Catalyst for preparing benzenediol from phenol and preparation method thereof

Abstract

The invention provides a catalyst for preparing benzenediol from phenol and a preparation method thereof. The catalyst comprises: a carrier comprising a mesoporous molecular sieve modified by an acid; the first metal is loaded on the carrier, and the first metal is selected from lanthanide series elements in the periodic table of elements; the catalyst comprises a carrier and a phosphoric acid-containing modified metal cluster loaded on the carrier, the phosphoric acid-containing modified metal cluster is a phosphoric acid-containing modified composite metal cluster comprising a second metal and a third metal, the second metal is selected from VIIB and VIII group elements in the periodic table of elements, and the third metal is selected from VB and VIB group elements in the periodic table of elements. The invention also provides a method for preparing benzenediol from phenol by using the catalyst.

Description

Technical Field

[0001] This application relates to the field of catalysts, and more specifically, to a catalyst for the hydroxylation of phenol to produce hydroquinone and a method for preparing the same. Background Technology

[0002] The hydroxylation of phenol is the core reaction in the synthesis of catechol and hydroquinone. Both are important fine chemicals widely used in the synthesis of antioxidants, developers, bactericides, and epoxy resin monomers, with a global annual demand exceeding 800,000 tons. Traditional processes, such as the cumene process, suffer from problems such as high acetone production as a byproduct and high energy consumption (reaction temperature >200℃). However, using hydrogen peroxide (…)… While catalytic processes using green oxidants meet atom economy requirements, their catalyst systems still face the technical bottleneck of difficulty in synergistically optimizing activity, selectivity, and stability. Molecular sieve-based catalysts, with their tunable acidic sites, shape-selectivity, and high hydrothermal stability, have become a research focus in this field. Patent CN105080592A uses ZSM-5 supported on Fe... The catalyst, however, only achieved a phenol conversion rate of 58%, and after 100 hours of operation, pore blockage due to coke deposition increased catalyst regeneration energy consumption by 40%. Patent CN107413245A uses heteropoly acids (such as...) P Molecular sieves modified with [P], but heteropolyacid anions ([P]) in liquid-phase reactions ] It is easy to dissolve from the carrier surface (the acid content decreases by more than 35% after 5 cycles), resulting in decreased activity and product contamination. Summary of the Invention

[0003] To address the aforementioned issues, this application provides a catalyst that combines high activity, high selectivity, and high stability for the hydroxylation of phenol to produce hydroquinone, thereby improving reaction efficiency, simplifying the process, and saving costs.

[0004] A first aspect of this application provides a catalyst for the production of hydroquinone from phenol, the catalyst comprising: a support comprising an acid-modified mesoporous molecular sieve; a first metal supported on the support, wherein the first metal is selected from lanthanides in the periodic table; and a phosphoric acid-modified bimetallic site supported on the support, the phosphoric acid-modified bimetallic site being a composite bimetallic site comprising a second metal and a third metal modified with phosphoric acid, wherein the second metal is selected from elements in groups VIIB and VIII of the periodic table, and the third metal is selected from elements in groups VB and VIB of the periodic table.

[0005] A second aspect of this application provides a method for preparing a catalyst for the production of hydroquinone from phenol, the method comprising the following steps: (1) Treating a support, which comprises a mesoporous molecular sieve, with acid to obtain a modified mesoporous molecular sieve; (2) A first metal is loaded onto a modified mesoporous molecular sieve, wherein the first metal is selected from the lanthanides in the periodic table; (3) Loading phosphoric acid-modified bimetallic sites onto the carrier treated in step (2), wherein the phosphoric acid-modified bimetallic sites are phosphoric acid-modified composite bimetallic sites including a second metal and a third metal, wherein the second metal is selected from group VIIB and VIII elements in the periodic table, and wherein the third metal is selected from group VB and VIB elements in the periodic table.

[0006] A third aspect of this application provides a method for preparing hydroquinone from phenol, the method comprising the following steps: (1) Providing a catalyst for the first aspect; and (2) In water, phenol is reacted with hydrogen peroxide and the catalyst to obtain hydroquinone, wherein the hydroquinone includes catechol and hydroquinone. Detailed Implementation

[0007] The "range" disclosed herein is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is expected that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0008] Unless otherwise specified in this application, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0009] Unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0010] In this application, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0011] In this application, unless otherwise specified, the terms "comprising" and "including" as used herein are open-ended or closed-ended. For example, "comprising" and "including" may mean that other components not listed may also be included, or that only the listed components may be included.

[0012] In the description of this article, it should be noted that, unless otherwise stated, "above" and "below" include the number itself, and "several" in "one or more" means two or more.

[0013] In this description, unless otherwise stated, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0014] Unless otherwise specified, percentages (%) or parts refer to weight percentages or parts by weight of the composition.

[0015] Unless otherwise stated herein, the sum of the contents of the components in the composition is 100%.

[0016] Unless otherwise stated herein, the sum of the parts of each component in the composition may be 100 parts by weight.

[0017] In this document, unless otherwise stated, “combination of” means a multi-component mixture of the elements, such as two, three, four, and up to the maximum possible multi-component mixture.

[0018] Unless otherwise specified, the term "a" as used in this specification means "at least one".

[0019] In this paper, unless otherwise stated, all reactions were carried out at room temperature and pressure.

[0020] In this article, the term "metal" can refer to either an elemental metal or a metal ion.

[0021] In this document, unless otherwise stated, all reactions, including treatments and mixing, are carried out at atmospheric pressure.

[0022] The catalyst and its preparation method of this application will now be described in detail. In one embodiment, the present invention provides a catalyst for the production of hydroquinone from phenol, the catalyst comprising: The carrier comprises an acid-modified mesoporous molecular sieve; A first metal loaded on a carrier, wherein the first metal is selected from lanthanide elements in the periodic table; and A heteropolyacid supported on a support, wherein the heteropolyacid is a phosphoric acid containing a second metal and a third metal. The second metal is selected from elements in groups VIIB and VIII of the periodic table. The third metal is selected from elements in groups VB and VIB of the periodic table.

[0023] In one embodiment, the modified mesoporous molecular sieve is modified by an acid. For example, the acid includes, but is not limited to, one or more of nitric acid, oxalic acid, hydrochloric acid, and phosphoric acid. According to embodiments of this application, the mesoporous molecular sieve includes MCM-41, SBA-3, or a combination thereof. In one embodiment, the mesoporous molecular sieve is MCM-41. In another embodiment, the mesoporous molecular sieve is SBA-3. According to embodiments of this application, the pore size of the mesoporous molecular sieve is in the range of 1.5 nm to 5.0 nm. Preferably, the pore size is in the range of 2 nm to 4 nm. For example, the pore size of the mesoporous molecular sieve can be 2.5 nm, 3 nm, or 3.5 nm. It should be noted that, unless otherwise stated, the terms "modified carrier," "modified mesoporous molecular sieve," and "molecular sieve" are used interchangeably throughout this application.

[0024] According to embodiments of this application, the lanthanide elements in the periodic table include, but are not limited to, La, Ce, Pr, Nd, Eu, Gd, Er, Yb, or combinations thereof. According to embodiments of this application, the group VIIB elements in the periodic table include, but are not limited to, Mn, Re, or combinations thereof. According to embodiments of this application, the group VIII elements in the periodic table include, but are not limited to, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, or combinations thereof. According to embodiments of this application, the group VB elements in the periodic table include, but are not limited to, V, Nb, Ta, or combinations thereof. According to embodiments of this application, the group VIB elements in the periodic table include, but are not limited to, Cr, Mo, W, or combinations thereof.

[0025] In this application, the term "phosphoric acid" refers to an acid containing elemental phosphorus. The phosphoric acid can be either an inorganic or organic acid. According to one embodiment, the phosphoric acid is an inorganic acid. According to another embodiment, the phosphoric acid is an organic acid. For example, the phosphoric acid includes, but is not limited to, alkali metal dihydrogen phosphate, hydrogen phosphate, orthophosphate, or combinations thereof. In one or more embodiments, the phosphoric acid can be sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium orthophosphate, potassium orthophosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, or combinations thereof. For example, the phosphoric acid can be a combination of sodium dihydrogen phosphate and disodium hydrogen phosphate in a 1:1 mass ratio.

[0026] As a precursor to the first metal, the precursor may include, but is not limited to, one or more of the sulfate, nitrate, and chloride salts of the first metal. According to embodiments, the precursor to the first metal may be one or more of lanthanum nitrate, lanthanum chloride, cerium chloride, praseodymium chloride, praseodymium sulfate, neodymium nitrate, erbium sulfate, gadolinium nitrate, ytterbium sulfate, and ytterbium nitrate.

[0027] As a precursor to the second metal, the precursor may include, but is not limited to, one or more of the sulfates, nitrates, and chlorides of the second metal. According to embodiments, the precursor to the second metal may be one or more of ferric nitrate, manganese chloride, ferric sulfate, cobalt chloride, nickel nitrate, manganese sulfate, and nickel chloride.

[0028] As a precursor to the third metal, the precursor may include, but is not limited to, one or more of the ammonium salt, oxalate, potassium salt, and sodium salt of the third metal. According to embodiments, the precursor to the third metal may be one or more of ammonium tungstate, potassium tungstate, ammonium niobate oxalate, potassium niobate oxalate, potassium molybdate, sodium molybdate, ammonium molybdate, sodium vanadate, and ammonium vanadate.

[0029] In this application, based on the mass of the modified support and the mass of the first metal ions, the mass ratio of the modified support to the first metal ions can be 1:0.01~0.05, for example 1:0.01~0.03 or 1:0.03~0.05. For example, 1:0.02 or 1:0.04.

[0030] In this application, based on the mass of the modified support and the mass of the second and third metal ions, the mass ratio of the modified support to the second and third metal ions can be 1:0.002~0.02:0.002~0.02, for example 1:0.002~0.005:0.002~0.02, 1:0.002~0.01:0.002~0.02, or 1:0.002~0.015:0.002~0.02.

[0031] In this application, the mass ratio of the modified carrier to the phosphoric acid-containing acid anion can be 1:0.005~0.05, for example 1:0.002~0.05, 1:0.003~0.02 or 1:0.004~0.04.

[0032] In this application, the mass ratio of the first metal ion, the second metal ion, and the third metal ion can be 1:0.5~4:0.5~4, for example, 1:1~3:1~3, or 1:2~3.5:2~3.5.

[0033] In one embodiment of this application, the catalyst may further comprise optional additives, including binders, lubricants, or any additives known in the art, or combinations thereof. According to embodiments of this application, the binder includes, but is not limited to, one or more of polyvinyl alcohol, animal glue, molasses, sodium carboxymethyl cellulose, aluminum phosphate, and silicate cement. According to embodiments of this application, the lubricant includes, but is not limited to, one or more of stearic acid, sodium stearate, paraffin wax, guar gum, polyethylene wax, and zinc stearate.

[0034] This application also provides a method for preparing a catalyst for the production of hydroquinone from phenol, the method comprising the following steps: (1) Treating a support, which comprises a mesoporous molecular sieve, with acid to obtain a modified mesoporous molecular sieve; (2) A first metal is loaded onto a modified mesoporous molecular sieve, wherein the first metal is selected from the lanthanides in the periodic table; (3) Loading phosphoric acid-modified bimetallic sites onto the carrier treated in step (2), wherein the phosphoric acid-modified bimetallic site heteropolyacid is a composite bimetallic site including a second metal and a third metal modified with phosphoric acid, wherein the second metal is selected from group VIIB and VIII elements in the periodic table, and wherein the third metal is selected from group VB and VIB elements in the periodic table.

[0035] In one or more embodiments, the lanthanide elements in the periodic table may include, but are not limited to, La, Ce, Pr, Nd, Eu, Gd, Er, Yb, or combinations thereof. In one or more embodiments, the group VIIB elements in the periodic table may include, but are not limited to, Mn, Re, or combinations thereof. In one or more embodiments, the group VIII elements in the periodic table may include, but are not limited to, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, or combinations thereof. In one or more embodiments, the group VB elements in the periodic table may include, but are not limited to, V, Nb, Ta, or combinations thereof. In one or more embodiments, the group VIB elements in the periodic table may include, but are not limited to, Cr, Mo, W, or combinations thereof.

[0036] According to embodiments of this application, the phosphoric acid-containing anion includes dihydrogen phosphate, hydrogen phosphate, orthophosphate, or a combination thereof.

[0037] Step (1): Treat the carrier with acid

[0038] In one or more embodiments, step (1) is carried out in water. In one or more embodiments, the mass ratio of the carrier, acid and water is 1:0.1~2:5~20, for example 1:0.5~1:8.5~10, 1:1~1.5:9~9.5, and the solid is filtered, washed and dried after acid treatment.

[0039] In one or more embodiments, the acid used to treat the carrier includes, but is not limited to, one or more of nitric acid, oxalic acid, hydrochloric acid, and phosphoric acid. In one or more embodiments, the acid includes, but is not limited to, at least 5-30% by mass of nitric acid, 5-30% by mass of oxalic acid, 5-30% by mass of hydrochloric acid, and 5-30% by mass of phosphoric acid. For example, the acid may be 20% by mass of nitric acid. For example, the acid may be 20% by mass of oxalic acid. For example, the acid may be 20% by mass of hydrochloric acid. For example, the acid may be 20% by mass of phosphoric acid.

[0040] According to embodiments of this application, the mesoporous molecular sieve includes MCM-41, SBA-3, or a combination thereof. In one embodiment, the mesoporous molecular sieve is MCM-41. In another embodiment, the mesoporous molecular sieve is SBA-3. According to embodiments of this application, the pore size of the mesoporous molecular sieve is in the range of 1.5 nm to 5.0 nm. Preferably, the pore size is in the range of 2 nm to 4 nm. For example, the pore size of the mesoporous molecular sieve can be 2.5 nm, 3 nm, or 3.5 nm.

[0041] In this embodiment, the acid treatment in step (1) can be performed at a temperature of 60-100°C. For example, the temperature is in the range of 60-70°C, 70-80°C, 80-90°C, or 90-100°C. In one or more embodiments, the temperature can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, or 95°C.

[0042] In this embodiment, the acid treatment in step (1) is performed for 1 to 36 hours. For example, the acid treatment is performed for 1 to 6 hours, 6 to 12 hours, 12 to 18 hours, or 18 to 24 hours.

[0043] In one or more embodiments of this application, the filtration may be atmospheric pressure filtration, pressurized filtration, or depressurized filtration.

[0044] In one or more embodiments of this application, washing can be performed using one or more of ultrapure water, methanol, and ethanol.

[0045] In embodiments of this application, the drying in step (1) can be carried out at a temperature of 80~120°C, for example, 80~90°C, 90~100°C, 100~110°C, or 110~120°C, for example, 85°C, 95°C, 105°C, or 115°C. In one or more embodiments, the drying in step (1) lasts for 2~24 hours, for example, 2~6 hours, 6~10 hours, 10~14 hours, 14~18 hours, 18~20 hours, or 20~24 hours.

[0046] Step (2): Load the first metal onto the modified mesoporous molecular sieve.

[0047] In one or more embodiments, step (2) includes the following steps: (2-a) The modified mesoporous molecular sieve from step (1) is impregnated in an aqueous solution containing the first metal precursor, and after impregnation, it is filtered and the solid is dried. (2-b) The dried solid is first calcined to obtain a carrier loaded with the first metal.

[0048] In one or more embodiments, the first metal precursor comprises one or more of the sulfate, nitrate, and chloride salts of a first metal. In one or more embodiments, the first metal precursor may be one or more of lanthanum nitrate, lanthanum chloride, cerium chloride, praseodymium chloride, praseodymium sulfate, neodymium nitrate, erbium sulfate, gadolinium nitrate, ytterbium sulfate, and ytterbium nitrate.

[0049] According to one or more embodiments, in step (2-a), the mass ratio of modified mesoporous molecular sieve, first metal ion, and water can be 1:0.01~0.05:1~10, for example 1:0.01~0.03:1~10, 1:0.01~0.03:1~5, or 1:0.01~0.05:1~5.

[0050] According to one or more embodiments, the impregnation in step (2-a) can be excessive impregnation, equal-volume impregnation, or multiple impregnations. In one or more embodiments, the impregnation temperature in step (2-a) can be 40~80°C, for example 40~50°C, 50~60°C, 60~70°C, or 70~80°C. According to one or more embodiments, the impregnation time in step (2-a) can be 2~72 hours, for example 2~12 hours, 12~24 hours, 24~36 hours, 36~48 hours, 48~60 hours, or 60~72 hours.

[0051] According to one or more embodiments, the drying in step (2-a) is carried out at a temperature of 80-120°C, for example, 80-90°C, 90-100°C, 100-110°C, or 110-120°C. According to one or more embodiments, the drying time can be 24-48 hours, for example, 24-30 hours, 30-36 hours, 36-42 hours, or 42-48 hours.

[0052] In one or more embodiments, the first calcination in step (2-b) is performed at a temperature of 500-700°C, for example, 500-600°C or 600-700°C. In one or more embodiments, the first calcination time is in the range of 2-36 hours, for example, 2-12 hours, 12-24 hours, 24-32 hours, or 32-36 hours. In one or more embodiments, step (2-b) is performed in air or an atmosphere containing an inert gas. In one or more embodiments, step (2-b) is performed in air. In one or more embodiments, step (2-b) is performed in an atmosphere containing an inert gas. In one or more embodiments, step (2-b) is performed in an atmosphere containing an inert gas. The inert gas may be selected from one or more of nitrogen, helium, argon, and neon.

[0053] In this application, the first metal may be supported on the support in the form of a first metal oxide, a first metal chloride, a first metal sulfide, a first metal nitride, or a combination thereof. For example, the first metal may be supported on the support in the form of La2O3, Ce2O3, CeO2, PrO2, Nd2O3, Eu2O3, Gd2O3, Er2O3, or Yb2O3.

[0054] Step (3): Load the phosphoric acid-modified bimetallic sites onto the support treated in step (2).

[0055] According to one or more embodiments, step (3) includes the following steps: (3-a) Mix the first calcined solid, the second metal precursor, and the third metal precursor in water to obtain a first mixture; (3-b) Add a phosphate-containing compound to the first mixture to obtain a second mixture; (3-c) The second mixture is filtered, and the solids are washed and dried; (3-d) The dried solid was subjected to a second calcination to obtain the catalyst.

[0056] In one or more embodiments, the second metal precursor comprises one or more of the sulfate, nitrate, and chloride salts of a second metal. In one or more embodiments, the second metal precursor may be, for example, one or more of ferric nitrate, manganese chloride, ferric sulfate, cobalt chloride, nickel nitrate, manganese sulfate, and nickel chloride.

[0057] In one or more embodiments, the third metal precursor comprises one or more of an ammonium salt, oxalate salt, potassium salt, and sodium salt of a third metal. In one or more embodiments, the third metal precursor may be, for example, one or more of ammonium tungstate, potassium tungstate, ammonium niobium oxalate, potassium niobium oxalate, potassium molybdate, sodium molybdate, ammonium molybdate, sodium vanadate, and ammonium vanadate.

[0058] In one or more embodiments, the mass ratio of the first calcined solid, the second metal ion, the third metal ion, and water can be 1:0.002~0.02:0.002~0.02:1~10, for example 1:0.002~0.005:0.002~0.005:1~5, 1:0.01~0.02:0.02~0.005:5~20, 1:0.015~0.002:0.015~0.002:5~9.

[0059] According to one or more embodiments, the phosphate-containing salt includes, but is not limited to, alkali metal dihydrogen phosphate, hydrogen phosphate, orthophosphate, or combinations thereof. In one or more embodiments, the phosphoric acid-containing salt may be sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium orthophosphate, potassium orthophosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, or combinations thereof. For example, the phosphoric acid-containing salt may be a combination of sodium dihydrogen phosphate and disodium hydrogen phosphate in a mass ratio of 1:1.

[0060] According to one or more embodiments, in step (3-b), the mass ratio of the solid after the first calcination to the phosphoric acid-containing acid anion can be 1:0.005~0.05, for example 1:0.008~0.02, 1:0.01~0.04.

[0061] According to one or more embodiments, step (3-b) is performed at a temperature of 60~100°C, for example, 60~80°C or 80~100°C.

[0062] According to one or more embodiments, the time for step (3-b) can be 6 to 24 hours, for example 6 to 12 hours, 12 to 18 hours or 18 to 24 hours.

[0063] According to one or more embodiments, in step (3-c), washing is performed using one or more of ultrapure water, methanol, and ethanol. For example, in one or more embodiments, ultrapure water is used for washing.

[0064] According to one or more embodiments, the drying temperature in step (3-c) can be 70~120°C, for example 70~100°C or 100~120°C. For example, 80°C, 90°C, 100°C or 110°C.

[0065] According to one or more embodiments, the drying duration of step (3-c) can be 2 to 24 hours, for example 2 to 6 hours, 6 to 10 hours, 10 to 14 hours, 14 to 18 hours, 18 to 20 hours or 20 to 24 hours.

[0066] According to one or more embodiments, the second calcination in step (3-d) is carried out under an inert gas atmosphere. For example, the second calcination in step (3-d) is carried out in one or more of nitrogen, helium, argon, and neon.

[0067] According to one or more embodiments, the second calcination in step (3-d) is carried out at a temperature of 300~500°C, for example, 300~400°C or 400~500°C. For example, the second calcination in step (3-d) is carried out at 350 or 450°C.

[0068] According to one or more embodiments, the second roasting in step (3-d) is carried out for 24 to 48 hours, for example 24 to 30 hours, 31 to 37 hours, 38 to 42 hours or 43 to 48 hours.

[0069] According to one or more embodiments, the method further includes a step of mixing the carrier with optional additives prior to acid treatment, said additives potentially comprising binders, lubricants, or combinations thereof. In one or more embodiments, the binder comprises one or more of polyvinyl alcohol, animal glue, molasses, sodium carboxymethyl cellulose, aluminum phosphate, and silicate cement. In one or more embodiments, the lubricant comprises one or more of stearic acid, sodium stearate, paraffin wax, guar gum, polyethylene wax, and zinc stearate.

[0070] This application also provides a method for preparing hydroquinone from phenol, the method comprising the following steps: (1) Providing a catalyst prepared by the aforementioned method; and (2) In water, phenol is reacted with hydrogen peroxide and the catalyst to obtain hydroquinone, wherein the hydroquinone includes catechol and hydroquinone.

[0071] According to one or more embodiments, in step (2), the space velocity of phenol can be 0.1~2h. -1 For example, 0.5~1h -1 According to one or more embodiments, the concentration of hydrogen peroxide can be 10-30% by weight, for example, 15-25% by weight. According to one or more embodiments, the mass ratio of phenol to hydrogen peroxide can be 1:0.09-0.36. According to one or more embodiments, the reaction temperature of step (2) can be 30-80°C, for example, 35-50°C, 50-60°C, 60-70°C, or 70-80°C.

[0072] The beneficial effects of this invention are: This invention achieves a leapfrog upgrade of molecular sieve catalysts from single acidic sites to multi-level composite active centers through a synergistic design of rare earth doping and heteropolyacid-like bimetallic site anchoring, wherein: 1. The catalyst of this application is constructed with a heteropolyacid-like structure and activated by rare earth Lewis acids. The phosphorus-containing Brønsted acid directional adsorption bifunctional mechanism enhances the activation ability of hydrogen peroxide and strengthens the activity of phenol hydroxylation. 2. The catalyst of this application constructs a size matching effect between bimetallic sites composed of heteropolyacids and molecular sieve channels, which overcomes the problem of compatibility between shape selectivity and mass transfer efficiency, greatly improves the selectivity of phenol hydroxylation, and avoids the further generation of excessive oxidation byproducts.

[0073] Example

[0074] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0075] Main reagents for the experiment

[0076] Main instruments for the experiment

[0077] Specific test methods used in the embodiments

[0078] High Performance Liquid Chromatography (HPLC) Test Methods

[0079] Hydrogen peroxide concentration determination: The hydrogen peroxide concentration in this application was determined by potassium permanganate titration. The specific method is as follows: Approximately 0.16 g of sample, accurate to 0.00028 g, was weighed using the reduction method in a 10 ml to 25 ml dropping bottle and placed in a 250 ml Erlenmeyer flask containing 100 ml of acid solution. Titration was performed with potassium permanganate standard solution until the solution turned pink and the color did not disappear within 30 seconds, which was the endpoint. The results were calculated as follows:

[0080] In the formula: V --The volume of potassium permanganate standard titration solution consumed in the titration, expressed in milliliters (mL); c --The accurate value of the concentration of the potassium permanganate standard titration solution, in moles per liter (mol / L); M --The molar mass of hydrogen peroxide (1 / 2H₂O₂) is numerical (M=17.01), in grams per mole (g / mol); m --The mass of the sample, expressed in grams (g).

[0081] Method for determining metal content: Take the dried catalyst and use inductively coupled plasma atomic emission spectrometry (ICP-AES) to determine the metal content. Test of genus content.

[0082] Conversion rate and selectivity testing methods

[0083] The catalyst activity in this application is mainly reflected by the hydrogen peroxide utilization rate; a higher utilization rate indicates stronger catalyst activity. The selectivity in this application is reflected by the selectivity for hydroquinone and the byproduct p-benzoquinone. Higher selectivity for hydroquinone and / or lower selectivity for p-benzoquinone indicates higher catalyst selectivity. The catalyst stability in this application is mainly reflected by the reaction time. A longer reaction time indicates that the catalyst can withstand a longer reaction without deactivation.

[0084] In this application, the conversion rate (%), H2O2 utilization rate, and selectivity (%) are calculated using the following methods: Methods for calculating conversion rate and selectivity: The reaction liquid was collected and its components were analyzed by liquid chromatography. The concentrations of each component were calculated using the external standard method based on the ultraviolet absorption of different substances at different wavelengths. Conversion rate (%) = 1 - (substrate concentration after reaction / substrate concentration before reaction) × 100%, Selectivity (%) = 1 - (Concentration of the corresponding substance / Sum of concentrations of all products) × 100% H2O2 utilization rate: 1 - (hydrogen peroxide concentration after reaction / hydrogen peroxide concentration before reaction) × 100%.

[0085] Example 1

[0086] 100g of 2nm MCM-41 molecular sieve, 200g of 20% nitric acid, and 1800g of water were mixed and added to a reactor, and reacted at 60℃ for 36h. The wet solid was washed with ultrapure water and then dried at 80℃ for 24h. The dried solid was then added to 100g of water with 2g of lanthanum sulfate and impregnated at 40℃ for 72h. The impregnated wet solid was dried at 120℃ for 24h, and then calcined at 500℃ for 36h in a tube furnace under air atmosphere. The calcined solid, 0.58g of ferric chloride, 0.35g of potassium tungstate, and 100g of water were mixed and added to a reactor, and reacted at 60℃ for 24h. Then, 0.63g of sodium dihydrogen phosphate was added, and the reaction was continued at 60℃ for 48h. The wet solid after the reaction was washed with ultrapure water and then dried at 70°C for 24 h. After that, it was calcined at 300°C for 48 h in a tube furnace under a nitrogen atmosphere to obtain the phenol hydroxylation catalyst PFeW / La-MCM-41-2. The ICP data of the supported metals are: La: 0.72%, Fe: 0.192%, W: 0.195%, P: 0.154%.

[0087] Airspeed is 0.1 h -1 A 20 wt% aqueous solution of phenol, and a space velocity of 0.027 h⁻¹. -1 A 30wt% hydrogen peroxide aqueous solution was subjected to a hydroxylation reaction in a fixed bed at 40℃. The phenol conversion rate was 45.7%, the hydrogen peroxide utilization rate was 92.2%, the selectivity of catechol was 14.6%, the selectivity of hydroquinone was 75.8%, and the selectivity of p-benzoquinone was 2.2%.

[0088] Comparative Example 1

[0089] 100g of 2nm MCM-41 molecular sieve, 200g of 20% nitric acid, and 1800g of water were mixed and added to a reactor, and reacted at 60℃ for 36h. The wet solid after reaction was washed with ultrapure water and then dried at 80℃ for 24h. The dried solid was then added to 100g of water with 2g of lanthanum sulfate and impregnated at 40℃ for 72h. The impregnated wet solid was dried at 120℃ for 24h, and then calcined at 500℃ for 36h in a tube furnace under air atmosphere. The calcined solid, 0.58g of ferric chloride, 0.35g of potassium tungstate, and 100g of water were mixed and added to a reactor, and reacted at 60℃ for 24h. The wet solid after the reaction was washed with ultrapure water, dried at 70°C for 24 h, and then calcined at 300°C for 48 h in a tube furnace under nitrogen atmosphere to obtain the phenol hydroxylation catalyst FeW / La-MCM-41-2. The supported metal ICP data are: La: 0.72%, Fe: 0.194%, W: 0.196%. Airspeed is 0.1 h -1 A 20 wt% aqueous solution of phenol, and a space velocity of 0.027 h⁻¹. -1 A 30wt% hydrogen peroxide aqueous solution was subjected to a hydroxylation reaction in a fixed bed at 40℃. The phenol conversion rate was 27.3%, the selectivity of catechol was 26.5%, the hydrogen peroxide utilization rate was 61.3%, the selectivity of hydroquinone was 58.6%, and the selectivity of p-benzoquinone was 1.6%.

[0090] Comparative Example 2

[0091] 100g of 2nm pore size MCM-41 molecular sieve, 200g of 20% nitric acid, and 1800g of water were mixed and added to a reactor, and reacted at 60℃ for 36h. The wet solid after reaction was washed with ultrapure water and then dried at 80℃ for 24h. The dried solid, 0.58g of ferric chloride, 0.35g of potassium tungstate, and 100g of water were mixed and added to the reactor, and reacted at 60℃ for 24h. Then, 0.63g of sodium dihydrogen phosphate was added, and the reaction was carried out at 60℃ for 48h. The wet solid after reaction was washed with ultrapure water and then dried at 70℃ for 24h. Finally, it was calcined at 300℃ for 48h in a tube furnace under a nitrogen atmosphere to obtain the phenol hydroxylation catalyst PFeW-MCM-41-2. The ICP data for the supported metals are: Fe: 0.192%, W: 0.190%, P: 0.151%.

[0092] Airspeed is 0.1 h -1 A 20 wt% aqueous solution of phenol, and a space velocity of 0.027 h⁻¹. -1A 30wt% hydrogen peroxide aqueous solution was subjected to a hydroxylation reaction in a fixed bed at 40℃. The phenol conversion rate was 36.4%, the selectivity of catechol was 17.5%, the hydrogen peroxide utilization rate was 41.6%, the selectivity of hydroquinone was 71.8%, and the selectivity of p-benzoquinone was 1.8%.

[0093] Examples 2-5

[0094] Based on Example 1, the type and pore size of the molecular sieve in step (1) were changed, and the catalyst performance evaluation results are as follows: Table 1. Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments.

[0095] Examples 6-9

[0096] Based on Example 1, the following changes were made to step (1): the mass ratio of molecular sieve, 20% nitric acid, and water; the treatment temperature and time of the nitric acid solution; and the catalyst performance evaluation results. Table 2 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments

[0097] Examples 10-17

[0098] Based on Example 1, the type of the first metal precursor and the mass ratio of the modified support, the first metal ion, and the water solvent in step (2) were changed. The catalyst performance evaluation results are as follows: Table 3 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments.

[0099] Examples 18-21

[0100] Based on Example 1, the impregnation temperature and impregnation time in step (2) were changed, and the catalyst performance evaluation results are as follows: Table 4 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments

[0101] Examples 22-25

[0102] Based on Example 1, the calcination temperature and calcination time in step (3) were changed, and the catalyst performance evaluation results are as follows: Table 5 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments.

[0103] Examples 26-33

[0104] Based on Example 1, the types of the second and third metal precursors, as well as the mass ratio of the modified support, second metal ion, third metal ion, and solvent in step (4) were changed. The catalyst performance evaluation results are as follows: Table 6 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments.

[0105] Examples 34-38

[0106] Based on Example 1, the type of phosphate and the mass ratio of modified support and phosphate in step (4) were changed. The catalyst performance evaluation results are as follows: Table 7 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments.

[0107] Examples 39-42

[0108] Based on Example 1, the inert gas atmosphere, calcination temperature, and calcination time in step (5) were changed, and the catalyst performance evaluation results are as follows: Table 8 Comparison of the results of fixed-bed phenol hydroxylation reactions using catalysts prepared in different embodiments.

[0109] Example 43

[0110] Based on Example 1, the reaction time was extended, and the catalyst performance evaluation results are as follows: Table 11. Results of the catalyst in Example 1 for fixed-bed phenol hydroxylation reaction

Claims

1. A catalyst for the production of dihydric phenols from phenol, the catalyst comprising: a support comprising a mesoporous molecular sieve modified by an acid; a first metal supported on the support, wherein the first metal is selected from the lanthanide series of the periodic table; and a phosphorus-containing acid-modified bimetallic site supported on the support, the phosphorus-containing acid-modified bimetallic site being a composite bimetallic site comprising a second metal and a third metal modified by a phosphorus-containing acid, wherein the second metal is selected from the group consisting of Group VIIB and Group VIII elements of the periodic table, the third metal is selected from the group consisting of Group VB and Group VIB elements of the periodic table.

2. The catalyst of claim 1, wherein: the acid used for modification comprises one or more of nitric acid, oxalic acid, hydrochloric acid, phosphoric acid; and / or the mesoporous molecular sieve comprises MCM-41, SBA-3, or a combination thereof; and / or the mesoporous molecular sieve has a pore size in the range of 1.5 nm to 5.0 nm, for example 2 nm to 4 nm, for example 2.5 nm, 3 nm, or 3.5 nm; and / or the lanthanide series of the periodic table comprises La, Ce, Pr, Nd, Eu, Gd, Er, Yb, or a combination thereof; and / or and / or the Group VIIB elements of the periodic table comprise Mn, Re, or a combination thereof; and / or the Group VIII elements of the periodic table comprise Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, or a combination thereof; and / or the Group VB elements of the periodic table comprise V, Nb, Ta, or a combination thereof; and / or the Group VIB elements of the periodic table comprise Cr, Mo, W, or a combination thereof; and / or the phosphorus-containing acid radical comprises dihydrogen phosphate, hydrogen phosphate, orthophosphate, or a combination thereof; and / or as a precursor of the first metal, the precursor comprises one or more of a sulfate salt, a nitrate salt, a chloride salt of the first metal, for example one or more of lanthanum nitrate, lanthanum chloride, cerium chloride, praseodymium chloride, praseodymium sulfate, neodymium nitrate, erbium sulfate, gadolinium nitrate, ytterbium sulfate, ytterbium nitrate; and / or as a precursor of the second metal, the precursor comprises one or more of a sulfate salt, a nitrate salt, a chloride salt of the second metal, for example one or more of iron nitrate, manganese chloride, iron sulfate, cobalt chloride, nickel nitrate, manganese sulfate, nickel chloride; and / or as a precursor of the third metal, the precursor comprises one or more of an ammonium salt, an oxalate salt, a potassium salt, a sodium salt of the third metal, for example one or more of ammonium tungstate, potassium tungstate, ammonium niobium oxalate, potassium niobium oxalate, potassium molybdate, sodium molybdate, ammonium molybdate, sodium vanadate, ammonium vanadate.

3. The catalyst of any one of claims 1-2, wherein: the mass ratio of the modified support to the first metal ion is 1:0.01~0.05 based on the mass of the modified support and the mass of the ion of the first metal; and / or the mass ratio of the modified support to the second metal ion, the third metal ion is 1:0.002~0.02:0.002~0.02 based on the mass of the modified support and the mass of the ion of the second metal, the third metal; and / or the mass ratio of the modified support to the phosphorus-containing acid radical is 1:0.005~0.05; and / or the mass ratio of the modified support to the phosphorus-containing acid radical is 1:0.005~0.05; and / or The mass ratio of the first metal ion, the second metal ion, and the third metal ion is 1:0.5-4:0.5-4.

4. The catalyst of any one of claims 1-3, wherein: The catalyst further comprises an optional additive comprising a binder, a lubricant, or a combination thereof, wherein the binder comprises one or more of polyvinyl alcohol, animal glue, molasses, sodium carboxymethyl cellulose, aluminum phosphate, Portland cement; and the lubricant comprises one or more of stearic acid, sodium stearate, paraffin wax, sesbania gum, polyethylene wax, zinc stearate.

5. A method of preparing a catalyst for the production of a benzenediol from a phenol, the method comprising the steps of: (1) treating a support with an acid, the support comprising a mesoporous molecular sieve, thereby obtaining a modified mesoporous molecular sieve; (2) loading a first metal on the modified mesoporous molecular sieve, wherein the first metal is selected from the lanthanide series of the periodic table; (3) loading a phosphorus acid-containing modified bimetallic site on the support treated in step (2), wherein the phosphorus acid-containing modified bimetallic site is a composite bimetallic site comprising a second metal and a third metal modified with a phosphorus acid, wherein the second metal is selected from the group VIIB and VIII elements of the periodic table, and wherein the third metal is selected from the group VB and VIB elements of the periodic table.

6. The method of claim 5, wherein: the lanthanide series of the periodic table comprises La, Ce, Pr, Nd, Eu, Gd, Er, Yb, or a combination thereof; and / or the group VIIB elements of the periodic table comprise Mn, Re, or a combination thereof; and / or the group VIII elements of the periodic table comprise Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, or a combination thereof; and / or the group VB elements of the periodic table comprise V, Nb, Ta, or a combination thereof; and / or the group VIB elements of the periodic table comprise Cr, Mo, W, or a combination thereof; and / or the phosphorus acid-containing anion comprises dihydrogen phosphate, hydrogen phosphate, orthophosphate, or a combination thereof; and / or step (1) is performed in water, and the mass ratio of the support, the acid, and the water is 1:0.1-2:5-20, for example 1:0.1-1:5-10, 1:1-2:10-20, and filtration, washing, and drying of the solid are performed after the acid treatment; and / or the acid comprises one or more of nitric acid, oxalic acid, hydrochloric acid, phosphoric acid, for example at least 20 mass% of nitric acid; and / or the mesoporous molecular sieve comprises MCM-41, SBA-3, or a combination thereof; and / or the mesoporous molecular sieve has a pore size in the range of 1.5 nm to 5.0 nm, for example 2 nm to 4 nm, for example 2.5 nm, 3 nm, or 3.5 nm; and / or the acid treatment of step (1) is performed at a temperature in the range of 60-100 °C, for example the temperature is in the range of 60-70 °C, 70-80 °C, 80-90 °C, or 90-100 °C; and / or the acid treatment of step (1) is performed for 1-36 hours, for example 1-6 hours, 6-12 hours, 12-18 hours, or 18-24 hours; and / or the acid treatment of step (1) is performed for 1-36 hours, for example 1-6 hours, 6-12 hours, 12-18 hours, or 18-24 hours; and / or the filtration comprises normal pressure filtration, pressure filtration or reduced pressure filtration, and / or the washing is performed using one or more of ultrapure water, methanol, ethanol, and / or the drying is performed at a temperature of 80-120°C, wherein the drying is performed for a time period of 2-24 hours.

7. The method of any one of claims 5-6, wherein: step (2) comprises the following steps: (2-a) impregnating the modified mesoporous molecular sieve of step (1) in an aqueous solution comprising a first metal precursor, and performing filtration and drying the solid after impregnation, and (2-b) performing a first calcination of the dried solid to obtain a support loaded with a first metal, wherein: the first metal precursor of step (2-a) comprises one or more of a sulfate salt, a nitrate salt, a chloride salt of the first metal; and / or in step (2-a), the mass ratio of the modified mesoporous molecular sieve, the first metal ion, water is 1:0.01-0.05:1-10; and / or the impregnation temperature of step (2-a) is 40-80°C, and the impregnation time is 2-72 hours; and / or the drying of step (2-a) is performed at a temperature of 80-120°C, and the drying time is 24-48 hours; and / or the first calcination of step (2-b) is performed at a temperature of 500-700°C, and the first calcination time is in the range of 2-36 hours; and / or step (2-b) is performed in air or an atmosphere comprising an inert gas, wherein the inert gas comprises one or more of nitrogen, helium, argon, neon.

8. The method of any one of claims 5-7, wherein: step (3) comprises the following steps: (3-a) mixing the first calcined solid, a second metal precursor, a third metal precursor in water to obtain a first mixture; (3-b) adding a phosphorus-containing salt to the first mixture to obtain a second mixture; (3-c) performing filtration on the second mixture, and washing and drying the solid; (3-d) performing a second calcination of the dried solid to obtain a catalyst; wherein: the second metal precursor comprises one or more of a sulfate salt, a nitrate salt, a chloride salt of the second metal, such as one or more of iron nitrate, manganese chloride, iron sulfate, cobalt chloride, nickel nitrate, manganese sulfate, nickel chloride; and / or the third metal precursor comprises one or more of an ammonium salt, an oxalate salt, a potassium salt, a sodium salt of the third metal, such as one or more of ammonium tungstate, potassium tungstate, ammonium niobium oxalate, potassium niobium oxalate, potassium molybdate, sodium molybdate, ammonium molybdate, sodium vanadate, ammonium vanadate; and / or the mass ratio of the first calcined solid, the second metal ion, the third metal ion, water is 1:0.002-0.02:0.002-0.02:1-10, such as 1:0.002-0.005:0.002-0.005:1-5, 1:0.01-0.02:0.02-0.005:5-20, 1:0.015-0.002:0.015-0.002:5-9; the phosphate-containing acid comprises sodium phosphate monobasic, sodium phosphate dibasic, sodium orthophosphate, potassium orthophosphate, potassium phosphate monobasic, potassium phosphate dibasic, or a combination thereof, for example, a combination of sodium phosphate monobasic and sodium phosphate dibasic in a mass ratio of 1:1; and / or in step (3-b), the mass ratio of the first calcined solid to the phosphate-containing acid is 1:0.005-0.05; and / or step (3-b) is performed at a temperature of 60-100°C; and / or step (3-b) is performed for a time of 6-24 hours; in step (3-c), washing is performed using one or more of ultrapure water, methanol, and ethanol; and / or the drying temperature of step (3-c) is 70-120°C; and / or the duration of drying of step (3-c) is 2-24 hours; and / or the second calcination of step (3-d) is performed under an inert gas atmosphere, the inert gas being selected from one or more of nitrogen, helium, argon, and neon; and / or the second calcination of step (3-d) is performed at a temperature of 300-500°C; and / or the second calcination of step (3-d) is performed for a time of 24-48 hours; and / or the method further comprises a step of mixing the support with an optional additive prior to the acid treatment, the additive comprising a binder, a lubricant, or a combination thereof, wherein the binder comprises one or more of polyvinyl alcohol, animal glue, molasses, sodium carboxymethyl cellulose, aluminum phosphate, Portland cement; and the lubricant comprises one or more of stearic acid, sodium stearate, paraffin wax, sesbania gum, polyethylene wax, and zinc stearate.

9. A method of preparing a benzenediol from a phenol, the method comprising the steps of: (1) providing the catalyst of any one of claims 1-5; and (2) reacting the phenol in water using hydrogen peroxide and the catalyst to obtain the benzenediol, wherein the benzenediol comprises catechol and hydroquinone.

10. The method of claim 9, wherein: In step (2), the space velocity of phenol is 0.1-2 h -1 ; and / or the concentration of the hydrogen peroxide is 10-30 wt%; and / or the mass ratio of the phenol to the hydrogen peroxide is 1:0.09-0.36; and / or the reaction temperature of step (2) is 30-80°C.

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