阅读说明：本技术 一种合成气制取芳烃的催化剂及其应用 (Catalyst for preparing aromatic hydrocarbon from synthesis gas and application thereof ) 是由 钟良枢 林铁军 孙涛 孙予罕 于 2020-04-08 设计创作，主要内容包括：本发明提供一种合成气制取芳烃的催化剂及其应用,所述催化剂包括如下质量百分比的各组分：含CoMn尖晶石结构的复合氧化物20％～70％；沸石分子筛30％～80％。该催化剂在固定床使用时既可以用于双床层催化剂状态模式,也可以用于单床层混合型催化剂状态模式,同时还可以用于串联双反应器中使用。该催化剂在合成气制芳烃反应中表现出活性高、甲烷选择性低及芳烃选择性高的特点,应用前景广泛。(The invention provides a catalyst for preparing aromatic hydrocarbon from synthesis gas and application thereof, wherein the catalyst comprises the following components in percentage by mass: 20-70% of composite oxide containing CoMn spinel structure; 30 to 80 percent of zeolite molecular sieve. When the catalyst is used in a fixed bed, the catalyst can be used in a double-bed catalyst state mode, a single-bed mixed catalyst state mode and a series double reactor. The catalyst has the characteristics of high activity, low methane selectivity and high aromatic hydrocarbon selectivity in the reaction of preparing aromatic hydrocarbon from synthesis gas, and has wide application prospect.)

1. The catalyst for preparing the aromatic hydrocarbon from the synthesis gas is characterized by comprising the following components in percentage by mass: 20-70% of composite oxide containing CoMn spinel structure;

30 to 80 percent of zeolite molecular sieve.

2. The catalyst of claim 1, further comprising at least one of the following technical features:

1) the general formula of the composite oxide containing the CoMn spinel structure is Co_xMn_yO-M_zO or Co_xMn_yO-M_zO-N; wherein M is at least one of IA group elements, IIA group elements, IIIA group elements, IIIB group elements, IIB group elements and IVB group elements, and N is a carrier;

2) the zeolite molecular sieve is selected from at least one of MFI structure molecular sieve, CHA structure molecular sieve, FAU structure molecular sieve, BEA structure molecular sieve, ME L structure molecular sieve and AE L structure molecular sieve;

3) the mole ratio of Si/Al of the zeolite molecular sieve is 10-500.

3. The catalyst of claim 2, further comprising at least one of the following technical features:

a1) in feature 1), the M is at least one selected from the group consisting of Na, K, Rb, Cs, Ca, Mg, Sr, Ba, Al, L a, Ce, Zn, Cd and Zr;

a2) in feature 1), N is selected from SiO₂、Al₂O₃、TiO₂At least one of SiC and carbon materials;

a3) in the characteristic 1), the molar ratio x/y of the Co element to the Mn element is 0.1-10: 1;

a4) in feature 1), M_zO is a stable oxide of M and z is such that M is satisfied_zThe molar amount of M required for the valency of the elements in the O oxide;

a5) in the characteristic 1), the mass percentage of M in the composite oxide containing the CoMn spinel structure is as follows: 0.1 to 15 percent;

a6) in the characteristic 1), the mass percentage of N in the composite oxide containing the CoMn spinel structure is 0-80%;

a7) in the characteristic 1), the composite oxide containing a CoMn spinel structure is obtained by at least one preparation method of a coprecipitation method, a sol-gel method, a complexation method and an impregnation method;

b1) in feature 2), the zeolite molecular sieve is a modified molecular sieve, and the modifying element is at least one selected from Zn, Si, Ce, L a, Na, K, Sn, Zr, and Ga.

4. The catalyst according to claim 3, characterized in that characteristic b1) further comprises at least one of the following technical characteristics:

b11) the mass percentage of the modified elements in the zeolite molecular sieve is not more than 10 percent;

b12) the modified molecular sieve is obtained by at least one preparation method of an impregnation method, an ion exchange method and a liquid phase deposition method.

5. The catalyst of any one of claims 1 to 4, which is used for producing aromatic hydrocarbon from synthesis gas.

6. Use according to claim 5, characterised in that it also comprises one of the following technical features:

1) when the catalyst is used for preparing aromatic hydrocarbon from synthesis gas in a single reactor, a single-bed mixed catalyst state mode is adopted, and the composite oxide containing the CoMn spinel structure and the zeolite molecular sieve are mixed in a mechanical physical mixing mode;

2) when the catalyst is used for preparing aromatic hydrocarbon from synthesis gas in a single reactor, a double-bed catalyst state mode is adopted, the composite oxide containing the CoMn spinel structure is filled at the upper part of a constant temperature area of the reactor, and the zeolite molecular sieve is filled at the lower part of the constant temperature area of the reactor;

3) when the catalyst is used for preparing aromatic hydrocarbon from synthesis gas in a series-connection double reactor, the series-connection double reactor sequentially comprises a first reactor and a second reactor, the composite oxide containing the CoMn spinel structure is placed in a constant temperature area of the first reactor, and the zeolite molecular sieve is placed in a constant temperature area of the second reactor.

7. The use according to claim 6, wherein in characteristic 1) the mechanical-physical mixing means is selected from at least one of the group consisting of wet powder mixing, powder milling, powder ball milling and particle mixing.

8. Use according to claim 5, wherein the CoMn spinel structure-containing composite oxide is reduced prior to use in synthesis gas for aromatics production.

9. Use according to claim 8, wherein the reducing conditions are: the reduction temperature is 200-500 ℃; the reduction time is 1-24 h; the reduction space velocity is 2000 ml/(g.h) to 20000 ml/(g.h); the reduction pressure is 0.1MPa to 2 MPa; the reducing atmosphere is at least one of hydrogen, CO, diluted hydrogen, diluted CO and diluted synthesis gas, the diluted gas is inert gas, and the volume content of the diluted gas is less than 90%.

10. Use according to claim 5, characterised in that it also comprises one of the following technical features:

1) the reaction conditions for preparing aromatic hydrocarbon by using the single-reactor synthesis gas are as follows: the reaction temperature is 200-400 ℃, the reaction pressure is 0.1-4 MPa, and the reaction space velocity is 500h^-1～10000h^-1The synthesis gas comprises H₂And CO, and H₂The volume ratio of the carbon dioxide to CO is 0.1-10: 1.

2) The reaction conditions for preparing aromatic hydrocarbon by using synthesis gas of the series double reactors are as follows: the reaction pressure is 0.1MPa to 4MPa, and the reaction space velocity is 500h^-1～10000h^-1The synthesis gas comprises H₂And CO, and H₂The volume ratio of the carbon dioxide to CO is 0.1-10: 1, the reaction temperature of the first reactor is 200-350 ℃, and the reaction temperature of the second reactor is 300-500 ℃.

Technical Field

The invention belongs to the technical field of catalytic conversion of synthesis gas, and particularly relates to a catalyst for preparing aromatic hydrocarbon from synthesis gas and application thereof.

Background

Aromatic hydrocarbon is a kind of hydrocarbon containing benzene ring, is a very important basic raw material for organic chemical industry and high molecular chemical industry, and can be used for synthesizing fine chemicals such as rubber, resin, fiber, polystyrene, polyethylene terephthalate and the like. Traditional aromatics are mainly derived from the by-products of catalytic reforming of naphtha. With the increasing depletion of oil and gas resources and the gradual extraction of naphtha as a cracking raw material from shale gas and the like, the yield of petroleum-based aromatic hydrocarbons tends to be greatly reduced, and a new non-petroleum resource route is urgently developed.

In recent years, the chemical route of C1 has received particular attention. Development of coal, natural gas, biomass, shale gas, and even CO₂The preparation of clean liquid fuels and chemicals from non-oil gas resources such as greenhouse gases via the Fischer-Tropsch synthesis route (syngas conversion) is gaining increasing attention and has also made an important progress. One of the traditional syngas conversion routes is fischer-tropsch synthesis. Fuels such as gasoline, diesel oil, aviation kerosene, high-end paraffin and the like, and high value-added chemicals such as olefin, aromatic hydrocarbon, oxygen-containing compounds and the like can be obtained through Fischer-Tropsch synthesis. However, the product selectivity of the traditional Fischer-Tropsch route is difficult to control, the product is limited by the classical ASF distribution rule, and the yield of aromatic hydrocarbon is not more than 15 percent at most. Therefore, the development of new catalysts based on syngas conversion, improving process efficiency and product selectivity, has become an endeavor for researchers.

Currently, the preparation of aromatics from synthesis gas mainly comprises two routes: one is to adopt indirect method, the synthesis gas is firstly converted into methanol, and then the methanol is subjected to aromatization reaction on a molecular sieve to generate aromatic hydrocarbon, commonly called MTA process, and the process is not industrialized yet. The second is a direct method, and comprises two types, one is that a series connection double reactor is adopted, synthetic gas is firstly converted into intermediate products of olefin, methanol and dimethyl ether through a first reactor, and then aromatic hydrocarbon is generated through aromatization reaction in a second reactor; the other is direct method, the synthetic gas is directly used to prepare aromatic hydrocarbon in a single reactor, and the catalyst is a dual-function composite catalyst. For example, chinese patent CN106215972A, CN106540740A discloses a Zr-based oxide and zeolite molecular sieve composite catalyst for preparing aromatic hydrocarbons, which couples the methanol synthesis process with the aromatization process, and the intermediate species of the catalytic system is mainly methanol/dimethyl ether. In addition, chinese patents CN 106607083a, CN 110385141 a, and CN105944751A disclose that a composite molecular sieve containing Fe group and zeolite molecular sieve is used for the synthesis of aromatic hydrocarbon, the process couples Fe-based fischer-tropsch synthesis and aromatization synthesis, and the intermediate product is mainly olefin. The activity of the catalytic systems via methanol intermediates reported so far is usually less than 30% due to thermodynamic limitations; the catalytic system of the olefin intermediate is mainly a catalyst containing Fe base, the carbon deposition is serious, and the total aromatic selectivity is not high. If the Co-containing catalyst is adopted, the performance of preparing aromatic hydrocarbon from the synthesis gas is very poor, the selectivity of the aromatic hydrocarbon is lower than 20 percent, and the catalyst system is hardly developed and is rarely documented. How to strengthen the reaction performance of the Co-based catalyst and improve the selectivity of a target product and the activity of the catalyst through the design of the catalyst is a core scientific problem for preparing aromatic hydrocarbon from synthesis gas.

Disclosure of Invention

In view of the above disadvantages of the prior art, the present invention aims to provide a catalyst for preparing aromatic hydrocarbons from synthesis gas and its application, wherein the catalyst comprises the following components by mass percent: 20-70% of composite oxide containing CoMn spinel structure; 30 to 80 percent of zeolite molecular sieve. When the catalyst is used in a fixed bed, the catalyst can be used in a double-bed catalyst state mode, a single-bed mixed catalyst state mode and a series double reactor. The catalyst has the characteristics of high activity, low methane selectivity and high aromatic hydrocarbon selectivity in the reaction of preparing aromatic hydrocarbon from synthesis gas, and has wide application prospect.

In order to achieve the above objects and other related objects, the present invention is achieved by the following technical solutions:

the invention provides a catalyst for preparing aromatic hydrocarbon from synthesis gas, which comprises the following components in percentage by mass:

20-70% of composite oxide containing CoMn spinel structure; such as 20% -25%, 25% -28.6%, 28.6% -33.3%, 33.3% -40%, 40% -50%, 50% -60%, 60% -66.7% or 66.7% -70%;

30-80% of zeolite molecular sieve; such as 30% -33.3%, 33.3% -40%, 40% -50%, 50% -60%, 60% -66.7%, 66.7% -71.4%, 71.4% -75% or 75% -80%.

Preferably, at least one of the following technical features is also included:

1) the general formula of the composite oxide containing the CoMn spinel structure is Co_xMn_yO-M_zO or Co_xMn_yO-M_zO-N; wherein M is at least one of IA group elements, IIA group elements, IIIA group elements, IIIB group elements, IIB group elements and IVB group elements, and N is a carrier;

2) the zeolite molecular sieve is selected from at least one of MFI structure molecular sieve, CHA structure molecular sieve, FAU structure molecular sieve, BEA structure molecular sieve, ME L structure molecular sieve and AE L structure molecular sieve;

3) the zeolite molecular sieve has a Si/Al molar ratio of 10-500, such as 10-100, 100-200, 200-300, 300-350, 350-400 or 400-500.

More preferably, at least one of the following technical characteristics is also included:

a1) in feature 1), the M is at least one selected from the group consisting of Na, K, Rb, Cs, Ca, Mg, Sr, Ba, Al, L a, Ce, Zn, Cd and Zr;

a2) in feature 1), N is selected from SiO₂、Al₂O₃、TiO₂At least one of SiC and carbon materials;

a3) in the characteristic 1), the molar ratio x/y of the Co element to the Mn element is 0.1-10: 1, such as 0.1 to 0.33: 1. 0.33 to 0.5: 1. 0.5-2: 1. 2-3: 1. 3-5: 1. 5-6: 1 or 6-10: 1;

a4) in feature 1), M_zO is a stable oxide of M and z is such that M is satisfied_zThe molar amount of M required for the valency of the elements in the O oxide;

a5) in the characteristic 1), the mass percentage of M in the composite oxide containing the CoMn spinel structure is as follows: 0.1% -15%, such as 0.1% -0.64%, 0.64% -2%, 2% -2.5%, 2.5% -3.2%, 3.2% -3.5%, 3.5% -4.5%, 4.5% -5.9%, 5.9% -6%, 6% -9.1%, 9.1% -10%, 10% -13.2% or 13.2% -15%;

a6) in the characteristic 1), the mass percentage of N in the composite oxide containing the CoMn spinel structure is 0-80 percent, such as 0-40 percent, 40-60 percent or 60-80 percent;

a7) in the characteristic 1), the composite oxide containing a CoMn spinel structure is obtained by at least one preparation method of a coprecipitation method, a sol-gel method, a complexation method and an impregnation method;

b1) in feature 2), the zeolite molecular sieve is a modified molecular sieve, and the modifying element is at least one selected from Zn, Si, Ce, L a, Na, K, Sn, Zr, and Ga.

Even more preferably, in the feature b1), at least one of the following technical features is further included:

b11) the mass percentage of the modified element in the zeolite molecular sieve is not more than 10%, such as 0.1-1%, 1-1.3%, 1.3-1.5%, 1.5-5%, 5-5.5%, 5.5-6.8% or 6.8-10%;

b12) the modified molecular sieve is obtained by at least one preparation method of an impregnation method, an ion exchange method and a liquid phase deposition method.

In a second aspect, the present invention provides the use of the above catalyst for the production of aromatics from synthesis gas.

Preferably, one of the following technical features is also included:

1) when the catalyst is used for preparing aromatic hydrocarbon from synthesis gas in a single reactor, a single-bed mixed catalyst state mode is adopted, and the composite oxide containing the CoMn spinel structure and the zeolite molecular sieve are mixed in a mechanical physical mixing mode;

2) when the catalyst is used for preparing aromatic hydrocarbon from synthesis gas in a single reactor, a double-bed catalyst state mode is adopted, the composite oxide containing the CoMn spinel structure is filled at the upper part of a constant temperature area of the reactor, and the zeolite molecular sieve is filled at the lower part of the constant temperature area of the reactor;

3) when the catalyst is used for preparing aromatic hydrocarbon from synthesis gas in a series-connection double reactor, the series-connection double reactor sequentially comprises a first reactor and a second reactor, the composite oxide containing the CoMn spinel structure is placed in a constant temperature area of the first reactor, and the zeolite molecular sieve is placed in a constant temperature area of the second reactor.

More preferably, in the feature 1), the mechanical physical mixing means is at least one selected from the group consisting of a powder wet mixing method, a powder milling method, a powder ball milling method, and a particle mixing method.

Preferably, the composite oxide containing the CoMn spinel structure is reduced before being used for producing aromatic hydrocarbons from synthesis gas.

More preferably, the reducing conditions are: the reduction temperature is 200-500 deg.C, such as 200-300 deg.C, 300-320 deg.C, 320-350 deg.C, 350-400 deg.C or 400-500 deg.C; the reduction time is 1-24 h; the reduction space velocity is 2000 ml/(g.h) to 20000 ml/(g.h), such as 2000 ml/(g.h) to 4000 ml/(g.h), 4000 ml/(g.h) to 8000 ml/(g.h), 8000 ml/(g.h) to 10000 ml/(g.h) or 10000 ml/(g.h) to 20000 ml/(g.h); the reduction pressure is 0.1MPa to 2MPa, such as 0.1MPa to 0.5MPa, 0.5MPa to 1MPa or 1MPa to 2 MPa; the reducing atmosphere is at least one of hydrogen, CO, diluted hydrogen, diluted CO and diluted synthesis gas, the diluted gas is inert gas, and the volume content of the diluted gas is less than 90%.

Preferably, one of the following technical features is also included:

1) the reaction conditions for preparing aromatic hydrocarbon by using the single-reactor synthesis gas are as follows: the reaction temperature is 200-400 deg.C, such as 200-280 deg.C, 280-300 deg.C, 300-320 deg.C or 320-400 deg.C, and the reaction pressure is0.1MPa to 4MPa, such as 0.1MPa to 0.5MPa, 0.5MPa to 1MPa, 1MPa to 2MPa or 2MPa to 4MPa, and the reaction space velocity is 500h^-1～10000h^-1E.g. 500h^-1～1000h^-1、1000h^-1～2000h^-1、2000h^-1～3000h^-1、3000h^-1～4000h^-1Or 4000h^-1～10000h^-1The synthesis gas comprises H₂And CO, and H₂The volume ratio of the carbon dioxide to CO is 0.1-10: 1, such as 0.1-0.5: 1, 0.5-1: 1, 1-2: 1 or 2-10: 1.

2) The reaction conditions for preparing aromatic hydrocarbon by using synthesis gas of the series double reactors are as follows: the reaction pressure is 0.1MPa to 4MPa, such as 0.1MPa to 1MPa, 1MPa to 2MPa or 2MPa to 4MPa, and the reaction space velocity is 500h^-1～10000h^-1E.g. 500h^-1～2000h^-1、2000h^-1～3000h^-1、3000h^-1～4000h^-1Or 4000h^-1～10000h^-1The synthesis gas comprises H₂And CO, and H₂The volume ratio of the carbon dioxide to CO is 0.1-10: 1, such as 0.1-0.5: 1, 0.5-2: 1 or 2-10: 1, the reaction temperature of a first reactor is 200-350 ℃, such as 200-250 ℃, 250-265 ℃, 265-280 ℃ or 280-350 ℃, the reaction temperature of a second reactor is 300-500 ℃, such as 300-320 ℃, 320-330 ℃, 330-400 ℃ or 400-500 ℃.

Compared with the prior art, the invention has at least one of the following characteristics:

1) the invention provides a brand-new Co-based catalyst design scheme, olefin is used as an intermediate product, and the catalyst comprises a composite oxide containing a CoMn spinel structure and a zeolite molecular sieve.

2) The catalyst has excellent catalytic performance, and the product distribution shows low methane selectivity (< 5%) and high aromatic hydrocarbon selectivity (> 55%).

3) In the catalyst, the composite oxide containing the CoMn spinel structure is used for efficiently catalyzing CO hydrogenation to obtain an olefin intermediate product, and the zeolite molecular sieve can efficiently convert the intermediate product into aromatic hydrocarbon.

4) The preparation process of the catalyst is simple and easy to repeat, and the catalyst can be prepared in a large scale.

Drawings

Fig. 1 is an XRD spectrum of the complex oxide containing a CoMn spinel structure obtained in example 8.

FIG. 2 is an XRD pattern of modified HZSM-5 obtained in example 8.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

[ example 1 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting a coprecipitation method. Mixing Co (NO)₃)₂·6H₂O、50％Mn(NO₃)₂Aqueous solution, Al (NO)₃)₃·9H₂Dissolving O in a certain amount of deionized water according to a molar ratio of Co/Mn/Al-5/1/1 to form a mixed solution with a total metal concentration of 0.5 mol/L, stirring for 2 hours at 60 ℃, marking as a solution A, dissolving sodium carbonate in a certain amount of deionized water to form an alkali liquor with a concentration of 0.5 mol/L, stirring for 0.5 hour at 60 ℃, marking as a solution B, simultaneously dropping the AB two solutions into a beaker C containing a certain amount of deionized water for coprecipitation, wherein the precipitation temperature is 60 ℃, the precipitation pH is 9, after precipitation is finished, aging for 4 hours at the same temperature, centrifuging and washing, placing the finally obtained filter cake into a 120 ℃ oven for drying for 24 hours, then transferring into a muffle furnace, heating to 400 ℃ by a program of 1 ℃/min, and roasting for 4 hours to obtain the composite oxide containing the CoMn spinel structure, wherein the mass content of Na in the roasted CoMn spinel structure composite oxide is 1.0%, and the mass content of Al in the roasted CoMn spinel structure composite oxide is 5.0%.

The zeolite molecular sieve is modified by an impregnation method. Soaking 5g of HZSM-5 molecular sieve with the silica-alumina ratio of 300 in an ethanol solution of zinc nitrate to prepare a Zn modified molecular sieve, wherein the load mass of Zn is 1%, drying the molecular sieve in a vacuum oven at 100 ℃ for 12H after the soaking is finished, and then roasting the molecular sieve at 500 ℃ for 10H to obtain the Zn/H-ZSM5 molecular sieve.

The single-reactor single-bed mixed catalyst state mode is adopted. And grinding and mixing the prepared composite oxide powder containing the CoMn spinel structure and a Zn/H-ZSM5 molecular sieve according to the mass ratio of 1:2, tabletting, forming and sieving to obtain the bifunctional composite catalyst for preparing the aromatic hydrocarbon from the synthesis gas.

Putting the obtained bifunctional composite catalyst into a fixed bed high-pressure microreactor, and introducing 10% H₂/N₂Reduction is carried out, the space velocity of reduction is 10000ml g^-1·h^-1The reduction temperature is 300 ℃, the reduction time is 5h, and the reduction pressure is 1 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 1. The reaction pressure is 1MPa, and the reaction space velocity is 3000ml g^-1·h^-1The reaction temperature was 280 ℃ and the reaction results are shown in Table 1.

[ example 2 ]

The preparation method of the composite oxide containing a CoMn spinel structure is the same as that of example 1.

The zeolite molecular sieve is modified by a liquid phase deposition method. Taking 5g of HZSM-5 molecular sieve with the silicon-aluminum ratio of 400, placing the HZSM-5 molecular sieve into a round-bottom flask containing 100ml of n-octane, simultaneously adding 0.2g of tetraethoxysilane, stirring the mixture at the reflux temperature of 80 ℃ for 4 hours, then transferring the mixture into a rotary evaporator to remove the solution, drying the mixture in a vacuum oven at the temperature of 120 ℃ for 12 hours, and finally roasting the mixture in a muffle furnace at the temperature of 400 ℃ for 3 hours at the speed of 1 ℃/min. And (3) soaking the obtained powder sample in an ethanol solution of zinc nitrate, drying the powder sample in a vacuum oven at 100 ℃ for 12 hours after soaking, and then roasting the powder sample at 500 ℃ for 10 hours to obtain the Si-Zn/H-ZSM5 molecular sieve. Wherein the load mass of Zn is 1% of the mass of the molecular sieve, and the load mass of Si is 9% of the mass of the molecular sieve.

A dual reactor series mode was used. 1g of the composite oxide powder containing the CoMn spinel structure is subjected to tabletting and molding, and then is placed in a first reactor constant-temperature area of a series reactor; 2g of Si-Zn/H-ZSM5 molecular sieveTabletting and forming are carried out, and then the obtained product is placed in a constant-temperature area of a second reactor of the reactors connected in series. Firstly, reducing the catalyst, wherein the reduction temperature of the first reactor is set to be 300 ℃, the reduction temperature of the second reactor is set to be 400 ℃, and the reduction gas is 10% H₂Ar, reduction space velocity of 20000ml g^-1·h^-1The reduction time is 5h, and the reduction pressure is 0.5 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a CO ratio of 0.5. The reaction pressure is 1MPa, and the reaction space velocity is 4000ml g^-1·h^-1The reaction temperature of the first reactor of the series reactor was 265 ℃ and the reaction temperature of the second reactor of the series reactor was 320 ℃, and the reaction results are shown in table 1.

[ example 3 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting an impregnation method. The activated carbon is taken as a carrier, and the mass percentage of the activated carbon is 80 percent. Immersing activated carbon into a mixed solution containing cobalt nitrate, manganese acetate and potassium nitrate, and stirring. The molar ratio of Co to Mn is 6. The content of the potassium element in the oxide catalyst is 2 percent by mass. Transferring to a rotary evaporator to be evaporated after the dipping is finished, then carrying out vacuum oven treatment at 80 ℃ for 12h, transferring to a tubular furnace, and roasting at 350 ℃ for 5h in nitrogen flow of 30ml/min to obtain the composite oxide containing the CoMn spinel structure.

And (2) adopting an impregnation method to modify the zeolite molecular sieve, taking 5g of HZSM-11 molecular sieve with the silica-alumina ratio of 100, impregnating the HZSM-11 molecular sieve in an ethanol solution of cerium nitrate and lanthanum nitrate to prepare L a and Ce modified molecular sieve, wherein the mass contents of L a and Ce are respectively 5%, drying the molecular sieve in a vacuum oven at 150 ℃ for 24h after impregnation is finished, and then roasting the molecular sieve at 550 ℃ for 10h to obtain the Ce-L a/HZSM-11 molecular sieve.

The method comprises the following steps of adopting a single-reactor single-bed mixed catalyst state mode, firstly mixing wet powder of a catalyst, pouring the prepared composite oxide powder containing the CoMn spinel structure and Ce-L a/HZSM-11 molecular sieve powder into a beaker filled with ethanol according to the mass ratio of 3:2, ultrasonically stirring, then carrying out rotary evaporation to remove ethanol solution, finally drying in an oven at 150 ℃, carrying out tabletting molding on the mixed catalyst powder, and sieving to obtain the dual-function composite catalyst for preparing aromatic hydrocarbon by using synthesis gas.

Putting the obtained bifunctional composite catalyst into a fixed bed high-pressure microreactor, and introducing 10% CO/N₂The reduction is carried out, the space velocity of the reduction is 2000ml g^-1·h^-1The reduction temperature is 350 ℃, the reduction time is 10h, and the reduction pressure is 0.1 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 2. The reaction pressure is 2MPa, and the reaction space velocity is 10000ml g^-1·h^-1The reaction temperature was 320 ℃ and the reaction results are shown in Table 1.

[ example 4 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting an impregnation method. With TiO₂As a support, TiO₂The mass percentage of (B) is 40%. Adding TiO into the mixture₂Immersing into a mixed solution containing cobalt nitrate, manganese nitrate, zinc nitrate and lanthanum nitrate, and stirring. The molar ratio of Co to Mn is 10. The zinc element and the lanthanum element respectively account for 5 percent of the mass percentage of the calcined oxide catalyst. Transferring to a rotary evaporator to be dried by distillation after the impregnation is finished, then carrying out vacuum oven treatment at 80 ℃ for 12h, transferring to a muffle furnace, and roasting at 450 ℃ for 3h to obtain the composite oxide containing the CoMn spinel structure.

The zeolite molecular sieve is modified by an impregnation method. Soaking 5g of HZSM-34 molecular sieve with the silica-alumina ratio of 500 in an ethanol solution of gallium nitrate, wherein the gallium accounts for 0.1% of the mass content of the molecular sieve, drying in a vacuum oven at 100 ℃ for 24h after soaking, and then roasting at 400 ℃ for 15h to obtain the Ga/HZSM-34 molecular sieve.

The single-reactor single-bed mixed catalyst state mode is adopted. And carrying out powder ball milling and mixing on the prepared composite oxide powder containing the CoMn spinel structure and the Ga/HZSM-34 molecular sieve according to the mass ratio of 1:4, then tabletting, forming and sieving to obtain the bifunctional composite catalyst for preparing the aromatic hydrocarbon from the synthesis gas.

Putting the obtained bifunctional composite catalyst into a fixed bed high-pressure microreactor, and introducing 10% CO/N₂The reduction is carried out, the space velocity of the reduction is 8000ml g^-1·h^-1The reduction temperature is 350 ℃, the reduction time is 10h, and the reduction pressure is 1 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 10. The reaction pressure is 2MPa, and the reaction space velocity is 10000ml g^-1·h^-1The reaction temperature was 320 ℃ and the reaction results are shown in Table 1.

[ example 5 ]

Cobalt nitrate, manganese nitrate, barium nitrate and sodium nitrate are dissolved in a certain amount of ethanol solution according to the molar ratio of Co/Mn/Ba/Na which is 5/1/0.1/0.1 to form a mixed solution with the total metal concentration of 2 mol/L, the mixed solution is stirred for 4 hours at 30 ℃ and is marked as solution A, oxalic acid is dissolved in a certain amount of ethanol solution to form 2 mol/L alkali liquor which is marked as solution B, the solution B is quickly added into the solution A to form precipitate, the precipitate is aged for 24 hours at the same temperature, then the solution is filtered and washed to obtain a filter cake, the filter cake is placed in a 120 ℃ oven for treatment for 48 hours, then the filter cake is transferred into a muffle furnace for programmed heating to 500 ℃ for roasting for 5 hours to obtain the composite oxide with the CoMn spinel structure, wherein the Ba element and the Na element account for 2.7 percent and 0.5 percent of the oxide catalyst by mass respectively.

The zeolite molecular sieve is modified by a liquid phase deposition method and an impregnation method. 5g of SSZ-13 molecular sieve with a Si/Al ratio of 10 was taken and placed in a round bottom flask containing 100ml of n-heptane, while adding ethyl orthosilicate, stirred under reflux at 80 ℃ for 4h, then transferred to a rotary evaporator to remove the solution and dried in a vacuum oven at 120 ℃ for 12h, and finally calcined in a muffle furnace at a rate of 1 ℃/min up to 500 ℃ for 5 h. And (3) soaking the obtained powder sample in an ethanol solution of stannous chloride, drying the powder sample in a vacuum oven at 100 ℃ for 12h after soaking, and then roasting the powder sample at 500 ℃ for 10h to obtain the modified Si-Sn/SSZ-13 molecular sieve. Wherein the load mass of Si is 6.7% of the molecular sieve, and the load mass of Sn is 0.1% of the molecular sieve.

A dual reactor series mode was used. 2g of the composite oxide powder containing the CoMn spinel structure is subjected to tabletting and molding, and then is placed in a first reactor constant-temperature area of a series reactor; 5g of Si-Sn/SSZ-13 molecular sieves were also tableted and shaped and then placed in the second reactor thermostatic zone of the series reactor. Firstly, reducing the catalyst, wherein the reduction temperature of the first reactor is set to be 200 ℃, the reduction time is 24h, the reduction temperature of the second reactor is set to be 500 ℃, the reduction time is 5h, the reduction gas is pure hydrogen, and the reduction space velocity is 10000 ml.g^-1·h^-1The reduction pressure was 0.1 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a CO ratio of 0.1. The reaction pressure is 2MPa, and the reaction space velocity is 500ml g^-1·h^-1The reaction temperature of the first reactor of the series reactor was 265 ℃ and the reaction temperature of the second reactor of the series reactor was 400 ℃ and the reaction results are shown in Table 1.

[ example 6 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting an impregnation method. SiC is used as a carrier, and the mass percentage of the SiC is 60%. SiC was immersed in a mixed solution containing cobalt nitrate, manganese nitrate, cesium nitrate, and chromium nitrate and stirred. Stirring for 2h, transferring to a rotary evaporator for drying by distillation, then carrying out vacuum oven treatment at 100 ℃ for 12h, transferring to a muffle furnace, and roasting at 350 ℃ for 10h to obtain the composite oxide containing the CoMn spinel structure, wherein the Co/Mn molar ratio is 1/2, and the Cs element and the Cd element account for 1% and 2.5% of the mass percentage of the oxide catalyst respectively.

The zeolite molecular sieve is modified by an impregnation method. And (2) soaking 5g of SAPO-34 molecular sieve with the silicon-aluminum ratio of 350 in an ethanol solution of zirconium nitrate, drying in a vacuum oven at 100 ℃ for 24h after soaking, and then roasting at 500 ℃ for 5h to obtain the modified Zr/SAPO-34 molecular sieve. Wherein, the mass content of the zirconium element is 0.1 percent of the molecular sieve.

The single-reactor single-bed mixed catalyst state mode is adopted. And (2) tabletting, crushing and screening the prepared composite oxide containing the CoMn spinel structure and Zr/SAPO-34 respectively according to the mass ratio of 3:2 to obtain catalyst particles of 80-100 meshes, and then physically mixing to prepare the bifunctional composite catalyst for preparing the aromatic hydrocarbon from the synthesis gas.

The obtained double workThe catalyst can be compounded and placed in a high-pressure microreactor of a fixed bed, and 5% of H is introduced₂/N₂The reduction is carried out, the space velocity of the reduction is 8000ml g^-1·h^-1The reduction temperature is 350 ℃, the reduction time is 10h, and the reduction pressure is 0.5 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 1. The reaction pressure is 1MPa, and the reaction space velocity is 2000ml g^-1·h^-1The reaction temperature was 320 ℃ and the reaction results are shown in Table 1.

[ example 7 ]

And preparing the composite oxide containing the CoMn spinel structure by adopting coprecipitation. Mixing Co (NO)₃)₂·6H₂O、50％Mn(NO₃)₂Dissolving an aqueous solution and sodium nitrate in a certain amount of deionized water to form a mixed solution with the total metal concentration of 3 mol/L, stirring for 2 hours at 30 ℃, marking as a solution A, preparing aqueous ammonia into an aqueous solution with the concentration of 5%, marking as a solution B, simultaneously dropping the solution AB and the solution B into a beaker C for coprecipitation, wherein the precipitation temperature is 30 ℃, the precipitation pH is 8, after the precipitation is finished, aging for 2 hours at the same temperature, filtering to obtain a filter cake, placing the finally obtained filter cake into a 120 ℃ drying oven for drying for 24 hours, transferring to a muffle furnace, and heating to 400 ℃ by program to roast for 4 hours to obtain the composite oxide containing the CoMn spinel structure, wherein the molar ratio of Co to Mn is 0.1, and the Na element accounts for 0.24% of the mass of the oxide catalyst.

The zeolite molecular sieve is modified by an impregnation method. Taking 5g of MOR molecular sieve with the silicon-aluminum ratio of 300, then soaking the MOR molecular sieve in an ethanol solution of zinc nitrate and tin chloride, ultrasonically stirring for 2h, then transferring the MOR molecular sieve to a rotary evaporator to remove water, then placing the MOR molecular sieve in a drying oven for drying at 120 ℃ for 12h, and finally roasting at 500 ℃ for 10h to obtain the Zn-Sn/MOR molecular sieve. Wherein the load mass of Zn and Sn is 2.5 percent of the mass of the molecular sieve respectively,

the single-reactor single-bed mixed catalyst state mode is adopted. And ball-milling and mixing the prepared composite oxide powder containing the CoMn spinel structure and a Zn-Sn/MOR molecular sieve according to the mass ratio of 2:3, tabletting, forming and sieving to obtain the dual-function composite catalyst for preparing the aromatic hydrocarbon from the synthesis gas.

Putting the obtained bifunctional composite catalyst into a fixed bed high-pressure microreactor, and introducing 10% H₂/N₂The reduction is carried out, the space velocity of the reduction is 8000ml g^-1·h^-1The reduction temperature is 320 ℃, the reduction time is 5h, and the reduction pressure is 1 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 2. The reaction pressure is 1MPa, and the reaction space velocity is 1000ml g^-1·h^-1The reaction temperature was 300 ℃ and the reaction results are shown in Table 1.

[ example 8 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting a coprecipitation method. Mixing Co (NO)₃)₂·6H₂O、50％Mn(NO₃)₂Aqueous solution, Al (NO)₃)₃·9H₂Dissolving O in a certain amount of deionized water according to a molar ratio of Co/Mn/Al of 2/1/0.5 to form a mixed solution with a total metal concentration of 0.5 mol/L, stirring the mixed solution at 40 ℃ for 2 hours to obtain a solution A, dissolving sodium hydroxide in a certain amount of deionized water to form an alkali liquor with a concentration of 0.5 mol/L, stirring the alkali liquor at 40 ℃ for 0.5 hour to obtain a solution B, dispersing silica aerosol in a beaker C containing a certain amount of deionized water, wherein the adding amount of silica is 20% of the total mass of the final oxide, dropping the solution AB and the solution C simultaneously for coprecipitation, wherein the precipitation temperature is 40 ℃, the precipitation pH is 10, after precipitation is finished, aging the mixed solution at the same temperature for 4 hours, centrifuging and washing the obtained mixed solution, placing the obtained filter cake in an oven at 120 ℃ for 24 hours, then transferring the obtained filter cake to a muffle furnace, heating the obtained filter cake to 400 ℃ by a program of 1 ℃/min, and roasting the obtained composite oxide with a CoMn spinel structure, wherein the mass content of Al in the roasted oxide is 4.9%, and the sintered oxide is roasted in an XRD (shown in figure of 1.1.1.1).

The zeolite molecular sieve is modified by a liquid phase deposition method and an impregnation method. Taking 5g of HZSM-5 molecular sieve with the silicon-aluminum ratio of 400, placing the HZSM-5 molecular sieve into a round-bottom flask containing 100ml of n-octane, simultaneously adding 0.2g of tetraethoxysilane, stirring the mixture at the reflux temperature of 80 ℃ for 4 hours, then transferring the mixture into a rotary evaporator to remove the solution, drying the mixture in a vacuum oven at the temperature of 120 ℃ for 12 hours, and finally roasting the mixture in a muffle furnace at the temperature of 400 ℃ for 3 hours at the speed of 1 ℃/min. And (3) soaking the obtained powder sample in an ethanol solution of zinc nitrate, wherein the load mass of Si is 0.5% of the mass of the molecular sieve, the load mass of Zn is 1% of the mass of the molecular sieve, drying the powder sample in a vacuum oven at 100 ℃ for 12h after soaking is finished, and then roasting the powder sample at 500 ℃ for 10h to obtain the Si-Zn/HZSM-5 molecular sieve, wherein an XRD (X-ray diffraction) spectrum is shown in figure 2.

The single-reactor single-bed mixed catalyst state mode is adopted. And grinding and mixing the prepared composite oxide powder containing the CoMn spinel structure and a Si-Zn/HZSM-5 molecular sieve according to the mass ratio of 1:2, tabletting, forming and sieving to obtain the bifunctional composite catalyst for preparing the aromatic hydrocarbon from the synthesis gas.

Putting the obtained bifunctional composite catalyst into a fixed bed high-pressure microreactor, and introducing 10% H₂/N₂Reduction is carried out, and the space velocity of reduction is 20000ml g^-1·h^-1The reduction temperature is 350 ℃, the reduction time is 5h, and the reduction pressure is 0.5 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a CO ratio of 0.5. The reaction pressure is 1MPa, and the reaction space velocity is 4000ml g^-1·h^-1The reaction temperature was 320 ℃ and the reaction results are shown in Table 1.

[ example 9 ]

The method comprises the steps of preparing a composite oxide containing a CoMn spinel structure by a sol-gel method, dissolving cobalt nitrate, manganese nitrate, magnesium nitrate and zinc nitrate in a certain amount of deionized water solution according to a certain proportion to form a mixed solution with a total metal concentration of 2 mol/L, stirring the mixed solution at 80 ℃ for 1h to obtain a solution A, preparing citric acid and ethylene glycol with equal mass into a4 mol/L solution to obtain a solution B, dropwise adding the solution B into the solution A, stirring the solution B at 80 ℃ until gel appears, transferring the gel into a drying oven at 150 ℃ to dry the gel for 24h, then burning the gel in a muffle furnace at 500 ℃ for 8h to obtain an oxide solid, dipping the solution with sodium nitrate into the solid by an equal volume dipping method, drying the solution at 120 ℃, then roasting in the muffle furnace at 400 ℃ for 3h to obtain the composite oxide containing the CoMn spinel structure, wherein the molar ratio of Co to Mn is 2/1, the mass percent of the Mg element is 4.1 percent, the Zn element is 4.5 percent, and the Na element is 0.5 percent.

The zeolite molecular sieve is modified by a liquid phase deposition method. Taking 5g of HY molecular sieve with the silicon-aluminum ratio of 10, placing the HY molecular sieve in a round bottom flask containing 100ml of n-heptane, simultaneously adding 0.5g of tetraethoxysilane, refluxing and stirring at 80 ℃ for 4h, then transferring to a rotary evaporator to remove the solution, drying in a vacuum oven at 120 ℃ for 12h, and finally roasting in a muffle furnace at the speed of 1 ℃/min to 500 ℃ for 5h to obtain the Si/Y molecular sieve, wherein Si accounts for 1.3% of the mass of the Y molecular sieve.

Carrying out tabletting and forming on 1g of the composite oxide powder containing the CoMn spinel structure by adopting a double-reactor series mode, then placing the powder in a constant-temperature area of a first reactor of a series reactor, carrying out tabletting and forming on 3g of Si/Y- β, then placing the powder in a constant-temperature area of a second reactor of the series reactor, firstly reducing the catalyst, setting the reduction temperature of the first reactor to be 350 ℃, the reduction time to be 3 hours, setting the reduction temperature of the second reactor to be 400 ℃, the reduction time to be 5 hours, and setting the reduction gas to be 10% H₂He, reduction space velocity of 10000ml g^-1·h^-1The reduction pressure was 0.5 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 1. The reaction pressure is 1MPa, and the reaction space velocity is 2000ml g^-1·h^-1The reaction temperature of the first reactor of the series reactor was 280 ℃ and the reaction temperature of the second reactor of the series reactor was 330 ℃ and the reaction results are shown in Table 1.

[ example 10 ]

And preparing the composite oxide containing the CoMn spinel structure by adopting coprecipitation. Mixing Co (NO)₃)₂·6H₂O and 50% Mn (NO)₃)₂Dissolving the water solution in a certain amount of deionized water according to a molar ratio of Co/Mn to 1/3 to form a mixed solution with a total metal concentration of 1 mol/L, stirring at 30 ℃ for 2h to obtain a solution A, dissolving ammonium carbonate in a certain amount of deionized water to form an alkali solution with a concentration of 0.5 mol/L, stirring at 60 ℃ for 0.5h to obtain a solution B, and dissolving the two solutions AB and AB in a certain amount of deionized waterThe solution is simultaneously dropped into a beaker C containing a certain amount of deionized water for coprecipitation, the precipitation temperature is 30 ℃, and the precipitation pH is 8. After the precipitation is finished, aging is carried out for 2h at the same temperature, and then suction filtration and washing are carried out to obtain a filter cake. And (3) drying the finally obtained filter cake in a 120 ℃ drying oven, soaking a sodium nitrate solution into the dry filter cake in an equal volume, drying again, transferring to a muffle furnace, and carrying out temperature programming to 400 ℃ for roasting for 4 hours to obtain the composite oxide containing the CoMn spinel structure, wherein the mass percent of the Na element is 0.4%.

The zeolite molecular sieve is modified by an ion exchange method. 5g of HZSM-5 molecular sieve with the silica-alumina ratio of 200 is taken, potassium nitrate aqueous solution with the mass concentration of 0.1% is poured, reflux stirring is carried out for 24h at the temperature of 80 ℃, then washing and drying are carried out, and roasting is carried out for 4h at the temperature of 500 ℃ in a muffle furnace to obtain the K/HZSM-5 molecular sieve. Wherein the loading amount of K is 0.1 percent of the mass of the molecular sieve.

The single-reactor single-bed mixed catalyst state mode is adopted. And grinding and mixing the prepared composite oxide powder containing the CoMn spinel structure and a K/HZSM-5 molecular sieve according to the mass ratio of 2:1, tabletting, forming and sieving to obtain the bifunctional composite catalyst for preparing the aromatic hydrocarbon from the synthesis gas.

Putting the obtained bifunctional composite catalyst into a fixed bed high-pressure microreactor, and introducing 10% H₂/N₂The reduction is carried out, and the space velocity of the reduction is 4000ml g^-1·h^-1The reduction temperature is 320 ℃, the reduction time is 5h, and the reduction pressure is 0.1 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a CO ratio of 0.5. The reaction pressure is 4MPa, and the reaction space velocity is 2000ml g^-1·h^-1The reaction temperature was 280 ℃ and the reaction results are shown in Table 1.

[ example 11 ]

The method comprises the steps of dissolving cobalt nitrate, manganese carbonate, calcium nitrate and strontium nitrate in a certain amount of deionized water solution according to a certain proportion to form a mixed solution with the total metal concentration of 1 mol/L, stirring the mixed solution at 70 ℃ for 1h to obtain a solution A, preparing citric acid and ethylene glycol with equal mass into a4 mol/L solution to obtain a solution B, dropwise adding the solution B into the solution A, stirring the solution B at 70 ℃ until gel appears, transferring the gel into a drying oven at 150 ℃ to dry for 48h, then burning the gel in a muffle furnace at 600 ℃ for 6h to obtain an oxide solid, soaking the solution with potassium nitrate into the solid by adopting an equal-volume impregnation method, drying the solution at 120 ℃, then roasting the solution in the muffle furnace at 400 ℃ for 3h to obtain the composite oxide with the CoMn spinel structure, wherein the Co/Mn molar ratio is 5/1, the Ca element accounts for 0.8% of the mass of the Sr, the oxide element accounts for 1.2% of the oxide after roasting, and the K element accounts for 2.5% of the oxide after roasting.

A L PO-11 molecular sieve with the silica-alumina ratio of 200 is taken and 5g is placed in a round bottom flask containing 100ml of n-heptane, simultaneously a certain amount of ethyl orthosilicate is added, the mixture is refluxed and stirred for 4h at 80 ℃, then the mixture is transferred to a rotary evaporator to remove the solution, the solution is dried for 12h in a vacuum oven at 120 ℃, and finally the solution is roasted for 5h in a muffle furnace at the speed of 1 ℃/min and the temperature is increased to 500 ℃, thus obtaining the Si/A L PO-11 molecular sieve, wherein Si accounts for 3.5 percent of the mass of the molecular sieve.

Carrying out tabletting and forming on 3g of the composite oxide powder containing the CoMn spinel structure by adopting a single-reactor double-bed catalyst state mode, then placing the powder on the upper part of a reactor constant-temperature area, carrying out tabletting and forming on 1.5g of Si/A L PO-11 molecular sieve, then placing the powder on the lower part of the reactor constant-temperature area, firstly reducing the catalyst, setting the reduction temperature to be 300 ℃, the reduction time to be 10 hours, and the reduction gas to be 20% of H₂He, reduction space velocity of 10000ml g^-1·h^-1The reduction pressure was 0.5 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 1. The reaction temperature is 320 ℃, the reaction pressure is 1MPa, and the reaction space velocity is 4000ml g^-1·h^-1The reaction results are shown in Table 1.

[ example 12 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting an impregnation method. The carbon nanotubes are used as a carrier, and the mass percentage of the carbon nanotubes is 50 percent. Titrating a mixed solution containing cobalt nitrate, manganese nitrate and rubidium nitrate into the carbon nano-tube for impregnation by adopting an isometric impregnation method. And transferring the obtained product to a vacuum oven to dry for 24 hours at the temperature of 60 ℃ after the impregnation is finished, transferring the product to a tube furnace, and roasting the product for 5 hours at the temperature of 400 ℃ in nitrogen flow of 30ml/min to obtain the composite oxide containing the CoMn spinel structure. Wherein, the molar ratio of Co to Mn is 5, and the Rb element accounts for 0.1 percent of the mass of the oxide catalyst.

An ion exchange method is adopted to modify a zeolite molecular sieve, 10g of β molecular sieve with the silica-alumina ratio of 100 is taken, lanthanum nitrate aqueous solution with the concentration of 1% is poured, the mixture is refluxed and stirred for 24h at the temperature of 60 ℃, then washed for a plurality of times, dried in a baking oven at the temperature of 120 ℃, and roasted for 10h at the temperature of 550 ℃ in a muffle furnace, and the L a/β molecular sieve is obtained, wherein L a accounts for 2% of the mass of the molecular sieve.

2g of the composite oxide powder containing the CoMn spinel structure is tabletted and formed by adopting a double-reactor series mode, and then is placed in a constant temperature area of a first reactor, and 2g of the L a/β molecular sieve is tabletted and formed, and then is placed in a constant temperature area of a second reactor.

Firstly, the catalyst is reduced, and the reducing gas is pure H₂The reduction space velocity is 10000ml g^-1·h^-1The reduction pressure is 1.0MPa, the reduction temperature of the first reactor is 200 ℃, the reduction time is 24 hours, the reduction temperature of the second reactor is 400 ℃, and the reduction time is 4 hours. After the reduction is finished, the temperature of the two reactors is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 2. The pressure of the series reactor is 1.0MPa, and the reaction space velocity is 3000 ml/g^-1·h^-1. The reaction temperature in the first reactor was set to 250 ℃ and the reaction temperature in the second reactor was set to 500 ℃ and the results are shown in Table 1.

[ example 13 ]

The composite oxide containing the CoMn spinel structure is prepared by adopting a coprecipitation method. Mixing Co (NO)₃)₂·6H₂O、50％Mn(NO₃)₂Aqueous solution, Al (NO)₃)₃·9H₂Dissolving O in deionized water at a certain proportion to obtain a mixed solution with total metal concentration of 1.5 mol/L, stirring at 30 deg.C for 0.5 hr to obtain solution A, dissolving sodium carbonate in a certain proportionAnd (2) adding the AB two solutions into deionized water with the amount of 1.5 mol/L to form alkali liquor with the concentration of 1.5 mol/L, stirring for 0.5h at 30 ℃, marking as a solution B, simultaneously dropping the two solutions into a beaker C containing a certain amount of deionized water for coprecipitation, wherein the precipitation temperature is 30 ℃, the precipitation pH value is 8, after the precipitation is finished, aging for 2h at the same temperature, centrifuging and washing, placing the finally obtained filter cake into a 120 ℃ oven for baking for 24h, then transferring the filter cake into a muffle furnace, and heating to 400 ℃ by a program of 1 ℃/min for baking for 4h to obtain the composite oxide containing the CoMn spinel structure, wherein the Co/Mn molar ratio is 3, the mass content of Na in the baked composite oxide of the CoMn spinel structure is 3.2%, and the mass content of Al in the baked composite oxide of the CoMn spinel structure is 10%.

5g of HZSM-5 molecular sieve with the silica-alumina ratio of 300 is taken and roasted in a muffle furnace at 500 ℃ for 5h for standby.

A dual reactor series mode was used. 1g of the composite oxide powder containing the CoMn spinel structure is subjected to tabletting and molding, and then is placed in a constant temperature area of a first reactor; 4g of the HZSM-5 molecular sieve was subjected to tabletting and molding, and then placed in a constant temperature region of a second reactor.

Firstly, the catalyst is reduced, the reducing gas is 10 percent CO/Ar, and the reduction space velocity is 8000ml g^-1·h^-1The reduction pressure is 0.1MPa, the reduction temperature of the first reactor is 500 ℃, the reduction time is 2 hours, the reduction temperature of the second reactor is 200 ℃, and the reduction time is 24 hours. After the reduction is finished, the temperature of the two reactors is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a/CO ratio of 2. The pressure of the series reactor is 4.0MPa, and the reaction space velocity is 2000 ml/g^-1·h^-1. The reaction temperature in the first reactor was set to 220 ℃ and the reaction temperature in the second reactor was set to 300 ℃ and the results are shown in Table 1.

[ example 14 ]

The preparation method comprises the steps of dissolving cobalt nitrate, manganese nitrate, chromium nitrate and potassium nitrate in a certain amount of ethanol solution according to a certain proportion to form a mixed solution with the total metal concentration of 2 mol/L, stirring for 4 hours at 30 ℃ to obtain a solution A, dissolving oxalic acid in a certain amount of ethanol solution to form 2 mol/L alkali liquor, obtaining a solution B, quickly adding the solution B into the solution A to form a precipitate, aging for 24 hours at the same temperature, carrying out suction filtration and washing to obtain a filter cake, placing the filter cake in a 120 ℃ drying oven for treatment for 48 hours, transferring the filter cake to a muffle furnace, carrying out temperature programming to 500 ℃ and roasting for 5 hours to obtain the composite oxide with the CoMn spinel structure, wherein the molar ratio of Co/Mn is 2, and the mass percentages of Cd and K in the oxide catalyst are respectively 2% and 0.5%.

The zeolite molecular sieve is modified by a liquid phase deposition method and an impregnation method. 5g of H-ZSM5 molecular sieve with a silica to alumina ratio of 350 was taken and placed in a round bottom flask containing 100ml of n-heptane with simultaneous addition of ethyl orthosilicate, stirred under reflux at 80 ℃ for 4H, then transferred to a rotary evaporator to remove the solution and dried in a vacuum oven at 120 ℃ for 12H and finally calcined in a muffle furnace at a rate of 1 ℃/min up to 500 ℃ for 5H. And (3) soaking the obtained powder sample in an ethanol solution of stannous chloride, drying the powder sample in a vacuum oven at 100 ℃ for 12H after the soaking is finished, and then roasting the powder sample at 500 ℃ for 10H to obtain the modified Si-Sn/H-ZSM5 molecular sieve. Wherein the load mass of Si is 9.5% of the molecular sieve, and the load mass of Sn is 0.5% of the molecular sieve.

A single reactor dual bed catalyst regime was used. 2g of the composite oxide powder containing the CoMn spinel structure is tabletted and formed, and then is placed on the upper part of a constant temperature area of a reactor; 4g of Si-Sn/H-ZSM5 molecular sieve was also tableted and shaped and then placed in the lower part of the reactor in the constant temperature zone. Firstly, reducing the catalyst at 350 deg.C for 6H with 10% H as reducing gas₂He, reduction space velocity of 10000ml g^-1·h^-1The reduction pressure was 0.5 MPa. After the reduction process is finished, the temperature is reduced to room temperature, and H is introduced₂The reaction was carried out with synthesis gas having a CO ratio of 0.5. The reaction temperature is 320 ℃, the reaction pressure is 0.5MPa, and the reaction space velocity is 2000ml g^-1·h^-1The reaction results are shown in Table 1.

Catalytic Performance data in the examples of Table 1

Note: c_2-4Is the sum of C2-4 olefins and alkanes, aromatic hydrocarbons (benzene, toluene, xylene and polymethylbenzene), other C₅₊Is the sum of olefin and alkane with carbon number more than or equal to 5.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.