Method for producing phosphorus-modified metal oxides
A simplified process for producing phosphorus-modified metal oxides by controlling the temperature and contact time of a phosphorus source with a metal oxide addresses inefficiencies in existing methods, achieving effective phosphorus modification with reduced complexity and costs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MITSUI MINING & SMELTING CO LTD
- Filing Date
- 2024-10-30
- Publication Date
- 2026-05-15
AI Technical Summary
Existing methods for phosphorus modification of metal oxides, such as vapor deposition and high-temperature calcination, are inefficient, complex, and costly, leading to low utilization of phosphorus-containing compounds and high equipment costs.
A method involving the preparation of a metal oxide and a phosphorus source with specific melting and mass loss temperatures, followed by contacting them at an intermediate temperature and heating to 1200°C or less, allowing phosphorus modification without the need for vacuum chambers or high-temperature calcination.
This method enables simple and efficient production of phosphorus-modified metal oxides, exhibiting improved phosphorus modification effects with reduced equipment complexity and costs.
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Abstract
Description
Technical Field
[0001] The present invention relates to a method for producing a phosphorus-modified metal oxide.
Background Art
[0002] As a means for imparting performance such as improved heat resistance and biocompatibility to metal oxides such as zeolites, a technique for modifying metal oxides with phosphorus is known. Patent Document 1 describes a method of depositing a phosphorus-containing compound on zeolite, and a method of contacting a solution containing a phosphorus-containing compound with zeolite and performing calcination after evaporation to dryness or solid-liquid separation. Patent Document 2 also describes a technique of melting and coating calcium phosphate on a base material such as alumina or zirconia.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] The vapor deposition method described in Patent Document 1 requires a vacuum chamber, and the utilization efficiency of the phosphorus-containing compound is not high. In addition, the solution method tends to make the process complicated. In the technique described in Patent Document 2, it is necessary to perform the fusion of calcium phosphate and subsequent calcination at a high temperature, which causes problems such as high equipment costs and reduced energy efficiency.
[0005] Therefore, an object of the present invention is to provide a method for producing a phosphorus-modified metal oxide that can be carried out with simple processes and equipment and can sufficiently exhibit the effect of phosphorus modification. [Means for solving the problem]
[0006] The gist of this invention is as follows:
[0007] [1] Step 1 involves preparing a metal oxide and a phosphorus source that satisfies the following condition A. Condition A: When the melting point of the phosphorus source is T1 and the 5% mass loss temperature of the phosphorus source is T2, T1 exists and T1 is less than T2. Step 2 involves bringing the phosphorus source into contact with the metal oxide at a temperature between T1 and T2 such that the phosphorus source becomes liquid, and Step 3 involves heating the metal oxide and the phosphorus source, which are in contact, to a temperature of T2 greater than 1200°C or less. A method for producing phosphorus-modified metal oxides, including the method described above. [2] The method for producing a phosphorus-modified metal oxide according to [1], wherein in step 2, the time during which the phosphorus source is at a temperature of T1 or higher and T2 or lower is 1 minute or more. [3] A method for producing a phosphorus-modified metal oxide according to [1] or [2], wherein the temperature T1 is 40°C or higher. [4] A method for producing a phosphorus-modified metal oxide according to any one of [1] to [3], wherein the metal oxide comprises a zeolite. [5] The specific surface area of the zeolite is 50 m². 2 A method for producing phosphorus-modified metal oxides according to [4], wherein the amount is 1 / g or more. [6] The zeolite contains an aluminum element, A method for producing a phosphorus-modified metal oxide according to [4] or [5], wherein the ratio of the amount of substance of phosphorus element contained in the phosphorus source to the amount of substance of aluminum element contained in the zeolite is 0.10 or more and 1.00 or less. [Effects of the Invention]
[0008] According to the present invention, it is possible to provide a method for producing a phosphorus-modified metal oxide that can be carried out with simple processes and equipment and can fully exhibit the effect of phosphorus modification.
Embodiments for Carrying Out the Invention
[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail.
[0010] [Method for Producing Phosphorus-Modified Metal Oxide] The method for producing a phosphorus-modified metal oxide of the present invention (also referred to as "the production method of the present invention") is Step 1 of preparing a metal oxide and a phosphorus source that satisfies the following condition A, Condition A: When the melting point of the phosphorus source is T1 and the 5% mass reduction temperature of the phosphorus source is T2, T1 exists and T1 is smaller than T2. Step 2 of bringing the phosphorus source into contact with the metal oxide at a temperature of T1 or higher and T2 or lower so that the phosphorus source is in a liquid state, and Step 3 of heating the contacted metal oxide and the phosphorus source to a temperature of higher than T2 and 1200 °C or lower, which is a method for producing a phosphorus-modified metal oxide. That phosphorus is modified on the metal oxide means a state in which phosphorus elements are physically or chemically adsorbed or retained on the outer surface or the inner surface of pores of the metal oxide. According to the production method of the present invention, a state in which phosphorus is modified on the metal oxide can be realized.
[0011] (Step 1) Step 1 of the production method of the present invention will be described. Step 1 is a step of preparing a metal oxide and a phosphorus source that satisfies the following condition A. Condition A: When the melting point of the phosphorus source is T1 and the 5% mass reduction temperature of the phosphorus source is T2, T1 is smaller than T2.
[0012] [Metal Oxide] Metal oxides are oxides of metals or metalloid elements such as Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, In, Si, Ge, and Sn, or composite oxides thereof. Metal oxides are, for example, particulate. When metal oxides are particulate, the average particle size of the metal oxide particles is, for example, 1 μm to 100 μm, preferably 2 μm to 50 μm. The average particle size of the metal oxide particles is the particle size D50 at which the cumulative volume accounts for 50% in the volume-based particle size distribution obtained by laser diffraction-scattering particle size distribution measurement. It is preferable that the metal oxide contains zeolite. When the metal oxide contains zeolite, the mass of the zeolite is preferably 70% to 100% by mass, more preferably 80% to 100% by mass, and even more preferably 90% to 100% by mass, based on the total mass of the metal oxide. Zeolites are crystalline substances in which TO4 units (where T is the central atom) having a tetrahedral structure share oxygen (O) atoms and are three-dimensionally linked to form open and regular micropores. Specifically, it includes silicates, germanium salts, and arsenates described in the structure committee dataset of the International Zeolite Association. Here, silicates include, for example, aluminosilicates, gallosilicates, ferrisilicates, titanosilicates, borosilicates, etc. Germanium salts include, for example, aluminogermanium salts, etc. Arsenates include, for example, aluminoarsenates, etc. Aluminosilicates used as zeolites, for example, also include those in which a part of Si or Al in the framework is substituted with divalent or trivalent cations such as Ti, Ga, Mg, Mn, Fe, Co, Zn, etc. Examples of zeolites include zeolites of various types such as AFI type, ATO type, Beta type, CON type, FAU type, GME type, LTL type, MOR type, MTW type, OFF type, MSE type, AEL type, EUO type, FER type, HEU type, MEL type, MFI type, NES type, TON type, WEI type, AEI type, AFX type, ANA type, CHA type, DDR type, ERI type, GIS type, KFI type, LTA type, MRT type, PAU type, YUG type, etc. Zeolites preferably contain aluminum element, and more preferably contain crystalline aluminosilicates. In particular, among zeolites, zeolites with a small Si / Al molar ratio (the ratio of the amount of substance of silicon element to the amount of substance of aluminum element contained in the zeolite) are excellent in chemical properties but inferior in heat resistance, so improvement in heat resistance by phosphorus modification is required. The Si / Al molar ratio of the zeolite is preferably 1 or more and 50 or less, more preferably 2 or more and 45 or less, and even more preferably 3 or more and 40 or less. It is preferable that the zeolite contains an aluminum element and the ratio of the amount of substance of phosphorus element contained in the phosphorus source to the amount of substance of aluminum element contained in the zeolite (also referred to as "P / Al") is 0.01 or more and 2.00 or less, more preferably 0.02 or more and 1.50 or less, even more preferably 0.10 or more and 1.00 or less, particularly preferably 0.20 or more and 0.80 or less, and most preferably 0.40 or more and 0.80 or less. The specific surface area of zeolite is 50 m². 2 It is preferable that it be 200m or more per gram. 2 It is more preferable that it be 300m or more per gram. 2 It is even more preferable that the amount be 1 / g or more. The specific surface area of a metal oxide can be calculated using the BET method.
[0013] The metal oxide prepared in step 1 may be one type or two or more types.
[0014] <Phosphorus sources that satisfy condition A> A phosphorus source is a phosphorus-containing material used to modify metal oxides with phosphorus, and is either phosphorus or a phosphorus-containing compound. The phosphorus source used in this invention satisfies the following condition A. Condition A: When the melting point of the phosphorus source is T1 and the 5% mass loss temperature of the phosphorus source is T2, T1 is less than T2. A phosphorus source that satisfies condition A is also called "phosphorus source A".
[0015] The melting point (T1) of the phosphorus source is measured by the following method. T1 is defined as the melting point observed when 5 mg of phosphorus source is heated from 20°C to temperature T3 at a rate of 10°C / min using a differential scanning calorimeter in an atmospheric environment. Here, temperature T3 is the highest temperature in the process in which phosphorus modification is actually to be performed. When measuring T1, first determine a suitable temperature T3. If the melting point is not observed by temperature T3, T1 is considered to be greater than T3 (also written as "T3<"). If the melting point is not observed by the previously determined temperature T3, temperature T3 may be set to an even higher temperature and T1 may be measured in the same manner. If the phosphorus source is liquid at 20°C, T1 is considered to be 20°C or lower. If the 5% mass loss temperature (T2), described later, is observed before the melting point is observed during the heating process, T1 is considered to not exist.
[0016] The 5% mass loss temperature (T2) of the phosphorus source is measured by the following method. The phosphorus source of 5 mg is heated from 20 °C to temperature T3 at a rate of 10 °C / min in a differential scanning calorimeter under an air atmosphere, and the temperature when the mass decreases by 5% from the initial mass is defined as T2. When the mass reduction does not show more than 5% by the time of reaching temperature T3, T2 is set to be above T3 (also described as "T3 <"). Temperature T3 may be the one determined when measuring the aforementioned T1, or when T2 is not confirmed by the time of reaching the previously determined temperature T3, temperature T3 may be reset to a higher temperature, and T2 may be measured in the same manner.
[0017] T2 means the temperature at which the phosphorus source decomposes or boils, that is, the temperature at which the molten state cannot be maintained. Condition A (T1 < T2) represents that the phosphorus source does not sublime or decompose before melting. The phosphorus source A may be liquid or solid at room temperature, but is preferably solid from the viewpoint of handling property. T1 is preferably 30 °C or higher, more preferably 40 °C or higher, still more preferably 40 °C or higher and 800 °C or lower, and particularly preferably 40 °C or higher and 600 °C or lower. T2 is preferably 31 °C or higher and 1000 °C or lower, and more preferably 41 °C or higher and 800 °C or lower.
[0018] As the phosphorus source A, for example, it can be selected from compounds satisfying condition A among phosphoric acid esters, phosphorous acid esters, phosphines, phosphine oxides, inorganic phosphates, and inorganic phosphorus compounds, and among these, phosphoric acid esters are preferred. Examples of the phosphorus source A corresponding to phosphoric acid esters include triphenyl phosphate, trimethyl phosphate, tri-p-cresyl phosphate, tris(2-ethylhexyl) phosphate, etc. Examples of the phosphorus source A other than phosphoric acid esters include phosphorus pentoxide, triphenyl phosphite, and triphenylphosphine.
[0019] The phosphorus source A prepared in step 1 may be one kind or two or more kinds.
[0020] The amounts of metal oxide and phosphorus source A prepared in step 1 are not particularly limited and can be adjusted according to the amount of phosphorus to be modified in the metal oxide. However, the ratio of the mass of the metal oxide to the mass of phosphorus source A (mass of metal oxide:mass of phosphorus source A) is typically between 1000:1 and 1:100, between 100:1 and 1:10, and more typically between 10:1 and 2:1.
[0021] In step 1, in addition to phosphorus source A, a phosphorus source that does not satisfy condition A may also be prepared.
[0022] (Process 2) Step 2 of the manufacturing method of the present invention will now be described. Step 2 is a step in which phosphorus source A is brought into contact with a metal oxide at a temperature between T1 and T2 such that phosphorus source A is in a liquid state. In step 2, phosphorus can be added to the metal oxide without the need for a solution by bringing the phosphorus source into contact with the metal oxide in a liquid state. Because no solution is used, phosphorus modification can be carried out in a simple process.
[0023] When performing step 2, the state of the metal oxide and phosphorus source A is not particularly limited. For example, if phosphorus source A is solid, step 2 may be performed with the metal oxide and phosphorus source A kneaded together using a mortar and pestle, or with the metal oxide and phosphorus source A simply shaken together in a container without kneading, or with the metal oxide and phosphorus source A simply placed in the same container. Also, if phosphorus source A is liquid, step 2 may be performed with the metal oxide added to the liquid phosphorus source A.
[0024] In step 2, the temperature of phosphorus source A may or may not be constant.
[0025] From the viewpoint of ensuring sufficient contact between the metal oxide and the phosphorus source A, it is preferable that in step 2, the time during which the phosphorus source A is at a temperature between T1 and T2 (also referred to as "t12") is 1 minute or more. Here, the statement that the time during which the phosphorus source A is at a temperature between T1 and T2 is 1 minute or more does not mean that the phosphorus source A is continuously at a temperature between T1 and T2 for 1 minute or more, but rather that the total time during which the phosphorus source A is at a temperature between T1 and T2 is 1 minute or more. In step 2, the time during which phosphorus source A is at a temperature between T1 and T2 is more preferably 2 minutes or more and 180 minutes or less, and even more preferably 2 minutes or more and 120 minutes or less.
[0026] In step 2, it is sufficient to bring phosphorus source A into contact with the metal oxide at a temperature between T1 and T2 such that phosphorus source A is in a liquid state. Step 2 may also be performed with phosphorus source A mixed with a phosphorus source that does not satisfy condition A.
[0027] (Step 3) Step 3 of the manufacturing method of the present invention will now be described. Step 3 is a step in which the metal oxide and phosphorus source A, which are in contact, are heated to a temperature of T2 greater than 1200°C or less. In step 3, the metal oxide and phosphorus source A are heated in contact to perform calcination, thereby obtaining a phosphorus-modified metal oxide. Since the upper limit of the heating temperature in step 3 is 1200°C or less, step 3 can be carried out with simple equipment. The heating temperature in step 3 is preferably greater than T2 and 1000°C or less, more preferably between T2+10°C and 900°C, and even more preferably between T2+20°C and 800°C.
[0028] The heating temperature in step 3 may or may not be constant.
[0029] In step 3, the time during which the metal oxide and phosphorus source A are at a temperature above T2 but below 1200°C is typically between 1 minute and 300 minutes, and more typically between 60 minutes and 240 minutes. Here, the statement that the time during which the metal oxide and phosphorus source A are at a temperature above T2 but below 1200°C is between 1 minute and 300 minutes does not mean that the metal oxide and phosphorus source A are continuously at a temperature above T2 but below 1200°C for 1 minute or more but below 300 minutes; it is sufficient that the total time during which the metal oxide and phosphorus source A are at a temperature above T2 but below 1200°C is between 1 minute and 300 minutes. [Examples]
[0030] The embodiments of the present invention will now be specifically described with reference to the following examples, but the present invention is not limited to these embodiments.
[0031] Triphenyl phosphate, diammonium hydrogen phosphate ((NH4)2HPO4), and tricalcium phosphate (Ca3(PO4)2) were prepared as phosphorus sources.
[0032] <Thermogravimetric-differential thermal analysis (TG-DTA)> The melting points (T1) of triphenyl phosphate, diammonium hydrogen phosphate, and tricalcium phosphate, and the 5% mass loss temperature (T2) of the phosphorus source were measured. A differential thermal / thermogravimetric analyzer STA7300 manufactured by Hitachi High-Tech Science Corporation was used as the measuring instrument, and the measurement conditions were as follows: The measurement start temperature was 20°C. The maximum temperature (temperature T3) of the phosphorus modification process described later was set to 600°C. The measurement results are shown in Table 1 below. Reference material Al2O3 Atmospheric gas and flow rate: Air (200 mL / min) Material of sample pan: Al2O3 Heating rate: 10°C / min
[0033] <Manufacturing of proton-type beta zeolite> NH4-type Beta zeolite (Si / Al molar ratio = 5) was prepared. Proton-type Beta zeolite was obtained by calcining this NH4-type Beta zeolite in air at 600°C for 3 hours.
[0034] <Example 1> Triphenyl phosphate and proton-type beta zeolite were prepared. The mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the amount of P (phosphorus element) in triphenyl phosphate and the amount of Al (aluminum element) in proton-type beta zeolite were P / Al (molar ratio) = 0.25. Triphenyl phosphate and proton-type beta zeolite were kneaded using a mortar and pestle for 15 minutes. The mixture was then placed in a dish-shaped open container. The dish-shaped open container containing the mixture was placed in an electric furnace and heated from 20°C to 600°C in 7 minutes in air, and then fired at 600°C for 3 hours to obtain the material of Example 1. The melting point T1 of triphenyl phosphate is 48°C and the 5% mass loss temperature T2 is 220°C. Therefore, in the above operation, when the temperature is between 48°C and 220°C, it corresponds to step 2, and the time (t12) was 2 minutes.
[0035] <Example 2> Triphenyl phosphate and proton-type beta zeolite were prepared in the same manner as in Example 1. First, the triphenyl phosphate was placed in the same dish-shaped open container as in Example 1, and then the proton-type beta zeolite was placed in the dish-shaped open container containing the triphenyl phosphate. Subsequently, the dish-shaped open container was placed in an electric furnace and fired in the same manner as in Example 1 to obtain the material for Example 2. In other words, in Example 2, the step of kneading with a mortar and pestle for 15 minutes, as performed in Example 1, was not carried out.
[0036] <Comparative Example 1> The same procedure as in Example 1 was followed to obtain the material for Comparative Example 1, except that diammonium hydrogen phosphate ((NH4)2HPO4) was used instead of triphenyl phosphate. Since diammonium hydrogen phosphate does not have a melting point T1, there is no step corresponding to step 2 in the above procedure.
[0037] <Comparative Example 2> The procedure for Comparative Example 2 was performed, except that tricalcium phosphate (Ca3(PO4)2) was used instead of triphenyl phosphate. T1 and T2 of tricalcium phosphate were not detected from 20°C to temperature T3 (600°C). Since heating to a temperature above the melting point T1 of tricalcium phosphate was not performed in the above procedure, there is no step corresponding to step 2.
[0038] <Example 3> The mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the molar ratio of P in triphenyl phosphate to Al in proton-type beta zeolite was P / Al = 0.05. Furthermore, the mixing method of triphenyl phosphate and proton-type beta zeolite was changed from kneading with a mortar and pestle to shaking the powders in a glass container. The materials for Example 3 were obtained in the same manner as in Example 1.
[0039] <Example 4> The material for Example 4 was obtained in the same manner as in Example 3, except that the mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the amount of P in triphenyl phosphate and the amount of Al in proton-type beta zeolite were P / Al (molar ratio) = 0.15.
[0040] <Example 5> The material for Example 5 was obtained in the same manner as in Example 3, except that the mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the P / Al molar ratio of P in triphenyl phosphate to Al in proton-type beta zeolite was 0.35.
[0041] <Example 6> The material for Example 6 was obtained in the same manner as in Example 3, except that the mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the P / Al molar ratio of P in triphenyl phosphate to Al in proton-type beta zeolite was 0.50.
[0042] <Example 7> The material for Example 7 was obtained in the same manner as in Example 3, except that the mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the P / Al molar ratio of P in triphenyl phosphate to Al in proton-type beta zeolite was 0.75.
[0043] <Example 8> The material for Example 8 was obtained in the same manner as in Example 3, except that the mixing ratio of triphenyl phosphate and proton-type beta zeolite was adjusted so that the P / Al molar ratio of P in triphenyl phosphate to Al in proton-type beta zeolite was 1.00.
[0044] <Durability treatment> Each material from Examples 1-8 and Comparative Examples 1-2 was subjected to heat treatment at 950°C for 2 hours under an N2 atmosphere to obtain materials after durability treatment.
[0045] <Performance Evaluation> The specific surface area of the materials in Examples 1-8 and Comparative Examples 1-2 before and after durability treatment was measured using a BELSORP-miniII manufactured by Nippon Bell Co., Ltd. The specific surface area was calculated using the BET method. The retention rate of the specific surface area was calculated as (specific surface area after durability treatment) ÷ (specific surface area before durability treatment) × 100.
[0046] The evaluation results are shown in Table 1 below. In the table, t12 represents the time during which phosphorus source A is at a temperature between T1 and T2.
[0047] [Table 1]
[0048] Table 1 shows that the materials of Examples 1 to 8 had a higher retention rate of specific surface area after durability treatment than the materials of Comparative Examples 1 to 2, and that the heat resistance, which is the effect of phosphorus modification, was fully exhibited even with a simple process and equipment.
Claims
1. Step 1: Prepare a metal oxide and a phosphorus source that satisfies the following condition A. Condition A: When the melting point of the phosphorus source is T1 and the 5% mass loss temperature of the phosphorus source is T2, T1 exists and T1 is less than T2. Step 2 involves bringing the phosphorus source into contact with the metal oxide at a temperature of T1 or higher and T2 or lower such that the phosphorus source becomes liquid, and Step 3: Heat the metal oxide and the phosphorus source, which are in contact, to a temperature T2 greater than 1200°C or less. A method for producing phosphorus-modified metal oxides, including the method described above.
2. The method for producing a phosphorus-modified metal oxide according to claim 1, wherein in step 2, the time during which the phosphorus source is at a temperature of T1 or higher and T2 or lower is 1 minute or more.
3. The method for producing a phosphorus-modified metal oxide according to claim 1, wherein the temperature T1 is 40°C or higher.
4. The method for producing a phosphorus-modified metal oxide according to claim 1, wherein the metal oxide contains a zeolite.
5. The specific surface area of the zeolite is 50 m² ２ A method for producing a phosphorus-modified metal oxide according to claim 4, wherein the amount is 1 / g or more.
6. The zeolite contains an aluminum element, The method for producing a phosphorus-modified metal oxide according to claim 5, wherein the ratio of the amount of phosphorus element contained in the phosphorus source to the amount of aluminum element contained in the zeolite is 0.10 or more and 1.00 or less.