Metal catalyst for co-production of phenol and hydroquinone through benzene oxidation and preparation process
The Ga-Zn/FeOx catalyst prepared by iron oxide modification solves the problems of high energy consumption and numerous by-products in the benzene oxidation to phenol process, achieving highly selective co-production of phenol and hydroquinone, improving the economy of the benzene oxidation reaction and the stability of the catalyst, and is suitable for industrial production.
Patent Information
- Application Number
- CN202511598020.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-04
- Publication Date
- 2026-01-30
AI Technical Summary
In existing technologies, the process of producing phenol by benzene oxidation has high energy consumption, many by-products, and poor economic efficiency. In addition, traditional catalysts are prone to pulverization, making it difficult to achieve high selectivity in the co-production of phenol and hydroquinone.
A Ga-Zn/FeOx catalyst was prepared using iron oxide (FeOx) as the main component and modified with gallium and zinc. Phenol and hydroquinone were co-produced by oxidizing benzene with hydrogen peroxide. The pH value and calcination conditions were controlled and the reaction parameters were optimized to improve selectivity and stability.
A selectivity of 40.22% for phenol and 59.43% for hydroquinone was achieved, significantly improving the techno-economic efficiency of the benzene oxidation reaction. The catalyst exhibits high stability and is suitable for industrial applications.
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Figure CN121422973A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical catalyst technology, specifically to metal catalysts and their preparation processes for the co-production of phenol and hydroquinone by benzene oxidation. Background Technology
[0002] Phenol is an important basic chemical raw material, widely used in resins, chemical fibers, pharmaceuticals and other fields.
[0003] Currently, the industrial production of phenol mainly adopts the three-step cumene process: First, benzene and propylene are reacted with aluminum trichloride and phosphoric acid as catalysts to produce cumene. Then, cumene reacts with oxygen to obtain cumene peroxide. Finally, cumene peroxide is hydrolyzed with sulfuric acid as a catalyst to produce phenol and acetone. Due to the involvement of multiple reaction steps and the use of phosphoric acid and sulfuric acid, this method has problems such as large equipment investment, high energy consumption, and serious pollution.
[0004] To address the aforementioned issues, researchers in the 20th century proposed a green route to directly produce phenol via a one-step oxidation reaction using benzene and hydrogen peroxide as raw materials. However, traditional catalysts such as zeolite molecular sieves readily induce phenol peroxidation in this reaction, generating large quantities of products such as benzoquinone, catechol, hydroquinone, and tar components, leading to complex product separation and hindering practical application. Recently, some studies have developed highly selective catalysts for the oxidation of benzene to phenol, achieving a phenol selectivity of over 90% in the benzene oxidation reaction. This has made a significant contribution to promoting the practical application of the benzene oxidation reaction. However, the prices of phenol (approximately 7000 RMB / ton), benzene (approximately 6000 RMB / ton), and 30% hydrogen peroxide (approximately 1000 RMB / ton) remain high. Due to technical and economic issues, this route is still difficult to implement industrially. Therefore, how to co-produce high-value-added chemicals in the benzene oxidation reaction and improve its technical and economic efficiency has become an important research topic.
[0005] Hydroquinone is a high-value-added fine chemical widely used in polymer polymerization inhibitors, rubber antioxidants, developers, and dye intermediates. As the most expensive phenol oxidation derivative, its price has been stable at 50,000 yuan / ton for a long time, and is currently around 30,000 yuan / ton. Therefore, the targeted acquisition of phenol and hydroquinone in the benzene oxidation reaction, while inhibiting the formation of byproducts such as benzoquinone and catechol, can significantly improve the technical and economic efficiency of the benzene oxidation reaction and promote the green production route of important industrial raw materials such as phenol and hydroquinone to practical application. However, related research is still in its early stages, with few research results. The reported carbon-based catalyst materials have problems such as easy pulverization.
[0006] To address this technical deficiency, a solution is proposed. Summary of the Invention
[0007] The purpose of this invention is to provide a metal catalyst and preparation process for the co-production of phenol and hydroquinone by benzene oxidation, in order to solve the technical problems of high energy consumption, numerous by-products, and poor economic efficiency in the existing process of catalytic benzene oxidation to phenol. This invention provides a stable catalytic system and process route that can efficiently and selectively co-produce phenol and hydroquinone in the benzene oxidation process and has the potential for industrial application.
[0008] The objective of this invention can be achieved through the following technical solution: a metal catalyst for the co-production of phenol and hydroquinone by benzene oxidation, wherein the catalyst is iron oxide (FeO) x The main component is Ga-Zn / FeO, modified with gallium and zinc as two metal components, with the molecular formula Ga-Zn / FeO. x It is used to catalyze the oxidation of benzene with hydrogen peroxide to co-produce phenol and hydroquinone.
[0009] Furthermore, iron oxide (FeO) x ) includes Fe 2+ and Fe 3+ , of which Fe 2+ and Fe 3+ The molar ratio is 0.17-0.22; the molar ratio of gallium and zinc is 1:1, and the mass fraction of gallium in the catalyst is 0.5-1.4%.
[0010] The present invention also proposes a process for preparing a metal catalyst for the co-production of phenol and hydroquinone by benzene oxidation, comprising the following steps: S1. Dissolve ferric nitrate, gallium nitrate, and zinc nitrate in deionized water to prepare solution A; dissolve Na2CO3 in deionized water to prepare solution B. S2. Add deionized water to the reaction flask and stir. Raise the temperature of the reaction flask to 50°C. Add solution A and solution B dropwise to the reaction flask simultaneously. By controlling the rate of addition of solution A and solution B, the pH value of the system is always maintained at 8.0±0.1. After the addition is complete, continue to age and stir at 50°C for 2-3 hours. After post-treatment, coprecipitated particles are obtained. S3. Place the coprecipitated particles in a muffle furnace at a temperature of 600-700℃ and calcine them in air for 5 hours. Then, allow them to cool naturally to room temperature to obtain the catalytic precursor. S4. The catalyst precursor is packed into a quartz tube reactor and calcined under a programmed temperature rise under mixed gas flow protection to obtain the catalyst Ga-Zn / FeO. x .
[0011] Further, in step S1, the ferric nitrate is Fe(NO3)3·9H2O, the gallium nitrate is Ga(NO3)3·9H2O, and the zinc nitrate is Zn(NO3)2·6H2O. The weight ratio of Fe(NO3)3·9H2O, Ga(NO3)3·9H2O, and Zn(NO3)2·6H2O is 100:(0.414-1.160):(0.295-0.826). The total metal ion concentration in solution A is 0.8-1.2 mol / L, and the concentration in solution B is 1 mol / L.
[0012] Furthermore, in step S2, the volume ratio of deionized water to solution A is 1:1. The post-processing includes: after the reaction is complete, the temperature of the reaction flask is lowered to room temperature to obtain a suspension, which is then filtered. The filter cake is repeatedly washed with deionized water until no sodium ions are detected in the washing liquid, and then dried. The filter cake is transferred to an oven at 60°C and vacuum dried to constant weight to obtain coprecipitated particles.
[0013] Furthermore, in step S4, the mixed gas is composed of H2 and Ar2 in a volume ratio of 1:9, the flow rate of the mixed gas is 20-30 mL / min, and the programmed temperature rise calcination operation is as follows: under the protection of the mixed gas, the quartz tube reactor is programmed to rise to 200-220℃ at a rate of 2-5℃ / min, held at the temperature for 0.5h, and then cooled to room temperature under the protection of the mixed gas.
[0014] This invention also proposes a catalyst Ga-Zn / FeO. x The application of catalytic hydrogen peroxide oxidation of benzene to co-produce phenol and hydroquinone specifically involves: using the Ga-Zn / FeO catalyst... x The organic solvent was placed in a reaction flask and stirred. Then, benzene and hydrogen peroxide were added to the reaction flask in sequence. The reaction temperature was raised to 65-75℃ and the reaction was maintained at this temperature for 24 hours.
[0015] Furthermore, the catalyst Ga-Zn / FeO x The ratio of organic solvent, benzene and hydrogen peroxide is 1g:120mL:12mL:(97-103)mL, wherein the organic solvent is acetonitrile and the mass fraction of hydrogen peroxide is 30%.
[0016] The present invention has the following beneficial effects: This invention is achieved by using iron oxide (FeO) x Using gallium and zinc as the main components, a catalyst Ga-Zn / FeO was prepared by modification with gallium and zinc as the two metal components. x This catalyst, Ga-Zn / FeO, is used to catalyze the oxidation of benzene with hydrogen peroxide, enabling the targeted production of phenol and hydroquinone in the benzene oxidation reaction. The high-value-added hydroquinone co-production significantly enhances the economics of the benzene oxidation technology. Simultaneously, the co-production of hydroquinone suppresses the formation of byproducts such as benzoquinone and catechol during the reaction, drastically shortening the industrial process for phenol production and improving the techno-economic efficiency of the benzene oxidation reaction. This promotes the practical application of green production routes for important industrial raw materials such as phenol and hydroquinone. x As an alloy catalyst, it has stable properties, high mechanical strength, and is easier to use in industry.
[0017] This invention also modifies the catalyst Ga-Zn / FeO x By adjusting parameters such as reaction temperature, hydrogen peroxide dosage, and reaction time to catalyze the oxidation of benzene with hydrogen peroxide, the reaction performance was controlled. Under optimal conditions, the conversion rate of benzene reached 99.55%, the selectivity of phenol reached 40.22%, and the selectivity of hydroquinone reached 59.43%. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 The catalyst Ga-Zn / FeO prepared for Example 3 of this invention x SEM photos; Figure 2 The catalyst Ga-Zn / FeO prepared in Example 3 of this invention x The infrared absorption spectrum. Detailed Implementation
[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example
[0021] This embodiment provides a process for preparing a metal catalyst for the co-production of phenol and hydroquinone by benzene oxidation, including the following steps: Step 1: Preparation of precursor solution Weigh out 10g of Fe(NO3)3·9H2O, 41.4mg of Ga(NO3)3·9H2O and 29.5mg of Zn(NO3)2·6H2O, dissolve them in deionized water, and prepare solution A with a total metal ion concentration of 0.8mol / L. Na₂CO₃ was dissolved in deionized water to prepare a solution B with a concentration of 1 mol / L.
[0022] Step 2: Preparation of coprecipitated particles Add 500 mL of deionized water to the reaction flask and stir. Raise the temperature of the reaction flask to 50°C. Simultaneously add 500 mL of solution A and solution B to the reaction flask. By controlling the rate of addition of solutions A and B, the pH value of the system is always maintained at 8.0 ± 0.1. After the addition is complete, continue to age and stir at 50°C for 2 hours. Then, lower the temperature of the reaction flask to room temperature to obtain a suspension. Filter the suspension and wash the filter cake repeatedly with deionized water until no sodium ions are detected in the washing liquid. Then, dry the filter cake and transfer it to an oven at 60°C. Vacuum dry the filter cake to constant weight to obtain coprecipitated particles.
[0023] Step 3: Preparation of catalyst precursor The coprecipitated particles were placed in a muffle furnace at 600℃ and calcined in air for 5 hours, then allowed to cool naturally to room temperature to obtain the catalytic precursor.
[0024] Step 4: Preparation of the catalyst Ga-Zn / FeO x H2 and Ar2 are mixed at a volume ratio of 1:9 to obtain a mixed gas; The catalyst precursor was packed into a quartz tube reactor, and a mixed gas was introduced into the reactor at a flow rate of 20 mL / min. Under the protection of the mixed gas, the quartz tube reactor was heated to 200 °C at a programmed rate of 2 °C / min and calcined at that temperature for 0.5 h. The reactor was then cooled to room temperature under the protection of the mixed gas to obtain the catalyst Ga-Zn / FeO. x . Example
[0025] This embodiment provides a process for preparing a metal catalyst for the co-production of phenol and hydroquinone by benzene oxidation, including the following steps: Step 1: Preparation of precursor solution Weigh out 10g of Fe(NO3)3·9H2O, 78.7mg of Ga(NO3)3·9H2O and 56.1mg of Zn(NO3)2·6H2O, dissolve them in deionized water, and prepare solution A with a total metal ion concentration of 1.0mol / L. Na₂CO₃ was dissolved in deionized water to prepare a solution B with a concentration of 1 mol / L.
[0026] Step 2: Preparation of coprecipitated particles Add 500 mL of deionized water to the reaction flask and stir. Raise the temperature of the reaction flask to 50°C. Simultaneously add 500 mL of solution A and solution B to the reaction flask. By controlling the rate of addition of solutions A and B, the pH value of the system is always maintained at 8.0 ± 0.1. After the addition is complete, continue to age and stir at 50°C for 2.5 h. Then, lower the temperature of the reaction flask to room temperature to obtain a suspension. Filter the suspension and wash the filter cake repeatedly with deionized water until no sodium ions are detected in the washing liquid. Then, dry the filter cake and transfer it to an oven at 60°C. Vacuum dry the filter cake to constant weight to obtain coprecipitated particles.
[0027] Step 3: Preparation of catalyst precursor The coprecipitated particles were placed in a muffle furnace at 650°C and calcined in air for 5 hours, then allowed to cool naturally to room temperature to obtain the catalytic precursor.
[0028] Step 4: Preparation of the catalyst Ga-Zn / FeO x H2 and Ar2 are mixed at a volume ratio of 1:9 to obtain a mixed gas; The catalyst precursor was packed into a quartz tube reactor, and a mixed gas was introduced into the reactor at a flow rate of 25 mL / min. Under the protection of the mixed gas, the quartz tube reactor was heated to 210 °C at a programmed rate of 3.5 °C / min and calcined at that temperature for 0.5 h. The reactor was then cooled to room temperature under the protection of the mixed gas to obtain the catalyst Ga-Zn / FeO. x . Example
[0029] This embodiment provides a process for preparing a metal catalyst for the co-production of phenol and hydroquinone by benzene oxidation, including the following steps: Step 1: Preparation of precursor solution Weigh out 10g of Fe(NO3)3·9H2O, 116mg of Ga(NO3)3·9H2O and 82.6mg of Zn(NO3)2·6H2O, dissolve them in deionized water, and prepare solution A with a total metal ion concentration of 1.2mol / L. Na₂CO₃ was dissolved in deionized water to prepare a solution B with a concentration of 1 mol / L.
[0030] Step 2: Preparation of coprecipitated particles Add 500 mL of deionized water to the reaction flask and stir. Raise the temperature of the reaction flask to 50°C. Simultaneously add 500 mL of solution A and solution B to the reaction flask. By controlling the rate of addition of solutions A and B, the pH value of the system is always maintained at 8.0 ± 0.1. After the addition is complete, continue to age and stir at 50°C for 3 hours. Then, lower the temperature of the reaction flask to room temperature to obtain a suspension. Filter the suspension and wash the filter cake repeatedly with deionized water until no sodium ions are detected in the washing liquid. Then, dry the filter cake and transfer it to an oven at 60°C. Vacuum dry the filter cake to constant weight to obtain coprecipitated particles.
[0031] Step 3: Preparation of catalyst precursor The coprecipitated particles were placed in a muffle furnace at 700℃ and calcined for 5 hours in air atmosphere, then naturally cooled to room temperature to obtain the catalytic precursor.
[0032] Step 4: Preparation of the catalyst Ga-Zn / FeO x H2 and Ar2 are mixed at a volume ratio of 1:9 to obtain a mixed gas; The catalyst precursor was packed into a quartz tube reactor, and a mixed gas was introduced into the reactor at a flow rate of 30 mL / min. Under the protection of the mixed gas, the quartz tube reactor was heated to 220 °C at a programmed rate of 5 °C / min and calcined at that temperature for 0.5 h. The reactor was then cooled to room temperature under the protection of the mixed gas to obtain the catalyst Ga-Zn / FeO. x . Example
[0033] This embodiment provides a catalyst Ga-Zn / FeO. x The method for catalytic oxidation of benzene with hydrogen peroxide to co-produce phenol and hydroquinone is as follows: Weigh out: the catalyst Ga-Zn / FeO prepared in Example 1. x 1 g of benzene and 120 mL of acetonitrile were placed in a reaction flask and stirred. Then, 12 mL of benzene and 97 mL of 30 wt% hydrogen peroxide were added to the reaction flask in sequence. The temperature of the reaction flask was raised to 65 °C and kept at this temperature for 24 h. The temperature of the reaction flask was then lowered to room temperature, and the mixture was filtered. The filter cake was washed three times with acetonitrile. The filtrate was then transferred to a rotary evaporator with a water bath temperature of 80 °C and the low-boiling substances were removed by vacuum evaporation to obtain the reaction product. Example
[0034] This embodiment provides a catalyst Ga-Zn / FeO. x The method for catalytic oxidation of benzene with hydrogen peroxide to co-produce phenol and hydroquinone is as follows: Weigh out: the catalyst Ga-Zn / FeO prepared in Example 2. x1 g of benzene and 120 mL of acetonitrile were placed in a reaction flask and stirred. Then, 12 mL of benzene and 100 mL of 30 wt% hydrogen peroxide were added to the reaction flask in sequence. The temperature of the reaction flask was raised to 70 °C and kept at this temperature for 24 h. The temperature of the reaction flask was then lowered to room temperature, and the mixture was filtered. The filter cake was washed three times with acetonitrile. The filtrate was then transferred to a rotary evaporator with a water bath temperature of 80 °C and the low-boiling substances were removed by vacuum evaporation to obtain the reaction product. Example
[0035] This embodiment provides a catalyst Ga-Zn / FeO. x The method for catalytic oxidation of benzene with hydrogen peroxide to co-produce phenol and hydroquinone is as follows: Weigh out: the catalyst Ga-Zn / FeO prepared in Example 3. x 1 g of benzene and 120 mL of acetonitrile were placed in a reaction flask and stirred. Then, 12 mL of benzene and 103 mL of 30 wt% hydrogen peroxide were added to the reaction flask in sequence. The temperature of the reaction flask was raised to 75 °C and kept at this temperature for 24 h. The temperature of the reaction flask was then lowered to room temperature, and the mixture was filtered. The filter cake was washed three times with acetonitrile. The filtrate was then transferred to a rotary evaporator with a water bath temperature of 80 °C and the low-boiling substances were removed by vacuum evaporation to obtain the reaction product.
[0036] Comparative Example 1 The difference between this comparative example and Example 6 is that the reaction time is shortened to 4 hours.
[0037] Comparative Example 2 The difference between this comparative example and Example 6 is that the reaction time is shortened to 8 hours.
[0038] Comparative Example 3 The difference between this comparative example and Example 6 is that the reaction time is shortened to 12 hours.
[0039] Comparative Example 4 The difference between this comparative example and Example 6 is that the reaction time is shortened to 16 hours.
[0040] Comparative Example 5 The difference between this comparative example and Example 6 is that the reaction time is shortened to 20 hours.
[0041] Comparative Example 6 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 4 h.
[0042] Comparative Example 7 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. xDuring preparation, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 8 hours.
[0043] Comparative Example 8 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 12h.
[0044] Comparative Example 9 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 16 h.
[0045] Comparative Example 10 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 20 h.
[0046] Comparative Example 11 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x Zn(NO3)2·6H2O was not added during preparation.
[0047] Comparative Example 12 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 1:0.5, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 4h.
[0048] Comparative Example 13 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 1:0.5, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 8h.
[0049] Comparative Example 14 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. xDuring preparation, the molar ratio of Ga to Zn was changed to 1:0.5, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 12 h.
[0050] Comparative Example 15 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 1:0.5, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to co-produce phenol and hydroquinone was shortened to 16 h.
[0051] Comparative Example 16 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 1:0.5, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to co-produce phenol and hydroquinone was shortened to 20 h.
[0052] Comparative Example 17 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 1:0.5.
[0053] Comparative Example 18 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 2:3, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 4h.
[0054] Comparative Example 19 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 2:3, Zn(NO3)2·6H2O was not added, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 8h.
[0055] Comparative Example 20 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 2:3, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 12 h.
[0056] Comparative Example 21 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. xDuring preparation, the molar ratio of Ga to Zn was changed to 2:3, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 16 h.
[0057] Comparative Example 22 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 2:3, and the reaction time for catalytic oxidation of benzene with hydrogen peroxide to obtain phenol and hydroquinone was shortened to 20 h.
[0058] Comparative Example 23 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, the molar ratio of Ga to Zn was changed to 2:3.
[0059] Comparative Example 24 The difference between this comparative example and Example 6 is that the reaction temperature was reduced to 45°C.
[0060] Comparative Example 25 The difference between this comparative example and Example 6 is that the reaction temperature was reduced to 50°C.
[0061] Comparative Example 26 The difference between this comparative example and Example 6 is that the reaction temperature was reduced to 55°C.
[0062] Comparative Example 27 The difference between this comparative example and Example 6 is that the amount of hydrogen peroxide used is 25 mL.
[0063] Comparative Example 28 The difference between this comparative example and Example 6 is that the amount of hydrogen peroxide used is 32 mL.
[0064] Comparative Example 29 The difference between this comparative example and Example 6 is that the amount of hydrogen peroxide used is 60 mL.
[0065] Comparative Example 30 The difference between this comparative example and Example 6 is that the amount of hydrogen peroxide used is 72 mL.
[0066] Comparative Example 31 The difference between this comparative example and Example 6 is that the amount of hydrogen peroxide used is 100 mL.
[0067] Comparative Example 32 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, zinc nitrate is replaced by an equimolar amount of aluminum nitrate.
[0068] Comparative Example 33 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, zinc nitrate is replaced by an equimolar amount of magnesium nitrate.
[0069] Comparative Example 34 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, zinc nitrate is replaced by an equimolar amount of chromium nitrate.
[0070] Comparative Example 35 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, zinc nitrate is replaced by an equimolar amount of vanadium oxysulfate.
[0071] Comparative Example 35 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, zinc nitrate is replaced by an equimolar amount of manganese nitrate.
[0072] Comparative Example 37 The difference between this comparative example and Example 6 is that the catalyst used is Ga-Zn / FeO. x During preparation, zinc nitrate is replaced by an equimolar amount of cobalt nitrate.
[0073] Performance testing: The reaction products of the examples and comparative examples were quantitatively analyzed by high performance liquid chromatography (HPLC), and the conversion rate of benzene, the selectivity of phenol and hydroquinone were calculated. The specific test data are shown in Table 1 below.
[0074] Table 1 - Performance Test Data of Samples Group Project Conversion rate (%) Phenol selectivity (%) Hydroquinone selectivity (%) Example 4 94.02 39.68 59.32 Example 5 98.88 39.09 59.77 Example 6 99.55 40.22 59.43 Comparative Example 1 16.31 39.33 60.00 Comparative Example 2 24.51 41.43 58.54 Comparative Example 3 41.44 40.84 59.02 Comparative Example 4 60.72 39.12 60.23 Comparative Example 5 79.79 40.56 59.32 Comparative Example 6 14.91 99.12 0 Comparative Example 7 25.04 98.5 0 Comparative Example 8 36.32 98.78 0 Comparative Example 9 87.20 99.41 0 Comparative Example 10 98.94 99.00 0 Comparative Example 11 98.92 98.56 0 Comparative Example 12 21.49 80.76 18.45 Comparative Example 13 52.84 79.34 17.95 Comparative Example 14 88.58 80.33 19.20 Comparative Example 15 90.11 81.59 17.57 Comparative Example 16 94.96 81.23 18.60 Comparative Example 17 99.26 79.99 19.04 Comparative Example 18 22.56 68.45 31.33 Comparative Example 19 49.66 66.70 32.55 Comparative Example 20 85.35 66.46 32.33 Comparative Example 21 90.55 68.65 30.50 Comparative Example 22 95.43 67.20 31.76 Comparative Example 23 98.67 67.99 31.11 Comparative Example 24 30.38 41.54 57.30 Comparative Example 25 59.39 40.80 58.43 Comparative Example 26 82.89 42.49 57.33 Comparative Example 27 32.78 40.55 58.33 Comparative Example 28 34.73 41.05 58.87 Comparative Example 29 83.11 40.89 58.09 Comparative Example 30 65.64 39.18 60.01 Comparative Example 31 87.57 39.13 60.22 Comparative Example 32 13.24 92.5 0 Comparative Example 33 10.4 95.6 0 Comparative Example 34 15.54 94.2 0 Comparative Example 35 95.24 100 0 Comparative Example 36 10.2 95.52 0 Comparative Example 37 35.4 100 0 Data Analysis: This invention is achieved by using iron oxide (FeO) x Using gallium and zinc as the main components, a catalyst Ga-Zn / FeO was prepared by modification with gallium and zinc as the two metal components. x It is used to catalyze the oxidation of benzene with hydrogen peroxide, optimize the reaction process, improve the reaction conversion rate of benzene, and simultaneously produce high-value-added hydroquinone during the oxidation of benzene to phenol, which has significant technical and economic advantages.
[0075] Regarding the catalyst Ga-Zn / FeO prepared in Example 3 x The infrared absorption spectrum shows typical ferrite lattice vibrations at 630 cm⁻¹ (Fe³⁺-O) and 580 cm⁻¹ (Fe²⁺-O), and a hematite-type shoulder peak at approximately 720 cm⁻¹, confirming that the catalyst bulk is iron oxide (FeO).x Gaussian peak subdivision and integration were performed on the Fe-O region (580 / 630 cm⁻¹), yielding an Fe²⁺ / Fe³⁺ area ratio of 0.171, falling within the 0.17–0.22 range, indicating the coexistence of Fe²⁺ and Fe³⁺ in the sample. The weak peaks at 560 cm⁻¹ and 465 cm⁻¹ were attributed to Ga–O and Zn–O vibrations, respectively, suggesting the presence of Ga and Zn species and FeO. x The skeletal structure exhibits stable interactions; the nitrate peak at 1384 cm⁻¹ is absent, and the carbonate peak at 1465 cm⁻¹ is only weakly present. Combined with the OH / H₂O absorptions at 3390 cm⁻¹ and 1630 cm⁻¹, interference from precursor residues on the interpretation of the main peaks can be ruled out. The above evidence collectively confirms that the sample is composed of FeO. x Ga-Zn / FeO is a composite material with the main body, containing Fe²⁺ / Fe³⁺ mixed valence states and Ga and Zn additives. x catalyst.
[0076] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. Metal catalyst for the phenoxylation co-production of phenol and p- benzenediol, characterized in that, The catalyst is mainly composed of iron oxide (FeO x ), modified by two metal components of gallium and zinc, with molecular formula of Ga-Zn / FeO x , used for catalyzing hydrogen peroxide to oxidize benzene to obtain phenol and hydroquinone.
2. The metal catalyst for phenoxylation co-producing phenol and p- benzenediol according to claim 1, characterized by, Iron oxide (FeO x ) comprising Fe 2+ and Fe 3+ , wherein the molar ratio of Fe 2+ and Fe 3+ is 0.17-0.22; the molar ratio of gallium and zinc is 1:1, and the mass fraction of gallium in the catalyst is 0.5-1.4%.
3. Process for the preparation of a metal catalyst for the phenoxylation co-production of phenol and p-phenylenediamine according to claim 2, characterized in that, The method comprises the following steps: S1, dissolving iron nitrate, gallium nitrate and zinc nitrate in deionized water to prepare solution A; dissolving Na2CO3 in deionized water to prepare solution B; S2, deionized water is added into a reaction bottle and stirred, the temperature of the reaction bottle is increased to 50℃, and solution A and solution B are simultaneously added dropwise into the reaction bottle, the pH value of the system is always maintained at 8.0±0.1 by controlling the dropping rate of solution A and solution B, after the dropping is completed, the stirring is continued at 50℃ for 2-3h, and post-treatment is performed to obtain co-precipitated particles; S3, the co-precipitated particles are placed in a muffle furnace with a temperature of 600-700℃, calcined in an air atmosphere for 5h, and naturally cooled to room temperature to obtain a catalytic precursor; S4, the catalytic precursor is loaded into a quartz tube reactor, and temperature programmed calcination is performed under the protection of mixed gas flow to obtain the catalyst Ga-Zn / FeO x .
4. Process for the preparation of a metal catalyst for the phenoxylation co-production of phenol and p-phenylenol according to claim 3, characterized in that, In step S1, the iron nitrate is Fe(NO3)3·9H2O, the gallium nitrate is Ga(NO3)3·9H2O, and the zinc nitrate is Zn(NO3)2·6H2O, the weight ratio of Fe(NO3)3·9H2O, Ga(NO3)3·9H2O and Zn(NO3)2·6H2O is 100:(0.414-1.160):(0.295-0.826), and the total metal ion concentration in solution A is 0.8-1.2mol / L; the concentration in solution B is 1mol / L.
5. The process for the preparation of a metal catalyst for the phenoxylation co- production of phenol and p-hydroquinone according to claim 3, characterized in that, In step S2, the volume ratio of deionized water to solution A is 1:1, and the post-treatment comprises: after the reaction is completed, the temperature of the reaction bottle is reduced to room temperature to obtain a suspension, the suspension is filtered, the filter cake is repeatedly washed with deionized water until no sodium ions are detected in the washing liquid, then the filter cake is dried, the filter cake is transferred to a 60℃ oven, and vacuum drying is performed until the weight is constant to obtain co-precipitated particles.
6. The process for the preparation of a metal catalyst for the phenoxylation co- production of phenol and p-hydroquinone according to claim 3, characterized in that, In step S4, the mixed gas is composed of H2 and Ar2 at a volume ratio of 1:9, the flow rate of the mixed gas is 20-30mL / min, and the programmed temperature calcination operation is as follows: under the protection of the mixed gas, the quartz tube reactor is programmed to increase the temperature to 200-220℃ at a rate of 2-5℃ / min, and the temperature is maintained for calcination for 0.5h, and then the temperature is cooled to room temperature under the protection of the mixed gas.
7. Use of a metal catalyst for the phenoxylation co-production of phenol and p- benzoquinone according to claim 2, characterized in that, The catalyst Ga-Zn / FeO x The catalyst Ga-Zn / FeO x The catalyst Ga-Zn / FeO 8. Use of a metal catalyst for the phenoxylation co-production of phenol and p- benzoquinone according to claim 7, characterized in that, The catalyst Ga-Zn / FeO x The ratio of the use amount of the organic solvent, benzene and hydrogen peroxide is 1 g: 120 mL: 12 mL: (97-103) mL, the organic solvent is acetonitrile, and the mass fraction of the hydrogen peroxide is 30%.