阅读说明：本技术 一种协同位点催化剂、其制备方法及其在硫醇和硫醚制备中的应用 (Coordinated site catalyst, preparation method thereof and application thereof in preparation of mercaptan and thioether ) 是由 王勇 陈志荣 王哲 王正江 胡柏剡 尹红 陈聪 吴可军 张凯超 李其川 严辉焕 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种协同位点催化剂,该协同位点催化剂包括活性组分和载体,所述活性组分以M-(a)N-(b)O的基本组成形式存在,其中M为Na、K和Cs中的一种、两种或者三种,N为Mo、W、Re中的一种、两种或者三种,0<a<3,0<b<2,所述载体为金属氧化物,所述活性组分呈纳米颗粒状分布于所述载体表面。本发明进一步公开了所述催化剂的制备方法以及该催化剂在甲醇以及C-(2)-C-(8)的醇类与硫化氢生成硫醇和硫醚反应中的应用。(The invention discloses a synergistic site catalyst which comprises an active component and a carrier, wherein the active component is M a N b O exists in a basic composition form, wherein M is one, two or three of Na, K and Cs, N is one, two or three of Mo, W and Re, and 0<a<3，0<b<2, the carrier is metal oxide, and the active component is distributed on the surface of the carrier in a nano-granular manner. The invention further discloses a preparation method of the catalyst and the application of the catalyst in methanol and C 2 ‑C 8 The alcohols of (a) are reacted with hydrogen sulphide to form mercaptans and thioethers.)

1. The catalyst is characterized by comprising an active component and a carrier, wherein the active component is M_aN_bO, wherein M is one, two or three of Na, K and Cs, N is one, two or three of Mo, W and Re, and 0<a<3，0<b<2, the carrier is metal oxide, and the active component is distributed on the surface of the carrier in a nano-granular manner.

2. The catalyst of claim 1, wherein the nanoparticles formed by the active component have an average particle size of less than 12 nm.

3. The catalyst of claim 1 wherein the metal oxide in the support comprises alumina, the alumina being present in the support in an amount of greater than 80% by mass.

4. The catalyst according to claim 3, wherein the carrier further comprises one or more elements selected from the group consisting of Si, Mg, Ca, Ti, Zr, Ce, V, Cr, Mn, Zn, Ga, Ge, Sn, Bi, Y, Nb, La, and preferably wherein the carrier further comprises one or more elements selected from the group consisting of Ti, Zr, Ce, Zn, Mn, Nb, Y, La.

5. The catalyst according to claim 1, wherein the carrier has a particle diameter of 0.005 to 1 μm and a specific surface area of 20 to 450m²/g。

6. A method for preparing a co-site catalyst according to any of claims 1 to 5, comprising the steps of:

(1) dissolving or dispersing a precursor of an active component I and a biomass derivative in water together, carrying out hydrothermal reaction, and washing, filtering and drying after the reaction is finished to obtain a first solid;

the active component I contains one, two or three elements of Mo, W and Re;

(2) adding the first solid into a solution containing a precursor of an active component II, adsorbing for a period of time, adding a carrier, continuously adsorbing, and drying at a certain temperature to obtain a second solid;

the active component II contains one, two or three elements of Na, K and Cs;

(3) and calcining the second solid in a specific atmosphere to obtain the catalyst.

7. The method of claim 6, wherein the precursor of active component I is selected from (NH)₄)₁₀W₁₂O₄₁、H₂₈N₆W₁₂O₄₁、Na₂WO₄·2H₂O、Na₆W₁₂O₃₉、H₂WO₄、K₂WO₄、Cs₂WO₄、(NH₄)₂Mo₂O₇、(NH₄)₂Mo₄O₁₃·2H₂O、H₂MoO₄、K₂MoO₄、Cs₂MoO₄、(NH₄)₆Mo₇O₂₄·4H₂O、Na₂MoO₄·2H₂O、H₂ReO₄、HReO₄、NH₄ReO₄、KReO₄One or more of (a).

8. The method of claim 6, wherein the biomass derivative is selected from one or more of cellulose, chitin, chitosan, hemicellulose, trehalose, glucose, fructose, sorbitol, lyxose, erythrose, threose, glyceraldehyde, and glycerol.

9. The preparation method of the catalyst according to claim 6, wherein the mass ratio of the precursor of the active component I to the biomass derivative is 0.1-5: 1; preferably 0.3-3: 1.

10. The method of claim 6, wherein the reaction temperature in step (1) is 120 to 250 ℃ and the reaction time is 2 to 48 hours.

11. The method of claim 6, wherein the precursor of the active component II is selected from Na₂CO₃、NaOH、NaHCO₃、K₂CO₃、KOH、KHCO₃、Cs₂CO₃、CsOH、CsHCO₃One or more of (a).

12. The method of claim 6, wherein the calcining atmosphere of the second solid is air, oxygen or a mixed gas containing oxygen, and the mixed gas further contains one or more of nitrogen, argon, helium, carbon monoxide and carbon dioxide;

the calcination temperature of the second solid is 300-1000 ℃, and the calcination time is 0.1-12 hours.

13. Use of a catalyst according to any one of claims 1 to 5 in the reaction of an alcohol with hydrogen sulphide to form a thiol and/or thioether.

14. The use according to claim 13, wherein the catalyst is pretreated with a hydrogen sulphide-containing gas mixture before the reaction.

15. The use according to claim 14, wherein in the step of hydrogen sulfide pretreatment, the pretreatment temperature is 200 to 600 ℃ and the pretreatment time is 1 to 12 hours;

in the step of hydrogen sulfide pretreatment, the volume content of hydrogen sulfide in the pretreated gas flow is 5-100%;

in the step of hydrogen sulfide pretreatment, the pretreatment gas stream may further comprise one or more of hydrogen, nitrogen, argon, helium, and carbon monoxide.

16. The use according to any one of claims 13 to 15, wherein the alcohol is methanol, the thiol is methyl mercaptan and the thioether is dimethyl sulfide.

17. The use according to claim 16, wherein the reaction temperature is 250 to 450 ℃ and the reaction pressure is 0.1 to 5 MPa;

the molar ratio of hydrogen sulfide to methanol in the reaction raw materials is 0.5-2.0: 1.

18. the use according to any one of claims 13 to 15, wherein the alcohol is C₂-C₈Alcohols of (2).

19. Use of a catalyst according to any one of claims 1 to 5 in the preparation of thioethers by addition reaction of a thiol with an α, β -unsaturated aldehyde.

20. The use according to claim 19, wherein the α, β -unsaturated aldehyde is acrolein;

the mercaptan is methyl mercaptan;

the thioether is 3-methylthiopropanal.

Technical Field

The invention belongs to the technical field of catalysts, and particularly relates to a coordinated site catalyst, a preparation method thereof and application thereof in preparation of mercaptan and thioether.

Background

Methyl mercaptan is a very important chemical intermediate and is commonly used for producing products such as amino acid, pesticide, dye and the like. Dimethyl sulfide is an edible spice and has high application value. Both products can be synthesized by methanol and hydrogen sulfide over heterogeneous catalysts. Wherein the reaction temperature, pressure, ratio of methanol to hydrogen sulfide in the raw material, space velocity and other conditions have influence on the yield of methyl mercaptan and dimethyl sulfide. In addition to the formation of methyl mercaptan and dimethyl sulfide, some side reactions may occur, resulting in the formation of dimethyl ether, methane, carbon monoxide and carbon dioxide as by-products. Therefore, how to modulate the composition and the micro-nano structure of the catalyst, realize the effective regulation of product selectivity and the remarkable improvement of catalytic activity is always a great challenge of the reaction.

The alumina catalyst has certain catalytic performance, large specific surface area, low price and easy availability, and is generally regarded as an ideal catalyst for the reaction, especially gamma-Al₂O₃. In order to further improve the catalytic performance, especially the selectivity of methyl mercaptan, some auxiliary components are often introduced. Among them, salts of alkali metal elements are most commonly used. In addition, some tungstates may also be used as auxiliaries. US 2820062 uses an impregnation process to prepare an alumina catalyst containing an alkali metal tungstate. However, the supporting amount of the promoter is difficult to exceed 25% by weight, which makes the catalytic performance unsatisfactory, limited by the process itself. Although EP 0832878A2 can achieve higher loadings using repeated impregnation techniques, such an operation is relatively time consuming and laborious. And limited by the limitations of the impregnation method, the insufficient synergy between the active sites on the surface of the carrier leads to low utilization efficiency of the active components, and the loading capacity has to be increased to maintain sufficient performance, which undoubtedly increases the cost of the catalyst.

Besides the improvement of the loading capacity of the auxiliary agent, the regulation and control of the micro-nano structure of the active center is also an important method for realizing performance optimization. However, the composition of the active center and its regulation method are rarely reported in this reaction.

The 3-methylthio propionaldehyde can be used as edible essence and is also an important intermediate for producing methionine. Its preparation is obtained by reaction of methyl mercaptan and acrolein, often with an organic base as catalyst. Organic bases are readily soluble in the reaction system and, in order to avoid condensation between aldehydes, organic acids are usually added, which causes difficulties in isolation and purification of the product. The catalyst not only contains alkaline components such as alkali metals, but also can contain acidic components such as tungsten, molybdenum and the like, and the micro-nano structure of the catalyst can be regulated and controlled, so that the catalyst can be widely applied to the production of 3-methylthiopropanal. Compared with the traditional organic base and organic acid, the use of the heterogeneous catalyst can effectively reduce the separation cost of the product and the operation efficiency of the process.

Disclosure of Invention

Based on the catalyst, the invention develops and prepares a series of catalysts for catalyzing alcohol and hydrogen sulfide to prepare mercaptan and thioether from two aspects of catalyst microstructure design and preparation method innovation, and the catalysts have higher catalytic activity and can improve the conversion rate and selectivity of reaction.

The technical scheme of the invention is as follows:

a co-site catalyst comprises an active component in the form of nanoparticles and a carrier, wherein the active component has a composition M_aN_bO exists in the form of nano-particles, wherein M is one, two or three of Na, K and Cs, N is one, two or three of Mo, W and Re, and 0<a<3，0<b<2, the carrier is a metal oxide; preferably, 0<a<2，0<b<0.3; further preferably, 0.5<a<1.7，0.05<b<0.25。

Preferably, the nanoparticles formed by the active component have an average particle size of 12nm or less, and further preferably, in the nanoparticles, the N is mainly distributed in the inner part, and the M is mainly distributed on the surface.

Preferably, the average particle diameter of the nanoparticles is less than or equal to 10 nm; more preferably, the average particle size of the nanoparticles is between 1nm and 10 nm.

Preferably, the alumina content in the carrier is 80% by mass or more, and may further contain one or more elements selected from Si, Mg, Ca, Ti, Zr, Ce, V, Cr, Mn, Zn, Ga, Ge, Sn, Bi, Y, Nb, and La, and preferably, the carrier further contains one or more elements selected from Ti, Zr, Ce, Zn, Mn, Nb, Y, and La.

Preferably, the total loading amount of the active components except oxygen is 0.1-75% by mass, wherein the loading amount refers to the mass percentage of the rest components and the carrier.

Preferably, the carrier has a particle diameter of 0.005 to 1 μm and a specific surface area of 20 to 450m²The carrier preferably has a particle diameter of 0.05 to 1 μm.

The invention also provides a preparation method of the coordinated site catalyst, which comprises the following steps:

(1) dissolving or dispersing a precursor of an active component I and a biomass derivative in water together, carrying out hydrothermal reaction, and after the reaction is finished, washing with water, filtering, and drying to obtain a first solid;

(2) adding the first solid into a solution containing a precursor of an active component II, adsorbing for a period of time, adding a carrier, continuing to adsorb, and drying to obtain a second solid;

(3) and calcining the second solid in a specific atmosphere to obtain the catalyst.

Preferably, the precursor of the active component I is selected from (NH)₄)₁₀W₁₂O₄₁、H₂₈N₆W₁₂O₄₁、Na₂WO₄·2H₂O、Na₆W₁₂O₃₉、H₂WO₄、K₂WO₄、Cs₂WO₄、(NH₄)₂Mo₂O₇、(NH₄)₂Mo₄O₁₃·2H₂O、H₂MoO₄、K₂MoO₄、Cs₂MoO₄、(NH₄)₆Mo₇O₂₄·4H₂O、Na₂MoO₄·2H₂O、H₂ReO₄、HReO₄、NH₄ReO₄、KReO₄Preferably Na₂WO₄·2H₂O、K₂WO₄、Cs₂WO₄、K₂MoO₄、Cs₂MoO₄、(NH₄)₆Mo₇O₂₄·4H₂O、Na₂MoO₄·2H₂O、NH₄ReO₄、KReO₄One or more of; the biomass derivative is selected from one or more of cellulose, chitin, chitosan, hemicellulose, trehalose, glucose, fructose, sorbitol, lyxose, erythrose, threose, glyceraldehyde and glycerol; the mass ratio of the precursor of the active component I to the biomass derivative is 0.1-5: 1, preferably 0.3-3: 1; the reaction temperature for preparing the first solid is 120-250 ℃, the reaction time is 2-48 hours, the reaction temperature is further preferably 120-180 ℃, and the reaction time is 24-48 hours.

Preferably, the precursor of the active component II is selected from Na₂CO₃、NaOH、NaHCO₃、K₂CO₃、KOH、KHCO₃、Cs₂CO₃、CsOH、CsHCO₃One or more of; the mass content of the alumina in the carrier is more than 80%, and one or more elements of Si, Mg, Ca, Ti, Zr, Ce, V, Cr, Mn, Zn, Ga, Ge, Sn, Bi, Y, Nb and La can be contained.

Preferably, the calcination temperature of the second solid is 300-1000 ℃, preferably 500-1000 ℃, and the calcination time is 0.1-12 hours, preferably 2-12 hours; the calcining atmosphere is air, oxygen or mixed gas containing oxygen, and the mixed gas further contains one or more of nitrogen, argon, helium, carbon monoxide and carbon dioxide.

Preferably, in the step of hydrogen sulfide pretreatment, the pretreatment temperature is 200-600 ℃, preferably 400-600 ℃, and the pretreatment time is 0.1-24 hours, preferably 2-12 hours; the volume content of hydrogen sulfide in the pretreated gas flow is 5-100 percent; the pre-treatment gas stream may also comprise one or more of hydrogen, nitrogen, argon, helium, carbon monoxide.

The invention also provides application of the catalyst in the reaction of alcohol and hydrogen sulfide to generate corresponding mercaptan and/or thioether, wherein the alcohol can be methanol or C2-C8 alcohol. .

Preferably, the reaction temperature for preparing the mercaptan and/or the thioether is 250-450 ℃, and the reaction pressure is 0.1-5 MPa; preferably, the reaction temperature for preparing the mercaptan and/or the thioether is 300-400 ℃, and the reaction pressure is 0.5-2.5 MPa;

preferably, the molar ratio of hydrogen sulfide to alcohol in the reaction raw materials is 0.5-2.0: 1, more preferably 1.0 to 2.0: 1.

the invention also provides application of the catalyst in preparation of thioether through addition reaction of mercaptan and alpha, beta-unsaturated aldehyde. Further, the alpha, beta-unsaturated aldehyde is acrolein, the mercaptan is methyl mercaptan, and the thioether is 3-methylthiopropanal.

Preferably, the reaction temperature of the addition reaction is 30-100 ℃, and more preferably 30-80 ℃;

preferably, the molar ratio of the mercaptan to the alpha, beta-unsaturated aldehyde in the reaction raw materials is 0.5-2.0: 1, more preferably 1.0 to 2.0: 1.

according to the preparation method of the catalyst provided by the embodiment of the invention, the acidic environment generated under the hydrothermal condition of the biomass derivative is utilized to promote the nucleation of Mo, W, Re and other substances, and the Mo, W, Re nano oxides formed after the nucleation have a special bonding effect with the biomass derivative, so that the biomass derivative is subjected to polymerization growth and carbonization on the surface of the nano oxides to form porous hydrothermal carbon; the porous hydrothermal carbon has strong adsorption capacity, can adsorb a large amount of precursors of active components II, can accelerate the adsorption process in an alkaline environment generated by an aqueous solution, is combined on the surface of a carrier, and is calcined to remove the hydrothermal carbon to obtain a special structure shown in figure 1, wherein the active component of the structure is M_aN_bO nanoparticles, wherein M is one, two or three of Na, K and Cs, N is one or more of Mo, W and Re, and 0<a<3，0<b<2。

The adjustment of the size of the active component can be realized by controlling the conditions such as reaction temperature, precursor concentration and proportion, reaction time and the like, so that the size of the active component is below 12 nm. Compared with the traditional impregnation method, the method can well combine the precursors of the active components tightly, improve the utilization efficiency of each component, reduce the consumption of the precursors in the preparation process and reduce the cost of the catalyst while not damaging the catalytic performance; the method has strong universality, the raw materials are cheap and easy to obtain, the proportion of each active site in the catalyst and the acid-base property are easy to regulate and control, multi-step series catalysis can be realized, high-density active nano particles can be formed on the surface of an alumina carrier with high specific surface area, and the mass loading capacity of the active component can reach 75 percent at most.

The catalyst provided by the embodiment of the invention has a large amount of nano particles, the high exposure rate of active components obviously improves the activity of the catalyst, and components such as Na, K, Cs, Mo, W, Re and the like have strong interaction with an alumina carrier, so that the active components of the catalyst are not easy to agglomerate and run off, and the catalyst has excellent stability.

Drawings

FIG. 1 is a schematic diagram of the catalyst structure;

FIG. 2 is a transmission electron micrograph of the catalyst prepared in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below by way of embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a co-site catalyst which can be used for catalyzing the reaction of alcohol and hydrogen sulfide to prepare mercaptan and thioether, and comprises an active component and a carrier, wherein the active component exists in a nano particle form (the average particle size is less than 12nm), and the active component is M_aN_bO exists in the form of nano-particles, wherein M is one, two or three of Na, K and Cs, N is one, two or three of Mo, W and Re, and 0<a<3，0<b<2, the carrier is metal oxide.

In one embodiment, the particle size of the active component is 10nm or less. The smaller the particle size of the active component, the more the number of atoms exposed on the surface, the more active sites, and the higher the catalyst activity.

In one embodiment, the active component is 0.1 to 75% by mass of oxygen.

In one embodiment, the mass content of the alumina in the carrier is more than 80%, and one or more elements of Si, Mg, Ca, Ti, Zr, Ce, V, Cr, Mn, Zn, Ga, Ge, Sn, Bi, Y, Nb, and La may be further included, and preferably, one or more elements of Ti, Zr, Ce, Zn, Mn, Nb, Y, and La are further included in the carrier.

The particle size and specific surface area of the carrier are not particularly limited, and the particle size of the carrier can be preferably 0.05-1 μm and the specific surface area can be preferably 100-450 m under the condition of being more beneficial to the loading and dispersion of the active component²/g。

The invention also provides a preparation method of the catalyst, which comprises the following steps:

s10, dissolving or dispersing the precursor of the active component I and the biomass derivative in water, placing the mixture in a closed container, heating the mixture to a certain temperature, reacting for a period of time, washing with water, filtering and drying to obtain a first solid;

s20, adding the first solid into a solution containing an active component II, adsorbing for a period of time at room temperature, adding a certain amount of carrier for continuous adsorption, and drying at a certain temperature to obtain a second solid;

and S30, calcining the second solid in a specific atmosphere to obtain the catalyst.

According to the preparation method of the catalyst provided by the embodiment of the invention, the acidic environment generated under the hydrothermal condition of the biomass derivative is utilized to promote the nucleation of Mo, W, Re and other substances, and the Mo, W, Re nano oxides formed after the nucleation have a special bonding effect with the biomass derivative, so that the biomass derivative is polymerized and grown on the surface of the nano oxides to form the porous hydrothermal carbon; the porous hydrothermal carbon has strong adsorption capacity and can adsorb a large amount of active componentsII, and the precursor of the active component II can accelerate the adsorption process in an alkaline environment generated by an aqueous solution, so that a special structure with the oxide of the active component I inside and the porous hydrothermal carbon adsorbing the active component II outside is formed, and after the structure is combined with the surface of the carrier, the hydrothermal carbon is removed through calcination, so that the catalyst shown in the figure 1 can be obtained; the catalyst has an active component M_aN_bO nanoparticles, wherein M is one, two or three of Na, K and Cs, N is one or more of Mo, W and Re, and 0<a<3，0<b<2。

According to the preparation method of the catalyst of the embodiment of the invention, the kind of the precursor of the active component I is not particularly limited, and may be conventionally selected. The precursor may be any substance soluble in water at 25 deg.C, and may be selected from (NH)₄)₁₀W₁₂O₄₁、H₂₈N₆W₁₂O₄₁、Na₂WO₄·2H₂O、Na₆W₁₂O₃₉、H₂WO₄、K₂WO₄、Cs₂WO₄、(NH₄)₂Mo₂O₇、(NH₄)₂Mo₄O₁₃·2H₂O、H₂MoO₄、K₂MoO₄、Cs₂MoO₄、(NH₄)₆Mo₇O₂₄·4H₂O、Na₂MoO₄·2H₂O、H₂ReO₄、HReO₄、NH₄ReO₄、KReO₄One or more of; the biomass derivative needs to contain a polyol structure, can form a unique bonding effect with a precursor of an active component I, and can be selected from one or more of cellulose, chitin, chitosan, hemicellulose, trehalose, glucose, fructose, sorbitol, lyxose, erythrose, threose, glyceraldehyde and glycerol; the mass ratio of the precursor of the active component I to the biomass derivative is not particularly limited, and the mass ratio is preferably 0.3-3: 1 in order to regulate the size and content of the formed nano oxide; the above-mentionedThe reaction conditions for preparing the first solid need to ensure the nucleation of the active component and the carbonization of the biomass derivative, the reaction temperature is 120-250 ℃, and the reaction time is 2-48 hours.

The preparation method of the catalyst of the embodiment of the invention has no particular limitation on the kind of the precursor of the active component II, can be selected conventionally, and can be selected from Na₂CO₃、NaOH、NaHCO₃、K₂CO₃、KOH、KHCO₃、Cs₂CO₃、CsOH、CsHCO₃One or more of; the mass content of the alumina in the carrier is more than 80%, and one or more elements of Si, Mg, Ca, Ti, Zr, Ce, V, Cr, Mn, Zn, Ga, Ge, Sn, Bi, Y, Nb and La can be contained.

In one embodiment, step S30, calcining the second solid in a specific atmosphere to remove the hydrothermal charcoal, wherein the calcining temperature of the second solid is 300 ℃ to 1000 ℃ and the calcining time is 0.1 hour to 12 hours; the calcining atmosphere is air oxygen or mixed gas containing oxygen, and the mixed gas can also contain one or more of nitrogen, argon, helium, carbon monoxide and carbon dioxide.

The embodiment of the invention further provides the application of the catalyst or the catalyst obtained by the preparation method in methanol or C₂-C₈The alcohol and hydrogen sulfide in the reaction of preparing corresponding mercaptan or thioether, or in the reaction of preparing 3-methylthio propionaldehyde by series reaction.

In one application example, the catalyst provided by the invention can be used for catalyzing methanol and H₂S reacts to generate methyl mercaptan and dimethyl sulfide.

Wherein the series reaction refers to the reaction of methanol and H₂The product of S after reaction and separation is further reacted with acrolein to obtain 3-methylthio propionaldehyde, and the catalyst is the catalyst provided by the invention.

Example 1

S10, weighing 0.95g K₂WO₄Dissolving 2g of glucose in 50mL of water, transferring the solution into a hydrothermal kettle, heating to 180 ℃, and reactingFiltering for 24 hours, washing with water, and drying at 80 ℃ to obtain a first solid;

s20, weighing 0.5g Cs₂CO₃Adding 30mL of water, adding the first solid, stirring at room temperature for 2 hr, adding 5g of alumina (particle size of 0.1 μm, specific surface area of 210 m)²(g) stirring for 2 hours at 80 ℃ until the solvent is evaporated to dryness to obtain a second solid;

s30, calcining the obtained second solid in air for 2 hours at the heating rate of 3 ℃/min and at the temperature of 500 ℃ to obtain the alumina supported catalyst, wherein the active component is K_0.442Cs_0.233W_0.221O, the loading was 10.7% by mass of W.

Example 2

Substantially the same as in example 1 except that Cs is used in step S20₂CO₃Was added in an amount of 0.2g, to obtain a catalyst in which the active component had a composition of K_0.475Cs_0.100W_0.237O, the loading was 10.7% by mass of W.

Example 3

Substantially the same as in example 1, except that the precursor of active component I in the step S10 was 1g of Na₂WO₄·2H₂O, an alumina-supported catalyst in which the composition of the active component is Na is obtained_0.448Cs_0.206W_0.224O, the loading amount was 11.2% by mass of W.

Example 4

Substantially the same as in example 1 except that glucose was replaced with 2g of cellulose in step S10.

Example 5

Substantially the same as in example 1, except that the precursor of active component I in step S10 contained 0.5g K₂WO₄And 0.3g K₂MoO₄An alumina-supported catalyst can be obtained in which the active component has the composition K_0.440Cs_0.242Mo_0.099W_0.121O, amount of supporting5.6% by mass of W.

Example 6

Substantially the same as in example 1 except that 5% SiO was contained in the alumina used in step S20₂And (4) components.

Comparative example 1

0.95g K by conventional dipping method₂WO₄、0.5g Cs₂WO₄Carried on carrier Al₂O₃A surface. Firstly 0.95g K₂WO₄、0.5g Cs₂CO₃Dissolved in 50mL of water, and 5g of Al was added₂O₃Immersed in the solution, stirred for 2 hours, dried at 80 ℃ and then calcined, the procedure being the same as in example 1.

The average particle diameters of the active component particles in the catalysts prepared in examples 1 to 5 and comparative example 1 were obtained by observing the catalysts prepared in examples 1 to 5 and comparative example 1 with a transmission electron microscope and measuring, counting, and averaging the results using image processing software, and the results are shown in table 1, in which fig. 2 is a transmission electron microscope photograph of the catalyst prepared in example 1.

TABLE 1

	Average particle diameter of active ingredient particles
		Catalyst prepared in example 1	6.4nm
Example 2 catalyst	7.6nm
		Catalyst prepared in example 3	7.5nm
Example 4 catalyst	11.8nm
		Catalyst prepared in example 5	5.2nm
Catalyst prepared in comparative example 1	22.1nm

Application example 1 methanol with H₂Selective production of methyl mercaptan by the S reaction

The reaction was catalyzed using the catalysts prepared in examples 1-4 and comparative example 1, with the catalyst being in H before the reaction₂Pretreating for 2H in S atmosphere at 300 deg.C in 20 vol% of H₂S, the rest is N₂. The specific reaction conditions are as follows: a fixed bed reactor was used, and 25g of catalyst, H, was charged₂The mol ratio of S to methanol is 1.5:1, and the liquid space velocity of methanol is 1.5h^-1The reaction pressure was 1MPa, the reaction temperature was set at 300-360 deg.C, and the results of the gas chromatographic analysis of the reaction products are shown in Table 2.

TABLE 2

From the above results, it is understood that the catalyst obtained by the method of the present invention has a smaller average particle diameter of the active component. The catalyst is adopted to catalyze the reaction for preparing mercaptan or/and thioether, the conversion rate of methanol is obviously improved, and the sum of the selectivity of the mercaptan and thioether is also improved; and the change of the proportion of active components in the catalyst (the reduction of the proportion of Cs leads to the increase of the selectivity of thioether) can cause the change of the proportion of the mercaptan and the thioether, thereby having larger regulation space.

Application examples 21-propanol and H₂S reaction for selectively generating 1-propanethiol

The reaction was catalyzed by the catalyst prepared in example 1, the catalyst being in H before the reaction₂Pretreating for 2H in S atmosphere at 320 deg.C in 20 vol% of H₂S, the rest is N₂. The specific reaction conditions are as follows: a fixed bed reactor was used, and 25g of catalyst, H, was charged₂The liquid space velocity of the S and the 1-propanol with the molar ratio of 2:1, 1-propanol is 1.2h^-1The reaction pressure is 1MPa, the reaction temperature is set to be 320 ℃, and the conversion rate of 1-propanol is 98.7 percent and the selectivity of 1-propanethiol is 92.1 percent by analyzing the reaction products through gas chromatography.

Application example 3 preparation of 3-methylthiopropanal by series reaction

The catalyst prepared in example 1 was used to carry out a reaction under the reaction conditions of application example 1, followed by separation of the product, introduction of the resulting methyl mercaptan product into a reaction vessel containing 3-methylthiopropanal and the catalyst of example 5 while adding acrolein in an amount equimolar to methyl mercaptan, and controlling the reactor temperature to 40 ℃ and the amount of 3-methylthiopropanal in the vessel to be continuously increased, the yield of 3-methylthiopropanal based on methyl mercaptan was more than 99%, and almost no by-product was produced.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.