A method for removing sulfur-containing organic compounds in oil products by using a porous carbon nanosheet loaded bimetallic phosphide catalyst

Abstract

The application discloses a method for removing sulfur-containing organic compounds in oil products by using a porous carbon nanosheet loaded bimetallic phosphide catalyst, and the method is to catalytically oxidize and treat sulfur-containing organic compounds in oil products by using the porous carbon nanosheet loaded bimetallic phosphide catalyst, wherein the porous carbon nanosheet loaded bimetallic phosphide catalyst comprises porous carbon nanosheets and molybdenum phosphide / wolfram phosphide nano-heterojunction loaded on the porous carbon nanosheets. In the method, the porous carbon nanosheet loaded bimetallic phosphide catalyst has the advantages of high catalytic activity, high selectivity and good stability, can realize rapid and effective removal of various sulfur-containing organic compounds in oil products under the premise of ensuring the quality of the oil products, can achieve ultra-high efficiency and ultra-depth oxidation desulfurization, has very good adaptability, and has the advantages of simple process, convenient operation, low cost, high removal efficiency, good removal effect and the like, and has excellent economic benefits and application prospect.

Description

Technical Field

[0001] This invention belongs to the field of heterogeneous catalysis technology and petrochemical technology, and relates to a method for removing sulfur-containing organic compounds from oil products, specifically a method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets. Background Technology

[0002] In the petrochemical industry, residual sulfides in fuel oil products are a significant concern. If not properly treated, these sulfides can pose environmental risks, including acid rain and smog. Therefore, effectively eliminating sulfides from fuel oil is crucial for mitigating these potential environmental risks. To address these issues, various countries and regions have implemented strict regulations and standards to control the sulfur content in fuel oil. In many countries and regions, the permissible sulfur content in fuel oil is capped at less than 10 ppm. In this context, fuel oil desulfurization becomes a critical task. Currently, hydrodesulfurization (HDS) is the most commonly used industrial process for fuel oil desulfurization. However, this method is limited by high energy consumption and hydrogen consumption. Furthermore, during the HDS process, dibenzothiophene (DBT) and its derivatives are converted into hydrogen sulfide (H2S), a product with low economic value and the risk of environmental pollution. Therefore, exploring alternative, environmentally sustainable desulfurization methods that conform to green chemistry principles to minimize environmental impact and improve resource utilization efficiency is imperative.

[0003] To address the limitations of HDS (High-Desulfurization Scheme), researchers have developed numerous non-HDS technologies as alternatives, including Adsorption Desulfurization (ADS), Biological Desulfurization (BDS), Extractive Desulfurization (EDS), and Oxidative Desulfurization (ODS). Among these alternatives, ODS stands out as a promising strategy due to its efficient removal of aromatic sulfides under mild reaction conditions. Furthermore, ODS offers the added advantage of converting undesirable DBT and its derivatives into valuable sulfones, which typically possess high added value and can be easily separated through simple separation operations. These advantages make ODS a highly attractive desulfurization method for effectively converting and removing sulfur-containing compounds from fuel oils. However, the efficiency of oxidative desulfurization always depends on the activity of the catalyst. Therefore, developing high-performance catalysts is a key scientific challenge for realizing this technology.

[0004] Among various ODS catalysts, transition metal-based catalysts have attracted widespread attention due to their low cost, large supply, and flexible adjustment of surface properties. However, limited activity and stability are the main obstacles to their practical application. In addition, the aforementioned catalysts are prone to causing equipment corrosion during preparation or reaction, and the leaching concentration is relatively high, which makes most catalysts less than ideal in practical applications. To this end, the inventors of this application propose a molybdenum phosphide composite catalyst, comprising nitrogen and phosphorus co-doped carbon nanosheets and molybdenum phosphide nanoparticles supported thereon. By loading molybdenum phosphide particles onto nitrogen and phosphorus co-doped carbon nanosheets, the interaction between the metal and the support can be enhanced by regulating the interfacial charge. This can improve the catalytic activity of molybdenum phosphide while effectively inhibiting metal leaching and enhancing catalyst stability. Furthermore, the inventors of this application have found in actual research that: (1) by optimizing the thickness of the heterogeneous carbon nanosheets, it is beneficial to increase the specific surface area and active sites of the catalyst, thereby providing more sites for the attachment of active sites and the catalytic reaction, which is conducive to the formation of more unsaturated metal sites on the catalyst surface; (2) by optimizing the type of active sites, more unsaturated metal sites can be formed on the catalyst surface, which is beneficial to further improve the catalytic activity of the catalyst. In particular, by optimizing the combination of active sites, it is beneficial to promote the reconstruction of the electronic structure on the catalyst surface, which is beneficial to improve the oxidation resistance of the catalyst, thus making the active components on the catalyst surface less prone to oxidation during actual use and resulting in better structural stability. Furthermore, the inventors of this application have discovered that by optimizing the catalyst preparation method, it is beneficial to obtain a support material with a large specific surface area and numerous active sites. Simultaneously, the original morphology of the support material can be maintained while controlling the loading of the active component, which helps avoid deficiencies such as carbon nanosheet aggregation or encapsulation of active site particles, thereby improving the accessibility of surface active sites. Therefore, obtaining an ODS catalyst with strong catalytic activity, high selectivity, and good stability, along with a simple, convenient, and low-cost preparation method, is of great significance for the effective conversion of sulfur-containing organic pollutants in petroleum products and for improving the usability of petroleum products. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for removing sulfur-containing organic compounds from oil products by using a porous carbon nanosheet-supported bimetallic phosphide catalyst that is low in cost, high in removal efficiency, and good in removal effect.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst, wherein the method employs a porous carbon nanosheet-supported bimetallic phosphide catalyst to catalytically oxidize the sulfur-containing organic compounds in the oil product; the porous carbon nanosheet-supported bimetallic phosphide catalyst comprises porous carbon nanosheets and molybdenum phosphide / tungsten phosphide nanoheterojunctions, wherein the molybdenum phosphide / tungsten phosphide nanoheterojunctions are supported on the porous carbon nanosheets.

[0008] The above-described method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in that the mass ratio of the molybdenum phosphide / tungsten phosphide nanoheterostructure to the porous carbon nanosheets is 0.1–0.8:1; the porous carbon nanosheets have uniformly distributed nanoscale pores; the mass content of molybdenum phosphide in the molybdenum phosphide / tungsten phosphide nanoheterostructure is 20%–60%; and the average particle size of the molybdenum phosphide / tungsten phosphide nanoheterostructure is 20 nm–60 nm.

[0009] The above-described method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst is further improved by comprising the following steps:

[0010] S1. Prepare a Mo / W precursor solution by mixing ammonium heptamolybdate and ammonium metatungstate.

[0011] S2. Mix the Mo / W precursor solution obtained in step S1 and the porous carbon nanosheet / melamine dispersion, stir, and sonicate to obtain the precursor dispersion.

[0012] S3. Add the phosphorus source to the precursor dispersion obtained in step S2, stir, filter, and dry to obtain catalyst precursor powder.

[0013] S4. The catalyst precursor powder obtained in step S3 is calcined to obtain a porous carbon nanosheet supported bimetallic phosphide catalyst.

[0014] The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in step S2 by the following modifications: the volume ratio of the Mo / W precursor solution to the porous carbon nanosheet / melamine dispersion is 0.5–1:1; the sum of the concentrations of ammonium heptamolybdate and ammonium metatungstate in the Mo / W precursor solution is 0.01 mol / L–0.06 mol / L; the molar ratio of ammonium heptamolybdate to ammonium metatungstate in the Mo / W precursor solution is 0.4–7:1; the porous carbon nanosheet / melamine dispersion is prepared by mixing melamine, porous carbon nanosheets, and water; the sum of the concentrations of melamine and porous carbon nanosheets in the porous carbon nanosheet / melamine dispersion is 50 g / L–80 g / L; and the mass ratio of melamine to porous carbon nanosheets in the porous carbon nanosheet / melamine dispersion is 4–6:1.

[0015] The above-described method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in step S3, wherein the phosphorus source is an H3PO4 solution and / or a phytic acid solution; the mass concentration of the H3PO4 solution and the phytic acid solution is 85%; and the volume ratio of the precursor dispersion to the phosphorus source is 18-24:1.

[0016] The above-described method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved by comprising the following steps in the preparation method of the porous carbon nanosheets:

[0017] (1) Sodium citrate was calcined under an inert atmosphere to obtain porous carbon nanosheet precursor material;

[0018] (2) The porous carbon nanosheet precursor material obtained in step (1) is added to hydrochloric acid solution for reaction, washed, and dried to obtain porous carbon nanosheets.

[0019] The above-mentioned method for removing sulfur-containing organic compounds from oil products using porous carbon nanosheets supported on bimetallic phosphide catalysts is further improved in that, in step (1), the calcination is carried out at a temperature of 750℃~800℃; the calcination time is 60min~180min; and the inert atmosphere is a nitrogen or argon atmosphere.

[0020] The above-mentioned method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in step (2) by wherein the mass ratio of the hydrochloric acid solution to the porous carbon nanosheet precursor material is 20-30:1; the concentration of the hydrochloric acid solution is 1.5 mol / L-2.5 mol / L; and the reaction time is 24-48 h.

[0021] The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in that, in step S2, the stirring time is 0.5 h to 2 h, and the ultrasonication time is 30 min to 60 min.

[0022] The above-described method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in that, in step S3, the stirring is carried out at a temperature of 60℃~80℃; the stirring time is 12h~16h; the drying process is carried out under vacuum conditions; the drying temperature is 60℃~80℃; and the drying time is 2h~12h.

[0023] The above-described method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in that, in step S4, the calcination is carried out under an argon atmosphere; the gas flow rate is controlled at 20 mL / min during the calcination process; the heating rate during the calcination process is 5 °C / min; the calcination temperature is 800 °C to 900 °C; and the calcination time is 2 h to 3 h.

[0024] The above-mentioned method for removing sulfur-containing organic compounds from oil products using porous carbon nanosheets supported by bimetallic phosphide catalysts is further improved by using porous carbon nanosheets supported by bimetallic phosphide catalysts to catalytically oxidize sulfur-containing organic compounds in oil products, which includes the following steps: mixing porous carbon nanosheets supported by bimetallic phosphide catalysts, hydrogen peroxide, and sulfur-containing organic compound oil products to carry out catalytic oxidation reaction, thereby completing the removal of sulfur-containing organic compounds from the oil products.

[0025] The above-described method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst is further improved by adding 0.2g to 1g of the porous carbon nanosheet-supported bimetallic phosphide catalyst per liter of oil containing sulfur-containing organic compounds; and the molar ratio of hydrogen peroxide to sulfur in the oil containing sulfur-containing organic compounds is 4:1.

[0026] The above-described method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in that the sulfur-containing organic compounds in the oil product are at least one of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene; the initial sulfur concentration of the sulfur-containing organic compounds in the oil product is ≤3000ppm; the catalytic oxidation reaction is carried out at a temperature of 30℃~90℃; the catalytic oxidation reaction time is 10min~120min; and the catalytic oxidation reaction is carried out under stirring conditions.

[0027] The above-mentioned method for removing sulfur-containing organic compounds from oil products using porous carbon nanosheets supported on bimetallic phosphide catalysts is further improved by the fact that the catalytic oxidation reaction is carried out at a temperature above 45°C, which results in a better removal effect of sulfur-containing organic compounds from oil products.

[0028] The above-mentioned method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets is further improved in that the initial sulfur concentration of the sulfur-containing organic compounds in the oil product is 200ppm to 1000ppm; and the catalytic oxidation reaction time is 30min to 120min.

[0029] In this invention, acetonitrile is also added to the catalytic oxidation reaction system to carry out the catalytic oxidation reaction under acetonitrile conditions, and is used to retain the products in the catalytic oxidation reaction system (such as dibenzothiophene sulfone obtained by conversion of dibenzothiophene).

[0030] Compared with the prior art, the advantages of the present invention are as follows:

[0031] (1) This invention provides a method for removing sulfur-containing organic compounds from petroleum products using a porous carbon nanosheet-supported bimetallic phosphide catalyst. The porous carbon nanosheet-supported bimetallic phosphide catalyst has the advantages of strong catalytic activity, high selectivity, and good stability. It can be widely used to remove sulfur-containing organic compounds (such as 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene) from petroleum products. It can also achieve rapid and effective removal of sulfur-containing organic compounds from petroleum products. Therefore, when the porous carbon nanosheet-supported bimetallic phosphide catalyst is used to catalytically oxidize sulfur-containing organic compounds in petroleum products, it can quickly and efficiently achieve the effective conversion of sulfur-containing organic compounds in fuel products. It can achieve ultra-high efficiency and ultra-deep oxidative desulfurization. It has the advantages of simple process, convenient operation, low cost, high removal efficiency, and good removal effect. It has excellent economic benefits and excellent application prospects. More importantly, the porous carbon nanosheet-supported bimetallic phosphide catalyst used in this invention can selectively remove organic sulfur compounds from oil products. It can achieve rapid and complete removal of organic sulfur compounds from oil products while ensuring oil quality, showing very good adaptability and high application value and promising prospects.

[0032] (2) The porous carbon nanosheet supported bimetallic phosphide catalyst used in this invention includes porous carbon nanosheets and molybdenum phosphide / tungsten phosphide nanoheterojunctions, and the molybdenum phosphide / tungsten phosphide nanoheterojunctions are supported on the porous carbon nanosheets. On the one hand, compared with conventional nitrogen and phosphorus co-doped carbon nanosheets, the porous carbon nanosheets used in this invention have a two-dimensional layered structure and uniformly distributed pores on the surface, thus having a larger specific surface area. This not only provides more surface area for the attachment of active sites but also provides more sites for catalytic reactions. On the other hand, compared with single molybdenum phosphide nanoparticles, the molybdenum phosphide / tungsten phosphide nanoheterojunction used in this invention as the active site has a richer and more tunable electronic structure and exposes more unsaturated metal sites on the surface, thus exhibiting stronger catalytic activity. In particular, electron transfer between the molybdenum phosphide / tungsten phosphide heterojunction interface can lead to the reconstruction of the electronic structure on the catalyst surface. While further improving the catalytic activity of molybdenum phosphide, it can also effectively improve the antioxidant properties of the active sites, thereby effectively preventing the decomposition and failure of the active sites. This significantly enhances the stability of the catalyst and exhibits better reusability. Therefore, the porous carbon nanosheet-supported bimetallic phosphide catalyst of this invention has the advantages of strong catalytic activity and good stability. It is a novel and efficient oxidative desulfurization catalyst with excellent performance and wide applicability. When used to remove organic sulfur compounds in oil, it can achieve effective degradation of organic sulfur compounds with less dosage. At the same time, it can achieve rapid and selective removal of sulfur-containing organic compounds in oil and realize ultra-deep oxidative desulfurization. It has high application value and good application prospects.

[0033] (3) In the porous carbon nanosheet-supported bimetallic phosphide catalyst used in this invention, by optimizing the mass ratio of molybdenum phosphide / tungsten phosphide nanoheterostructure to porous carbon nanosheets to 0.1–0.8:1, a sufficient number of active sites on the catalyst surface can be ensured, thereby exhibiting superior catalytic activity and stability. Furthermore, by optimizing the content of molybdenum phosphide and tungsten phosphide in the molybdenum phosphide / tungsten phosphide nanoheterostructure, a catalyst with excellent catalytic activity and stability can also be obtained. This is because the ratio of tungsten phosphide to molybdenum phosphide in the molybdenum phosphide / tungsten phosphide nanoheterostructure has a significant impact on the electronic structure of the active sites on the catalyst surface, thus affecting the catalyst's activity.

[0034] (4) To address the shortcomings of existing molybdenum phosphide composite catalyst preparation methods, such as difficulty in controlling the number of active sites and the morphology of the support material, and the resulting poor catalytic activity and stability, this invention creatively provides a method for preparing a porous carbon nanosheet-supported bimetallic phosphide catalyst. Using ammonium heptamolybdate and ammonium metatungstate as molybdenum and tungsten sources, respectively, melamine as a crosslinking agent, phosphoric acid as a phosphorus source, and porous carbon nanosheets as the support, ammonium heptamolybdate and ammonium metatungstate are first prepared into a Mo / W precursor solution, and then combined with porous carbon nanosheets... A mixture of carbon nanosheets and melamine dispersion is stirred, and the cross-linking effect of melamine induces strong coordination between molybdenum and tungsten ions, anchoring them onto porous carbon nanosheets. Then, H3PO4 solution is added, and through stirring and the cross-linking effect of melamine, the phosphorus source is anchored onto the porous carbon nanosheets. Finally, a simple one-step pyrolysis process forms molybdenum phosphide / tungsten phosphide nanoheterojunctions, which are then anchored onto the porous carbon nanosheets. This yields a porous carbon nanosheet-supported bimetallic phosphide catalyst with strong catalytic activity and good stability. The preparation method of this invention allows for easy optimization of catalyst performance by adjusting the amount of molybdenum / tungsten precursors during synthesis. It has advantages such as simple process, convenient operation, low cost, and environmental friendliness. Furthermore, it does not use flammable phosphorus or highly toxic phosphine as phosphating agents, has low equipment requirements, high repeatability, and can achieve large-scale production, which is beneficial for industrial applications. Attached Figure Description

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0036] Figure 1 The diagram shows the sulfur conversion effect of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 1 of this invention when removing 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene from fuel.

[0037] Figure 2 The graph shows the sulfur conversion effect of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 2 of this invention when removing dibenzothiophene from fuel under different oxidant dosage conditions.

[0038] Figure 3 The graph shows the sulfur conversion effect of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 3 of this invention when removing dibenzothiophene from fuel under different temperature conditions.

[0039] Figure 4This is a graph showing the selective removal efficiency of dibenzothiophene from fuel oil by the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 4 of the present invention under the presence of different representative interfering substances.

[0040] Figure 5 This is a GC-FPD signal diagram before and after the reaction of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 5 of the present invention to remove sulfur-containing organic compounds from hydrotreated diesel.

[0041] Figure 6 This is a GC-FPD signal diagram before and after the reaction of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 6 of the present invention to remove sulfur-containing organic compounds from straight-run diesel. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0043] In this embodiment of the invention, all raw materials and instruments used are commercially available. Unless otherwise specified, the process used is a conventional process, the equipment used is conventional equipment, and the data obtained are all average values ​​from three or more repeated experiments.

[0044] Example 1

[0045] A method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets, specifically involving the removal of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets, includes the following steps:

[0046] Take 3 mg of each of the four groups of porous carbon nanosheet-supported bimetallic phosphide catalysts, and add them to 10 mL of 3-methylbenzothiophene-n-dodecane solution (i.e., simulated fuel containing benzothiophene), dibenzothiophene-n-dodecane solution (i.e., simulated fuel containing dibenzothiophene), 4-methyldibenzothiophene-n-dodecane solution (i.e., simulated fuel containing 4-methyldibenzothiophene), and 4,6-dimethyldibenzothiophene-n-dodecane solution (i.e., simulated fuel containing 4,6-dimethyldibenzothiophene) with a sulfur concentration of 500 ppm. Add 2 mL of 99% acetonitrile solution to each solution and stir for 10 min to reach extraction equilibrium. Then, 48 μL of a 30% hydrogen peroxide solution (oxidant, O / S molar ratio of 4) was added, and the catalytic oxidation reaction was carried out for 120 min at 60℃ with magnetic stirring (800 r / min) to complete the removal of sulfur-containing organic compounds from the oil.

[0047] The catalytic oxidation reaction takes place in acetonitrile, where organic sulfur compounds are converted into corresponding sulfone products and retained in the acetonitrile, thus removing sulfur-containing organic compounds from the oil. After the reaction is complete, the acetonitrile phase (lower layer) is separated from the oil phase (upper layer) to obtain clean fuel. The entire reaction is carried out in a double-necked flask equipped with a condenser.

[0048] In this embodiment, a porous carbon nanosheet-supported bimetallic phosphide catalyst is used. The catalyst comprises porous carbon nanosheets on which tungsten phosphide / molybdenum phosphide nanoheterojunctions are loaded. The mass contents of molybdenum and tungsten are 10% and 20%, respectively. The mass ratio of the molybdenum phosphide / tungsten phosphide nanoheterojunctions to the porous carbon nanosheets is 0.58:1. Uniform nanoscale pores are distributed on the porous carbon nanosheets. The average particle size of the molybdenum phosphide / tungsten phosphide nanoheterojunctions is 42.9 nm, and the mass content of molybdenum phosphide in the molybdenum phosphide / tungsten phosphide nanoheterojunctions is 37%. The specific surface area of ​​the porous carbon nanosheet-supported bimetallic phosphide catalyst is as high as 289.83 m². 2 / g.

[0049] In this embodiment, the preparation method of the porous carbon nanosheet-supported bimetallic phosphide catalyst includes the following steps:

[0050] (1) Weigh 10.0g of sodium dihydrogen citrate and place it in a quartz boat. Place the boat in a tube furnace and heat it to 780℃ under a nitrogen atmosphere for 2h. Then cool it naturally to room temperature to obtain a porous carbon nanosheet precursor. Add 60mL of hydrochloric acid solution (2M) to the above 3g porous carbon nanosheet precursor and react at room temperature for 24h. Collect the black product by filtration and wash it several times with deionized water and ethanol. Dry it at 70℃ for 2h to obtain porous carbon nanosheets, denoted as PCNS.

[0051] (2) Weigh 0.2g of the porous carbon nanosheets obtained in step (1) and 1g of melamine, disperse them in 20mL of ultrapure water to prepare a porous carbon nanosheet / melamine dispersion.

[0052] (3) Weigh 0.074g of ammonium metatungstate and 0.053g of ammonium heptamolybdate, dissolve them in 18mL of ultrapure water to prepare a molybdenum / tungsten precursor solution.

[0053] (4) The porous carbon nanosheets / melamine dispersion obtained in step (2) and the molybdenum / tungsten precursor solution obtained in step (3) are slowly mixed, stirred for 30 min, sonicated for 30 min, and then 2 mL of phosphoric acid solution with a mass concentration of 85% is slowly added. The mixture is transferred to 80 °C for reaction (solvent-thermal reaction) for 12 h. The reaction product is filtered and recovered, and dried at 80 °C for 12 h to obtain catalyst precursor powder.

[0054] (5) The catalyst precursor powder obtained in step (4) is placed in a quartz boat and transferred to a tube furnace. Under an argon atmosphere, the temperature is increased to 900℃ for 2h at a heating rate of 5℃ / min. During the calcination process, the gas flow rate is controlled at 20mL / min. After the calcination is completed, the mixture is naturally cooled to room temperature to obtain a porous carbon nanosheet supported bimetallic phosphide catalyst, denoted as MoWP2 / PCNS.

[0055] In this embodiment, samples were taken from the reaction system at 5 min, 10 min, 20 min, 30 min, 45 min, 60 min, 90 min, and 120 min of reaction time. The contents of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene in the product solution were measured at the corresponding reaction times. The conversion rates of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene were calculated, and the results are as follows. Figure 1 As shown.

[0056] Figure 1 This image shows the sulfur conversion efficiency of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 1 of this invention for removing 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene from fuel oil. Figure 1 It is evident that the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) of this invention can rapidly and efficiently remove sulfur-containing organic compounds from fuel oil. After 60 min of reaction, the removal rates of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene reached 86.10%, 100%, 98.90%, and 94.77%, respectively. After 120 min of reaction, the removal rates of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene all reached 100%. These results demonstrate that the porous carbon nanosheet-supported bimetallic phosphide catalyst prepared in this invention possesses excellent catalytic oxidation performance. The total sulfur content in the fuel oil treated with the porous carbon nanosheet-supported bimetallic phosphide catalyst prepared in this invention is 0 (<10 ppm), meeting the Euro VI fuel oil standard, with a total desulfurization rate as high as 100%. In particular, the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) exhibits excellent catalytic oxidation of sulfur-containing organic compounds under conditions of low catalyst and oxidant dosage, demonstrating good economic benefits and promising industrial application prospects.

[0057] Example 2

[0058] A method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst is disclosed. Specifically, the method involves using a porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) to remove dibenzothiophene from the oil products. This method is essentially the same as that in Example 1, except that the oxidative desulfurization reaction in Example 2 used different amounts of hydrogen peroxide, namely 24 μL, 36 μL, 48 μL, 60 μL, and 72 μL, with corresponding O / S molar ratios of 2, 3, 4, 5, and 6, respectively.

[0059] Figure 2 This image shows the sulfur conversion effect of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 2 of this invention when removing dibenzothiophene from fuel oil under different oxidant dosages. Figure 2 It can be seen that with the increase of hydrogen peroxide dosage, the catalytic oxidation removal efficiency of dibenzothiophene in oil by the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) continuously improves. When the hydrogen peroxide dosage reaches 48 μL (O:S = 4), the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) can completely remove dibenzothiophene with a sulfur concentration of 500 ppm in simulated fuel within 60 min. The results indicate that the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) can achieve good desulfurization efficiency in the presence of a small amount of oxidant, demonstrating high economic practicality.

[0060] Example 3

[0061] A method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst is disclosed. Specifically, the method involves using a porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) to remove dibenzothiophene from the oil products. This method is basically the same as that in Example 1, except that the oxidative desulfurization reaction in Example 3 was carried out at different reaction temperatures, namely 30°C, 60°C, and 90°C.

[0062] Figure 3 This image shows the sulfur conversion effect of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 3 of this invention when removing dibenzothiophene from fuel oil under different temperature conditions. Figure 3It was found that even at 30℃, the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) still exhibited catalytic oxidation of dibenzothiophene in fuel oil. At 60℃, it completely removed dibenzothiophene with a sulfur concentration of 500 ppm from simulated fuel oil within 60 minutes. When the temperature was further increased to 90℃, the oxidative desulfurization efficiency accelerated further, achieving complete removal of dibenzothiophene within 20 minutes. These results demonstrate that the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) possesses excellent environmental stability, a large temperature adaptability window, and significant potential for practical applications.

[0063] Example 4

[0064] A method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst is disclosed. Specifically, the method involves using a porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) to remove dibenzothiophene from the oil product. This method is essentially the same as that in Example 1, except that 5% by mass of cyclohexane, 1-octene, toluene, and naphthalene were added to the simulated petroleum containing dibenzothiophene in Example 4.

[0065] Figure 4 This is a graph showing the selective removal efficiency of dibenzothiophene from fuel oil by the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) in Example 4 of this invention under the presence of different representative interfering substances. Figure 4 It was found that when 5% cyclohexane, 1-octene, toluene, and naphthalene were present in the oil, the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) achieved removal rates of 100%, 100%, 100%, and 97.70% for dibenzothiophene with a sulfur concentration of 500 ppm, respectively. The results indicate that the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) can selectively catalyze the oxidation and removal of sulfur-containing organic matter from oil.

[0066] Example 5

[0067] A method for removing sulfur-containing organic compounds from petroleum products using a bimetallic phosphide catalyst supported on porous carbon nanosheets, specifically involving the removal of sulfur-containing organic compounds from hydrotreated diesel fuel using a bimetallic phosphide catalyst supported on porous carbon nanosheets, includes the following steps:

[0068] 3 mg of the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) prepared in Example 1 was added to 10 mL of hydrotreated diesel oil with a sulfur concentration of 370 ppm. Then, 2 mL of 99% acetonitrile solution was added, and the mixture was stirred for 10 min to reach extraction equilibrium. Finally, 40 μL of 30% hydrogen peroxide solution (oxidant, O / S molar ratio of 4) was added, and the reaction was carried out at 60 °C with magnetic stirring (800 r / min) for 120 min. The catalytic oxidation reaction was conducted in acetonitrile, where organic sulfur compounds were converted into corresponding sulfone products and retained in acetonitrile, thus removing sulfur-containing organic compounds from the oil. After the reaction was complete, the acetonitrile phase (lower layer) was separated from the oil phase (upper layer) to obtain clean hydrotreated diesel oil. The entire reaction was carried out in a double-necked flask equipped with a condenser.

[0069] In this embodiment, the hydrogenated diesel oil used is a finished oil obtained by multiple heat exchanges after hydrogenation treatment in an oil refinery. Its main components are benzothiophene and dibenzothiophene and their derivatives, and the total sulfur concentration is 370 ppm.

[0070] In this embodiment, samples were taken from the reaction system at the start of the reaction and at 120 min of the reaction. Gas chromatography was used to determine the change in the content of organic sulfur in the product solution obtained over the reaction time. The results are as follows: Figure 5 As shown.

[0071] Figure 5 This is a GC-FPD signal diagram before and after the reaction in Example 5 of this invention, showing the removal of sulfur-containing organic compounds from hydrotreated diesel fuel using a porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS). Figure 5 It is known that the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) of this invention can rapidly and efficiently remove sulfur-containing organic compounds from hydrotreated diesel. After 120 min of reaction, the concentration of organic sulfur compounds in hydrotreated diesel is lower than the detection limit (ppb level) of the FPD detector, achieving complete removal of organic sulfur compounds.

[0072] Example 6

[0073] A method for removing sulfur-containing organic compounds from oil products using a porous carbon nanosheet-supported bimetallic phosphide catalyst is disclosed. Specifically, the method involves removing sulfur-containing organic compounds from straight-run diesel fuel using a porous carbon nanosheet-supported bimetallic phosphide catalyst. This method is essentially the same as that in Example 1, except that the oxidative desulfurization in Example 6 is designed for straight-run diesel fuel with a higher sulfur concentration, and the amount of hydrogen peroxide (290 μL) and the amount of catalyst (10 mg) are adjusted accordingly.

[0074] In this embodiment, the main components of the straight-run diesel oil used are benzothiophene and dibenzothiophene and their derivatives, with a total sulfur concentration of 2676 ppm.

[0075] In this embodiment, samples were taken from the reaction system at the start of the reaction and at 120 min of the reaction. Gas chromatography was used to determine the change in the content of organic sulfur in the product solution obtained over the reaction time. The results are as follows: Figure 6 As shown.

[0076] Figure 6 This is a GC-FPD signal diagram before and after the reaction in Example 6 of the present invention, showing the removal of sulfur-containing organic compounds from straight-run diesel fuel using a porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS). Figure 6 It is evident that the porous carbon nanosheet-supported bimetallic phosphide catalyst (MoWP2 / PCNS) of this invention can rapidly and efficiently remove sulfur-containing organic compounds from straight-run diesel fuel. After 120 min of reaction, the concentration of organic sulfur compounds in the hydrotreated diesel fuel is below the detection limit (ppb level) of the FPD detector, achieving complete removal of organic sulfur compounds. These results demonstrate that the porous carbon nanosheet-supported bimetallic phosphide catalyst prepared in this invention possesses excellent catalytic oxidation performance. The total sulfur content in the oil treated with the porous carbon nanosheet-supported bimetallic phosphide catalyst prepared in this invention is 0 (<10 ppm), meeting the Euro VI fuel standard and possessing significant practical application potential.

[0077] As can be seen from the above results, the porous carbon nanosheet-supported bimetallic phosphide catalyst used in this invention has advantages such as strong catalytic activity, high selectivity, and good stability. It can be widely used to remove sulfur-containing organic compounds (such as 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene) from petroleum products, and can achieve rapid and effective removal of sulfur-containing organic compounds from petroleum products. Therefore, when the porous carbon nanosheet-supported bimetallic phosphide catalyst is used for catalytic oxidation treatment of sulfur-containing organic compounds in oil products, it can achieve rapid and efficient effective conversion of sulfur-containing organic compounds in fuel products, and can achieve ultra-efficient and ultra-deep oxidative desulfurization. It has advantages such as simple process, convenient operation, low cost, high removal efficiency, and good removal effect, and has excellent economic benefits and excellent application prospects. More importantly, the porous carbon nanosheet-supported bimetallic phosphide catalyst used in this invention can selectively remove organic sulfur compounds from oil products. It can achieve rapid and complete removal of organic sulfur compounds from oil products while ensuring oil quality, showing very good adaptability and high application value and promising prospects.

[0078] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets, characterized in that, The method employs a porous carbon nanosheet-supported bimetallic phosphide catalyst to catalytically oxidize sulfur-containing organic compounds in oil products. The porous carbon nanosheet-supported bimetallic phosphide catalyst comprises porous carbon nanosheets and molybdenum phosphide / tungsten phosphide nanoheterojunctions, wherein the molybdenum phosphide / tungsten phosphide nanoheterojunctions are supported on the porous carbon nanosheets. The mass ratio of the molybdenum phosphide / tungsten phosphide nanoheterojunctions to the porous carbon nanosheets is 0.1–0.8:

1. The mass content of molybdenum phosphide in the molybdenum phosphide / tungsten phosphide nanoheterojunctions is 20%–60%. The preparation method of the porous carbon nanosheet-supported bimetallic phosphide catalyst includes the following steps: S1. Prepare a Mo / W precursor solution by mixing ammonium heptamolybdate and ammonium metatungstate. S2. The Mo / W precursor solution and porous carbon nanosheet / melamine dispersion obtained in step S1 are mixed, stirred, and sonicated to obtain a precursor dispersion; the volume ratio of the Mo / W precursor solution to the porous carbon nanosheet / melamine dispersion is 0.5 to 1:1; the sum of the concentrations of ammonium heptamolybdate and ammonium metatungstate in the Mo / W precursor solution is 0.01 mol / L to 0.06 mol / L; the molar ratio of ammonium heptamolybdate to ammonium metatungstate in the Mo / W precursor solution is 0.4 to 7:1; the porous carbon nanosheet / melamine dispersion is prepared by mixing melamine, porous carbon nanosheets, and water; the sum of the concentrations of melamine and porous carbon nanosheets in the porous carbon nanosheet / melamine dispersion is 50 g / L to 80 g / L; the mass ratio of melamine to porous carbon nanosheets in the porous carbon nanosheet / melamine dispersion is 4 to 6:1; S3. Add the phosphorus source to the precursor dispersion obtained in step S2, stir, filter, and dry to obtain catalyst precursor powder. S4. The catalyst precursor powder obtained in step S3 is calcined to obtain a porous carbon nanosheet-supported bimetallic phosphide catalyst.

2. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 1, characterized in that, The porous carbon nanosheets have uniformly distributed nanoscale pores; the average particle size of the molybdenum phosphide / tungsten phosphide nanoheterostructure is 20 nm to 60 nm.

3. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 2, characterized in that, In step S3, the phosphorus source is an H3PO4 solution and / or a phytic acid solution; the mass concentration of the H3PO4 solution and the phytic acid solution is 85%; and the volume ratio of the precursor dispersion to the phosphorus source is 18-24:

1.

4. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 3, characterized in that, The method for preparing the porous carbon nanosheets includes the following steps: (1) Sodium dihydrogen citrate was calcined under an inert atmosphere to obtain porous carbon nanosheet precursor material; (2) The porous carbon nanosheet precursor material obtained in step (1) is added to hydrochloric acid solution for reaction, washed, and dried to obtain porous carbon nanosheets.

5. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 4, characterized in that, In step (1), the calcination is carried out at a temperature of 750℃~800℃; the calcination time is 60 min~180 min; and the inert atmosphere is nitrogen or argon atmosphere. In step (2), the mass ratio of the hydrochloric acid solution to the porous carbon nanosheet precursor material is 20-30:1; the concentration of the hydrochloric acid solution is 1.5 mol / L-2.5 mol / L; and the reaction time is 24 h-48 h.

6. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 2, characterized in that, In step S2, the stirring time is 0.5 h to 2 h; the ultrasonication time is 30 min to 60 min. In step S3, the stirring is carried out at a temperature of 60℃ to 80℃; the stirring time is 12 h to 16 h; the drying process is carried out under vacuum conditions; the drying temperature is 60℃ to 80℃; and the drying time is 2 h to 12 h. In step S4, the calcination is carried out under an argon atmosphere; the gas flow rate is controlled at 20 mL / min during the calcination process; the heating rate during the calcination process is 5℃ / min; the calcination temperature is 800℃~900℃; and the calcination time is 2 h~3 h.

7. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to any one of claims 1 to 6, characterized in that, When using a porous carbon nanosheet-supported bimetallic phosphide catalyst to catalytically oxidize sulfur-containing organic compounds in oil, the following steps are included: mixing the porous carbon nanosheet-supported bimetallic phosphide catalyst, hydrogen peroxide, and sulfur-containing organic compound oil to carry out a catalytic oxidation reaction, thereby removing the sulfur-containing organic compounds from the oil.

8. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 7, characterized in that, The amount of the porous carbon nanosheet-supported bimetallic phosphide catalyst is 0.2 g to 1 g per liter of sulfur-containing organic compound oil; the molar ratio of hydrogen peroxide to sulfur in the sulfur-containing organic compound oil is 4:

1.

9. The method for removing sulfur-containing organic compounds from oil products using a bimetallic phosphide catalyst supported on porous carbon nanosheets according to claim 7, characterized in that, The sulfur-containing organic compound in the oil is at least one of 3-methylbenzothiophene, dibenzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene; the initial sulfur concentration of the sulfur-containing organic compound in the oil is ≤3000 ppm; the catalytic oxidation reaction is carried out at a temperature of 30℃ to 90℃; the catalytic oxidation reaction time is 10 min to 120 min; and the catalytic oxidation reaction is carried out under stirring conditions.

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