A method for preparing high performance fuel cage hydrocarbon compounds

Abstract

The application provides a method for preparing high-performance fuel cage hydrocarbon compounds, which comprises: under light conditions, contacting a heterogeneous photocatalyst and a bicyclic compound shown in formula (1) in a photosensitive organic solvent to generate an intramolecular cycloaddition reaction to obtain a cage compound shown in formula (2); in formula (1) and formula (2), R1 to R7 are each independently hydrogen or an organic group containing 1-5 carbon atoms, and the organic group is an alkyl group, an alkoxy group, an aldehyde group or an ester group; wherein the amount of the bicyclic compound shown in formula (1) is 0.1-8 g and the amount of the heterogeneous photocatalyst is 0.001-1 g per 100 mL of the photosensitive organic solvent. Through the technical scheme, the photocatalytic reaction preparation method of the five-ring decalin cage hydrocarbon derivative provided by the application is simple in process and short in reaction time. In addition, the photocatalyst used in the reaction is cheap and easy to obtain, the selectivity and yield of the target product are relatively high, and the method has high application value.

Description

Technical Field

[0001] This invention relates to the field of organic chemistry, and more specifically, to a method for preparing high-performance fuel cage-like hydrocarbon compounds. Background Technology

[0002] For aerospace vehicles, such as those with turbines, ramjet engines, rocket-ramjet engines, and turbine-ramjet combined-engines, the amount of power provided by the power source directly determines the vehicle's speed, range, payload, and other performance characteristics. Propellant is crucial for providing power to a vehicle; the higher its energy density (the heat released by the complete combustion of fuel per unit volume, MJ / L), the more total energy it provides. Higher propellant density also allows for a larger mass of fuel carried by the vehicle. Furthermore, while maintaining the same range and speed, it can reduce the size of the fuel tank, enabling miniaturization and improving maneuverability and penetration capabilities. Propellants with high volumetric calorific value and high density not only meet the propulsion requirements of new high-performance aerospace vehicles (high speed, large payload, long range, and strong maneuverability) but also rapidly and cost-effectively improve the propulsion performance of existing vehicles. Therefore, their synthesis and development are of great significance.

[0003] High-density hydrocarbon fuels are a class of propellants with advantages such as high density, high volumetric calorific value, high safety factor, and low toxicity. They can be a single component or a mixture of multiple hydrocarbons, and their density is generally greater than 0.80 g / cm³. 3 These fuels typically have a volumetric calorific value greater than 38.0 MJ / L and are generally in liquid or solid form. Solid fuels include cage-like hydrocarbon compounds such as adamantane, cubane, tetrahedral, tetracycloheptane, tricyclohexane, and pentacycloundecane. These fuels are all hydrocarbons with compact structures, high carbon-to-hydrogen ratios, and high ring strain. Among them, cage-like hydrocarbon compounds have a twisted CH bond angle of 60-90° (less than 109.5°), thus exhibiting higher strain energy. Simultaneously, their relatively compact molecular structure makes them a promising class of high-density hydrocarbon fuels.

[0004] Reference 1 (Li Chunying et al., Photocatalytic Synthesis of High-Density Cage-like Hydrocarbon Pentane, Proceedings of the 4th National Conference on Industrial Catalysis Technology and Application, 2007) disclosed that a certain amount of dicyclopentadiene was dissolved in acetone, added to a quartz flask, magnetically stirred, refluxed for a period of time under high-pressure mercury lamp illumination, and the product pentane was obtained after the solvent was evaporated. However, the reaction time was long and the yield was low.

[0005] Reference 2 (CN111375404A) discloses a method for synthesizing fuels from fuel substrates using a p-type TiO2 / n-type WO3 heterojunction catalyst under illumination. The fuel substrates include at least one of norbornene, dicyclopentadiene, norbornene, isophorone, and cyclohexenone; the fuels include at least one of pentacyclotetradecane, pentacyclodecadecane, and tetracycloheptane. However, this method suffers from long reaction times and low yields. Therefore, the reaction time of existing methods for synthesizing high-performance cage-like hydrocarbon fuels still needs to be further shortened, and the yield needs to be further improved. Summary of the Invention

[0006] The purpose of this invention is to shorten the reaction time and increase the yield of the method for synthesizing high-performance fuel cage-like hydrocarbon compounds.

[0007] To achieve the above objectives, the present invention provides a method for preparing high-performance fuel cage-like hydrocarbon compounds, the method comprising: under light irradiation conditions, contacting a heterogeneous photocatalyst and a bicyclic compound of formula (1) in a photosensitive organic solvent to undergo an intramolecular cycloaddition reaction to obtain a cage-like compound of formula (2);

[0008]

[0009] In formulas (1) and (2), R1 to R7 are each independently hydrogen or an organic group containing 1-5 carbon atoms, and the organic group shown is alkyl, alkoxy, aldehyde or ester; wherein, the heterogeneous photocatalyst is one or more of TiO2, CeO2, ZnO, CdS, ZnS, TiO2 supported on ZnO, TiO2 supported on CeO2, TiO2 supported on Fe2O3, TiO2 supported on CuO and TiO2 supported on NiO; relative to 100 mL of the photosensitive organic solvent, the amount of the bicyclic compound shown in formula (1) is 0.1-8 g, and the amount of the heterogeneous photocatalyst is 0.001-1 g.

[0010] Through the above technical solution, the photocatalytic reaction preparation method of pentacyclic decadecane cage-like hydrocarbon derivatives of the present invention is simple and has a short reaction time. Furthermore, the photocatalyst used in the reaction is inexpensive and readily available, and the selectivity and yield of the target product are both high, making it highly valuable for application.

[0011] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0012] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0013] Figure 1 The properties of the fuel obtained by blending the high-performance fuel cage-like hydrocarbon compound pentacyclodecadecane (BCU) obtained by the method of the present invention with JP-10 liquid fuel are described. Detailed Implementation

[0014] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0015] The present invention provides a method for preparing high-performance fuel cage-like hydrocarbon compounds, the method comprising: under light irradiation conditions, contacting a heterogeneous photocatalyst and a bicyclic compound of formula (1) in a photosensitive organic solvent to undergo an intramolecular cycloaddition reaction to obtain a cage-like compound of formula (2);

[0016]

[0017] In formulas (1) and (2), R1 to R7 are each independently hydrogen or an organic group containing 1-5 carbon atoms, and the organic group shown is alkyl, alkoxy, aldehyde or ester; wherein, the heterogeneous photocatalyst is one or more of TiO2, CeO2, ZnO, CdS, ZnS, TiO2 supported on ZnO, TiO2 supported on CeO2, TiO2 supported on Fe2O3, TiO2 supported on CuO and TiO2 supported on NiO; relative to 100 mL of the photosensitive organic solvent, the amount of the bicyclic compound shown in formula (1) is 0.1-8 g, and the amount of the heterogeneous photocatalyst is 0.001-1 g.

[0018] This invention achieves high reaction efficiency by selecting specific heterogeneous photocatalysts and the concentrations of reactants and heterogeneous photocatalysts in a photosensitive organic solvent. The heterogeneous photocatalyst refers to nano-oxides capable of catalyzing chemical reactions under light irradiation.

[0019] This invention utilizes both a photosensitizer as a solvent and a heterogeneous catalyst as a catalyst to simultaneously and synergistically promote the reaction, thus allowing for a lower catalyst dosage. The inventors have discovered that excessive catalyst usage in this reaction exacerbates the coupling reaction between photosensitizer molecules, leading to a decrease in the efficiency of the cyclization reaction within the DCPD molecule and a prolonged reaction time. Conversely, insufficient catalyst usage reduces photocatalytic efficiency.

[0020] Preferably, the amount of the bicyclic compound represented by formula (1) is 0.5-6 g relative to 100 mL of the photosensitive organic solvent.

[0021] Preferably, the amount of the heterogeneous photocatalyst is 0.05-0.5g per 100mL of the photosensitive organic solvent.

[0022] Optionally, the cycloaddition reaction conditions include: a temperature of 15-25℃ and a time of 3-12 hours; the illumination conditions include: a light source is an ultraviolet high-pressure mercury lamp with a radiation wavelength of 300-400nm, and a power of 300-500W relative to 100mL of the photosensitive organic solvent.

[0023] Preferably, the heterogeneous photocatalyst is one or more of CeO2, ZnO, CdS, TiO2 supported on ZnO, TiO2 supported on CeO2, TiO2 supported on Fe2O3, and TiO2 supported on NiO.

[0024] Optionally, the heterogeneous photocatalyst has a particle size of 8-20 nm and a specific surface area of ​​40-120 m². 2 / g.

[0025] Optionally, the preparation method of the heterogeneous photocatalyst includes: dropping a precipitant into an aqueous solution containing a metal source, causing the metal to precipitate in the form of hydroxide or sulfide, followed by solid-liquid separation, drying, and calcination to obtain the heterogeneous photocatalyst; the precipitant is an alkaline aqueous solution or an aqueous solution containing sulfide ions, preferably ammonia or sodium sulfide aqueous solution; the metal source is at least one water-soluble salt of Ti, Ce, Zn, Cd, Fe, Cu, and Ni.

[0026] Optionally, the concentration of ammonia water used as a precipitant is 25-28% by weight, and the concentration of sodium sulfide aqueous solution used as a precipitant is 6-10% by weight; the concentration of the aqueous solution containing the metal source is 2-20% by weight, based on the amount of metal element; the precipitation is carried out at a temperature of 20-60°C for 3-6 hours, with a pH value of 6.5-7.5; the drying temperature is 80-120°C for 8-14 hours; and the calcination temperature is 400-600°C for 2-6 hours.

[0027] Optionally, the photosensitive organic solvent is one or more of cyclopentanone, acetone, and butanone.

[0028] Optionally, in equations (1) and (2), R1 to R7 are each hydrogen.

[0029] Optionally, in formulas (1) and (2), R1, R2, R4, R6, and R7 are each hydrogen, and R3 and R5 are methyl groups.

[0030] The present invention will be further described in detail below through embodiments. Unless otherwise specified, the raw materials used in the embodiments are all commercially available.

[0031] The preparation method of the NiO-supported TiO2 catalyst used in the examples includes: preparing an aqueous solution of equimolar amounts of Ni(NO3)2 and Ti(SO4)2 (each with a concentration of 0.25 mol / L), stirring thoroughly for 0.5 h, adding saturated ammonia water dropwise to the mixed solution at a rate of 2 ml per minute (total amount added is 41 g), adjusting the pH value to about 7 with hydrochloric acid, stirring at room temperature for 4 h, washing and filtering, drying at 100 °C, calcining in a muffle furnace at 500 °C in an air atmosphere for 3 h, and cooling to obtain the NiO-supported TiO2 catalyst.

[0032] Example 1

[0033] The cage-like hydrocarbon compound was prepared using the following steps:

[0034] In a single-port jacketed glass reactor, 100 mL of acetone, 5 g of dicyclopentadiene, and 0.25 g of nano-sized photocatalyst ZnO were added. The reactor was then sealed, wrapped with tin foil, and condenser was turned on. The reaction was carried out under high-pressure mercury lamp irradiation (400 W, wavelength 365 nm) at 25 °C. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the reaction solution, qualitatively identify the products, and calculate the reaction conversion and product selectivity. The product yields are listed in Table 1. The cage-like hydrocarbon compound obtained from the reaction is named pentacyclic [5.2.1.0]. 2.5 .0 3.9 .0 4.8 Decane (BCU), its physicochemical properties are shown in Table 2, and the properties of the liquid fuel after blending with other high-performance liquid fuels are shown in the appendix. Figure 1 As shown.

[0035] Example 2

[0036] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that 100 mL of acetone, 3.33 g of dicyclopentadiene, and 0.17 g of nanoscale photocatalyst CeO2 were added to a single-port jacketed glass reactor. The product yields are listed in Table 1.

[0037] Example 3

[0038] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that 100 mL of acetone, 5 g of dicyclopentadiene, and 0.1 g of nanoscale photocatalyst (TiO2 supported on NiO) were added to a single-port jacketed glass reactor, and acetone was replaced with butanone. The product yields are listed in Table 1.

[0039] Example 4

[0040] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that 100 mL of acetone, 2 g of dicyclopentadiene, and 0.1 g of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor. The product yields are listed in Table 1.

[0041] Example 5

[0042] The cage-like hydrocarbon compound was prepared using the method of Example 1, except that 100 mL of acetone, 5 g of dimethyl dicyclopentadiene, and 0.15 g of nanoscale photocatalyst (TiO2 supported on ZnO) were added. The resulting product was named compound A, and the product yield is listed in Table 1. The physicochemical properties are shown in Table 2.

[0043] Example 6

[0044] The cage-like hydrocarbon compound was prepared using the method of Example 1, except that 100 mL of acetone, 1.67 g of dicyclopentadiene, and 0.08 g of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor.

[0045] Example 7

[0046] The cage-like hydrocarbon compound was prepared using the method of Example 1, except that 100 mL of acetone, 5 g of dicyclopentadiene, and 0.005 g of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor.

[0047] Example 8

[0048] The cage-like hydrocarbon compound was prepared using the method of Example 1, except that 100 mL of acetone, 5 g of dicyclopentadiene, and 0.75 g of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor.

[0049] Comparative Example 1

[0050] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that no photocatalyst was used. The product yields are listed in Table 1.

[0051] Comparative Example 2

[0052] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, the only difference being that nano-sized ZrO2 was used as the photocatalyst. The product yields are listed in Table 1.

[0053] Comparative Example 3

[0054] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that 10 g of dicyclopentadiene and 100 mL of acetone, along with 0.5 g of nanoscale photocatalyst ZnO, were added to a single-port jacketed glass reactor. The product yields are listed in Table 1.

[0055] Comparative Example 4

[0056] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that 5 g of dicyclopentadiene, 100 mL of acetone, and 1.5 g of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor. The product yields are listed in Table 1.

[0057] Comparative Example 5

[0058] The cage-like hydrocarbon compound BCU was prepared using the method of Example 1, except that 5 g of dicyclopentadiene and 100 mL of acetone and 0.1 mg of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor. The product yields are listed in Table 1.

[0059] Comparative Example 6

[0060] The cage-like hydrocarbon compound was prepared using the method of Example 1, except that 5g of dicyclopentadiene, 100mL of xylene, and 0.25g of nanoscale photocatalyst ZnO were added to a single-port jacketed glass reactor.

[0061] In Table 1, the units for raw material usage and catalyst usage are g / 100mL solvent.

[0062] Table 1

[0063]

[0064] Table 2

[0065] Appearance White crystals White crystals <![CDATA[Density (kg / m 3 )]]> 1.05 1.04 Volumetric calorific value (MJ / L) 42.7 41.5 Melting point (°C) 134 125

[0066] As can be seen from the data in Tables 1 and 2, when a specific heterogeneous photocatalyst is used and the amount of the bicyclic compound shown in formula (1) is 0.1-8 g relative to 100 mL of the photosensitive organic solvent, and the amount of the heterogeneous photocatalyst is 0.001-1 g, the reaction time can be shortened and the product yield can be increased; when the amount of the heterogeneous photocatalyst is preferably 0.05-0.5 g relative to 100 mL of the photosensitive organic solvent, the reaction time can be further shortened.

[0067] Appendix Figure 1 The properties of the liquid fuel obtained by blending BCU with other liquid fuels JP-10 are shown. It can be seen that as the proportion of BCU increases, the freezing point gradually decreases and the density gradually increases. When the mass ratio of BCU is 50%, the blended liquid fuel exhibits excellent performance, with a density as high as 0.99 g / cm³. 3 With a freezing point of -43.8℃, the high-performance fuel cage-like hydrocarbon compound prepared by the method of this invention has great application value.

[0068] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0069] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0070] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing high-performance fuel cage-like hydrocarbon compounds, characterized in that, The method includes: under light irradiation conditions, contacting a heterogeneous photocatalyst and a bicyclic compound of formula (1) in a photosensitive organic solvent to undergo an intramolecular cycloaddition reaction to obtain a cage-like compound of formula (2); Equation (1) Equation (2) In formulas (1) and (2), R1 to R7 are each independently hydrogen or an organic group containing 1 to 5 carbon atoms, wherein the organic group is alkyl; The heterogeneous photocatalyst is one or more of TiO2, CeO2, ZnO, CdS, ZnS, TiO2 supported on ZnO, TiO2 supported on CeO2, TiO2 supported on Fe2O3, TiO2 supported on CuO, and TiO2 supported on NiO; the amount of the bicyclic compound shown in formula (1) is 0.1-8 g relative to 100 mL of the photosensitive organic solvent, and the amount of the heterogeneous photocatalyst is 0.001-1 g. The heterogeneous photocatalyst has a particle size of 8-20 nm and a specific surface area of ​​40-120 m². 2 / g; The photosensitive organic solvent is one or more of cyclopentanone, acetone, and butanone.

2. The method according to claim 1, wherein, The amount of the bicyclic compound shown in formula (1) is 0.5-6 g relative to 100 mL of the photosensitive organic solvent.

3. The method according to claim 1 or 2, wherein, The amount of the heterogeneous photocatalyst used is 0.05-0.5 g per 100 mL of the photosensitive organic solvent.

4. The method according to claim 1 or 2, wherein, The conditions for the cycloaddition reaction include: a temperature of 15-25℃ and a time of 3-12 hours; the illumination conditions include: a light source is an ultraviolet high-pressure mercury lamp with a radiation wavelength of 300-400nm, and a power of 300-500W relative to 100mL of the photosensitive organic solvent.

5. The method according to claim 1 or 2, wherein, The heterogeneous photocatalyst is one or more of CeO2, ZnO, CdS, TiO2 supported on ZnO, TiO2 supported on CeO2, TiO2 supported on Fe2O3, and TiO2 supported on NiO.

6. The method according to claim 5, wherein, The method for preparing the heterogeneous photocatalyst includes: dropping a precipitant into an aqueous solution containing a metal source, causing the metal to precipitate in the form of hydroxides or sulfides, followed by solid-liquid separation, drying, and calcination to obtain the heterogeneous photocatalyst; the precipitant is an alkaline aqueous solution or an aqueous solution containing sulfide ions; the metal source is at least one water-soluble salt of Ti, Ce, Zn, Cd, Fe, Cu, and Ni.

7. The method according to claim 6, wherein, The precipitant is ammonia or sodium sulfide aqueous solution.

8. The method according to claim 6, wherein, The concentration of ammonia water used as a precipitant is 25-28% by weight; the concentration of sodium sulfide aqueous solution used as a precipitant is 6-10% by weight; the concentration of the aqueous solution containing the metal source is 2-20% by weight, based on the amount of metal element; the precipitation is carried out at a temperature of 20-60°C for 3-6 hours, with a pH value of 6.5-7.5; the drying temperature is 80-120°C for 8-14 hours; and the calcination temperature is 400-600°C for 2-6 hours.

9. The method according to claim 1 or 2, wherein, In equations (1) and (2), R1 to R7 are each hydrogen; Alternatively, in formulas (1) and (2), R1, R2, R4, R6, and R7 are each hydrogen, and R3 and R5 are methyl groups.

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