieves as carriers, such as Pd/Al ₂ O ₃ reported in patent CN104588041A, Ni reported in patent CN101875012A /MgO-Al ₂ O ₃ , Pd/H-[Ga]ZSM5 reported in patent 20084311655557, and other supports reported in the literature such as ZrO ₂ , ZnO-Cr ₂ O ₃ , Mg-A1 hydrotalcite, and various molecular sieves SAPO- 11 and AlPO4-11, MCM-22, MCM-49, MCM-56 supported palladium to obtain a supported palladium catalyst. Such catalysts have not yet been reported in practical applications because their activity and selectivity have not yet met the requirements of industrialization.

SUMMARY OF THE INVENTION

In recent years' work, the inventor found that fluorine-modified silica-supported titania is mixed with supported palladium, and the obtained mixed catalyst has excellent performance in the production of MIBK by acetone hydrogenation atmospheric pressure gas phase method, see patent CN106238079A. However, in order to increase the yield in industrial production, the mode of liquid-phase high-pressure reaction tends to be adopted. The inventors tried to use a mixed catalyst of fluorine-modified silica-supported titania and supported palladium for acetone and hydrogen as raw materials under high pressure. In the reaction of liquid-phase synthesis of methyl isobutyl ketone, it was found that the yield of MIBK was not higher than 20%. What puzzled the inventors was that the catalyst with excellent performance in the production of MIBK by the normal-pressure gas-phase method of acetone hydrogenation, why was it used in this catalyst? It cannot be efficiently implemented in a liquid-phase high-pressure reaction system. Therefore, the inventors also tried combinations of other catalysts, and found that the effects were not satisfactory. After unremitting in-depth research by the inventor, a new catalyst system with excellent performance in liquid phase high pressure reaction was found. Its three essential components are: fluorine-modified magnesium oxide, titanium dioxide and palladium; and to the inventor's surprise, The MIBK yield per unit mass of palladium of the catalyst is even higher than that of the US Dow Pd/resin catalyst widely used in industry.

Therefore, in view of the current state of the art, the present invention provides a catalyst with high activity, high selectivity and simple preparation method for acetone hydrogenation liquid phase high pressure synthesis of methyl isobutyl ketone.

Another object of the present invention is to provide an application method of the above catalyst.

The purpose of this invention is to realize through the following scheme:

A catalyst for acetone hydrogenation liquid-phase high-pressure synthesis of methyl isobutyl ketone comprises three effective components of fluorine-modified magnesium oxide, titanium dioxide and palladium.

The catalyst also contains carrier auxiliary components.

The combination of the three active ingredients of the catalyst includes:

a. The surface of the fluorine-modified magnesium oxide carrier is loaded with titanium dioxide and supported palladium, and the two are physically mixed;

b. Fluorine-modified magnesium oxide, titanium dioxide, and supported palladium, the three are physically mixed;

c. The fluorine-modified magnesium oxide supported palladium is physically mixed with titanium dioxide;

d. The fluorine-modified magnesium oxide carrier is first loaded with titanium dioxide and then loaded with palladium.

Fluorine-modified magnesium oxide is obtained by immersing magnesium oxide in a fluorine-containing aqueous solution, filtering and drying to obtain fluorine-modified magnesium oxide.

The fluorine-containing aqueous solution may be an aqueous solution of at least one of hydrofluoric acid, ammonium fluoride, sodium fluoride, tetrabutylammonium fluoride and cesium fluoride.

The inventor's preliminary research believes that although the present invention and the comparative document CN106238079A both use non-metallic F modified oxide, and then coordinate with titanium dioxide and palladium to regulate the acidity and alkalinity. However, due to the different reaction modes, the catalysts exhibit different properties. Under the general normal pressure gas phase reaction conditions, the acetone processing capacity per unit catalyst is low, and the space velocity is high, and the acetone gas passes through the surface of the raw material, so it mainly occurs on the surface of the catalyst, so the surface properties of the catalyst are more important. Under high pressure liquid phase conditions, the residence time is relatively long, and the amount of acetone treated per unit catalyst is large. At this time, the main properties of the catalyst and the surface properties should be equally important. In this way, it also means that the catalyst suitable for the reaction mode of the reference document CN106238079A is still unknown in the reaction system of the present invention, and the inventor's research process has indeed found this problem. In the research process, the inventor also tried to combine fluorine-modified calcium oxide and fluorine-modified alumina with titanium dioxide and palladium, but found that the catalytic performance was all unsatisfactory. The advantage of the present invention is that, by using the catalyst determined in the present invention for the one-pot synthesis of MIBK by acetone hydrogenation, under the high-pressure liquid-phase reaction conditions, the US Dow catalysts that exceed those reported in the existing literature and used for comparison are obtained. performance. The MIBK yield of the catalyst of the invention reaches 55.6%, and the MIBK yield per unit mass of palladium in the one-time reaction in the tank reactor reaches 45.6 mol MIBK/gPd. The Dow catalyst yield was 58.8%, and the MIBK yield per unit mass of palladium was 15.5 mol _MIBK /g _Pd . By using the catalyst system, the yield of methyl isobutyl ketone can be obtained far higher than that obtained by the similar method in the prior art. The outstanding features of the catalyst of the invention are: (1) the yield of MIBK is high; (2) the amount of palladium is low; (3) the catalyst preparation process is simple and can be produced on a large scale.

The preferred mass content of the magnesium oxide surface fluorine element in the catalyst is 0.5-10.0 wt%. A more preferred content is 1.0-5.0%.

The palladium exists in the form of metal palladium or palladium oxide. The preferred mass content of palladium in the catalyst is 0.01-5wt%. A more preferred content is 0.05-0.3%.

The preferred mass content of titanium dioxide in the catalyst is 30-70%. A more preferred content is 30-40%.

The preferred mass content of magnesium oxide in the catalyst is 30-90%. A more preferred content is 50-70%.

The carrier of the supported palladium can be a metal oxide or a carbon material.

The supported palladium uses palladium salt as a precursor, and the carrier material is immersed in a solution containing the palladium salt precursor, and is prepared by an immersion method or a precipitation method.

The palladium salt precursor solution can be chloropalladic acid, sodium chloropalladate, ammonia chloropalladate, palladium nitrate, palladium acetate or palladium acetylacetonate and the like.

The fluorine-modified magnesium oxide-supported palladium is prepared by impregnating the fluorine-modified magnesium oxide in a solution containing a palladium salt precursor by a dipping method or a precipitation method.

The fluorine-modified magnesium oxide-supported titanium dioxide is prepared by immersing the fluorine-modified magnesium oxide in a solution of a titanium dioxide precursor, and preparing the fluorine-modified magnesium oxide-supported titanium dioxide through an impregnation method or a precipitation method.

The fluorine-modified magnesium oxide is first loaded with titanium dioxide and then loaded with palladium, which is prepared by dipping the fluorine-modified magnesium oxide with titanium dioxide and then immersing it in a palladium precursor solution through a dipping method or a precipitation method.

The titanium dioxide precursor is tetrabutyl titanate, metatitanic acid, orthotitanic acid, titanium oxysulfate, titanium tetrachloride, titanium trichloride or titanium alkoxide and the like.

The magnesium oxide is limited to commercial magnesium oxide powder and magnesium oxide powder prepared from magnesium salts such as magnesium nitrate, magnesium chloride, magnesium sulfate, basic magnesium carbonate, magnesium hydroxide, and magnesium oxalate as precursors.

The form of the catalyst can be powder or catalyst shaped by any bonding and pore-making techniques.

The liquid-phase hydrogenation reaction process of acetone adopts a high-pressure liquid-phase batch reaction device or a high-pressure trickle-bed reaction device. In the reaction process, acetone is in the liquid phase, hydrogen is in the gas phase, the reaction pressure is 2-5MPa, and the reaction temperature is 100-200°C. The preferred reaction temperature of the present invention is 140-180°C.

Detailed ways

The present invention will be further described below through examples

[Example 1]

The surface of the fluorine-modified magnesium oxide carrier supports titanium dioxide and supported palladium, and the two are physically mixed to obtain a catalyst, which is denoted as TiO ₂ /MgO-F&Pd/Cor.

Step (1): Fluorine-modified magnesium oxide (denoted as MgO-F)

Weigh 1.85 g of NH ₄ F into a polytetrafluoroethylene beaker, add 100 ml of distilled water, stir to dissolve in water, and prepare a 0.5 mol/L NH ₄ F solution.

Weigh 6g of MgO powder into a polytetrafluoroethylene beaker, add 100ml of NH ₄ F solution (0.5mol/L or 1mol/L), stir at room temperature for 2h, and then use distilled water to suction filter and wash until the filtrate is neutral. The resulting filter cake was placed in an oven for drying at 100 °C for 6 h. The dried filter cake was calcined in a muffle furnace at 450 °C for 4 h to obtain MgO-F.

Step (2):

Step (2-a): Fluorine-modified magnesium oxide surface supported with titanium dioxide (denoted as TiO ₂ /MgO-F)

First, pour 10 ml of tetrabutyl titanate and 35 ml of absolute ethanol into a flat-bottomed flask, and stir vigorously on a magnetic stirrer for 30 min. Then weigh 5 g of MgO-F into the flat-bottomed flask, and continue stirring for 1 h. After that, pour the obtained liquid into a beaker, let it stand for precipitation, suck the supernatant with a dropper, and leave a white precipitate. After drying the white precipitate, put it in a crucible and bake it in a muffle furnace at 500°C. 3h, TiO ₂ /MgO-F was obtained. Grind and sieve, and take 200-400 mesh for use.

Step (2-b): the supported palladium catalyst (denoted as Pd/Cor) with cordierite as carrier

Immerse 5g of 40-60 mesh cordierite powder in 7.5mL of 0.01mol/L H ₂ PdCl ₄ solution, ultrasonicate for 0.5h, dry at 110°C, calcinate at 350°C for 3h, and reduce with potassium borohydride for 0.5 h. h, washing, suction filtration, and finally vacuum drying in a vacuum drying oven at 50° C. to obtain Pd/Cor (Pd loading 0.16wt%). The particle size range of the supported Pd component is between 5-10 nanometers as determined by transmission electron microscopy (TEM).

Step 3:

Physically mix the TiO ₂ /MgO-F prepared in step (2-a) and the Pd/Cor prepared in step (2-b) in a mass ratio of 1:1 to obtain a catalyst, denoted as TiO ₂ /MgO-F&Pd/ Cor.

[Comparative Example 1]

The need for fluorine

Compared with Example 1, the difference is that the fluorine modification treatment in step (1) is not carried out, and the fluorine-modified magnesium oxide obtained in step (2-a) in Example 1 is directly replaced by magnesium oxide. The prepared supported TiO ₂ product is denoted as TiO ₂ /MgO, ground and sieved, and 200-400 mesh is taken for use. Step (3) The prepared TiO ₂ /MgO is mixed with Pd/Cor, and the obtained catalyst is denoted as TiO ₂ /MgO & Pd/Cor.

[Comparative Example 2]

The need for titanium dioxide

Compared with Example 1, the difference is that the fluorine-modified magnesium oxide obtained in step (2-a) in Example 1 is ground, sieved, and 200-400 mesh is used for later use. Mixed with Pd/Cor, the resulting catalyst is denoted as MgO-F&Pd/Cor.

[Comparative Example 3]

The need for magnesium oxide

Compared with Example 1, the difference is that the fluorine-modified treatment in step (1) is performed with silica, instead of the fluorine-modified magnesium oxide obtained in step (2-a) in Example 1. The prepared supported TiO ₂ product is denoted as TiO ₂ /SiO ₂ -F, ground and sieved, and 200-400 mesh is taken for use. Step (3) The prepared TiO ₂ /SiO ₂ -F is mixed with Pd/Cor, and the obtained catalyst is denoted as TiO ₂ /SiO ₂ -F & Pd/Cor.

[Example 2]

Multifunctional catalysts used in acetone hydrogenation to prepare MIBK

Add 5.5 ml of acetone to the liner of the autoclave, add the mixed catalyst of supported titanium dioxide and supported palladium and a magnetic stirring bar, put the liner into the autoclave and seal the autoclave tightly. The high pressure reaction kettle is placed on the ZNCL-TS intelligent digital display magnetic electric heating mantle, and the stirring switch is turned on. The speed is 600r/min. First, nitrogen 0.2MPa is introduced into the high pressure reaction kettle, and the gas in the reaction kettle is discharged for 3 minutes. N ₂ was arranged twice, and the third time, hydrogen 0.2MPa was introduced, and the gas was discharged after 3 minutes. Close the exhaust valve, re-introduce hydrogen at 0.75MPa, close the intake valve and wait for the pressure gauge of the high-pressure reactor to stabilize at 0.75MPa for 5 minutes, then set the temperature of the ZNCL-TS intelligent digital display magnetic electric heating jacket to 180℃ (Note: Because the resin is only not resistant to high temperature, the reaction temperature for the Pd/resin catalyst is set to 120 °C). After the reaction for 2 hours, the temperature of the autoclave was cooled to room temperature of about 20°C, and the product was analyzed by sampling using a Shimadzu GC-2010 gas chromatograph. The chromatographic column model was RTX-50 and the detector was FID. The test results are shown in Table 1.

The performance of the catalyst catalyzed acetone hydrogenation synthesis MIBK of embodiment 1, comparative example 1, comparative example 2 and comparative example 3 is shown in Table 1:

Table 1 Comparison of performance of acetone hydrogenation to synthesize MIBK with catalysts with different compositions

It can be seen from Table 1 that in addition to palladium, fluorine, magnesium oxide and titanium dioxide are all necessary components of the catalyst. The acetone hydrogenation performance of the fluorine-modified TiO ₂ /MgO-F&Pd/Cor hybrid catalyst is much higher than that of the fluorine-modified TiO ₂ /MgO&Pd/Cor. It can also be seen from Table 1 that the performance of the TiO ₂ /MgO-F&Pd/Cor hybrid catalyst is also better than that of the TiO ₂ /SiO ₂ -F&Pd/Cor hybrid catalyst. This is because the first two steps of acetone condensation and dehydration are the control steps of the whole reaction. Its speed is closely related to the acid-base active center of the catalyst. Especially in the high-pressure liquid-phase reaction system, the contact between the reactant and the catalyst is not only limited to the surface, but also penetrates into the interior of the catalyst. Therefore, magnesium oxide, which has a medium and strong basicity, is more suitable for the reaction than inert silica. Require. Moreover, without TiO2, the performance of the MgO-F&Pd/Cor hybrid catalyst is lower than that of the _TiO2 /MgO-F&Pd/Cor hybrid catalyst. This shows that titanium dioxide plays an indispensable role in adjusting the acidity and alkalinity of the catalyst.

Next, the effects of different combinations of the three essential components in the catalyst on the catalytic performance were investigated.

[Example 2]

Fluorine-modified magnesium oxide, titanium dioxide, and supported palladium, physical mixture of the three, (denoted as MgO-F&TiO ₂ &Pd/Cor)

The fluorine-modified magnesium oxide (MgO-F) obtained in step (1) of Example 1 and the Pd/Cor obtained in step (2-b) of Example 1 were mixed in a mass ratio of 1:1, and then 0.0493 g of commercial Titanium dioxide powder. The three are physically mixed to form a mixed catalyst, denoted as MgO-F&TiO ₂ &Pd/Cor, ground, sieved, and 200-400 mesh is used for later use.

[Example 3]

The fluorine-modified magnesium oxide support was first loaded with titanium dioxide and then loaded with palladium (denoted as Pd/TiO ₂ /MgO-F)

Step (1): Fluorine-modified magnesium oxide carrier supports titanium dioxide

First, pour 10 ml of tetrabutyl titanate and 35 ml of absolute ethanol into a flat-bottomed flask, and stir vigorously on a magnetic stirrer for 30 min. Then weigh 5 g of MgO-F into the flat-bottomed flask, and continue stirring for 1 h. After that, the obtained liquid was poured into a beaker, and the precipitate was left to stand. The supernatant was sucked off with a dropper, leaving a white precipitate. After drying the white precipitate, it was put into a crucible and heated in a muffle furnace at 500 °C. After burning for 3 hours, a sample was obtained, which was recorded as TiO ₂ /MgO-F, ground, sieved, and 200-400 mesh was taken for use.

Step (2): TiO ₂ /MgO-F supported palladium

5 g of TiO ₂ /MgO-F obtained in step (1) was immersed in 7.5 mL of 0.01 mol/L H ₂ PdCl ₄ solution, ultrasonicated for 0.5 h, dried at 110 °C, calcined at 350 °C for 3 h, and then used Potassium borohydride was reduced for 0.5h, washed, filtered with suction, and finally vacuum-dried at 50°C in a vacuum drying oven to obtain a catalyst, denoted as Pd/TiO ₂ /MgO-F (Pd loading 0.16wt%)

[Example 4]

Fluorine-modified magnesium oxide supported palladium, physically mixed with titanium dioxide, denoted as Pd/MgO-F& _TiO2

Step (1): fluorine-modified magnesium oxide supported palladium

Immerse 5g MgO-F carrier in 7.5mL of 0.01mol/L toluene solution of palladium acetylacetonate, ultrasonicate for 0.5h, dry at 110°C, calcinate at 350°C for 3h, and reduce with potassium borohydride for 0.5h. Washing, suction filtration, and finally vacuum drying in a vacuum drying oven at 50° C. to obtain Pd/MgO-F (Pd loading 0.16wt%).

Step (2): Physically mix the fluorine-modified magnesium oxide Pd/MgO-F obtained in step (1) with commercial titanium dioxide powder to form a mixed catalyst, denoted as Pd/MgO-F&TiO ₂ , grind, sieve, take 200 -400 mesh spare.

The performance of the catalyst catalyzed acetone hydrogenation to synthesize MIBK of Example 1, Example 2, Example 3 and Example 4 is shown in Table 2:

Table 2 Effects of different combinations of three essential components in catalysts on catalytic performance

As can be seen from Table 2, when the combination of magnesium oxide, titanium dioxide and palladium is changed, the conversion rate and selectivity of the catalyst will change. From the perspective of MIBK yield, TiO ₂ /MgO-F&Pd/Cor has the highest MIBK yield.

Next, the effect of reaction temperature on the performance of catalyst TiO ₂ /MgO-F&Pd/Cor of Example 1 was investigated. The reaction temperature of the catalyst TiO ₂ /MgO-F&Pd/Cor of Example 1 in the high pressure liquid phase reaction was changed, and the measured performance of the catalyst is shown in Table 3.

Table 3 Effect of reaction temperature on the performance of catalyst TiO ₂ /MgO-F&Pd/Cor

It can be seen from Table 3 that with the increase of the reaction temperature, the conversion of acetone first increased and then decreased, the selectivity of MIBK gradually decreased, and the yield of MIBK did not change much within the reaction temperature range of 140-180 degrees. Therefore, it is appropriate to control the reaction temperature of the catalyst TiO ₂ /MgO-F&Pd/Cor between 140-180℃.

Next, the performance of Dow Pd/resin catalysts currently used in industry with different particle sizes and reaction temperatures was investigated. As shown in Table 4.

Table 4 Effect of catalyst particle size and reaction temperature on the performance of Dow Pd/resin catalyst (after grinding and sieving, 200-400 mesh)

Reaction temperature (℃) Acetone conversion (%) MIBK selectivity (%) MIBK yield (%) 80 61.8 96.4 58.8 100 63.4 96.0 60.8 120 60.1 89.5 53.8

It can be seen from Table 4 that the reaction temperature is 80-120 °C, and the Pd/resin catalyst has better performance.

In addition, the catalyst of the present invention has a palladium loading of 0.16%, as determined by plasma spectroscopy (ICP), while the Dow Pd/resin palladium loading is 0.7%. For precious metal palladium catalysts, the cost of palladium accounts for a large part of the catalyst cost. Therefore, the yield of the product is calculated according to the mass of palladium, and the comparison results are shown in Table 5.

The MIBK yield comparison of table 5 catalyst of the present invention and Dow Pd/resin catalyst per unit mass of palladium

catalyst Molar yield of MIBK per unit mass of palladium, mol_MIBK/g_Pd TiO₂/MgO-F&Pd/Cor(200-400 mesh) 45.6 Dow Pd/resin (200-400 mesh) 15.5

As can be seen from Table 5, the yield of the product is calculated according to the mass of palladium, and the catalyst of the present invention has obvious advantages. The catalyst of the present invention has a high utilization rate due to surface loading. The palladium of Pd/resin may be due to the low porosity and uniform loading of the resin, and the utilization rate is low. Therefore, to achieve the same yield, Pd/resin palladium requires higher palladium loadings. Therefore, compared with commercial catalysts, the catalysts of the present invention have advantages in cost.

Comparison of other metal oxides:

[Comparative Example 4]

Fluorine-modified alumina, titania, and supported palladium are physically mixed to obtain a catalyst, which is denoted as Al ₂ O ₃ -F&TiO ₂ &Pd/Cor.

Step (1): Fluorine-modified alumina (denoted as Al ₂ O ₃ -F)

Weigh 1.85 g of NH ₄ F into a polytetrafluoroethylene beaker, add 100 ml of distilled water, stir to dissolve in water, and prepare a 0.5 mol/L NH ₄ F solution.

Weigh 6g of active Al ₂ O ₃ powder in a polytetrafluoroethylene beaker, add 100ml of NH ₄ F solution (0.5mol/L or 1mol/L), stir at room temperature for 2h, and then wash with distilled water suction filtration until the filtrate is medium until sex. The resulting filter cake was placed in an oven for drying at 100 °C for 6 h. The dried filter cake was calcined in a muffle furnace at 450 °C for 4 h to obtain Al ₂ 0 ₃ -F.

Step (2): the supported palladium catalyst (denoted as Pd/Cor) with cordierite as carrier

Immerse 5g of 40-60 mesh cordierite powder in 7.5mL of 0.01mol/L H ₂ PdCl4 solution, ultrasonicate for 0.5h, dry at 110°C, calcinate at 350°C for 3h, and reduce with potassium borohydride for 0.5h , washing, suction filtration, and finally vacuum drying in a vacuum drying oven at 50° C. to obtain Pd/Cor (Pd loading 0.16wt%). Through transmission electron microscopy (TEM), the particle size of the supported Pd component is in the range of 5-10 nanometers.

Step 3:

The fluorine-modified magnesia (Al ₂ O ₃ -F) obtained in the step (1) of the comparative example 4 and the Pd/Cor obtained in the step (2) of the comparative example 4 were mixed in a mass ratio of 1:1, and then 0.0493 g was added. Commercial titanium dioxide powder. The three are physically mixed to form a mixed catalyst, denoted as Al ₂ O ₃ -F&TiO ₂ &Pd/Cor, which is ground, sieved, and 200-400 mesh is taken for use.

[Comparative Example 5]

Fluorine-modified calcium oxide, titanium dioxide, and supported palladium are physically mixed to obtain a catalyst, which is denoted as CaO-F&TiO ₂ &Pd/Cor.

Activated alumina was replaced with calcium oxide powder, and other preparation steps were the same as those of Comparative Example 4.

The performance of the catalysts of Example 2, Comparative Example 4 and Comparative Example 5 to catalyze the hydrogenation of acetone to synthesize MIBK is shown in Table 6.

Table 6 Effects of different fluorine-modified metal oxides on the catalytic performance of acetone hydrogenation to synthesize MIBK

As can be seen from Table 6, in the presence of the two active ingredients, titanium dioxide and palladium, we conducted experiments with different fluorine-modified metal oxides. Although the acetone conversion rate of Al ₂ O ₃ -F is 53.5%, which is not much different from the acetone conversion rate of MgO-F, the MIBK selectivity of Al ₂ O ₃ -F is greatly reduced, so that the yield of MIBK is only 5.46%, which is far Much lower than the MIBK yield of MgO-F. The conversion and selectivity of CaO-F are still much lower than those of MgO-F.

Claims (6)

1. a catalyst for acetone hydrogenation liquid phase high pressure synthesis methyl isobutyl ketone, is characterized in that, comprises three kinds of active ingredients of fluorine-modified magnesia, titanium dioxide and palladium; The mass content in the catalyst is 0.5-10.0 wt%; the mass content of palladium in the catalyst is 0.01-5 wt%; the mass content of titanium dioxide in the catalyst is 30-70%; the magnesium oxide in the catalyst The mass content of 30-90%. 2. The catalyst according to claim 1, wherein the combination of the catalyst comprises: a. The surface of the fluorine-modified magnesium oxide carrier is loaded with titanium dioxide, which is physically mixed with the supported palladium; b. Fluorine-modified magnesium oxide, titanium dioxide, and supported palladium, the three are physically mixed; c. Physical mixing of fluorine-modified magnesium oxide supported palladium and titanium dioxide; d. The fluorine-modified magnesium oxide carrier is first loaded with titanium dioxide and then loaded with palladium. 3. The catalyst according to claim 1 or 2, wherein the fluorine-modified magnesium oxide is obtained by immersing the magnesium oxide in a fluorine-containing aqueous solution, filtering and drying to obtain the fluorine-modified magnesium oxide. 4. The catalyst according to claim 1 or 2, wherein the palladium exists in the form of metal palladium or palladium oxide. 5. The catalyst according to claim 2, wherein the carrier of the supported palladium is a metal oxide or a carbon material. 6. the application of the described catalyzer of claim 1 or 2, described catalyzer is applied to acetone liquid phase hydrogenation reaction process, adopts high pressure liquid phase batch reaction device or high pressure trickle bed reaction device; In the reaction process, acetone is liquid The phase and hydrogen are gas phase, the reaction pressure is 2-5 MPa, and the reaction temperature is 100-200 °C.