A method for preparing aromatic hydrocarbons by catalytic hydrogenolysis of coal-based platform molecules under mild conditions

Abstract

The present application belongs to the technical field of coal chemical industry and fine chemical industry, and discloses a method for preparing aromatic hydrocarbons by catalytic hydrogenolysis of coal-based platform molecules under mild conditions, i.e. a method for realizing catalytic hydrogenolysis of coal-based platform molecules such as phenylbenzyl ether, dibenzyl ether, phenoxyethylbenzene and diphenyl ether to prepare toluene, phenol and ethylbenzene under mild conditions by using isopropyl alcohol as a solvent and by using a supported high-entropy alloy catalyst and a heteropoly acid catalyst for synergistic catalysis. The synergistic coupling of the multiple metal active sites of the high-entropy alloy catalyst is utilized, and silicon tungstate is added at the same time to promote hydrogen isomerization and reduce deoxidization energy, thereby reducing energy consumption of the reaction and realizing directional cracking of coal to prepare condensed aromatic compounds under mild conditions. The present application effectively realizes clean and efficient utilization of coal resources, promotes resource transformation and reconstruction of coal, and thus high-value-added fine chemicals are obtained. The reaction process is environmentally friendly, the utilization rate of raw materials is high, and the present application has a good industrial application prospect.

Description

Technical Field

[0001] This invention belongs to the fields of coal chemical and fine chemical technology, and relates to a method for preparing toluene, phenol and ethylbenzene by catalytic hydrogenolysis of coal-based platform molecules such as phenyl benzyl ether, dibenzyl ether, phenoxyethylbenzene and diphenyl ether under mild conditions using isopropanol as solvent and supported high-entropy alloy catalyst and heteropolyacid catalyst in synergistic catalysis. Background Technology

[0002] Under the "dual carbon" goal, improving the comprehensive utilization efficiency of coal as a chemical raw material and promoting the high-end, diversified, and low-carbon development of the coal chemical industry is urgently needed. Fully leveraging the natural aromatic ring structure of coal and developing technologies for the directional cracking of coal under mild conditions to prepare high-end fine chemicals, as a new non-energy utilization pathway for coal, can avoid the problem of homogenization between coal chemical and petrochemical product chains, increase the added value of coal-based products, and contribute to the healthy and sustainable development of the coal chemical industry. Currently, direct coal liquefaction involves using hydrogen-donating solvents and catalysts under high temperature and pressure to allow hydrogen to enter the molecular structure of coal, thereby converting coal into liquid fuel or chemical raw materials. The molecular model of coal is rich in aromatic compounds, linked by C=C and CO bonds, and contains oxygen-containing functional groups such as C=O and -OH. Liquefaction by breaking the bridging bonds in coal organic matter can yield chemical products with higher added value. Currently, research on CO bridging bonds still mainly focuses on model compounds: phenyl benzyl ether, dibenzyl ether, and diphenyl ether, aiming to achieve coal organic matter liquefaction through research on the breaking of bridging bonds with different bond energies. Direct coal liquefaction technology can produce feedstocks for gasoline, diesel, liquefied petroleum gas, jet fuel, and important olefins such as aromatics, maximizing the value of coal. However, the high bond-breaking reaction temperature, high energy consumption, and large catalyst dosage lead to high production costs, and the formation of products due to excessive hydrogenation directly affects the cost-effectiveness of the products.

[0003] Chinese patents CN116272999A and CN113117758A both report the use of supported Fe-based catalysts for the hydrogenolysis of carbon-oxygen bonds in model compounds. The drawbacks of this method are its long technical route, numerous influencing factors in the synthesis process leading to poor reproducibility, and excessively high reaction temperatures resulting in excessive energy consumption.

[0004] Chinese patent CN109926076A reports a supported catalyst with Co and Ni as the hydrogenation metal components. The hydrogenation temperature is 250-300℃ and the pressure is 3-5MPa. However, if the temperature is too high, an over-hydrogenation reaction occurs, resulting in a large number of by-products. The catalyst cannot retain aromatic compounds such as benzene rings, which reduces the added value of the product and decreases the utilization rate.

[0005] Chinese patent CN104084227A reports a molecular sieve catalyst that undergoes reaction in a high-pressure reactor at 450℃ and 19MPa hydrogen pressure. However, the excessively high temperature and pressure make industrialization difficult and pose significant risks. The harsh conditions, strong corrosiveness to equipment and catalyst, high catalyst consumption, and increased costs further exacerbate the problem.

[0006] In summary, through catalyst creation and process development, the efficient hydrogenolysis of CO bonds in coal model compounds can effectively achieve the clean and efficient utilization of coal resources and maximize their benefits. Therefore, a highly efficient metal catalyst for CO bond breaking through hydrogenolysis has been developed, characterized by mild reaction conditions, high aromatic yield, and good stability. This method is environmentally friendly, has high atom utilization, effectively achieves the clean and efficient utilization of waste resources, realizes the efficient utilization of coal resources, and yields high-value-added fine chemicals, demonstrating promising industrial application prospects. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned technical problems by proposing a method for preparing aromatics by catalytic hydrogenolysis of coal-based platform molecules under mild conditions.

[0008] The technical solution of this invention:

[0009] A method for preparing aromatics by molecularly catalytic hydrogenolysis of coal-based platforms under mild conditions, comprising the following steps:

[0010] Using coal-based platform molecules as raw materials, isopropanol as solvent, carbon black-supported high-entropy alloy as catalyst, and silicotungstic acid as acidic additive, aromatic compounds were produced by selective catalytic hydrogenolysis in a high-pressure autoclave reactor under the conditions of reaction temperature 50-100℃, reaction pressure 0.1-2MPa, and reaction time 1-6h.

[0011] The coal-based platform molecule is one or a mixture of two or more of phenyl benzyl ether, dibenzyl ether, diphenyl ether, and phenoxyethylbenzene.

[0012] The carbon black-supported high-entropy alloy catalyst has a high-entropy alloy loading of 1 wt.% to 5 wt.% and a composition of one of PtPdCoNiCu, PtRuCoNiCu, PtPdFeCoNi, and PtRuFeCoNi.

[0013] The mass ratio of the carbon black-supported high-entropy alloy catalyst to the coal-based platform molecules is 0.05:1 to 0.1:1, the mass ratio of the carbon black-supported high-entropy alloy catalyst to the silicotungstic acid additive is 1:2, and the mass concentration of the coal-based platform molecules in the reaction system is 1-30 wt.%.

[0014] The aromatic compounds mentioned are toluene, ethylbenzene, and phenol.

[0015] The carbon black-supported high-entropy alloy catalyst was prepared by a wet chemical method. Naphthyllithium was used as a reducing agent and added dropwise to an anhydrous tetrahydrofuran solution containing different masses of metal acetylacetonate salts. The reaction was stirred at 62°C for 4.5 h to obtain high-entropy alloy nanoparticles. Using a colloidal impregnation method, the high-entropy alloy nanoparticles and the carrier carbon black were added to the tetrahydrofuran solution at room temperature and stirred and impregnated overnight. The solvent was removed by rotary evaporation, dried in a vacuum oven, ground, and then calcined at 300°C in argon for 3 h. Finally, the catalyst was obtained by centrifugation and washing.

[0016] The beneficial effects of this invention are:

[0017] (1) This invention uses coal-based platform molecules as raw materials to produce aromatic compounds such as toluene, ethylbenzene, and phenol under mild conditions. The raw materials are abundant and the cost is low.

[0018] (2) The catalyst is prepared by a wet chemical-colloid impregnation method. The resulting catalyst exhibits a high entropy effect between the metals, and the five metals work synergistically to increase the hydrogenolysis activity and improve the catalyst stability.

[0019] (3) The present invention uses carbon black supported high-entropy alloy catalyst. The strong interaction between the metal and the support keeps the metal in a uniform small size during the high-temperature reaction. The stronger the interaction, the higher the temperature required for the metal to break free and combine with the adjacent metal particles, thereby inhibiting agglomeration.

[0020] (4) The present invention adds silicotungstic acid as a heteropoly acid, which promotes the heterolytic cracking of hydrogen into hydrogen ions, making it easier to remove oxygen, reduce reaction pressure, reduce hydrogen loss, and reduce deoxygenation energy, thereby reducing reaction energy consumption and realizing the economical use of resources.

[0021] (5) The catalyst preparation method of the present invention is simple and has good cycle performance. Under mild conditions, it can convert coal-based platform molecules into aromatic compounds such as toluene, ethylbenzene, and phenol, which can be applied to industrial production on a large scale. Attached Figure Description

[0022] Figure 1 The effect of catalysts at different reaction times on the catalytic hydrogenolysis of phenyl benzyl ether to produce phenol and toluene is investigated.

[0023] Figure 2 The effect of catalyst on the hydrogenolysis of dibenzyl ether to phenol and toluene at different reaction times is investigated. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0025] Example 1: Preparation of PtPdCoNiCu / C catalyst

[0026] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)₂, 0.0307 g Pd(acac)₂, 0.0265 g Co(acac)₂, 0.027 g Ni(acac)₂, and 0.027 g Cu(acac)₂ and dissolve and disperse them in 10 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2.5 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.9428 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 250°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0027] Example 2: Preparation of PtRuCoNiCu / C catalyst

[0028] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)2, 0.0411 g Ru(acac)3, 0.0265 g Co(acac)2, 0.027 g Ni(acac)2, and 0.027 g Cu(acac)2 and dissolve and disperse them in 10 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2.8 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.9428 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 250°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0029] Example 3: Preparation of PtPdFeCoNi / C catalyst

[0030] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)2, 0.0307 g Pd(acac)2, 0.036 g Fe(acac)3, 0.0265 g Co(acac)2, and 0.027 g Ni(acac)2 and dissolve and disperse them in 10 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2.8 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.9428 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 250°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0031] Example 4: Preparation of PtRuFeCoNi / C catalyst

[0032] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)2, 0.0411 g Ru(acac)2, 0.036 g Fe(acac)3, 0.0265 g Co(acac)2, and 0.027 g Ni(acac)2 and dissolve and disperse them in 10 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 3.0 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.9428 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 250°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0033] Example 5: Preparation of PtPdCoNi / C catalyst

[0034] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)₂, 0.0307 g Pd(acac)₂, 0.0265 g Co(acac)₂, and 0.027 g Ni(acac)₂ and dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.8137 g carbon black support and add 30 ml tetrahydrofuran solution, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0035] Example 6: Preparation of PtPdCoCu / C catalyst

[0036] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)₂, 0.0307 g Pd(acac)₂, 0.0265 g Co(acac)₂, and 0.027 g Cu(acac)₂ and dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.8221 g carbon black support and add 30 ml tetrahydrofuran solution, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0037] Example 7: Preparation of PtPdNiCu / C catalyst

[0038] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)₂, 0.0307 g Pd(acac)₂, 0.027 g Ni(acac)₂, and 0.027 g Cu(acac)₂ and dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2 ml of the prepared naphthyllithium solution and maintain the temperature at 62 °C while stirring for 4.5 h. Finally, weigh 0.8238 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0039] Example 8: Preparation of PtCoNi / C catalyst

[0040] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)₂, 0.0265 g Co(acac)₂, and 0.027 g Ni(acac)₂, dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stir for 10 min, then quickly add 1.5 ml of the prepared naphthyllithium solution, and maintain the temperature at 62 °C while stirring for 4.5 h. Then weigh 0.655 g carbon black support, add 30 ml tetrahydrofuran, and stir for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0041] Example 9: Preparation of PdCoNi / C catalyst

[0042] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0307 g Pt(acac)₂, 0.0265 g Co(acac)₂, and 0.027 g Ni(acac)₂, dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stir for 10 min, then quickly add 1.5 ml of the prepared naphthyllithium solution, and maintain the temperature at 62 °C while stirring for 4.5 h. Then weigh 0.6664 g carbon black support, add 30 ml tetrahydrofuran, and stir for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0043] Example 10: Preparation of PtNiCu / C catalyst

[0044] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0405 g Pt(acac)₂, 0.027 g Ni(acac)₂, and 0.027 g Cu(acac)₂ and dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 1.5 ml of the prepared naphthyllithium solution and stir at 62 °C for 4.5 h. Next, weigh 0.6866 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0045] Example 11: Preparation of PdNiCu / C catalyst

[0046] Weigh 0.0792 g Li and 1.538 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.0307 g Pd(acac)₂, 0.027 g Ni(acac)₂, and 0.027 g Cu(acac)₂ and dissolve and disperse them in 8 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 1.5 ml of the prepared naphthyllithium solution and stir at 62 °C for 4.5 h. Next, weigh 0.6752 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. The solvent tetrahydrofuran was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60°C. Subsequently, the sample was calcined in argon at 300°C for 3 hours, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60°C for 3 hours to obtain a catalyst with a theoretical metal loading of 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300°C for 3 hours under a mixed atmosphere of hydrogen and argon.

[0047] Example 12: Preparation of PtPd / C catalyst

[0048] 0.0792 g Li and 1.538 g naphthalene (NAPH) were weighed and dissolved in 22 ml tetrahydrofuran solution and stirred overnight. 0.0405 g Pt(acac)₂ and 0.0307 g Pd(acac)₂ were weighed and dissolved in 10 ml anhydrous tetrahydrofuran solution and stirred for 10 min. Then, 2.5 ml of prepared naphthyllithium solution was quickly added, and the mixture was stirred at 62 °C for 4.5 h. 0.5814 g carbon black support was weighed and added to 30 ml tetrahydrofuran solution and stirred for 12 h. The tetrahydrofuran solvent was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60 °C. Subsequently, the sample was calcined in argon at 300 °C for 3 h, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60 °C for 3 h. The theoretical metal loading of the catalyst was 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 200 °C for 3 h under a mixed atmosphere of hydrogen and argon.

[0049] Example 13: Preparation of Co / C catalyst

[0050] 0.0396 g Li and 0.0769 g naphthalene (NAPH) were weighed and dissolved in 22 ml tetrahydrofuran solution and stirred overnight. 0.053 g Co(acac)₂ was weighed and dissolved in 10 ml anhydrous tetrahydrofuran solution and stirred for 10 min. Then, 2 ml of prepared naphthyllithium solution was quickly added, and the mixture was stirred at 62 °C for 4.5 h. Next, 0.2306 g carbon black support was weighed and added to 30 ml tetrahydrofuran solution and stirred for 12 h. The tetrahydrofuran solvent was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60 °C. Subsequently, the sample was calcined in argon at 300 °C for 3 h, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60 °C for 3 h. The theoretical metal loading of the catalyst was 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300 °C for 3 h under a mixed atmosphere of hydrogen and argon.

[0051] Example 14: Preparation of Ni / C catalyst

[0052] 0.0396 g Li and 0.0769 g naphthalene (NAPH) were weighed and dissolved in 22 ml tetrahydrofuran solution and stirred overnight. 0.054 g Ni (acac)₂ was weighed and dissolved in 10 ml anhydrous tetrahydrofuran solution and stirred for 10 min. Then, 2 ml of prepared naphthyllithium solution was quickly added, and the mixture was stirred at 62 °C for 4.5 h. 0.2344 g carbon black support was weighed and added to 30 ml tetrahydrofuran solution and stirred for 12 h. The tetrahydrofuran solvent was then removed by rotary evaporation, and the sample was dried in a vacuum oven at 60 °C. Subsequently, the sample was calcined in argon at 300 °C for 3 h, washed by centrifugation with a 3:1 mixture of n-hexane and methanol, and dried in a vacuum oven at 60 °C for 3 h. The theoretical metal loading of the catalyst was 5 wt%. Before each reaction, the catalyst was pre-reduced in a tube furnace at 300 °C for 3 h under a mixed atmosphere of hydrogen and argon.

[0053] Example 15: Preparation of Cu / C catalyst

[0054] Weigh 0.0396 g Li and 0.0769 g naphthalene (NAPH) and dissolve and disperse them in 22 ml tetrahydrofuran solution, stirring overnight. Weigh 0.054 g Co(acac)2 and dissolve and disperse it in 10 ml anhydrous tetrahydrofuran solution, stirring for 10 min. Then, quickly add 2 ml of prepared naphthyllithium solution and maintain stirring at 62 °C for 4.5 h. Weigh 0.2508 g carbon black support and add 30 ml tetrahydrofuran, stirring for 12 h. Afterward, remove the solvent tetrahydrofuran by rotary evaporation, dry in a vacuum oven at 60 °C, then calcine the sample in argon at 300 °C for 3 h, wash with a 3:1 mixture of n-hexane and methanol by centrifugation, and dry in a vacuum oven at 60 °C for 3 h. The theoretical metal loading of the catalyst is 5 wt%. Before each reaction, the catalyst is pre-reduced in a tube furnace at 300 °C for 3 h under a mixed atmosphere of hydrogen and argon.

[0055] Example 16: PtPdCoNiCu / C catalysis of phenyl benzyl ether (BPE) in a high-pressure reaction vessel reactor.

[0056] Weigh out 0.5g of coal-based platform molecular phenyl benzyl ether, 0.05g of PtPdCoNiCu / C (metal loading of 5wt%), 30ml of isopropanol, and 0.1g of H4[Si(W3O] 10 The reaction was carried out at 4]·xH2O, with a hydrogen pressure of 0.1 MPa, a reaction temperature of 50℃, and a reaction time of 2 h. After cooling to room temperature, the catalyst was separated, and chromatographic analysis showed that the conversion rate of phenyl benzyl ether (BPE) was 99.9%.

[0057] like Figure 1 As shown, except for the reaction time, all other experimental conditions were the same as in Example 16. The effect of reaction time on the catalytic hydrogenolysis of BPE to produce toluene and phenol was investigated. With the increase of reaction time, the substrate conversion rate increased continuously and the reaction selectivity improved continuously. When the reaction time was 2 h, the selectivity of toluene and phenol obtained by hydrogenolysis of BPE was 99.3% and 99.5%, respectively.

[0058] Example 17: PtPdCoNiCu / C catalysis of dibenzyl ether (BE) in a high-pressure reaction vessel reactor.

[0059] Weigh out 0.5g of coal-based platform molecular dibenzyl ether, 0.05g of PtPdCoNiCu / C (metal loading of 5wt%), 30ml of isopropanol, and 0.1g of silicotungstic acid hydrate. The hydrogen pressure is 0.1MPa, the reaction temperature is 75℃, the reaction time is 3h, and after cooling to room temperature, the catalyst is separated. Chromatographic analysis shows that the conversion rate of dibenzyl ether (BE) is 99.9%.

[0060] like Figure 2 As shown, except for the reaction time, all other experimental conditions were the same as in Example 17. The effect of reaction time on the catalytic hydrogenolysis of BE to produce toluene was investigated. With the increase of reaction time, the substrate conversion rate increased continuously and the reaction selectivity improved continuously. When the reaction time was 3 h, the yield of toluene from BE hydrogenolysis was 99.8%.

[0061] Example 18: PtPdCoNiCu / C catalysis of phenoxyethylbenzene (PPE) in a high-pressure reaction vessel reactor.

[0062] Weigh 0.5g of coal-based platform molecular phenyl benzyl ether, 0.05g of PtPdCoNiCu / C (metal loading of 5wt%), 30ml of isopropanol, and 0.1g of silicotungstic acid hydrate. The hydrogen pressure is 0.1MPa, the reaction temperature is 100℃, the reaction time is 3h, and the mixture is cooled to room temperature. The catalyst is separated, and the chromatographic analysis shows that the conversion rate of phenoxyethylbenzene (PPE) is 99%, the yield of ethylbenzene is 99%, and the yield of phenol is 98%.

[0063] Example 19: PtPdCoNiCu / C catalysis of diphenyl ether (DPE) in a high-pressure reaction vessel reactor.

[0064] Weigh 0.5g of coal-based platform molecular phenyl benzyl ether, 0.05g of PtPdCoNiCu / C (metal loading of 5wt%), 30ml of isopropanol, and 0.1g of silicotungstic acid hydrate. The hydrogen pressure is 0.1MPa, the reaction temperature is 100℃, the reaction time is 3h, and the mixture is cooled to room temperature. The catalyst is separated, and the chromatographic analysis shows that the conversion rate of phenoxyethylbenzene (PPE) is 99% and the yield of phenol is 98%.

[0065] Example 20: PtPdCoNiCu / C catalyzes coal-based platform molecules in a high-pressure reaction vessel reactor without the presence of additives.

[0066] Weigh 0.5g of coal-based platform molecules, 0.05g of PtPdCoNiCu / C (metal loading of 5wt%), 30ml of isopropanol, hydrogen pressure 0.1MPa, reaction temperature 50-100℃, reaction time 1-3h, cool to room temperature, separate the catalyst, and chromatographic analysis shows that the conversion rate of phenyl benzyl ether (BPE) is 67.7%, the conversion rate of dibenzyl ether is 56.7%, the conversion rate of phenoxyethylbenzene is 30.2%, and the conversion rate of diphenyl ether is 12.5%.

[0067] The catalysts prepared in Examples 1 and 2-15 were evaluated for their catalytic performance. The reaction was carried out in a high-pressure reactor with 0.05 g of phenyl benzyl ether (BPE), 0.5 g of catalyst, 0.1 g of BPE, a reaction pressure of 0.1 MPa, 0.1 g of silicotungstic acid hydrate, a reaction temperature of 50 °C, and a reaction time of 2 h. Specific experimental parameters and reaction yields are shown in Table 1.

[0068] Table 1 Effect of different catalyst compositions on the catalytic activity of BPE

[0069]

[0070]

[0071] Note: Other substances include methylcyclohexane, cyclohexanol, cyclohexanone, cyclohexane, etc., and the overall material balance is maintained.

[0072] The catalytic performance of the catalysts prepared in Examples 1 and 2-15 was evaluated. The catalysts were prepared in a high-pressure reaction vessel reactor with dibenzyl ether (BE), 0.05 g catalyst, 0.5 g BE, and 0.1 g silicotungstic acid hydrate. The reaction pressure was 0.1 MPa, the reaction temperature was 75 °C, and the reaction time was 3 h. Specific experimental parameters and reaction yields are shown in Table 2.

[0073] Table 2 Effect of different catalyst compositions on BE catalytic activity

[0074]

[0075]

[0076] Note: Others include methylcyclohexane, cyclohexane, etc., and the overall material balance is maintained.

[0077] The catalytic performance of the catalysts prepared in Examples 1 and 2-15 was evaluated. In a high-pressure reactor, phenoxyethylbenzene (PPE) was reacted with 0.05 g of catalyst, 0.5 g of PPE, and 0.1 g of silicotungstic acid hydrate. The reaction pressure was 0.1 MPa, the reaction temperature was 100 °C, and the reaction time was 3 h. Specific experimental parameters and reaction yields are shown in Table 3.

[0078] Table 3 Effect of different catalyst compositions on the catalytic activity of PPE

[0079]

[0080]

[0081] Note: Others include cyclohexylethane, cyclohexanol, cyclohexanone, cyclohexane, etc., and the overall material balance is maintained.

[0082] The catalytic performance of the catalysts prepared in Examples 1 and 2-15 was evaluated. The catalysts were prepared in a high-pressure reaction vessel reactor with diphenyl ether (DPE), 0.05 g catalyst, 0.5 g DPE, and 0.1 g silicotungstic acid hydrate. The reaction pressure was 0.1 MPa, the reaction temperature was 100 °C, and the reaction time was 6 h. Specific experimental parameters and reaction yields are shown in Table 4.

[0083] Table 4. Effect of different catalyst compositions on the catalytic activity of DPE

[0084]

[0085]

[0086] Note: Others include cyclohexylphenyl ether, cyclohexanol, dicyclohexyl ether, etc., and the overall material balance is maintained.

[0087] Based on the above data, the interaction of the five elements in the PtPdCoNiCu / C high-entropy alloy catalyst, along with the synergistic effect of silicotungstic acid, significantly reduces the reaction temperature and energy consumption. The coal-based platform molecule exhibits excellent hydrogenolysis activity. In contrast, other multi-metal alloy catalysts or single-metal catalysts have relatively simple active components, fewer active sites, and weaker synergistic effects between metals, making it difficult to achieve the same catalytic effect as the high-entropy alloy catalyst.

[0088] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing aromatics by molecular-catalyzed hydrogenolysis of coal-based platforms under mild conditions, characterized in that, The steps are as follows: Using coal-based platform molecules as raw materials, isopropanol as solvent, carbon black-supported high-entropy alloy as catalyst, and silicotungstic acid as acidic additive, aromatic compounds were produced by selective catalytic hydrogenolysis in a high-pressure autoclave reactor under the conditions of reaction temperature 50-100℃, reaction pressure 0.1-2MPa, and reaction time 1-6 h. The coal-based platform molecule is one or a mixture of two or more of phenyl benzyl ether, dibenzyl ether, and phenoxyethylbenzene; The carbon black-supported high-entropy alloy catalyst has a high-entropy alloy loading of 1wt.%~5wt.% and a composition of one of PtPdCoNiCu, PtRuCoNiCu, PtPdFeCoNi, and PtRuFeCoNi. The carbon black-supported high-entropy alloy catalyst was prepared by a wet chemical method. Naphthyllithium was used as a reducing agent and added dropwise to an anhydrous tetrahydrofuran solution containing different masses of metal acetylacetonate salts. The reaction was stirred at 62°C for 4.5 h to obtain high-entropy alloy nanoparticles. Using a colloidal impregnation method, the high-entropy alloy nanoparticles and the carrier carbon black were added to the tetrahydrofuran solution at room temperature and stirred and impregnated overnight. The solvent was removed by rotary evaporation, dried in a vacuum oven, ground, and then calcined at 300°C in argon for 3 h. Finally, the catalyst was obtained by centrifugation and washing.

2. The method for preparing aromatics by molecular catalytic hydrogenolysis of coal-based platforms under mild conditions according to claim 1, characterized in that, The mass ratio of the carbon black-supported high-entropy alloy catalyst to the coal-based platform molecules is 0.05:1 to 0.1:1, the mass ratio of the carbon black-supported high-entropy alloy catalyst to the silicotungstic acid additive is 1:2, and the mass concentration of the coal-based platform molecules in the reaction system is 1-30 wt.%.

3. The method for preparing aromatics by molecular catalytic hydrogenolysis of coal-based platforms under mild conditions according to claim 1, characterized in that, The aromatic compounds mentioned are toluene and ethylbenzene.

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