Preparation method of copper-based catalyst and application of copper-based catalyst in acetylene hydration reaction
阅读说明：本技术 一种铜基催化剂的制备方法和在乙炔水合反应中的应用 (Preparation method of copper-based catalyst and application of copper-based catalyst in acetylene hydration reaction ) 是由 赵佳 庞祥雪 朱文锐 岳玉学 王赛赛 陈志� 王婷 冯涛 王涛 于 2021-02-07 设计创作，主要内容包括：本发明公开了一种铜基催化剂的制备方法和在乙炔水合反应中的应用。所述铜基催化剂的制备方法包括如下步骤：将含铜前驱体与贱金属助剂溶解在溶剂中,搅拌使其混合均匀,在25～35℃时,将所述混合液滴加到多孔固体载体上,在静电场作用下进行等体积浸渍,浸渍3～5小时,然后在35～120℃下干燥6～10小时,即得到铜基催化剂；所述的贱金属助剂为Bi、Ba、Fe、Mn、Zn、K、Ca、Ni中的一种或多种金属的盐。本发明提供了制得的铜基催化剂在乙炔水合反成生成乙醛中的应用,具有转化率高、稳定性好的优势。(The invention discloses a preparation method of a copper-based catalyst and application of the copper-based catalyst in acetylene hydration reaction. The preparation method of the copper-based catalyst comprises the following steps: dissolving a copper-containing precursor and a base metal auxiliary agent in a solvent, stirring to uniformly mix the copper-containing precursor and the base metal auxiliary agent, dripping the mixed liquid onto a porous solid carrier at 25-35 ℃, carrying out isometric impregnation under the action of an electrostatic field for 3-5 hours, and then drying at 35-120 ℃ for 6-10 hours to obtain a copper-based catalyst; the base metal auxiliary agent is one or more of Bi, Ba, Fe, Mn, Zn, K, Ca and Ni. The invention provides the application of the prepared copper-based catalyst in the synthesis of acetaldehyde by acetylene hydration reaction, and the copper-based catalyst has the advantages of high conversion rate and good stability.)
1. A preparation method of a copper-based catalyst comprises the following steps:
dissolving a copper-containing precursor and a base metal auxiliary agent in a solvent, stirring to uniformly mix the copper-containing precursor and the base metal auxiliary agent, dripping the mixed liquid onto a porous solid carrier at 25-35 ℃, carrying out isometric impregnation under the action of an electrostatic field for 3-5 hours, and then drying at 35-120 ℃ for 6-10 hours to obtain a copper-based catalyst; the base metal auxiliary agent is one or more of Bi, Ba, Fe, Mn, Zn, K, Ca and Ni.
2. The method of claim 1, wherein: in the copper-based catalyst, the copper loading is 10-30 wt%; the loading capacity of the base metal additive is 0.1-2 wt%.
3. The method of claim 1 or 2, wherein: the action conditions of the electrostatic field are as follows: the electric field intensity is 10-50 kv/cm, and the processing time is 0.5-2 h.
4. The method according to any one of claims 1 to 3, wherein: the copper-containing precursor is one of copper chloride, copper nitrate, copper sulfate, copper phosphate and copper pyrophosphate;
the base metal auxiliary agent is one or a mixture of bismuth chloride, barium chloride, ferric chloride, manganese chloride, zinc chloride, potassium chloride, calcium chloride, tin chloride and nickel chloride;
the solvent is one or more of deionized water, absolute ethyl alcohol, tetrahydrofuran, methanol, acetone, diethyl ether, cyclohexane, carbon tetrachloride and benzene.
5. The method according to any one of claims 1 to 3, wherein: the porous solid carrier is selected from one of activated carbon, activated carbon fiber, carbon nano tube, graphene, silicon dioxide, aluminum oxide, titanium dioxide and molecular sieve; wherein the active carbon is columnar carbon or spherical active carbon, the particle size is 20-100 meshes, and the specific surface area is 500-1500 m2The pore volume is 0.25-1.5 mL/g; the activated carbon fiber is processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 500-1600 m2The pore volume is 0.25-2.5 mL/g; the carbon nano tube is processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface is 250-1600 m2The pore volume is 0.25-2.5 mL/g; the graphene is processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 500-3000 m2The pore volume is 0.25-2.5 mL/g; the aluminum oxide is gamma-Al2O3And processed into columnar or spherical shape with particle size of 10-100 meshes and specific surface area of 250-800 m2The pore volume is 0.1-1.5 mL/g; the silicon dioxide is processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 250-800 m2The pore volume is 0.1-1.5 mL/g; the titanium dioxide is processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 250-800 m2The pore volume is 0.1-1.0 mL/g; the molecular sieve is ZSM-5, beta molecular sieve, gamma molecular sieve, 5A molecular sieve, 10X molecular sieve or 13X molecular sieve, the particle size is 10-100 meshes, and the specific surface area is 250-800 m2The pore volume is 0.1-1.8 mL/g.
6. The method of claim 5, wherein: the porous solid carrier is subjected to plasma treatment under the following conditions: the current is 1-5A, the voltage is 10-25V, and the treatment time is 0.5-2 h; the plasma treatment is carried out at N2Carried out under an atmosphere, N2The flow rate is 5-60 ml/min.
7. The method of claim 5 or 6, wherein: the activated carbon fiber is doped with nitrogen or phosphorus, and the doping process comprises the following steps: preparing a nitrogen-containing or phosphorus-containing precursor into an aqueous solution with the mass fraction of 10-15%, and then soaking the activated carbon fiber in the aqueous solution of the nitrogen-containing or phosphorus-containing precursor for 1-5 hours at the soaking temperature of 30-60 ℃; the nitrogen-containing precursor is ammonium chloride, urea or ethylenediamine, and the phosphorus-containing precursor is phosphoric acid.
8. The use of the copper-based catalyst prepared by the preparation method according to claim 1 in the reaction of acetylene hydration to form acetaldehyde.
9. The use according to claim 8, characterized in that the use is in particular: the reactor is filled with the catalyst, and feed gas H is introduced2O and C2H2And reacting at the reaction temperature of 100-200 ℃ and the reaction pressure of 0.01-2 MPa to obtain acetaldehyde.
10. The use of claim 9, wherein: the volume airspeed of acetylene is 5-500 h-1。
(I) technical field
The invention belongs to the technical field of catalysts, and particularly relates to a preparation method of a copper-based catalyst and application of the copper-based catalyst in acetylene hydration reaction.
(II) background of the invention
Acetaldehyde is an important organic chemical raw material and is used for producing secondary products of important basic organic synthesis such as acetic acid, acetic anhydride, butyraldehyde, butanol, octanol, pentaerythritol, chloral and the like. The acetaldehyde produced in industry mainly comprises four methods, namely an ethylene oxidation method, an ethanol dehydrogenation method, a low-carbon alkane oxidation method and an acetylene hydration method. Among them, the ethylene oxidation method is the most important method for producing acetaldehyde for the sixties of this century, and has been developed rapidly in recent years. In the developed countries of petrochemical industry, the ethylene process largely replaces the acetylene process, and the main reasons are as follows: (1) the development of petrochemical industry has provided a cheaper raw material for ethylene than acetylene; (2) the mercury sulfate-sulfuric acid catalyst used for acetylene hydration is extremely toxic and harmful to the health of workers.
The acetylene hydration process also has advantages over the ethylene oxidation process in certain respects. The acetylene hydration reaction does not need noble metal palladium catalyst, oxygen generating equipment and special acid-resistant materials. The resource structure of 'rich coal, lean oil and less gas' in China and the breakthrough of the technology of preparing acetylene from coal further expand the acetylene capacity, so that the acetaldehyde produced by the acetylene hydration method becomes the characteristic advantage route of the acetaldehyde production industry in China again.
The early research of acetylene hydration reaction uses mercury salt and acid as catalysts, however, due to the toxicity of mercury, the requirement of strong acid condition, and the reduction of activity caused by the fact that mercury is easy to be reduced in the reaction process, the wide application of acetylene hydration reaction is limited, and in order to better develop the acetylene hydration production to meet the current national requirement for acetaldehyde, a non-mercury catalyst which can be suitable for industrial production must be researched to replace a highly toxic mercury-based catalyst.
The research of acetylene gas phase hydration reaction non-mercury catalysts in China mainly focuses on cadmium calcium phosphate and zinc oxide systems. Cadmium in a cadmium calcium phosphate system is extremely toxic, has poor strength and high consumption, and a large amount of high polymers are easily generated on the surface of the catalyst, so that the production is abnormal and the product cost is high. The zinc oxide system has the advantages of non-toxic catalyst, high production capacity, low water-gas ratio, simple process flow, less three wastes and the like, but has the defects of poor selectivity, low conversion rate and the like. In addition, both systems require high temperature conditions of 400 ℃ to exhibit catalytic performance. From the viewpoint of industrial production, there is a problem of excessive energy consumption.
A series of zinc-copper bimetallic catalysts are prepared and used as catalysts for acetylene hydration reaction in the research of New J.chem.2018,42,6507-6514, and the influence of a copper additive on the performance of the zinc catalyst is studied in detail. The copper metal and the zinc ions have strong interaction, and the loss of the zinc ions in the reaction process is prevented, so that the catalytic activity of the bimetallic catalyst for preparing acetaldehyde by acetylene hydration is improved. At the reaction temperature of 260 ℃ and the space velocity of 90h-1Under the condition of (1), the conversion rate of acetylene in 10h of the Zn-10Cu/MCM catalyst is about 98%, but the selectivity to acetaldehyde is poor and is only about 50%.
The document CATALYSIS LETTERS,2018,11,3370-3377 investigated several organic compounds containing S as ligands for cu (i) catalyzed acetylene hydration under mercury-free conditions. The results show that the lowest selectivity to acetaldehyde is significantly increased from 3.61 due to the addition of mercaptosuccinic acidUp to 87.56%, and C2H2The minimum conversion of (a) also increased from 14.45 to 34.92%. The possible reasons for the increased selectivity of acetaldehyde were investigated by density functional theory calculations. The results show that the addition of an organic compound containing S can increase the Cu complex and C2H2The coordination ability of (a). Despite the increased selectivity of the added ligand, there is a distance from the conversion to the industrialization
Patent CN108311174A reports a catalytic system for preparing acetaldehyde by acetylene liquid phase hydration, which comprises cuprous chloride, inorganic acid, sulfo-organic acid and solvent, and also comprises inorganic chloride or organic nitrogen-containing hydrochloride. The system replaces the traditional mercury catalyst, and reduces the harmful effects on the environment and human bodies caused by the use of the mercury catalyst. At 60 ℃, the space velocity is introduced for 50h-1The acetylene conversion rate of the system is the highest, but the conversion rate is only 40 percent.
In summary, the copper-based catalyst, whether used as a main active component or a cocatalyst, has problems of low activity or poor selectivity. Therefore, it is very significant to invent a copper-based catalyst system to further improve the activity and stability in the acetylene hydration reaction.
Disclosure of the invention
The invention aims to solve the problems that the catalyst generates acetaldehyde in acetylene hydration reaction, the acetylene conversion rate is poor and the stability is poor, and provides a preparation method and application of the copper-based catalyst for the acetylene hydration reaction, which have high conversion rate and good stability.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a method for preparing a copper-based catalyst, comprising the steps of:
dissolving a copper-containing precursor and a base metal auxiliary agent in a solvent, stirring to uniformly mix the copper-containing precursor and the base metal auxiliary agent, dripping the mixed liquid onto a porous solid carrier at 25-35 ℃, carrying out isometric impregnation under the action of an electrostatic field for 3-5 hours, and then drying at 35-120 ℃ for 6-10 hours to obtain a copper-based catalyst; the base metal auxiliary agent is one or more of Bi, Ba, Fe, Mn, Zn, K, Ca and Ni.
Further, in the copper-based catalyst, the copper loading (relative to the mass of the carrier) is 10-30 wt%; the loading capacity (relative to the mass of the carrier) of the base metal auxiliary agent is 0.1-2 wt%.
Further, the copper-containing precursor is one of copper chloride, copper nitrate, copper sulfate, copper phosphate and copper pyrophosphate.
Further, the base metal auxiliary agent is one or a mixture of bismuth chloride, barium chloride, ferric chloride, manganese chloride, zinc chloride, potassium chloride, calcium chloride, tin chloride and nickel chloride.
Further, the solvent is one or a mixture of more of deionized water, absolute ethyl alcohol, tetrahydrofuran, methanol, acetone, diethyl ether, cyclohexane, carbon tetrachloride and benzene.
Further, the electrostatic field treatment conditions are as follows: the electric field intensity is 10-50 kv/cm, and the processing time is 0.5-2 h.
The porous solid carrier is selected from one of activated carbon, activated carbon fiber, carbon nano tube, graphene, silicon dioxide, aluminum oxide, titanium dioxide and molecular sieve. The activated carbon is preferably columnar carbon or spherical activated carbon, the particle size is 20-100 meshes, and the specific surface area is 500-1500 m2The pore volume is 0.25-1.5 mL/g. The activated carbon fiber is preferably processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 500-1600 m2The pore volume is 0.25-2.5 mL/g. The carbon nano tube is preferably processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface is 250-1600 m2The pore volume is 0.25-2.5 mL/g. The graphene is preferably processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 500-3000 m2The pore volume is 0.25-2.5 mL/g. The aluminum oxide is preferably gamma-Al2O3And processed into columnar or spherical shape with particle size of 10-100 meshes and specific surface area of 250-800 m2The pore volume is 0.1-1.5 mL/g. The silicon dioxide is preferably processed into a columnar shape or a spherical shape, the particle size is 10-100 meshes, and the specific surface area is 250-800 m2The pore volume is 0.1-1.5 mL/g. The titanium dioxide is preferably addedIs made into a columnar shape or a spherical shape, has a particle size of 10-100 meshes and a specific surface area of 250-800 m2The pore volume is 0.1-1.0 mL/g. The molecular sieve is preferably ZSM-5, a beta molecular sieve, a gamma molecular sieve, a 5A molecular sieve, a 10X molecular sieve or a 13X molecular sieve, the particle size is 10-100 meshes, and the specific surface area is 250-800 m2The pore volume is 0.1-1.8 mL/g.
Further, the porous solid support is subjected to plasma treatment.
Further, the plasma processing conditions are: the current is 1-5A, the voltage is 10-25V, and the treatment time is 0.5-2 h; the plasma treatment is carried out at N2Carried out under an atmosphere, N2The flow rate is 5-60 ml/min.
Further, the activated carbon fiber is doped with nitrogen or phosphorus, and the doping process is as follows: preparing a nitrogen-containing or phosphorus-containing precursor into an aqueous solution with the mass fraction of 10-15%, and then soaking the activated carbon fiber in the aqueous solution of the nitrogen-containing or phosphorus-containing precursor for 1-5 hours at the soaking temperature of 30-60 ℃; the nitrogen-containing precursor is ammonium chloride, urea or ethylenediamine, and the phosphorus-containing precursor is phosphoric acid.
In a second aspect, the invention provides the use of the copper-based catalyst in the reaction of acetylene hydration to form acetaldehyde.
The application specifically comprises the following steps: the reactor is filled with the catalyst, and feed gas H is introduced2O and C2H2The reaction temperature is 100-200 ℃, the reaction pressure is 0.01-2 MPa, and acetaldehyde is obtained through reaction.
Further, the volume space velocity of acetylene is 5-500 h-1。
Compared with the prior art, the invention has the following innovation points and technical advantages:
(1) the invention applies the electrostatic field technology to the preparation process of the catalyst, is beneficial to the high dispersion degree and effective anchoring of the active components of the catalyst on the surface of the carrier, reduces the agglomeration of the active components, exerts high activity and can keep stable in the long-time reaction process.
(2) The invention adopts plasma technology to treat the carrier, can increase the oxygen-containing groups on the surface of the carrier in a short time, and the oxygen-containing groups can act as active centers or act together with metal active components, thereby obviously improving the catalytic activity.
(3) The copper-based catalyst prepared by the invention gets rid of the traditional mercury-based catalyst, avoids the harm of mercury loss to the environment and human body, and has the advantages of high catalytic activity, good stability and low cost.
(4) According to the preparation method of the copper-based catalyst, when the carrier is the activated carbon fiber, the carrier is subjected to nitrogen or phosphorus doping pretreatment, so that the catalytic activity can be remarkably improved.
(5) The copper-based catalyst prepared by the invention is applied to the reaction of acetylene hydration to generate acetaldehyde, and has the advantages of high acetylene conversion rate, high acetaldehyde selectivity and good stability.
(IV) detailed description of the preferred embodiments
The present invention will be described with reference to specific examples. It should be noted that the examples are only intended to illustrate the invention further, but should not be construed as limiting the scope of the invention, which is in no way limited thereto. Those skilled in the art may make insubstantial modifications and adaptations to the invention described above.
Example 1
Selecting columnar active carbon as carrier, with particle diameter of 20 mesh and specific surface area of 1000m2The pore volume is 1 mL/g. At room temperature, at 5ml/min N2And performing plasma treatment under the atmosphere, wherein the current is 1A, the voltage is 10V, and the plasma is taken out for standby after treatment for 0.5 h.
20.96g of copper chloride and 0.21g of ZnCl were mixed2Dissolving in methanol, stirring, adding the mixture at 25 deg.C to 100g of activated carbon carrier treated by plasma, treating for 3 hr under electrostatic field condition with strength of 10kv/cm, taking out from electrostatic field, and oven drying at 70 deg.C for 6 hr to obtain copper-based catalyst with copper loading of 10%, ZnCl, and copper content of 10%2The loading was 0.1%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: at 100 deg.C and 0.01MPa, acetyleneVolume space velocity of 5h-1After 2000h of reaction, the acetylene conversion was 99.20% and the acetaldehyde selectivity was 98.21%.
Example 2
Active carbon fiber is selected as a carrier, the particle size of the carrier is 100 meshes, and the specific surface area is 800m2The pore volume is 0.25 mL/g. At room temperature, at 10ml/min N2Performing plasma treatment under the atmosphere, performing current of 2A and voltage of 15V, taking out after treating for 1h, then soaking the activated carbon fiber in ammonium chloride solution with mass fraction of 10% at 30 ℃, taking out after soaking for 5h, and drying for later use.
90g of copper nitrate and 2.25g of BiCl3Dissolving in deionized water, stirring, adding the mixture at 35 deg.C to 100g of activated carbon fiber carrier treated by plasma, treating for 4 hr under electrostatic field condition with strength of 20kv/cm, taking out from the electrostatic field, and oven drying at 120 deg.C for 10 hr to obtain copper-based catalyst with copper loading of 30% and BiCl3The loading was 2%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 100 ℃, the pressure is 0.05MPa, and the volume space velocity of acetylene is 250h-1Under the conditions of (1), after 2000h of reaction, the acetylene conversion rate is 98.97%, and the acetaldehyde selectivity is 99.20%.
Example 3
Selecting active carbon fiber as carrier with particle size of 50 mesh and specific surface area of 1600m2The pore volume is 2.5 mL/g. At room temperature, at 30ml/min N2Performing plasma treatment under the atmosphere, performing treatment for 1.5h at a current of 3A and a voltage of 20V, taking out, then soaking the activated carbon fiber in a phosphoric acid solution with the mass fraction of 10% at 30 ℃, taking out after soaking for 5h, and drying for later use.
90g of copper nitrate and 2.25g of BiCl3Dissolving in deionized water, stirring, adding the mixture at 30 deg.C to 100g of activated carbon fiber carrier treated by plasma, treating under electrostatic field for 5 hr with strength of 30kv/cm, taking out from the electrostatic field, and oven drying at 110 deg.C for 10 hr to obtain copper-based catalyst with copper loading capacity10％，ZnCl2The loading was 0.1%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 120 ℃, the pressure is 1.5MPa, and the volume space velocity of acetylene is 300h-1Under the condition of (1), after the reaction is carried out for 2000 hours, the acetylene conversion rate is 99.31 percent, and the acetaldehyde selectivity is 98.71 percent.
Example 4
Selecting carbon nano tube as carrier, its grain size is 80 meshes, specific surface area is 600m2The pore volume is 1.5 mL/g. At room temperature, at 60ml/min N2And performing plasma treatment under the atmosphere, wherein the current is 4A, the voltage is 25V, and the plasma is taken out for standby after 2 hours of treatment.
37.5g of copper sulfate and 3.6g of FeCl3Dissolving in carbon tetrachloride, stirring, adding the mixture at 26 deg.C to 100g of carbon nanotube treated by plasma, treating at electrostatic field for 3.5 hr with strength of 40kv/cm, taking out from the electrostatic field, and oven drying at 85 deg.C for 8 hr to obtain copper-based catalyst with copper loading of 15% and FeCl3The loading was 1.2%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 150 ℃, the pressure is 2MPa, and the volume space velocity of acetylene is 400h-1After 2000h of reaction, the acetylene conversion was 99.20% and the acetaldehyde selectivity was 98.20%.
Example 5
Selecting graphene as a carrier, wherein the particle size of the graphene is 60 meshes, and the specific surface area of the graphene is 2500m2The pore volume is 0.3 mL/g. At room temperature, at 40ml/minN2And performing plasma treatment under the atmosphere, treating for 0.25h at a current of 5A and a voltage of 16V, and taking out for later use.
78g of copper phosphate and 0.28g of CaCl2Dissolving in diethyl ether, stirring to mix uniformly, dripping the mixture on 100g of graphene treated by plasma at 28 ℃, performing action treatment for 4.5h under the condition of an electrostatic field with the strength of 50kv/cm, taking out from the electrostatic field, and drying for 7.5h under the condition of 40 ℃ to obtain the copper-based catalyst, wherein the copper loading is 13 percent, CaCl is added2The loading was 0.1%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 200 ℃, the pressure is 0.8MPa, and the volume space velocity of acetylene is 500h-1Under the condition of (1), after the reaction is carried out for 2000 hours, the conversion rate of acetylene is 99.31 percent, and the selectivity of acetaldehyde is 98.99 percent.
Example 6
ZSM-5 molecular sieve is selected as a carrier, the particle size is 70 meshes, and the specific surface area is 600m2The pore volume is 0.5 mL/g. At room temperature, at 20ml/min N2And performing plasma treatment under the atmosphere, wherein the current is 2.5A, the voltage is 18V, and the plasma is taken out for standby after treatment for 1.8 h.
Dissolving 41.92g of copper chloride and 3.81g of KCl in tetrahydrofuran, stirring to uniformly mix the copper chloride and the KCl, dropwise adding the mixture onto 100g of ZSM-5 molecular sieve treated by plasma at 28 ℃, performing action treatment for 4.6 hours under the condition of an electrostatic field with the strength of 25kv/cm, then taking out the mixture from the electrostatic field, and drying for 8 hours at 70 ℃ to obtain the copper-based catalyst, wherein the copper loading is 20% and the KCl loading is 2%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 180 ℃, the pressure is 0.6MPa, and the volume space velocity of acetylene is 350h-1After 2000h of reaction, the acetylene conversion was 99.01% and the acetaldehyde selectivity was 99.72%.
Comparative example 1
Comparative example 1 illustrates the non-substitutability of electrostatic field technology in the catalyst preparation process by comparison with example 1.
Selecting columnar active carbon as carrier, with particle diameter of 20 mesh and specific surface area of 1000m2The pore volume is 1 mL/g. At room temperature, at 5ml/min N2And performing plasma treatment under the atmosphere, wherein the current is 1A, the voltage is 10V, and the plasma is taken out for standby after treatment for 0.5 h.
20.96g of copper chloride and 0.21g of ZnCl were mixed2Dissolving in methanol, stirring, adding the mixture dropwise onto 100g of activated carbon carrier at 25 deg.C, and oven drying at 70 deg.C for 6 hr to obtain copper-based catalyst with copper loading of 10% and ZnCl content2The loading was 0.1%.
The catalyst is applied to the reactionIn the acetylene hydration reaction in the reactor, the reaction conditions are as follows: the temperature is 100 ℃, the pressure is 0.01MPa, and the volume space velocity of acetylene is 5h-1After 2000 hours of reaction time, the acetylene conversion was 67.25% and the acetaldehyde selectivity was 78.26%.
Comparative example 2
Comparative example 2 illustrates the non-substitutability of plasma technology in the preparation of a catalyst by comparison with example 1.
Selecting columnar active carbon as carrier, with particle diameter of 20 mesh and specific surface area of 1000m2The pore volume is 1 mL/g. 20.96g of copper chloride and 0.21g of ZnCl were mixed2Dissolving in methanol, stirring, adding the mixture to 100g of activated carbon carrier at 25 deg.C, treating for 3 hr under electrostatic field condition with strength of 10kv/cm, taking out from electrostatic field, and oven drying at 70 deg.C for 6 hr to obtain copper-based catalyst with copper loading of 10%, ZnCl, and copper content of 10%2The loading was 0.1%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 100 ℃, the pressure is 0.01MPa, and the volume space velocity of acetylene is 5h-1Under the condition of (1), after the reaction is carried out for 2000 hours, the acetylene conversion rate is 79.20 percent, and the acetaldehyde selectivity is 88.21 percent.
Comparative example 3
Comparative example 3 illustrates the effect of nitrogen doping of activated carbon fibers during catalyst preparation by comparison with example 2.
Active carbon fiber is selected as a carrier, the particle size of the carrier is 100 meshes, and the specific surface area is 800m2The pore volume is 0.25 mL/g. At room temperature, at 10ml/min N2In the atmosphere, plasma treatment was carried out at a current of 2A and a voltage of 15V, and the substrate was taken out after 1 hour of treatment.
90g of copper nitrate and 2.25g of BiCl3Dissolving in deionized water, stirring, adding the mixture at 35 deg.C to 100g of activated carbon fiber carrier treated by plasma, treating for 4 hr under electrostatic field condition with strength of 20kv/cm, taking out from the electrostatic field, and oven drying at 120 deg.C for 10 hr to obtain copper-based catalyst with copper loading of 30% and BiCl3The loading was 2%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 100 ℃, the pressure is 0.05MPa, and the volume space velocity of acetylene is 250h-1Under the conditions of (1), after 2000h of reaction, the acetylene conversion rate is 88.97 percent, and the acetaldehyde selectivity is 79.20 percent.
Comparative example 4
Comparative example 4 illustrates the effect of phosphorus doping of activated carbon fibers in the catalyst preparation process by comparison with example 3.
Selecting active carbon fiber as carrier with particle size of 50 mesh and specific surface area of 1600m2The pore volume is 2.5 mL/g. At room temperature, at 30ml/min N2In the atmosphere, plasma treatment was carried out at a current of 3A and a voltage of 20V for 1.5 hours, and then the substrate was taken out.
90g of copper nitrate and 2.25g of BiCl3Dissolving in deionized water, stirring, adding the mixture at 30 deg.C to 100g of activated carbon fiber carrier treated by plasma, treating under electrostatic field for 5 hr with strength of 30kv/cm, taking out from the electrostatic field, and oven drying at 110 deg.C for 10 hr to obtain copper-based catalyst with copper loading of 10% and ZnCl content2The loading was 0.1%.
The catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 120 ℃, the pressure is 1.5MPa, and the volume space velocity of acetylene is 300h-1After 2000h of reaction, the acetylene conversion was 88.31% and the acetaldehyde selectivity was 72.71%.
Comparative example 5
Comparative example 5 Zn-10Cu/MCM catalyst was prepared according to the document New j. chem.2018,42,6507-6514, and reacted with example 1 under the same reaction conditions, illustrating the superiority of the invention.
The Zn-10Cu/MCM catalyst prepared according to the literature is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 100 ℃, the pressure is 0.01MPa, and the volume space velocity of acetylene is 5h-1Under the condition of (1), after the reaction is carried out for 2000 hours, the acetylene conversion rate is 58.31 percent, and the acetaldehyde selectivity is 64.71 percent.
Comparative example 6
A conventional mercury sulfate-sulfuric acid catalyst was prepared and reacted with example 1 under the same reaction conditions, illustrating the superiority of the invention.
The traditional mercury sulfate-sulfuric acid catalyst is applied to acetylene hydration reaction in a reactor, and the reaction conditions are as follows: the temperature is 100 ℃, the pressure is 0.01MPa, and the volume space velocity of acetylene is 5h-1After 2000h of reaction, the acetylene conversion was 32.56% and the acetaldehyde selectivity was 55.16%.