WO2018157817A1

WO2018157817A1 - Selective hydrogenation catalyst, preparation method therefor, and evaluation method for catalytic preparation of 2-methylallyl alcohol

Info

Publication number: WO2018157817A1
Application number: PCT/CN2018/077562
Authority: WO
Inventors: 张然; 王杰华; 冯春峰; 明卫星; 杨伟光; 苑颖
Original assignee: 武汉凯迪工程技术研究总院有限公司
Priority date: 2017-03-01
Filing date: 2018-02-28
Publication date: 2018-09-07
Also published as: CN106902862A

Abstract

Provided are a selective hydrogenation catalyst, a preparation method therefor, and an evaluation method for a catalytic preparation of 2-methylallyl alcohol. The selective hydrogenation catalyst consists of two parts, namely, a carrier and an active component, wherein the active component comprises a precious metal material and a non-precious metal material, and the carrier is a mesoporous silicon material, wherein the precious metal material is the precious metal Ir, and the non-precious metal material is any one of the non-precious metals Mo, W, Ni and Co, and the atomic ratio of the non-precious metal material to the precious metal material is 0.1-1. The catalyst can catalytically reduce an unsaturated aldehyde into an unsaturated alcohol under relatively mild reaction conditions and in water.

Description

[Invention name established by ISA according to Rule 37.2] Selective hydrogenation catalyst, preparation method thereof and evaluation method for catalytic preparation of 2-methylallyl alcohol

Technical field

The invention relates to the field of catalytic hydrogenation technology, in particular to a selective hydrogenation catalyst and a preparation method thereof and a catalytic evaluation method for forming 2-methylallyl alcohol.

Background technique

At present, the mixed C4 component from petrochemical and coal chemical industry has not been well utilized, and most of the components used as liquefied petroleum gas are used as fuel, and the value is low. The production of methacrolein (MAL) by mixing isobutylene in the C4 component has been industrialized, and the selective hydrogenation of methacrolein, that is, C=O bond hydrogenation and retention of C=C bond, can be obtained. - methyl allyl alcohol. The selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols is one of the common synthetic steps in the fields of organic synthesis, fine chemicals, chemical medicine, etc., and the synthesis of a large number of fine chemicals, especially in the fields of perfumery, perfumery and pharmaceuticals. Both involve the selective reduction of unsaturated aldehyde groups. 2-Methylallyl alcohol (commonly known as "carbon tetraol") is a very important organic intermediate which can undergo self-polymerization and copolymerization. Methacrylic acid and esters can be prepared starting from 2-methylallyl alcohol. In addition, 2-methylallyl alcohol can also form an allyl ester with other organic acids. Therefore, 2-methylallyl alcohol is widely used in polymer monomers, surfactants, synthetic resin additives, polycarboxylic acid superplasticizers, pharmaceuticals, pesticides, flavors and fragrances, building materials, textiles, automotive exterior coatings, food additives. And other fields. The application fields of 2-methylallyl alcohol in foreign countries are mainly concentrated in the fields of polymers, perfumes, medicines, etc., and the quality of products is very high. Domestic 2-methylallyl alcohol is used on a large scale for the production of methyl allyl alcohol polyoxyethylene ether.

The hydrogenation product of the α,β-unsaturated aldehyde may be a saturated aldehyde, an unsaturated alcohol or further hydrogenated to a saturated alcohol and an alkane. Since the bond energy of the C=C bond (615 kJ/mol) is smaller than the bond energy of the C=O bond (715 kJ/mol), it is not easy to selectively hydrogenate the C=O bond while retaining the C=C double bond. Saturated aldehydes tend to be products that are thermodynamically favorable for formation. Therefore, how to improve the selectivity of unsaturated alcohols is a major problem for chemists. The key to solving this problem is to design and develop suitable selective hydrogenation catalysts.

The Chinese Patent Publication No. CN103755525A discloses a method for preparing an unsaturated alcohol, comprising the steps of: forming a 2-methylallyl lithium by a lithium exchange reaction in the presence of an inert gas; - The methallyl lithium and the formaldehyde material or the epoxy compound undergo a nucleophilic addition reaction to form an unsaturated alcohol lithium salt; the reaction is quenched with an aqueous solution of ammonium chloride, and purified. However, the process uses toxic materials and the process environment is unfriendly.

Chinese Patent Publication No. CN105218308A discloses a catalytic synthesis method of an unsaturated alcohol. The noble metal platinum supported by iron oxide is used as a catalyst, and the lithium salt or magnesium salt is used as an auxiliary agent to react in an autoclave. The reaction condition is 50-100 ° C, the hydrogen pressure is 1-1.5 MPa, and the solvent is unsaturated in the solvent n-hexane. The aldehyde is reduced to an unsaturated alcohol. Although the catalytic activity is high in the present invention, the synthesis step is complicated, the reaction conditions are harsh, and the organic substance is used as a reaction solvent, and the environment is unfriendly.

Summary of the invention

The object of the present invention is to provide a selective hydrogenation catalyst and a preparation method thereof, and a catalytic evaluation method for producing 2-methylallyl alcohol, which can be used in mild reaction conditions and an environmentally friendly green solvent water. The unsaturated aldehyde is catalytically reduced to an unsaturated alcohol.

In order to solve the above technical problem, a selective hydrogenation catalyst disclosed in the present invention is composed of a carrier and an active component, wherein the active component comprises a noble metal material and a non-precious metal material, and the carrier is a medium. a porous silicon material: wherein the noble metal material is a noble metal Ir, the non-precious metal material is any one of non-precious metals Mo, W, Ni, Co, and an atomic ratio of the non-precious metal material to the noble metal material is 0.1 ~1.

The invention also discloses a preparation method of the above selective hydrogenation catalyst, characterized in that it comprises the following steps:

Step 1: Weigh a part of the carrier in a beaker, and weigh another part of the carrier as a carrier for impregnation. Under stirring, deionized water is added to the beaker until the carrier in the beaker is just saturated, and the deionization is recorded. The volume of water, the water absorption of the unit mass carrier, that is, the saturated water absorption rate of the carrier W;

Step 2: the precious metal precursor is dissolved in water, heated at 45 ~ 55 ° C for 0.5 ~ 2.0 hours until the precious metal precursor is completely dissolved, labeled as solution A;

Step 3: dissolving the non-precious metal precursor in water, labeled as solution B;

Step 4: Mixing solution A and solution B uniformly, diluted, and reserved, labeled as impregnation liquid C, the volume of impregnation liquid C is equal to the weight of the impregnation carrier multiplied by the saturated water absorption rate W of the carrier;

Step 5: impregnating the carrier by an equal volume impregnation method, and dropping the impregnation liquid C onto the impregnation carrier under stirring, sequentially drying and calcining, and subjecting the calcined sample to reduction treatment, the reduction treatment is to treat the oxidation state precious metal The oxide is reduced to a metallic noble metal, and the non-precious metal high-valent oxide is reduced to a low-valent oxide, thereby obtaining a selective hydrogenation catalyst m%D(n); wherein m% is the loading amount of the noble metal Ir, n Indicates the atomic ratio of non-noble metals to precious metals.

The invention further discloses a catalytic reaction evaluation method for the above selective hydrogenation catalyst, characterized in that it comprises the following steps:

Step 100: taking 0.02 to 0.2 g of a selective hydrogenation catalyst, 0.3 to 2.0 g of 2-methylacrolein, 1.5 to 30 g of solvent water, and 0.015 to 0.1 g of an internal standard compound to be placed in the reaction vessel. In the lining, then the reactor is closed;

Step 200: filling the reaction vessel with nitrogen gas of 0.1-1.0 MPa, performing a gas exchange operation, excluding air in the reaction vessel, and then switching to hydrogen gas to perform a gas exchange operation on the reaction vessel, and replacing the nitrogen gas;

Step 300: Then charging the reaction vessel with hydrogen having a pressure in the range of 1.0 to 4.0 MPa;

Step 400: heating the reaction vessel to 50-80 ° C, stirring the reaction at a reaction pressure of 1 to 6 MPa for 4 to 10 hours to carry out a selective hydrogenation reaction;

Step 500: After the above selective hydrogenation reaction is finished, the reaction vessel is cooled, and after the temperature is lowered to below room temperature, the unreacted hydrogen gas is released;

Step 600: The reaction vessel is opened, the aqueous phase is extracted with an organic solvent, and after standing and layering, the upper organic solvent is taken out for chromatographic analysis, and the selective hydrogenation catalyst and water are left in the polytetrafluoro liner of the reaction vessel;

Step 700: The selective hydrogenation catalyst after the reaction in the step 600 is no longer taken out, the 2-methyl acrolein and the internal standard compound are directly added again, the reaction kettle is closed, and the operations described in steps 200 to 600 are repeated to selectively hydrogenate. The catalyst is applied for the first cycle;

Step 800: repeating the operations of steps 200-700 until the chromatographic analysis result of step 600 shows that the selective hydrogenation catalyst loses reactivity and the selectivity of the product 2-methylallyl alcohol, and the cycle of the selective hydrogenation catalyst is investigated. The number of times applied, that is, the life test.

The beneficial effects of the invention:

1. The precious metal Ir used in the present invention is relatively inexpensive, cost-effective, and the catalyst preparation method is simple.

2. The reaction medium used in the invention is green solvent water, does not use toxic and harmful raw materials, and has no environmentally friendly characteristics compared with the conventional chlorination hydrolysis method, which does not produce refractory wastewater containing salt and chlorine.

3. In the present invention, the temperature and pressure of the catalytic reaction are relatively low, the reaction conditions are relatively mild, and the atomic utilization rate is high, which can suppress the polymerization of the substrate well and improve the selective hydrogenation of the C=O double bond.

4. The oxidation and hydrogenation catalysts of the present invention have good selectivity, and the isobutylene consumed by the unit methyl allyl alcohol is lower than the conventional chlorination hydrolysis process by more than 5%.

5. The present invention can directly use t-butanol as a raw material, and compared with the chlorination hydrolysis method, the processing cost of dehydration of t-butanol or cracking of MTBE (methyl tert-butyl ether) to obtain isobutylene can be omitted.

detailed description

The present invention will be further described in detail below in conjunction with specific embodiments:

The invention relates to a selective hydrogenation catalyst, wherein the selective hydrogenation catalyst is composed of a carrier and an active component, wherein the active component comprises a precious metal material and a non-precious metal material, and the carrier is a mesoporous silicon material. Among them, the precious metal material is noble metal Ir, and the non-precious metal material is any one of non-precious metals Mo, W, Ni, Co. (The catalyst prepared by using these two kinds of materials is combined, and the surface thereof is more likely to cause hydrogen to be heterocracked to form hydrogen ion species. , which facilitates selective hydrogenation of a C=O double bond, thereby increasing the activity of the reaction and the selectivity of 2-methylallyl alcohol, and the atomic ratio of the non-precious metal material to the noble metal material is 0.1 to 1, Within the atomic ratio range, the catalytic reaction has better activity and higher selectivity to 2-methylallyl alcohol.

In the above technical solution, the loading amount of the noble metal Ir is 0.5 to 4% by weight of the entire catalyst, and the catalytic reaction has a better activity and a higher selectivity of 2-methylallyl alcohol in the loading range.

In the above technical solution, the mesoporous silicon material is one of SBA-15, SBA-16, MCM-41, and MCM-48, and the special structure of the material is more favorable for adsorption of the substrate 2-methylacrolein. And the dispersion and activation of the active component, so that the prepared catalyst has better reactivity and higher selectivity of 2-methylallyl alcohol.

A method for preparing the above selective hydrogenation catalyst, comprising the steps of:

Step 1: Weigh a part of the carrier in a beaker, and weigh another part of the carrier as a carrier for impregnation. Under stirring, deionized water is added to the beaker until the carrier in the beaker is just saturated, and the deionization is recorded. The volume of water, the water absorption per unit mass of the carrier, that is, the saturated water absorption of the carrier W unit is mL / g;

Step 5: impregnating the carrier by an equal volume impregnation method, and dropping the impregnation liquid C onto the impregnation carrier under stirring, sequentially drying and calcining, and subjecting the calcined sample to reduction treatment, the reduction treatment is to treat the oxidation state precious metal The oxide is reduced to a metallic noble metal, and the non-precious metal high-valent oxide is reduced to a low-valent oxide, thereby obtaining a selective hydrogenation catalyst m%D(n); wherein m% is the loading amount of the noble metal Ir, n It represents the atomic ratio of the non-noble metal to the noble metal, and D is the molecular formula of the hydrogenation catalyst. For example, when the hydrated antimony trichloride is used as the noble metal precursor and the ammonium paramolybdate is the non-precious metal precursor, the atomic ratio Mo/Ir=0.1-1. .

In the above technical solution, the noble metal precursor is hydrated antimony trichloride or hydrated antimony tetrachloride. The non-precious metal precursor is one of ammonium paramolybdate, ammonium molybdate, ammonium metatungstate, nickel nitrate, basic nickel carbonate, and cobalt nitrate.

In the above technical solution, the molar concentration of the noble metal atom in the immersion liquid C is in the range of 0.004 to 0.03 mol/L, and the molar concentration of the non-precious metal atom is in the range of 0.0004 to 0.03 mol/L (corresponding to the atomic ratio of the non-precious metal to the noble metal) 0.1 to 1), the loading amount of the noble metal Ir is 0.5 to 4% by weight of the entire catalyst.

In the fifth step of the above technical solution, the drying temperature is in the range of 40 to 110 ° C, preferably 60 to 90 ° C, the drying time is 10 to 30 hours, preferably 16 to 24 hours, and the dried sample is placed in a muffle furnace. The calcination is carried out at a calcination temperature of 400 to 600 ° C, preferably 500 to 550 ° C, and a calcination time of 3 to 6 hours; a reduction treatment temperature of 300 to 600 ° C, preferably 400 to 550 ° C; and a reduction treatment atmosphere of 5% H ₂ with a mixture of 95% N ₂ volume percent, the reduction treatment time is 2 to 4 hours. The catalyst active component obtained by using the above treatment conditions has a uniform distribution, and the interaction between the noble metal material and the non-precious metal material is moderate, so that the catalytic reaction activity is good, and the selectivity of 2-methylallyl alcohol is high.

A method for evaluating a catalytic reaction of the above selective hydrogenation catalyst, comprising the steps of:

Step 100: taking 0.02 to 0.2 g of a selective hydrogenation catalyst, 0.3 to 2.0 g of 2-methylacrolein, 1.5 to 30 g of solvent water, and 0.015 to 0.1 g of an internal standard compound of n-hexane in a high pressure of 50 mL of stainless steel. In the polytetrafluoro liner of the reaction vessel, the reactor is then closed;

Step 200: The reactor is filled with nitrogen gas of 0.1-1.0 MPa (99.99% by volume of high-purity nitrogen) (nitrogen is an inert gas, does not react with hydrogen and air, and is cheap and easy to obtain), and is ventilated. Operation, the air in the reaction kettle is removed, the gas exchange operation is repeated three times, and then the hydrogen is exchanged for the reaction kettle, the nitrogen gas is replaced, and the gas exchange operation is repeated three times, so that the reactor is sufficiently filled with hydrogen required for the reaction. Source hydrogen

Step 300: The reactor is then charged with hydrogen having a pressure in the range of 1.0 to 4.0 MPa; and used as a hydrogen source for selective hydrogenation;

Step 400: further heating the reaction vessel to 50-80 ° C in a heating jacket, stirring the reaction for 4 to 10 hours under a reaction pressure of 1 to 6 MPa, and performing a selective hydrogenation reaction;

Step 500: After the selective hydrogenation reaction is completed, the reaction kettle is cooled in an ice water bath, and after the temperature is lowered to below room temperature (25 ° C), the unreacted hydrogen gas is released;

Step 700: The selective hydrogenation catalyst after the reaction in the step 600 is no longer taken out, the fresh 2-methyl acrolein and the internal standard compound n-hexane are directly re-added, the reaction kettle is closed, and the operations described in steps 200 to 600 are repeated. Selective hydrogenation catalyst for the first cycle of application;

The above catalytic reaction evaluation method demonstrates that the selective hydrogenation catalyst of the present invention can catalytically reduce an unsaturated aldehyde to an unsaturated alcohol under milder reaction conditions and an environmentally friendly green solvent water.

In the above technical solution, the organic solvent extracted by chromatography in the step 600 is toluene or ethyl acetate, and the reaction solvent water cannot be used as a chromatographic injection, and the solvent can be used as a chromatographic injection. Importantly, the solvent is immiscible with water but dissolves products such as the substrates 2-methylallylaldehyde and 2-methylallyl alcohol, and thus is used as an extraction solvent to extract the substrate and product from the aqueous phase. Perform chromatographic analysis.

In the above technical solution, the quality of the internal standard compound is 5% of the mass of 2-methylacrolein, and the amount of the internal standard compound added in the control system prevents the dilution effect on the substrate 2-methylacrolein, and the influence The catalytic reaction is carried out; the addition of the solvent water is 5 to 15 times, preferably 8 to 12 times the mass of 2-methylpropenal, ensuring a suitable initial reaction concentration of 2-methylallylaldehyde, which facilitates efficient reaction. .

In the above technical solution, the preparation method of the mesoporous silicon material SBA-15 is as follows: The SBA-15 used in the present invention is prepared according to the preparation method provided by the reference (Science, 1998, 279 (5350): 548-552). Polyoxyethylene ether-polyoxypropylene ether-polyoxyethylene ether (P123) was used as a template in the preparation process, and the average molecular weight was 5,800. 0.25 g of P123, 0.55 g of TEOS, 1.3 ml of hydrochloric acid and 6.22 mL of deionized water were mixed, stirred at 30 ° C for 24 hours, and then the obtained product was transferred to a crystallization vessel and crystallized at 100 ° C. hour. The precipitate was then obtained by filtration, washed several times with water and ethanol, dried in an oven at 60 ° C for 12 hours, and calcined at 550 ° C for 5 hours to remove the templating agent, and finally SBA-15 was obtained.

Example 1:

Preparation of selective hydrogenation catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1), 4% is the loading of precious metal Ir:

Step 1: 0.286 g of SBA-15 was placed in a beaker, and deionized water was added dropwise until the carrier was saturated, and the volume of the consumed water was recorded as 4.0 mL, that is, the saturated water absorption W of the carrier was 14.0 mL/g;

Step 2: take 0.022g of hydrated antimony trichloride, dissolved in 1.0mL of water, heated at 50 ° C for 0.5 hours to form a transparent red solution, labeled as solution A;

Step 3: Take 0.001 g of ammonium paramolybdate, dissolved in 0.5 mL of water, labeled as solution B;

Step 4: Mix solution A and solution B uniformly, dilute to 4.0 mL with water, and mark as immersion liquid C. The molar concentration of noble metal atoms in immersion liquid C is 0.015 mol/L, and the molar concentration of non-precious metal atoms is 0.001 mol/L. ;

Step 5: Another 0.286 g of SBA-15 was placed in a beaker, and the impregnating solution C was dropped onto the carrier under stirring, and dried at 80 ° C for 24 hours. After drying, the sample was transferred to a muffle furnace and calcined at 550 ° C to be calcined. The latter sample was reduced in an atmosphere of a mixture of 5% H ₂ and 95% N _{2 by} volume at 400 ° C for 2 hours to obtain a catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1).

In the above technical solution, (0.1) represents an atomic ratio of the non-noble metal to the noble metal of 0.1.

Example 2:

Preparation of Selective Hydrogenation Catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9):

Step 1: 0.286 g of SBA-15 was placed in a beaker, and deionized water was added until the carrier was just saturated, and the volume of the consumed water was recorded as 4.0 mL, that is, the saturated water absorption W of the carrier was 14.0 mL/g;

Step 3: Take 0.01g of ammonium paramolybdate, dissolved in 0.5mL of water, labeled as solution B;

Step 4: Mix solution A and solution B uniformly, dilute to 4.0 mL with water, and mark as immersion liquid C. The molar concentration of noble metal atoms in immersion liquid C is 0.015 mol/L, and the molar concentration of non-precious metal atoms is 0.01 mol/L. ;

Step 5: Another 0.286 g of SBA-15 was placed in a beaker, and the impregnating solution C was dropped onto the carrier under stirring, and dried at 80 ° C for 24 hours. After drying, the sample was transferred to a muffle furnace and calcined at 550 ° C to be calcined. The latter sample was reduced in an atmosphere of a mixture of 5% H ₂ and 95% N _{2 by} volume at 400 ° C for 2 hours to obtain a catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9).

In the above technical solution, (0.9) indicates that the atomic ratio of the non-noble metal to the noble metal is 0.9, and 4% is the loading amount of the noble metal Ir.

Example 3:

The hydrogenation performance evaluation method of the selective hydrogenation catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1) is as follows:

Step 100: 0.1 g of 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1) catalyst, 0.45 g of 2-methylacrolein, 6 g of experimental water, and 0.0225 g of n-hexane were placed in a 50 mL stainless steel autoclave. In the PTFE liner, the reactor is then closed;

Step 200: The reactor is filled with nitrogen (99.99% by volume of high-purity nitrogen) to ventilate the reactor, the air in the reactor is removed, and the operation is repeated three times, and then switched to hydrogen to ventilate the reactor. Operate, replace the nitrogen, and repeat the operation three times;

Step 300: Then charging the reaction vessel with 2.0 MPa of hydrogen;

Step 400: The reaction kettle is placed in a heating mantle to be heated to 60 ° C, and the reaction is stirred for 8 hours to carry out a selective hydrogenation reaction;

Step 500: After the above selective hydrogenation reaction is finished, the reaction kettle is cooled in an ice water bath, and after the temperature is lowered to below room temperature, the unreacted hydrogen gas is released;

Step 600: After the hydrogen release is completed, the reaction kettle is opened, and the aqueous phase is extracted with an organic solvent toluene, and after standing and layering, the upper organic solvent is taken out for chromatographic analysis to complete the hydrogenation performance evaluation of the fresh catalyst, and the specific data is shown in Table 1 .

The above 4% is the loading amount of the precious metal Ir.

Example 4:

The hydrogenation performance of the selective hydrogenation catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9) was evaluated as:

Step 100: 0.1 g of 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9) catalyst, 0.45 g of 2-methylacrolein, 6 g of experimental water, and 0.0225 g of n-hexane were placed in a 50 mL stainless steel autoclave In the fluorine lining, the reactor is then closed;

Step 300: Then charging the reaction vessel with 2.0 MPa of hydrogen;

Step 600: After the hydrogen release is completed, the reaction kettle is opened, the aqueous phase is extracted with an organic solvent toluene, and after standing and layering, the upper organic solvent is taken out for chromatographic analysis to complete the hydrogenation performance evaluation of the fresh catalyst, and the specific data is shown in Table 2 .

The above 4% is the loading amount of the precious metal Ir.

Example 5:

The life of the selective hydrogenation catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1) was evaluated as:

The life test of the catalyst was carried out in a 50 mL batch reactor. The 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1) catalyst and solvent water after one reaction were not taken out from the polytetrafluoro liner, and fresh 2-methylacrolein and the internal standard compound n-hexane were directly re-added. The reactor was ventilated using high purity nitrogen, and the air in the reactor was removed, and the operation was repeated three times. Then switch to hydrogen to ventilate the reactor, replace the nitrogen, and repeat the operation three times. The reactor was then charged with 2.0 MPa of hydrogen. The reaction kettle was placed in a heating mantle to be heated to 60 ° C, and the reaction was stirred for 8 hours. After the reaction was completed, the reaction vessel was cooled in an ice water bath, and after the temperature was lowered to below room temperature, unreacted hydrogen gas was released. After the hydrogen release is completed, the reaction kettle is opened, and the aqueous phase is extracted with an organic solvent toluene. After standing to separate the layers, the upper organic solvent is taken out for chromatographic analysis, and a cycle test is completed. The total cycle is 6 times, and the catalytic activity is not significantly decreased. See attached table 1.

The above 4% is the loading amount of the precious metal Ir.

Example 6

The life of the selective hydrogenation catalyst 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9) was evaluated as follows: The life test of the catalyst was carried out in a 50 mL batch reactor. The 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9) catalyst and solvent water after one reaction were not taken out from the polytetrafluoro liner, and the fresh substrate and internal standard were directly added again to close the reaction vessel. The reactor was ventilated using high purity nitrogen, and the air in the reactor was removed, and the operation was repeated three times. Then switch to hydrogen to ventilate the reactor, replace the nitrogen, and repeat the operation three times. The reactor was then charged with 2.0 MPa of hydrogen. The reaction kettle was placed in a heating mantle to be heated to 60 ° C, and the reaction was stirred for 8 hours. After the reaction was completed, the reaction vessel was cooled in an ice water bath, and after the temperature was lowered to below room temperature, unreacted hydrogen gas was released. After the hydrogen release is completed, the reaction kettle is opened, and the aqueous phase is extracted with an organic solvent toluene. After standing to separate the layers, the upper organic solvent is taken out for chromatographic analysis, and a cycle test is completed. The total cycle is 6 times, and the catalytic activity is not significantly decreased. See attached table 2.

The above 4% is the loading amount of the precious metal Ir.

The selective hydrogenation reaction carried out by the present invention is:

Table 1: Performance Evaluation and Life Test Results of 4% Ir-MoO _{3 /} SBA- _{15 (} 0.1) Catalyst

Table 2, 4% Ir-MoO _{3 /} SBA- _{15 (} 0.9) Catalyst Performance Evaluation and Life Test Results

The contents not described in detail in the specification belong to the prior art known to those skilled in the art.

Claims

A selective hydrogenation catalyst consisting of a carrier and an active component, wherein the active component comprises a noble metal material and a non-precious metal material, the carrier being a mesoporous silicon material; wherein the noble metal material The noble metal Ir is any one of non-noble metals Mo, W, Ni, and Co, and the atomic ratio of the non-precious metal material to the noble metal material is 0.1 to 1.
The selective hydrogenation catalyst according to claim 1, wherein the noble metal Ir is supported in an amount of from 0.5 to 4% by weight based on the total of the catalyst.
The selective hydrogenation catalyst according to claim 1, wherein the mesoporous silicon material is one of SBA-15, SBA-16, MCM-41, and MCM-48.
A method of preparing a selective hydrogenation catalyst according to claim 1, characterized in that it comprises the following steps:

Step 1: Weigh a part of the carrier in a beaker, and weigh another part of the carrier as a carrier for impregnation. Under stirring, deionized water is added to the beaker until the carrier in the beaker is just saturated, and the deionization is recorded. The volume of water, the water absorption of the unit mass carrier, that is, the saturated water absorption rate of the carrier W;

Step 2: the precious metal precursor is dissolved in water, heated at 45 ~ 55 ° C for 0.5 ~ 2.0 hours until the precious metal precursor is completely dissolved, labeled as solution A;

Step 3: dissolving the non-precious metal precursor in water, labeled as solution B;

Step 4: Mixing solution A and solution B uniformly, diluted, and reserved, labeled as impregnation liquid C, the volume of impregnation liquid C is equal to the weight of the impregnation carrier multiplied by the saturated water absorption rate W of the carrier;

Step 5: impregnating the carrier by an equal volume impregnation method, and dropping the impregnation liquid C onto the impregnation carrier under stirring, sequentially drying and calcining, and subjecting the calcined sample to reduction treatment, the reduction treatment is to treat the oxidation state precious metal The oxide is reduced to a metallic noble metal, and the non-precious metal high-valent oxide is reduced to a low-valent oxide, thereby obtaining a selective hydrogenation catalyst m%D(n); wherein m% is the loading amount of the noble metal Ir, n Indicates the atomic ratio of non-noble metals to precious metals.
The method for preparing a selective hydrogenation catalyst according to claim 4, wherein the noble metal precursor is hydrated antimony trichloride or hydrated antimony tetrachloride.
The method for preparing a selective hydrogenation catalyst according to claim 4, wherein the non-precious metal precursor is ammonium paramolybdate, ammonium molybdate, ammonium metatungstate, nickel nitrate, basic nickel carbonate, cobalt nitrate One of them.
The method for preparing a selective hydrogenation catalyst according to claim 4, wherein in the immersion liquid C, the molar concentration of the noble metal atoms is in the range of 0.004 to 0.03 mol/L, and the molar concentration of the non-noble metal atoms is in the range of 0.0004 to ～. 0.03 mol/L, the loading amount of the noble metal Ir is 0.5 to 4% by weight of the entire catalyst.
The method for preparing a selective hydrogenation catalyst according to claim 4, wherein in the step 5, the drying temperature ranges from 40 to 110 ° C, the drying time is 10 to 30 hours, and the baking temperature is 400 to 600 ° C. The calcination time is 3 to 6 hours; the reduction treatment temperature is 300 to 600 ° C; the reduction treatment atmosphere is a mixture gas of 5% H 2 and 95% N 2 volume percent, and the reduction treatment time is 2 to 4 hours.
A catalytic evaluation method for producing 2-methylallyl alcohol by the selective hydrogenation catalyst according to claim 1, characterized in that it comprises the following steps:

Step 100: taking 0.02 to 0.2 g of a selective hydrogenation catalyst, 0.3 to 2.0 g of 2-methylacrolein, 1.5 to 30 g of solvent water, and 0.015 to 0.1 g of an internal standard compound to be placed in the reaction vessel. In the lining, then the reactor is closed;

Step 200: filling the reaction vessel with nitrogen gas of 0.1-1.0 MPa, performing a gas exchange operation, excluding air in the reaction vessel, and then switching to hydrogen gas to perform a gas exchange operation on the reaction vessel, and replacing the nitrogen gas;

Step 300: Then charging the reaction vessel with hydrogen having a pressure in the range of 1.0 to 4.0 MPa;

Step 400: heating the reaction vessel to 50-80 ° C, stirring the reaction at a reaction pressure of 1 to 6 MPa for 4 to 10 hours to carry out a selective hydrogenation reaction;

Step 500: After the above selective hydrogenation reaction is finished, the reaction vessel is cooled, and after the temperature is lowered to below room temperature, the unreacted hydrogen gas is released;

Step 600: The reaction vessel is opened, the aqueous phase is extracted with an organic solvent, and after standing and layering, the upper organic solvent is taken out for chromatographic analysis, and the selective hydrogenation catalyst and water are left in the polytetrafluoro liner of the reaction vessel;

Step 700: The selective hydrogenation catalyst after the reaction in the step 600 is no longer taken out, the 2-methyl acrolein and the internal standard compound are directly added again, the reaction kettle is closed, and the operations described in steps 200 to 600 are repeated to selectively hydrogenate. The catalyst is applied for the first cycle;

Step 800: repeating the operations of steps 200-700 until the chromatographic analysis result of step 600 shows that the selective hydrogenation catalyst loses reactivity and the selectivity of the product 2-methylallyl alcohol, and the cycle of the selective hydrogenation catalyst is investigated. The number of times applied, that is, the life test.
The method for catalytically evaluating 2-methylallyl alcohol according to claim 9, wherein the organic solvent extracted by chromatography in the step 600 is toluene or ethyl acetate.
The method for catalytically evaluating 2-methylallyl alcohol according to claim 9, wherein the internal standard compound is n-hexane.
The method for catalytically evaluating 2-methylallyl alcohol according to claim 9, wherein the quality of the internal standard compound is 5% of the mass of 2-methylacrolein; the quality of the solvent water is The mass of 2-methacrylaldehyde is 5 to 15 times.