A Ru / MoO 3-x Nanomaterials, methods of construction and applications thereof

Abstract

This invention relates to a Ru / MoO 3‑x Nanomaterials, their construction methods, and applications. Ru / MoO 3‑x Nanomaterials, including molybdenum oxide and ruthenium supported on the surface of the molybdenum oxide; the molecular formula of the molybdenum oxide is MoO. 3‑x Ru / MoO 3‑x The steps of the method for constructing nanomaterials are as follows: A molybdenum source, a ruthenium source, and water are mixed to obtain a mixture; the mixture is stirred and evaporated at a first preset temperature to obtain a solid, which is then dried to obtain an intermediate product; the intermediate product is calcined at a second preset temperature for a first preset time, and then calcined at a third preset temperature for a second preset time in a mixed atmosphere of hydrogen and argon to obtain Ru / MoO. 3‑x Nanomaterials. This invention also provides a Ru / MoO 3‑x The application of nanomaterials as catalysts in the preparation of organic acids. This invention solves the problem of low propionic acid yield in existing bio-based lactic acid to propionic acid synthesis processes.

Description

Technical Field

[0001] This invention relates to the field of nanocatalytic materials technology, specifically to a Ru / MoO2 material. 3-x Nanomaterials, their construction methods, and applications. Background Technology

[0002] Propionic acid, as an important raw material and preservative, has wide applications in chemical, pharmaceutical, and food industries. In recent years, the consumption of propionic acid and its derivatives has been increasing, but domestic production cannot meet demand. Currently, propionic acid is mainly produced through propionaldehyde oxidation, ethylene carbonyl synthesis, and as a byproduct of acetic acid synthesis from the oxidation of light hydrocarbons. Traditional propionic acid preparation methods primarily rely on petrochemical products as raw materials. Given the severe shortage and non-renewable nature of fossil fuels, utilizing renewable resources and adopting green production routes to produce propionic acid has gained increasing attention. Using bio-based lactic acid as a raw material, under certain catalytic conditions, hydrodeoxygenation to produce propionic acid is a green and efficient process route. However, the catalyst activity, stability, and lifespan still need further improvement. Therefore, preparing green and efficient catalysts and deeply exploring their structure-activity relationships are urgent problems to be solved in the hydrodeoxygenation reaction of bio-based lactic acid to produce propionic acid.

[0003] Currently, research on catalysts for the bio-based synthesis of propionic acid from lactic acid is relatively limited. There are reports of the application of a molybdenum dioxide acetylacetone catalytic system in this reaction, with a propionic acid yield of approximately 41%. Other literature reports iron-based catalysts used in gas-solid reaction synthesis of propionic acid, achieving a yield of around 50%. Co-Zn catalytic systems have also been proposed, increasing propionic acid selectivity to approximately 64.8%. Molybdenum oxide catalysts have also been reported for lactic acid deoxygenation in fixed-bed reactors, utilizing in-situ hydrogen from lactic acid decarboxylation or steam reforming; however, this generates a significant amount of byproducts, and the propionic acid selectivity remains only between 60% and 65%. Homogeneous NaI catalytic hydrodeoxygenation of lactic acid to propionic acid has been reported, following a free radical reaction mechanism, which improves the efficiency of lactic acid to propionic acid production. However, compared to heterogeneous reactions, homogeneous catalysis suffers from the drawback of difficulty in separating the product from the catalyst; therefore, homogeneous hydrodeoxygenation of lactic acid to propionic acid has not been widely adopted. Summary of the Invention

[0004] The purpose of this invention is to provide a Ru / MoO 3-x Nanomaterials, their construction methods, and applications are explored to address the problem of low propionic acid yield in existing bio-based lactic acid synthesis processes for propionic acid.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A Ru / MoO 3-xNanomaterials comprising molybdenum oxide and ruthenium supported on the surface of the molybdenum oxide; the molecular formula of the molybdenum oxide is MoO. 3-x The value of x ranges from 0 to 0.9, the ruthenium loading ranges from 0.1 to 0.6 wt%, and the Ru / MoO content is... 3-x The particle size of ruthenium (Ru) in nanomaterials is 1.7 nm.

[0007] Based on the above technical means, through MoO 3-x After being loaded with ruthenium, it can be used as a catalyst in the hydrodeoxygenation reaction process to effectively promote the adsorption of the reacting acid and the activation of hydrogen molecules, thereby improving the hydrogenolysis ability of the hydroxyl groups in the reacting acid during the hydrodeoxygenation of the reacting acid to prepare the product acid. This, in turn, improves the conversion rate of the reacting acid and the yield of the product acid. Furthermore, experiments have shown that Ru / MoO 3-x Nanomaterials, as catalysts in hydrodeoxygenation reactions, have the advantages of good cycle stability, reusability, and reduced material loss.

[0008] Preferably, the value range of x is: 0 <x≦0.9。

[0009] The present invention also provides a Ru / MoO as described in this invention. 3-x The method for constructing nanomaterials includes the following steps:

[0010] S1. Mix the molybdenum source, ruthenium source, and water to obtain a mixture;

[0011] S2. Stir and evaporate the mixture at a first preset temperature to obtain a solid, then dry the solid to obtain an intermediate product;

[0012] S3. The intermediate product is calcined at a second preset temperature for a first preset time, and then calcined at a third preset temperature for a second preset time in a mixed atmosphere of hydrogen and argon to obtain Ru / MoO. 3-x Nanomaterials.

[0013] According to the above-mentioned technical means, by using molybdenum and ruthenium sources as raw materials, a solid is obtained by stirring and evaporating at a first preset temperature, and then calcining at a second preset temperature to obtain pure-phase molybdenum oxide (MoO3). Further calcination at a mixed atmosphere of hydrogen and argon at the second preset temperature generates more oxygen vacancies on the material surface, resulting in molybdenum oxide (MoO3). 3-x This makes the prepared Ru / MoO 3-x Nanomaterials, as catalysts for hydrodeoxygenation, can significantly enhance reaction activity, thereby increasing the conversion rate of raw materials and the yield of products.

[0014] Preferably, in S1, the molybdenum source is selected from at least one of ammonium molybdate, sodium molybdate, potassium molybdate, and ammonium phosphomolybdate.

[0015] Preferably, in S1, the ruthenium source is selected from at least one of ruthenium chloride solution, ruthenium acetate solution, and ruthenium nitrate solution.

[0016] Preferably, in S1, the molybdenum source, ruthenium source, and water are in a ratio of 10g:0.1g:50mL to 10g:5g:50mL, calculated as g:g:mL.

[0017] Preferably, in S1, the molybdenum source, ruthenium source, and water are in a ratio of 2.68g:1g:5mL (g:g:mL).

[0018] By rationally controlling the addition ratio of molybdenum source and ruthenium source, the high dispersion of Ru was effectively promoted, which helped to enhance the interaction and electron transfer between Ru and molybdenum oxide.

[0019] Preferably, the molybdenum source is selected from ammonium molybdate.

[0020] Preferably, the ruthenium source is selected from ruthenium chloride solution.

[0021] Preferably, the water is deionized water.

[0022] Preferably, the addition ratio of ammonium molybdate, ruthenium chloride solution and deionized water is 2.68g:1g:5mL.

[0023] Preferably, the ruthenium chloride solution is a solution formed by dispersing ruthenium chloride in water, and the ratio of ruthenium chloride to water is 0.1g:50mL to 5g:50mL in g:mL.

[0024] Preferably, the ratio of ruthenium chloride to water is 1 g: 50 mL.

[0025] Preferably, in the ruthenium chloride solution, the ratio of ruthenium chloride to deionized water is 1g:50mL.

[0026] Preferably, in step S2, the first preset temperature is 20-60℃.

[0027] Preferably, in step S2, the first preset temperature is 40°C.

[0028] Preferably, in step S2, the stirring method is vigorous stirring, and the stirring speed is 500 to 1500 rpm.

[0029] By employing vigorous stirring, the mass transfer and diffusion of reactants and products were effectively promoted.

[0030] Preferably, in step S2, the drying temperature is 90–120°C and the drying time is 6–12 hours.

[0031] Preferably, in step S2, the drying temperature is 110°C and the drying time is 12 hours.

[0032] Preferably, in step S3, the second preset temperature is 400–600°C.

[0033] Preferably, in step S3, the second preset temperature is 500°C.

[0034] Preferably, in step S3, the third preset temperature is 200–400°C.

[0035] Preferably, in step S3, the third preset temperature is 350°C.

[0036] Preferably, in step S3, the first preset time is 2 to 4 hours.

[0037] Preferably, in step S3, the first preset time is 4 hours.

[0038] Preferably, in step S3, the second preset time is 1 to 3 hours.

[0039] Preferably, in step S3, the second preset time is 3 hours.

[0040] A first calcination at around 500℃ effectively promoted the formation of molybdenum oxide and the high dispersion of Ru. A second calcination at around 350℃ in a mixed atmosphere of hydrogen and argon effectively promoted the generation of defect structures and the partial reduction of Ru species.

[0041] Preferably, step S3 specifically includes: placing the intermediate product in a muffle furnace, heating it to a second preset temperature, calcining it for a first preset time, cooling it, and then placing the product in a tube furnace, heating it to a third preset temperature in a mixed atmosphere of hydrogen and argon, and calcining it for a second preset time to obtain Ru / MoO. 3-x Nanomaterials.

[0042] Preferably, in step S3, the heating method is programmed heating, and the heating rate of programmed heating is 5-10℃ / min.

[0043] Preferably, in step S3, the ratio of hydrogen to argon in the mixed atmosphere is 5%:95% to 20%:80%.

[0044] Preferably, the temperature rise rate of the programmed temperature rise is 5°C / min.

[0045] Preferably, in the mixed atmosphere of hydrogen and argon, the ratio of hydrogen to argon is 5%:95%.

[0046] The present invention also provides a Ru / MoO₂ constructed by the construction method described herein. 3-x Application of nanomaterials, namely Ru / MoO 3-xApplication of nanomaterials as catalysts in the preparation of organic acids.

[0047] Preferably, the organic acid includes at least one of acetic acid, propionic acid, and butyric acid.

[0048] Experiments have proven that the Ru / MoO constructed using this invention... 3-x Nanomaterials, as catalysts in the hydrodeoxygenation process for preparing organic acids, can significantly enhance the activity of the hydrodeoxygenation reaction, thereby increasing the conversion rate of the raw acid and the yield of the product acid.

[0049] Preferably, the Ru / MoO 3-x Application of nanomaterials as catalysts in the preparation of propionic acid by hydrogenation deoxygenation of lactic acid.

[0050] In recent years, the inventors of this case have been deeply engaged in research on the process of synthesizing propionic acid from bio-based lactic acid. Through long-term research and investigation, they discovered that the synthesis of propionic acid from lactic acid mainly employs a non-phase catalytic process. Although some progress has been made, the selectivity for propionic acid remains low. The main reasons for this are that the hydrogenation-deoxygenation reaction of lactic acid cannot fully utilize externally supplied hydrogen and that the catalyst cannot precisely and directionally activate the α-OH groups of lactic acid functional groups. Therefore, the inventors of this case have dedicated themselves to researching how to fully utilize externally supplied hydrogen and how to precisely and directionally activate the α-OH groups of lactic acid functional groups. After extensive and long-term experiments and numerous attempts, they discovered that Ru / MoO 3-x The nanomaterial is a ruthenium-modified defective MoO3 nanomaterial, which has strong reducing properties. As a catalyst in the preparation of propionic acid by hydrodeoxygenation, it can precisely activate both the α-OH in lactic acid molecules and the externally supplied molecular hydrogen, thus greatly improving the efficiency of preparing propionic acid from lactic acid.

[0051] Preferably, the Ru / MoO 3-x A method for preparing propionic acid from lactic acid using nanomaterials as a catalyst includes the following steps:

[0052] In a hydrogen atmosphere, the Ru / MoO2 solution is added to an aqueous lactic acid solution. 3-x Nanomaterials are stirred and reacted at a fourth preset temperature for a third preset time to obtain propionic acid.

[0053] Preferably, the mass concentration of lactic acid in the lactic acid aqueous solution is 10% to 50%.

[0054] Preferably, the lactic acid aqueous solution is reacted with Ru / MoO 3-x The mass ratio of nanomaterials is 10:0.05 to 10:0.5.

[0055] Preferably, the fourth preset temperature is less than 250°C.

[0056] Preferably, the third preset time is greater than 10 hours.

[0057] Based on the above-mentioned technical means, by adding the Ru / MoO of the present invention to a lactic acid aqueous solution in a hydrogen atmosphere... 3-x Nanomaterials, used as catalysts, can effectively improve the selectivity of propionic acid and reduce the amount of byproducts in hydrodeoxygenation reactions under certain temperature conditions. Experiments have shown that nano-Ru / MoO₂... 3-x As a catalyst, it exhibits strong reducing properties; nano-Ru / MoO 3-x The vacancies formed on the catalyst surface and the loading of the noble metal ruthenium promoted the adsorption of lactic acid and the activation of hydrogen molecules, thereby improving the hydrogenolysis ability of lactic acid hydroxyl groups during the hydrodeoxygenation of lactic acid to prepare propionic acid. Analysis revealed that nano-Ru / MoO₂... 3-x When the catalyst catalyzes the hydrodeoxygenation of lactic acid to prepare propionic acid, the conversion rate of lactic acid is greater than 70%, the selectivity of propionic acid is greater than 95%, and the nano-Ru / MoO₂ catalyst achieves this effect. 3-x Catalysts have the advantages of good cycle stability, reusability, and reduced material consumption.

[0058] The reaction formula for preparing propionic acid by hydrogen deoxygenation of lactic acid is as follows:

[0059]

[0060] Preferably, the Ru / MoO 3-x The preparation of propionic acid from lactic acid using nanomaterials is carried out in a batch reaction in a high-pressure reactor at a pressure of 3 MPa.

[0061] Preferably, the stirring is magnetic stirring, and the stirring speed is 500 rpm / min.

[0062] Preferably, the lactic acid aqueous solution has a lactic acid mass concentration of 10%.

[0063] Preferably, the lactic acid aqueous solution is reacted with Ru / MoO 3-x The mass ratio of the nanomaterials is 4:0.1.

[0064] Preferably, the fourth preset temperature is between 200℃ and 220℃.

[0065] Preferably, the fourth preset temperature is 215°C.

[0066] Preferably, the third preset time is between 10 and 15 hours.

[0067] Preferably, the third preset time is 12 hours.

[0068] The beneficial effects of this invention are:

[0069] 1) The Ru / MoO of the present invention 3-xNanomaterials, through MoO 3-x After being loaded with ruthenium, it can be used as a catalyst in the hydrodeoxygenation reaction process to effectively promote the adsorption of the reacting acid and the activation of hydrogen molecules, thereby improving the hydrogenolysis ability of the hydroxyl groups in the reacting acid during the hydrodeoxygenation of the reacting acid to prepare the product acid. This, in turn, improves the conversion rate of the reacting acid and the yield of the product acid. Furthermore, experiments have shown that Ru / MoO 3-x Nanomaterials, as catalysts in hydrodeoxygenation reactions, have the advantages of good cycle stability, reusability, and reduced material loss.

[0070] 2) The Ru / MoO of the present invention 3-x The method for constructing nanomaterials involves using molybdenum and ruthenium sources as raw materials. A solid is obtained by stirring and evaporating the solid at a first preset temperature, followed by calcination at a second preset temperature to obtain pure-phase molybdenum oxide (MoO3). Further calcination at the second preset temperature under a mixed atmosphere of hydrogen and argon generates more oxygen vacancies on the material surface, resulting in molybdenum oxide (MoO3). 3-x This makes the prepared Ru / MoO 3-x Nanomaterials, as hydrodeoxygenation catalysts, can significantly enhance reaction activity, thereby increasing the conversion rate of raw materials and the yield of products.

[0071] 3) The Ru / MoO constructed in this invention 3-x Nanomaterials, as catalysts in the hydrodeoxygenation process for preparing organic acids, can significantly enhance the activity of the hydrodeoxygenation reaction, thereby increasing the conversion rate of the raw acid and the yield of the product acid.

[0072] 4) The Ru / MoO constructed in this invention 3-x The method for preparing propionic acid from lactic acid using nanomaterials as catalysts involves adding the Ru / MoO₂ of this invention to an aqueous lactic acid solution in a hydrogen atmosphere. 3-x Nanomaterials, used as catalysts, can effectively improve the selectivity of propionic acid and reduce the amount of byproducts in hydrodeoxygenation reactions under certain temperature conditions. Experiments have shown that nano-Ru / MoO₂... 3-x As a catalyst, it exhibits strong reducing properties; nano-Ru / MoO 3-x The vacancies formed on the catalyst surface and the loading of the noble metal ruthenium promoted the adsorption of lactic acid and the activation of hydrogen molecules, thereby improving the hydrogenolysis ability of lactic acid hydroxyl groups during the hydrodeoxygenation of lactic acid to prepare propionic acid. Analysis revealed that nano-Ru / MoO₂... 3-x When the catalyst catalyzes the hydrodeoxygenation of lactic acid to prepare propionic acid, the conversion rate of lactic acid is greater than 70%, the selectivity of propionic acid is greater than 95%, and the nano-Ru / MoO₂ catalyst achieves this effect. 3-x Catalysts have the advantages of good cycle stability, reusability, and reduced material loss, and have great potential for widespread application in the field of nanocatalytic materials technology. Attached Figure Description

[0073] Figure 1 XRD patterns of different nanomaterials;

[0074] Figure 2 for Ru / MoO 3-x XPS full spectrum of nanomaterials;

[0075] Figure 3 for Ru / MoO 3-x High-resolution XPS spectra of nanomaterials (O, Mo, and Ru);

[0076] Figure 4 for Ru / MoO 3-x TEM images of nanomaterials;

[0077] Figure 5 for Ru / MoO 3-x Figure showing the cycle stability results of nanomaterials as catalysts. Detailed Implementation

[0078] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0079] Example 1

[0080] A Ru / MoO 3-x The method for constructing nanomaterials includes the following steps:

[0081] S1. Disperse 1g of ruthenium chloride in 50mL of deionized water to obtain a ruthenium chloride solution. Then, add the obtained ruthenium chloride solution and 2.68g of ammonium molybdate to 5mL of deionized water to dissolve and mix, thus obtaining a mixture.

[0082] S2. The mixture obtained in S1 is vigorously stirred and evaporated at 40°C and 500 r / min to produce solid powder. The solid powder is then transferred to a drying oven and dried at 110°C for 12 h to obtain the intermediate product.

[0083] S3. The intermediate product obtained in S2 is placed in a muffle furnace and heated to 500°C at a heating rate of 5°C / min. It is then calcined for 4 hours and cooled to obtain Ru / MoO3 nanomaterials.

[0084] S4. The Ru / MoO3 nanomaterial obtained in S3 is placed in a tube furnace, a mixed gas of hydrogen and argon is introduced, and the temperature is programmed to 350℃ at a heating rate of 5℃ / min. The material is calcined for 3 hours, then cooled to obtain Ru / MoO3 nanomaterials. 3-x Nanomaterials, with a value of x of 0.1; wherein the ratio of hydrogen and argon gas mixture is 5%:95%.

[0085] Example 2

[0086] A Ru / MoO 3-x The method for constructing nanomaterials includes the following steps:

[0087] S1. Disperse 1.0 g of ruthenium chloride in 50 mL of deionized water to obtain a ruthenium chloride solution. Then, add the obtained ruthenium chloride solution and 2.68 g of ammonium molybdate to 5 mL of deionized water to dissolve and mix, thus obtaining a mixture.

[0088] S2. The mixture obtained in S1 is vigorously stirred and evaporated at 40°C and 500 r / min to produce solid powder. The solid powder is then transferred to a drying oven and dried at 110°C for 12 h to obtain the intermediate product.

[0089] S3. The intermediate product obtained in S2 is placed in a muffle furnace and heated to 500°C at a heating rate of 5°C / min. It is then calcined for 4 hours and cooled to obtain Ru / MoO3 nanomaterials.

[0090] S4. The Ru / MoO3 nanomaterial obtained in S3 is placed in a tube furnace, a mixed gas of hydrogen and argon is introduced, and the temperature is programmed to 350℃ at a heating rate of 5℃ / min. The material is calcined for 3 hours, then cooled to obtain Ru / MoO3 nanomaterials. 3-x Nanomaterials, with a value of x of 0.12; wherein the ratio of hydrogen and argon gas mixture is 10%:90%.

[0091] Example 3

[0092] A Ru / MoO 3-x The method for constructing nanomaterials includes the following steps:

[0093] S1. Disperse 0.5g of ruthenium chloride in 50mL of deionized water to obtain a ruthenium chloride solution. Then, add the obtained ruthenium chloride solution and 2.68g of ammonium molybdate to 5mL of deionized water to dissolve and mix, thus obtaining a mixture.

[0094] S2. The mixture obtained in S1 is vigorously stirred and evaporated at 40°C and 500 r / min to produce solid powder. The solid powder is then transferred to a drying oven and dried at 110°C for 12 h to obtain the intermediate product.

[0095] S3. The intermediate product obtained in S2 is placed in a muffle furnace and heated to 500°C at a heating rate of 5°C / min. It is then calcined for 4 hours and cooled to obtain Ru / MoO3 nanomaterials.

[0096] S4. The Ru / MoO3 nanomaterial obtained in S3 is placed in a tube furnace, a mixed gas of hydrogen and argon is introduced, and the temperature is programmed to 350℃ at a heating rate of 5℃ / min. The material is calcined for 3 hours, then cooled to obtain Ru / MoO3 nanomaterials. 3-x Nanomaterials, with a value of x of 0.08; wherein the ratio of hydrogen and argon gas mixture is 5%:95%.

[0097] Example 4

[0098] The method for using the Ru / MoO3 nanomaterials prepared in Example 1 as a catalyst to catalyze the preparation of propionic acid from lactic acid includes the following steps:

[0099] S1. Place 20g of 10wt% lactic acid aqueous solution into an 80mL autoclave, and add 0.5g of Ru / MoO3 nanomaterial prepared in S3 of Example 1. Then, replace the air in the autoclave three times with high-purity hydrogen at a pressure of 0.5MPa, and then seal and pressurize to 3MPa.

[0100] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a propionic acid solution. Propionic acid is obtained after centrifugation.

[0101] Example 5

[0102] Ru / MoO prepared in Example 1 3-x A method for using nanomaterials as catalysts to catalyze the preparation of propionic acid from lactic acid includes the following steps:

[0103] S1. Place 20g of a 10wt% lactic acid aqueous solution into an 80mL autoclave, and add 0.5g of the Ru / MoO2 prepared in S4 of Example 1. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0104] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a propionic acid solution. Propionic acid is obtained after centrifugation.

[0105] Example 6

[0106] Ru / MoO prepared in Example 1 with different dosages 3-x A method for using nanomaterials as catalysts to catalyze the preparation of propionic acid from lactic acid includes the following steps:

[0107] S1. Take four 20g portions of a 10wt% lactic acid aqueous solution and place them in 80mL autoclaves respectively. Add 0.6g, 0.7g, 0.8g, and 0.9g of the Ru / MoO2 prepared in S4 of Example 1 respectively. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0108] S2. Place the autoclave in an electric heating furnace and heat it to 215°C. Turn on the stirring and set the stirring speed to 500 rpm. Start the reaction timer at the same time as stirring. After 12 hours of reaction, stop the reaction and cool it down. When the temperature drops to room temperature, release the pressure to obtain a propionic acid solution. After centrifugation, obtain propionic acid.

[0109] Example 7

[0110] Ru / MoO prepared in Example 1 3-x A method for using nanomaterials as catalysts to catalyze the preparation of acetic acid from glycolic acid includes the following steps:

[0111] S1. Place 20g of a 10wt% aqueous solution of glycolic acid into an 80mL autoclave, and add 0.5g of the Ru / MoO2 prepared in S4 of Example 1. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0112] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain an acetic acid solution. After centrifugation, acetic acid is obtained.

[0113] Example 8

[0114] Ru / MoO prepared in Example 1 3-xA method for using nanomaterials as catalysts to catalyze the preparation of propionic acid from 3-hydroxypropionic acid includes the following steps:

[0115] S1. Place 20g of a 10wt% aqueous solution of 3-hydroxypropionic acid into an 80mL autoclave, and add 0.5g of the Ru / MoO2 prepared in S4 of Example 1. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0116] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a propionic acid solution. Propionic acid is obtained after centrifugation.

[0117] Example 9

[0118] Ru / MoO prepared in Example 1 3-x A method for using nanomaterials as catalysts to catalyze the preparation of butyric acid from 2-hydroxybutyric acid includes the following steps:

[0119] S1. Place 20g of a 10wt% aqueous solution of 2-hydroxybutyric acid into an 80mL autoclave, and add 0.5g of the Ru / MoO2 prepared in S4 of Example 1. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0120] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a butyric acid solution. Butyric acid is obtained after centrifugation.

[0121] Example 9

[0122] Ru / MoO prepared in Example 1 3-x A method for using nanomaterials as catalysts to catalyze the lactic acid cycle to produce propionic acid includes the following steps:

[0123] S1. Place 20g of a 10wt% lactic acid aqueous solution into an 80mL autoclave, and add 0.5g of the Ru / MoO2 prepared in S4 of Example 1. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0124] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a propionic acid solution.

[0125] S3. Centrifuge the propionic acid solution obtained in S2 to obtain Ru / MoO. 3-x Nanomaterials and primary propionic acid were added, and 20g of a 10wt% lactic acid aqueous solution was added again. The reactions S1 and S2 were repeated, and this cycle was repeated 5 times to obtain secondary propionic acid, tertiary propionic acid, quaternary propionic acid and quinary propionic acid.

[0126] Comparative Example 1

[0127] A MoO 3-x The method for constructing nanomaterials includes the following steps:

[0128] S1. Ammonium molybdate was placed directly in a muffle furnace and heated to 500°C at a rate of 5°C / min. The mixture was calcined for 4 hours and then cooled to obtain MoO3 nanomaterials.

[0129] S2. The MoO3 nanomaterial obtained in S1 is placed in a tube furnace, a mixed gas of hydrogen and argon is introduced, and the temperature is programmed to 350℃ at a heating rate of 5℃ / min, calcined for 3 hours, and then cooled to obtain MoO3 nanomaterial. 3-x Nanomaterials, with a value of x of 0.1; wherein the ratio of hydrogen and argon gas mixture is 5%:95%.

[0130] Comparative Example 2

[0131] The method for using the MoO3 nanomaterials prepared in Example 1 to catalyze the preparation of propionic acid from lactic acid includes the following steps:

[0132] S1. Place 20g of a 10wt% lactic acid aqueous solution into an 80mL autoclave, and add 0.5g of the MoO3 nanomaterial prepared in S1 of Example 1. Then, replace the air in the autoclave three times with high-purity hydrogen at a pressure of 0.5MPa, and then seal and pressurize to 3MPa.

[0133] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a propionic acid solution. Propionic acid is obtained after centrifugation.

[0134] Comparative Example 3

[0135] MoO prepared in Comparative Example 1 3-x A method for using nanomaterials to catalyze the preparation of propionic acid from lactic acid includes the following steps:

[0136] S1. Place 20g of a 10wt% lactic acid aqueous solution into an 80mL autoclave, and add 0.5g of the MoO2 prepared in S2 of Example 1. 3-x Nanomaterials were used, and then the air inside the autoclave was replaced three times with high-purity hydrogen at a pressure of 0.5 MPa. After that, the autoclave was sealed and pressurized to 3 MPa.

[0137] S2. The pressure vessel is placed in an electric heating furnace and heated to 215°C. Stirring is started at a speed of 500 rpm. The reaction timer is started at the same time as stirring. After 12 hours of reaction, the reaction is stopped and the temperature is lowered. When the temperature drops to room temperature, the pressure is released to obtain a propionic acid solution. Propionic acid is obtained after centrifugation.

[0138] Detection and Analysis

[0139] 1) XRD analysis

[0140] For the Ru / MoO3 nanomaterials prepared in S3 of Example 1, and the Ru / MoO3 nanomaterials prepared in S4 3-x Nanomaterials and the MoO3 nanomaterials prepared in S1 and S2 of Comparative Example 1 3-x X-ray diffraction (XED) analysis of nanomaterials yielded the following results: Figure 1 As shown.

[0141] from Figure 1 Comparative analysis shows that Ru / MoO3 nanomaterials and Ru / MoO 3-x Nanomaterials, MoO3 nanomaterials and MoO 3-x The nanomaterials all showed diffraction peaks of MoO3 (JCPDS NO.05-0508). After loading the noble metal ruthenium, its XRD pattern changed slightly, but no obvious diffraction peak of ruthenium was observed, indicating the high dispersion of Ru species and the strong interaction between Ru and the support.

[0142] 2) The Ru / MoO prepared in S4 of Example 1 3-x The nanomaterials were characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), and the results are as follows: Figure 2 , Figure 3 and Figure 4 As shown.

[0143] from Figure 2 , Figure 3 and Figure 4Analysis of electron binding energy and lattice fringes in the data confirms the successful loading of ruthenium and its high dispersion and strong interaction on the MoO3 surface.

[0144] 3) Gas chromatography and liquid chromatography analysis

[0145] Gas chromatography and liquid chromatography were used to analyze and calculate the conversion rate (conversion rate refers to the ratio of the amount of lactic acid that was catalyzed to the amount of lactic acid before the reaction) and the selectivity of propionic acid (selectivity refers to the proportion of propionic acid in all products converted from lactic acid). The results are shown in Table 1.

[0146] Table 1. Effects of different catalysts on lactic acid conversion and propionic acid selectivity

[0147] catalyst Lactic acid conversion rate / % Propionic acid selectivity / % <![CDATA[MoO3]]> 32.9 47.1 <![CDATA[MoO 3-x ]]> 37.3 70.6 <![CDATA[Ru / MoO3]]> 44.8 82.4 <![CDATA[Ru / MoO 3-x ]]> 67.3 95.9

[0148] As can be seen from the comparative analysis in Table 1, MoO 3-x Due to the treatment of the hydrogen-argon mixture in a tubular furnace, the catalyst, compared to the pure-phase MoO3 catalyst obtained by calcination in a muffle furnace, exhibits higher efficiency in MoO3 production. 3-x More oxygen vacancies were generated on the catalyst surface. With a slight increase in lactic acid conversion (conversion refers to the ratio of lactic acid reacted to lactic acid before the reaction), the propionic acid selectivity (selectivity refers to the proportion of propionic acid among all products converted from lactic acid) was significantly improved. The lactic acid conversion increased from 32.9% to 37.3%, while the propionic acid selectivity increased from 47.1% to 70.6%. This demonstrates that oxygen vacancies can effectively improve the activity of this reaction. Ru / MoO 3-x Catalyst and MoO 3-x Compared to other catalysts, the successful loading of the noble metal ruthenium significantly improved both the lactic acid conversion and propionic acid selectivity. The lactic acid conversion increased from 37.3% to 67.3%, and the propionic acid selectivity increased from 70.6% to 95.9%. This demonstrates that loading with noble metals can effectively enhance the activity of the hydrodeoxygenation reaction. In conclusion, the presence of oxygen vacancies and noble metals can synergistically improve the activity of the hydrodeoxygenation reaction, thereby enhancing the catalytic activity.

[0149] The conversion rate (conversion rate refers to the ratio of the amount of lactic acid that is catalyzed to the amount of lactic acid before the reaction) and the selectivity of propionic acid (selectivity refers to the proportion of propionic acid in all products converted from lactic acid) used in Examples 5 and 6 were calculated by gas chromatography and liquid chromatography. The results are shown in Table 2.

[0150] Table 2 Effect of catalyst dosage on lactic acid conversion and propionic acid selectivity

[0151] catalyst / g Lactic acid conversion rate / % Propionic acid selectivity / % 0.5 67.3 95.9 0.6 77.1 95.6 0.7 84.8 96.4 0.8 90.2 95.6 0.9 96.0 95.7

[0152] As shown in Table 2, the selectivity of propionic acid is almost unaffected by the amount of catalyst, while the conversion rate of lactic acid increases with the increase of catalyst amount. When the amount of catalyst is increased to 0.9g, the conversion rate of lactic acid reaches as high as 96%, while the selectivity of propionic acid remains above 95%.

[0153] The conversion rate of lactic acid and the selectivity of propionic acid used in Example 5, the conversion rate of glycolic acid and the selectivity of acetic acid used in Example 7, the conversion rate of 3-hydroxypropionic acid and the selectivity of propionic acid used in Example 8, and the conversion rate of 2-hydroxybutyric acid and the selectivity of butyric acid used in Example 9 were calculated by gas chromatography and liquid chromatography. The results are shown in Table 3.

[0154] Table 3. Conversion and selectivity of different acids in preparation.

[0155]

[0156]

[0157] As can be seen from the analysis in Table 3, Ru / MoO 3-x The catalyst exhibits high conversion and selectivity in the hydrodeoxygenation of lactic acid to prepare propionic acid. This is because, during the reaction, oxygen vacancies effectively adsorb the α-C-OH group of the lactic acid molecule and weaken the CO bond. Specifically, the electrons captured by the oxygen vacancy are transferred to the adsorbed lactic acid molecule, breaking the CO bond and dissociating into OH groups. - At the same time, the introduced hydrogen molecules dissociate into H2O. + Some of H + The oxygen vacancy is replaced to produce propionic acid, and another part reacts with OH- to form propionic acid. - H₂O is generated. This is to demonstrate the Ru / MoO₂ ratio. 3-x To assess the versatility of the catalyst, other acids such as glycolic acid, propionic acid, 3-hydroxypropionic acid, and 2-hydroxybutyric acid were selected for hydrodeoxygenation reactions to investigate their effect on Ru / MoO₂. 3-x The effect of catalyst on hydrodeoxygenation reaction shows that Ru / MoO 3-x The synergistic effect of the catalysts can selectively generate their respective acids with high conversion and selectivity, thus proving that this series of catalysts is universally applicable to hydrodeoxygenation reactions and has certain reference value for hydrodeoxygenation reactions in this field.

[0158] Gas chromatography and liquid chromatography were used to analyze and calculate the conversion rate of lactic acid and the selectivity of propionic acid in each of the five cyclic reactions in Example 9. The results are as follows: Figure 5 As shown.

[0159] from Figure 5Analysis shows that the conversion rate of lactic acid used in each reaction is above 60%, and the selectivity of propionic acid used in each reaction is above 90%. Furthermore, after five cycles of the reaction, the Ru / MoO ratio is [value missing]. 3-x The catalytic activity of Ru / MoO2 did not decrease significantly, with a lactic acid conversion rate of 63.8% and a propionic acid selectivity of 91%, thus proving that Ru / MoO2... 3-x The catalyst exhibits good cycle stability, enabling it to be recycled multiple times and reducing material consumption.

[0160] In summary, the Ru / MoO of the present invention 3-x Nanomaterials, through MoO 3-x After being loaded with ruthenium, it can be used as a catalyst in the hydrodeoxygenation reaction process to effectively promote the adsorption of the reacting acid and the activation of hydrogen molecules, thereby improving the hydrogenolysis ability of the hydroxyl groups in the reacting acid during the hydrodeoxygenation of the reacting acid to prepare the product acid. This, in turn, improves the conversion rate of the reacting acid and the yield of the product acid. Furthermore, experiments have shown that Ru / MoO 3-x Nanomaterials, as catalysts in hydrodeoxygenation reactions, have the advantages of good cycle stability, reusability, and reduced material loss.

[0161] The Ru / MoO of the present invention 3-x The method for constructing nanomaterials involves using molybdenum and ruthenium sources as raw materials. A solid is obtained by stirring and evaporating the solid at a first preset temperature, followed by calcination at a second preset temperature to obtain pure-phase molybdenum oxide (MoO3). Further calcination at the second preset temperature under a mixed atmosphere of hydrogen and argon generates more oxygen vacancies on the material surface, resulting in molybdenum oxide (MoO3). 3-x This makes the prepared Ru / MoO 3-x Nanomaterials, as catalysts for hydrodeoxygenation, can significantly enhance reaction activity, thereby increasing the conversion rate of raw materials and the yield of products.

[0162] The Ru / MoO constructed in this invention 3-x Nanomaterials, as catalysts in the hydrodeoxygenation process for preparing organic acids, can significantly enhance the activity of the hydrodeoxygenation reaction, thereby increasing the conversion rate of the raw acid and the yield of the product acid.

[0163] The Ru / MoO constructed in this invention 3-x The method for preparing propionic acid from lactic acid using nanomaterials as catalysts involves adding the Ru / MoO₂ of this invention to an aqueous lactic acid solution in a hydrogen atmosphere. 3-x Nanomaterials, used as catalysts, can effectively improve the selectivity of propionic acid and reduce the amount of byproducts in hydrodeoxygenation reactions under certain temperature conditions. Experiments have shown that nano-Ru / MoO₂... 3-x As a catalyst, it exhibits strong reducing properties; nano-Ru / MoO 3-xThe vacancies formed on the catalyst surface and the loading of the noble metal ruthenium promoted the adsorption of lactic acid and the activation of hydrogen molecules, thereby improving the hydrogenolysis ability of lactic acid hydroxyl groups during the hydrodeoxygenation of lactic acid to prepare propionic acid. Analysis revealed that nano-Ru / MoO₂... 3-x When the catalyst catalyzes the hydrodeoxygenation of lactic acid to prepare propionic acid, the conversion rate of lactic acid is greater than 70%, the selectivity of propionic acid is greater than 95%, and the nano-Ru / MoO₂ catalyst achieves this effect. 3-x Catalysts have the advantages of good cycle stability, reusability, and reduced material loss, and have great potential for widespread application in the field of nanocatalytic materials technology.

[0164] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A Ru / MoO 3-x application of nanomaterials, characterized in that: The Ru / MoO 3-x Application of nanomaterials as catalysts in the hydrodeoxygenation of lactic acid to prepare propionic acid; the Ru / MoO 3-x The nanomaterial comprises a molybdenum oxide and ruthenium supported on the surface of the molybdenum oxide; the molecular formula of the molybdenum oxide is MoO. 3-x The value of x is 0 < x ≤ 0.9, and the ruthenium loading is 0.1~0.6 wt%.

2. The Ru / MoO 3-x The application of nanomaterials is characterized in that, The Ru / MoO 3-x The method for preparing propionic acid from lactic acid by using nanomaterials comprises the following steps: In a hydrogen atmosphere, the lactic acid aqueous solution is added with the Ru / MoO 3-x The nanomaterial is stirred for a third preset time under a fourth preset temperature condition to obtain propionic acid. The mass concentration of lactic acid in the aqueous lactic acid solution is 10-50%; The aqueous lactic acid solution and Ru / MoO 3-x The mass ratio of the nanomaterials is 10:0.05~10:0.5; The fourth preset temperature is less than 250 DEG C; The third preset time is greater than 10h.

3. The Ru / MoO 3-x The application of nanomaterials is characterized in that, The Ru / MoO 3-x The method for constructing nanomaterials comprises the following steps: S1, mixing a molybdenum source, a ruthenium source and water to obtain a mixture; S2, stirring and evaporating the mixture at 20-60 DEG C to obtain a solid, and then drying the solid to obtain an intermediate product; S3, calcining the intermediate product at 400-600°C for 2-4h, and then in a mixed atmosphere of hydrogen and argon at 200-400°C for 1-3h, to obtain Ru / MoO 3-x nanomaterials.

4. The Ru / MoO 3-x The application of nanomaterials is characterized in that, In S1, the molybdenum source is selected from at least one of ammonium molybdate, sodium molybdate, potassium molybdate and ammonium phosphomolybdate; The ruthenium source is selected from at least one of a ruthenium chloride solution, a ruthenium acetate solution and a ruthenium nitrate solution; 10g of the molybdenum source and 0.1g-5g of the ruthenium source are added to every 50mL of water.

5. The Ru / MoO 3-x The application of nanomaterials is characterized in that, The ruthenium chloride solution is a solution formed by dispersing ruthenium chloride in water, and 0.1g-5g of ruthenium chloride is added to every 50mL of water.

6. The Ru / MoO 3-x The application of nanomaterials is characterized in that, In S2, the stirring mode is vigorous stirring, and the stirring speed is 500-1500rpm; And / or the drying temperature is 90-120 DEG C, and the drying time is 6-12h.

7. The Ru / MoO 3-x The application of nanomaterials is characterized in that, The S3 specifically comprises: placing the intermediate product in a muffle furnace, heating to 400-600 DEG C, calcining for 2-4h, cooling, and then placing the product in a tube furnace, heating to 200-400 DEG C in a mixed atmosphere of hydrogen and argon, and calcining for 1-3h to obtain Ru / MoO 3-x nanomaterials; The heating mode is programmed heating, and the programmed heating rate is 5-10 DEG C / min; In the mixed atmosphere of hydrogen and argon, the ratio of hydrogen to argon is 5%:95%-20%:80%.

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