TWI391183B - Method for making metal oxides - Google Patents

Description

Method of making metal oxides Field of invention

The invention is generally directed to a misaligned oxide material. A miscellaneous oxide system contains an oxide of two or more different metal elements. It can be used for a variety of different purposes, including as a catalyst and a wide range of electronic materials. In a preferred embodiment, the present invention is directed to a method of making a porous, misaligned oxide having improved high temperature stability. In another aspect, the invention is also directed to a method of making a porous, non-refractory oxide.

Related technical description

In general, crystalline structures containing oxides of several different metal elements are more complex than simple oxides such as Al ₂ O ₃ and SiO ₂ . In addition, the phase purity (i.e., the presence of the crystalline phase and the lack of an undesired phase) is typically extremely difficult to achieve with such a compound. This is because these complex crystal structures are extremely sensitive to various variables of the chemical composition.

Therefore, in order to achieve a uniform and consistent nature that is important for many applications, it is desirable to ensure a uniform dispersion of the elements, which results in the desired purity of the oxides. One difficulty in achieving this uniform element distribution is that the behavior of individual elements during processing is different.

For example, precipitation and reaction rates vary widely for each element, resulting in segregation in processes such as precipitation and sol processing. The response of different elements to temperature and pressure is also very different. For example, many of the metal elements used to form the mis-oxide have a relatively low melting point. If a sufficiently reduced atmospheric pressure is present during the heat treatment, these elements will exist in a metal form (rather than an oxide type) and melt. This melting causes severe segregation, extensive formation of impure phases, and loss of surface area.

Even with such difficulties, various methods of making a mismatched oxide are known in the art.

These methods include: 'Shake and bake'. Total precipitation. Thermal evaporation and spraying technology. The polymer mismatch method, sol 'shake and bake' is the coarsest and simplest. An example is described in U.S. Patent No. 5,932,146. Different oxide powders (each containing one or more desired elements) are simply mixed together, ground, and then burned at a high temperature to uniformly mix the different elements via diffusion. The problem with this method is that the starting materials are extremely non-uniform; therefore, very high sintering temperatures are required in order to achieve uniformity. In general, intermediate grinding is also required. High sintering temperatures generally reduce surface area, and long sintering times, high temperatures, and intermediate grinding result in extremely high processing costs. To the impossible degree.

The co-precipitation method provides a more uniform precursor to relatively simple metal oxides. Examples of the application system is described in Catalyst A: General Theory (Applied Catalysis A: General), 235,79-92 page, 2002 (Zhang-Steenwinkel, Beckers and Bliek) and J.of Power Sources, 86, pp. 395-400, 2000 (Morie, Sammes & Tompsett). These methods have the disadvantage of being extremely difficult with several elements. Generally, different elements are precipitated at different rates, and therefore, for some materials, inhomogeneity is a major problem, and a reasonably high sintering temperature is still required. For example, the method of Zhang-Steenwinkel et al. requires a temperature in excess of 800 °C to form a suitable crystalline phase, and the method of Morie et al. requires 1000 °C. In addition, the precipitating agents required to achieve proper precipitation and chemical homogeneity are generally expensive.

Most thermal evaporation and spraying techniques are more relevant to the manufacture of oxide films or coatings. These include techniques such as gas condensation processing, chemical vapor condensation, plasma spraying, and spray pyrolysis. The most important of these techniques for overall processing is spray pyrolysis (Messing et al. 1994).

Spray pyrolysis is a method of producing a powder of a metal or oxide by thermally decomposing a metal salt or an organometallic solution. The solution is first converted to an aerosol by passing through an atomizing spray nozzle or by an ultrasonic transducer. The aerosol is then sprayed in a heated zone sufficient to cause evaporation of the solvent or on the heated surface, after which the metal or oxide is precipitated.

Generally, in the spray pyrolysis method, the basic operational variables of the aerosol decomposition parameter are changed by changing the reaction temperature and the carrier gas composition. In addition, the addition of, for example, the composition of the precursor, the nature of the solution, or the co-solvent is important to achieve the desired product properties and morphology. Limitations of spray pyrolysis methods include difficulty in controlling comparative examples, low production rates, and the formation of low density hollow particles.

The polymer-complex method also provides a reasonably uniform elemental distribution for relatively simple oxides. An example of a La-based perovskite is described in Key Engineering Materials, 206-213, pp. 1349-52, 2002 (Popa & Kakihana). The main problem with these methods is that the polymers used are prone to heat and fire. This makes processing difficult. Furthermore, for a multi-element compound, some elements may not be mismatched with the polymer, and therefore, a uniform element distribution cannot be obtained.

The sol method generally requires careful control of the processing conditions to form a uniform precursor. For example, La-Ca-Mn-based perovskite of the sol-gel process is described in Journal of Technical Sciences in a sol (J.Sol - Gel Science and Technology) 25,147-157 pages, 2002 (Mathur & Shen), and materials chemistry (Chemistry of Materials ) 14, 1981-88, 2002 (Pohl and Westin). When the miscibility of the compound increases, the sol becomes extraordinarily difficult, and some elements are simply not suitable for the sol method at all. Sols are typically difficult to scale up and the materials required can be extremely expensive.

U.S. Patent No. 6,752,979 (in the name of the applicant) describes a method of making a mismatched metal oxide with a uniformly distributed element. This method has proven useful for a wide range of different miscellaneous oxides. This method provides a pure phase oxide with a high surface area using a low processing temperature.

In addition to the correct oxide crystal structure and uniform elemental distribution, in many applications, the porosity present between the sintered oxide particles is extremely important for performance. Larger and interconnected hole openings (>~1 μm) are typically desirable for applications requiring good fluid (gas or liquid) transfer. For example, a method of providing a large hole in an oxide for a solid oxide fuel cell electrode is known (for example, U.S. Patent Nos. 4,883,497 and 6,017,647). Most of these methods use a variety of pore formers, i.e., materials that can leached or burn ceramic materials. These pore formations are typically greater than 1 [mu]m to allow the formation of pores of this size. Holes of this size are too large to significantly increase the surface area of the material.

Materials with a large number of small holes (<~7 nm) generally exhibit high surface area. High surface areas can be used for applications that utilize surface properties, such as catalysis. The small holes and high surface area can be obtained when the structure is composed of a large number of extremely small particles that are loosely packed together. Various organic pore formations can also be used to form very small pores. Small pores are generally not present at higher temperatures and, therefore, typically result in low high temperature stability.

Holes in the "middle" size range (~7 nm to ~250 nm) can also be used to improve fluid flow and are small enough to significantly contribute to surface area. It is believed to improve the high temperature stability of certain simple metal oxides. U.S. Patent No. 6,139,814 describes a method of making a Ce-based oxide having improved high temperature stability. Although the cause of thermal stability is not known, the patent assumes that the stability is due, at least in part, to the presence of an average pore size in the "intermediate grade" range (the examples show an average pore size of about 9 nm). The method of the '814 method involves absorbing a liquid solution of metal ions into a pore of a structured cellulosic material (e.g., filter paper). The liquid is dried and the material is ignited to remove the cellulose. Thus, solids form in the pores of the cellulose, and the pores of the cellulose cause the solid to 'form". However, this method has several drawbacks. Extremely high organic: Metal oxide ratios are used (up to >100:1), which, together with the relatively high cost of the appropriate cellulosic material, result in expensive processing. The absorption of liquid into solids such as paper is also a poorly amplified method. Finally, simply drying a solution of metal ions to form a solid is also undesirable for producing a uniform distribution of the different elements required for more complex materials.

A method of producing cristobalite having a pore size of about 10 nm range of the system is described in Journal of Porous Material (J.Porous Materials) 7,435-441 pages, 2000 (Ermakova et al). A variety of different carbon substrates are impregnated with vermiculite gel and dried and burned. The increased hole size is obtained using this method. The improved thermal stability is obtained when the catalytic fibrous carbon is used as a carbon source. Other pores of more spherical carbon particles have not been tested for thermal stability. Unfortunately, the sol process used is not desirable for forming many perovskite materials, particularly in commercial specifications. Further, the impregnated solid is a method which is inconvenient to enlarge the specification. Another problem is that the ratio of carbon material to oxide is quite high (up to 30). This increases production costs, reduces production rates, and exacerbates the problem of impurities in the carbon.

U.S. Patent No. 4,624,773 describes a process for the catalytic cracking of hydrocarbon feedstocks. One part of this method is to fabricate an aluminum-tellurate material having pores preferably from 100 to 600 nm to improve the flow of gas into the catalyst. The method involves making a gel of alumina and vermiculite and mixing it in reticulated carbon particles having a length of from about 50 to 3000 nm. After the aluminum-phthalate solids are formed, the carbon particles are burned off to form pores of the desired size range. This method requires smaller pores (providing a high surface area) within the aluminum-germanate zeolite structure to be unaffected by the combustion.

The gel technology used to form aluminum-phthalate solids by this method is not suitable for more complex materials requiring higher chemical uniformity, particularly in commercial specifications. Furthermore, the hole system used to maximize gas flow is greater than that required to produce a thermally stable surface area. Finally, carbon is a strong reducing agent and is widely used in mineral processing to reduce oxides to metals. Although this may not be related to the oxides of aluminum and antimony, because these oxides are extremely stable and difficult to reduce, many other metals (including metals commonly used for complex oxides) are oxides. More likely to be restored by carbon. The reducibility of different elements is generally expressed in the Ellingham diagram. The oxide at the bottom of this figure (such as Al) is difficult to reduce, while the top is easier to reduce. Metals such as iron, nickel, cobalt, manganese, chromium and potassium are more easily reduced than Al. The Ellingham diagram also shows the carbon reduction effect, especially in the heat treatment atmosphere of one of the carbon oxides.

In the processing of mis-oxides, particularly heat treatment, the presence of metals can be severely difficult due to segregation and/or inability to form desired oxide phases with other elements. Therefore, it is not clear whether the dense mixture of carbon particles and oxide or oxide precursors of the intermediate specification can properly develop the desired phase. Furthermore, the presence of metals or other reduced oxide forms can greatly increase sintering, resulting in severe surface area loss and poor thermal stability.

Examples of problems associated with the incorporation of carbon-based materials into oxide precursors are outlined in J. of Materials Science 35 (2000), pages 5639-5644, which describes the use of cellulose (which A method of forming a La _{0 . 8} Sr _{0 . 2} CoO ₃ material that is burned off. It has been found that if carbon dioxide is not removed quickly enough, carbonate will form in large quantities and, therefore, a higher calcination temperature is required in order to obtain phase purity.

GB 2 093 816 of Asia Oil Company Ltd and Mitsubishi Chemical Industries Ltd describes a process for producing a porous refractory inorganic oxide product. GB 2 093 816 provides a porous fire resistance with a well-defined peak distribution between 10 nm and 100 nm in diameter and a pore volume (porosity) of 0.11 cc/g or more between 10 nm and 50 nm. An inorganic oxide product which is formed by forming a mixture of carbon black and a refractory inorganic oxide and/or a refractory inorganic oxide precursor, allowing the product to be ignited in an oxygen-containing gas stream while simultaneously Carbon black is obtained by burning.

Obviously, the GB 2 093 816 case is longer than the manufacture of refractory inorganic oxide products. Typical refractory inorganic oxides used in GB 2 093 816 comprise inorganic oxides such as alumina, vermiculite, titanium oxide, zirconium oxide, cerium oxide, blue chalcedony, zeolite and clay. The practical examples shown in GB 2 093 816 show only refractory inorganic oxides which form alumina, vermiculite, titanium oxide, vermiculite alumina, blue chalcedony, zeolite, kaolin and sepiolite powder.

The examples shown in GB 2 093 816 all use a solid particulate starting material to obtain a mixed oxide product, except for Example 10, which uses titanium tetrachloride as a precursor for the precipitation reaction to form titanium oxide. The product of Example 10 is titanium oxide, a non-mixed oxide.

GB 2 093 816 uses carbon black with an average diameter of 15-300 nm. GB 2 093 816 also indicates that the final ignition temperature of the step of burning carbon black is about 500 ° C or higher, but the upper limit is not important as long as the porous refractory inorganic oxide product does not lose the activity of the support or catalyst. can.

The processing conditions and starting materials used in GB 2 093 816 require relatively high processing temperatures in order to obtain a miscible oxide matrix comprising a metal mixture. These processing conditions are not explicitly disclosed in GB 2 093 816, confirming that the mismatched metal oxide phase is not formed. Therefore, the inventors believe that the so-called mixed inorganic oxide formed in the case of GB 2 093 816 is actually composed of a mixture of individual particles or particles of the feed, and each individual particle or particle is only contained therein. material. Thus, GB 2 093 816 does not produce a miscible metal oxide phase comprising two or more individual metals from the different precursor components used to form the particles.

Reviewing the prior art emphasizes the lack of a commercially viable method of fabricating a misaligned metal oxide material having pores in the size range of 7 nm to 250 nm.

There is also a great need for misaligned oxide materials with improved thermal stability and methods of making such materials.

Brief description of the invention

In a first aspect, the present invention provides a method of making a porous, staggered oxide, the method comprising providing a mixture a) a precursor element suitable for the manufacture of a mis-oxide; or b) one or more suitable for manufacturing a precursor element of the oxide particle and one or more metal oxide particles; and c) a particulate carbon-containing material forming a hole, which is selected to provide a pore size ranging from about 7 nm to 250 nm, and the mixture is treated i) Forming a porous miscellaneous oxide, wherein the precursor element of two or more of the above (a) or one or more of the precursor elements of the above (b) and one or more of the metal oxide particles are And in a phase of the mismatched metal oxide, and the mismatched metal oxide has a particle size ranging from about 1 nm to 150 nm; and ii) the porous structure and composition of the mis-oxide are substantially retained The material forming the holes is removed under conditions.

Different from the method described in GB 2 093 816, which results in the formation of a metal oxide phase which simply reflects the metal oxide particle phase as a feed particle in the process, or its self-primary element produces only a single fire resistance. Metal metal oxide phase, the process of the invention produces a miscible metal oxide phase which results in two or more metals from the precursor or precursor of the feed and metal oxide particles (and in certain embodiments) , more than two metals can be incorporated into the metal oxide phase. It is understood that the metal oxide phase comprises a metal oxide matrix, and the matrix comprises an oxide structure of two or more metals. More or more metal systems are evenly distributed throughout the miscible metal oxide phase.

Suitably, a single phase mismatched metal oxide is formed. However, the invention also includes forming a miscible metal oxide phase and one or more other metal oxide phases, or forming two or more miscible metal oxide phases, with or without any other metal oxides. The formation of the phase. More suitably, each phase of the phase of the metal oxide phase phase formed is purified, i.e., the phase contains only the desired crystalline phase and has an undesired crystalline phase.

The miscible metal oxide may contain two or more metals, such as a group selected from the group consisting of metals of atomic order 3, 4, 11, 12, 19 to 32, 37 to 51, 55 to 84 and 87 to 103. Or more metals. In one embodiment, the two or more metals in the miscible metal oxide may comprise at least one non-refractory metal, such as selected from the group consisting of atomic sequences 3, 4, 11, 19-21, 23-32, 37- At least one metal of the metals of 39, 41-51, 55-84 and 87-103. In this embodiment, the metal oxide may contain other metals such as Ti, Al, Zr, and Mg in addition to the above non-flammable metal.

It has been surprisingly found that the thus formed porous miscellaneous oxide exhibits a significantly increased pore volume or surface area and has an enhanced high temperature stability, such as promoted high temperature stability over a temperature range of from about 750 °C to 1000 °C. The mis-oxides suitably further exhibit a substantially uniform composition within each phase. Applicants have surprisingly found that the misaligned oxide formed with the particle size of the above range and the pore size of the above range has a high initial surface area combined with increased surface area thermal stability.

Applicants have discovered that if the particle size of the mismatched oxide is greater than 150 nm, the material may not have sufficient surface area. Similarly, if the pore size is greater than about 250 nm, sufficient surface area may not be obtained after high temperature aging. If the pore size is less than about 10 nm, a high surface area can be obtained, but the pores and thus the surface area may be non-thermally stable at elevated temperatures.

Unlike the GB 2 093 816 case, the process of the invention can be used to form a non-fire resistant miscible metal oxide phase. The inventors have surprisingly found that the process of the invention need not be limited to the manufacture of refractory oxides that are difficult to reduce. In contrast, all embodiments of GB 2 093 816 produce an oxide phase of alumina, vermiculite, titania, vermiculite-alumina, blue chalcedony, zeolite, kaolin or sepiolite powder. All of these metal oxide phases are exceptionally non-reactive and extremely difficult to carbon reduce.

In this aspect of the invention, the mis-formed oxide thus formed may be of any suitable type. The mismatched metal oxide phase can be a perovskite. The crystal structure is a "perovskite" mineral, and the chemical formula is CaTiO ₃ . It has many different compounds with a perovskite crystal structure, including SrTiO ₃ , YBa ₂ Cu ₃ O _x superconductors, and many La-based perovskites, which act as catalysts and as electrodes for solid oxide fuel cells. The La-based perovskite contains LaMnO ₃ , LaCoO ₃ , LaFeO ₃ , and LaGaO ₃ .

Various substitutions of different elements within the oxide lattice can be made to achieve the desired physical properties. For example, a perovskite may be substituted for the A site (eg, replacing La in LaMnO ₃ with Sr) and/or the B site (eg, replacing Mn in LaMnO ₃ with Ni). The replacement of several elements at either or both locations can be used to further tailor the physical properties for a particular application. For example, a perovskite composition (Ln _{0 . 2} La _{0 . 4} Nd _{0 . 2} Ca _{0 . 2} ) (Mn _{0 . 9} Mg _{0 . 1} ) O ₃ , wherein the Ln system is approximately La _{0 . 5 9 8} Nd _{0 . 1 8 4} Pr _{0 . 8 1} Ce _{0 . 1 3 1} Ca _{0 . 0 0 2} Sr _{0 . 0 0 4} , described in U.S. Patent No. 5,932,146, for use in electrodes for solid oxide fuel cells .

There are numerous examples of other mis-oxides that have been developed for a wide range of applications, and the present invention is equally applicable to this.

The precursor element used in the mixture of the present invention may be in any suitable form depending on the complex oxide to be formed. Any suitable source of metal and metal cations can be used. Mixtures of metals and metal compounds containing one or more of oxides, acetates, nitrates, and the like can be used.

The precursor element, or the mixture of the oxides, and the material forming the pores may be in any suitable form. This mixture may be a solid phase mixture or formed as a solution, dispersion or the like.

In one embodiment, the precursor elements and the material forming the pores may be mixed to form a solid phase mixture, and the mis-oxides are subsequently formed by appropriate heat treatment as described below.

In a further embodiment, the misaligned oxide particles can be formed from suitable precursor elements, and the material forming the pores is mixed with the misaligned oxide particles to form a mixture.

The mixture may additionally be provided as a solution or dispersion. For example, the solid phase mixture can be formed first, then dispersed or dissolved in a suitable solvent.

In a further embodiment, the precursor element mixture may first form a solution, and the material forming the pores is thereafter added to the solution. Alternatively, the precursor element and at least a portion of the pore-forming material may be mixed to form a solid phase mixture, and the mixture is dissolved in a suitable solvent.

Most suitably, the precursor element forms part of a solution which is mixed with the material forming the pores and the metal oxide particles (if used).

If a dispersion or solution is formed, any suitable solvent can be used. Although inorganic and organic solvents such as acids (e.g., hydrochloric acid or nitric acid), ammonia, alcohols, ethers, and ketones can be used, water is preferred.

The mixture is preferably a surface surfactant. The surfactant can be in any suitable form. Surfactants of the type described in International Patent Application Publication No. WO 02/42201 (the applicant of the present application, which is incorporated herein by reference), have been found to be suitable.

Some examples include Brij C _{1 6} H _{3 3} (OCH ₂ CH ₂ ) ₂ OH, designed C _{1 6} EO ₂ , (Aldrich); Brij 30, C _{1 2} EO ₄ , (Aldrich); Brij 56, C _{1 6} EO _{1 0 ,} (Aldrich); Brij 58, C _{1 6} EO _{2 0} , (Aldrich); Brij 76, C _{1 8} EO _{1 0} , (Aldrich); Brij 78, C _{1 6} EO _{2 0 ,} (Aldrich); Brij 97, C _{1 8} H _{3 5} EO _{1 0} , (Aldrich); Brij 35, C _{1 2} EO _{2 3} , (Aldrich); Triton X-100, CH ₃ C(CH ₃ ) ₂ CH ₂ C (CH _{3 2} C ₆ H ₄ (OCH ₂ CH ₂ ) _x OH, x=10 (av), (Aldrich); Triton X-114, CH ₃ C(CH ₃ ) ₂ CH ₂ C(CH ₃ ) ₂ C ₆ H ₄ (OCH) ₂ CH ₂ ) ₅ OH (Aldrich); Tween 20, poly(ethylene oxide) (20) sorbitol kayrate (Aldrich); Tween 40, poly(ethylene oxide) ( 20) Sorbitol monopalmitate (Aldrich); Tween 60, poly(ethylene oxide) (20) sorbitol monostearate (Aldrich); Tween, poly(ethylene oxide) (20) sorbose Alcohol monooleate (Aldrich); and Span 40, sorbitol monopalmitate (Aldrich), Terital TMN 6, CH ₃ CH(CH ₃ )CH(CH ₃ )CH ₂ CH ₂ CH(CH ₃ ) ( OCH ₂ CH ₂ ) ₆ OH (Fulka); Tergital TMN 10, CH ₃ CH(CH ₃ )CH(CH ₃ )CH ₂ CH ₂ CH(CH ₃ )(OCH ₂ CH ₂ ) _{1 0} OH (Fulka); poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) with EO-PO centered on a (hydrophobic) poly(propylene glycol) core with two primary hydroxyl groups -EO) sequence block copolymer; Pluronic L121 ( _{M a v} = 4400), EO ₅ PO _{7 0} EO ₅ (BASF); Pluronic L64 ( _{M a v} = 2900), EP _{1 3} PO _{3 0} EO _{1 3} (BASF); Pluronic P65 ( _{M a v} = 3400), P _{2 0} PO _{3 0} EO _{2 0} (BASF); Pluronic P85 ( _{M a v} = 4600), EO _{2 6} PO _{3 9} EO _{2 6} (BASF); Pluronic P103 ( _{M a v} = 4950), EO _{1 7} PO _{5 6} EO _{1 7} (BASF); Pluronic P123 ( _{M a v} = 5800), EO _{2 0} PO _{7 0} EO _{2 0} , (Aldrich); Pluronic F68 ( _{M a v} =8400), EO _{8 o} PO _{3 0} EO _{8 0} (BASF); Pluronic F127 ( _{M a v} =12 600), EO _{1 0 6} PO _{7 0} EO _{1 0 6} (BASF); Pluronic F88 ( _{M a v} =11 400), EO _{1 0 0} PO _{3 9} EO _{1 0 0} (BASF); Pluronic 25R4 ( _{M a v} =3600), PO _{1 9} EO _{3 3} PO _{1 9} (BASF); with four attachments a star-shaped diblock copolymer terminated to the EO _n -PO _m chain of the ethylene diamine core (or upside down, four PO _n -EO _m chains) and terminated with a secondary hydroxyl group; Tetronic 908 ( _{M a v} =25 000 ),(EO _{1 1 3} PO _{2 2} ) ₂ NCH ₂ CH ₂ N(PO _{1 1 3} EO _{2 2} ) ₂ (BASF); Tetronic 901 ( _{M a v} = 4700), (EO ₃ PO _{1 8} ) ₂ NCH ₂ CH ₂ N(PO _{1 8} EO ₃ ) ₂ (BASF); And Tetronic 90R4 ( _{M a v} = 7240), (PO _{1 9} EO _{1 6} ) ₂ NCH ₂ CH ₂ N(EO _{1 6} PO _{1 9} ) ₂ (BASF).

The above surfactant is a nonionic surfactant. Other surfactants that may be used include: anionic surfactants: alcohol ethoxy carboxylate (R-(O-CH2-CH2)x-O-CH2-CH2-OH) (NEODOX AEC) alkyl B Oxycarboxylic acid (R-(O-CH2-CH2)x-O-CH2-CO2H) (EMPICOL C) sodium lauryl sulfate CH ₃ (CH ₂ ) _{1 1} OSO ₃ NA appears to have several manufacturers. An example of Sigma is.

Cationic Surfactant: Cetyltrimethylammonium Chloride CH ₃ (CH ₂ ) _{1 5} N(CH ₃ ) ₃ Cl Aldrich Cetyltrimethylammonium Bromide CH ₃ (CH ₂ ) _{1 5} N(CH ₃ ) ₃ BT Aldrich cetyl pyridinium chloride C _{2 1} H _{3 8} NCl Sigma.

This list should not be considered exhaustive.

The particles forming the pores can be of any suitable type. Such particles need to be sized to produce a "middle range" of pore size (e.g., a pore having a diameter of from about 7 nm to about 250 nm, preferably from about 10 nm to about 150 nm). Particle-forming particles in the range of about 7 nm to 300 nm (preferably from 10 nm to 150 nm, more preferably from about 10 nm to about 100 nm) can be used. Carbon particles, preferably carbon black particles, are preferred.

The carbonaceous particles which are pore formations in the process of the present invention are believed to be mismatched by the formation of the metal oxide phase by providing precursors/precursors and metal oxide particles therebetween, and thereafter removed The particles of the pores are formed to promote the formation of pores having a desired size range. Therefore, the pores forming the pores of the nanometer specification are necessary. This needs to be distinguished from other methods, which use a porous carbonaceous substrate such as filter paper or activated carbon to adsorb a liquid precursor mixture, followed by removal of the substrate. The size of the substrate used in such methods is typically greater than the number of levels of particles used to form the voids of the present invention. The methods of these prior art techniques are extremely difficult to scale up beyond laboratory specifications.

In a particularly preferred embodiment of the invention, carbon black is used as the particles forming the pores.

The particles forming the pores are preferably removed by heat treatment.

The components required to form the complex oxide need to be uniformly dispersed to form a mixture of precursor elements. These elements can be mixed by any suitable method known in the art. The particles forming the pores are also dispersed in the mixture using methods known in the art, including high speed shearing devices, ultrasonic equipment, rolling mills, ball milling, sanding, and the like. Applicants have discovered that the preferred dispersion of particles of carbon-containing pores at this stage results in more carbon-containing pore-forming particles being densely mixed with the precursor, and therefore, more pores are present in the desired size range. In a more preferred embodiment, the air is removed from the particles forming the pores by carbon prior to mixing with the liquid. Then, the liquid and the carbon system are mixed using a dispersion method. This results in better dispersion of the carbon particles in the solution, allowing more carbon particles to be densely mixed into the precursor and more pores in the preferred size range.

Prior to dispersion, the particles forming the pores may be wholly or partially contained within the mixture.

Treating the mixture to form a mis-oxide can be any suitable pattern that provides a mis-oxide having a substantially uniform composition.

The formation of a porous miscellaneous oxide may thus comprise two basic steps in one embodiment: 1. Making particles comprising a mixture of precursor elements and carbon particles of a mis-oxide or a mis-oxide.

2. The heat treatment step (1) of the particles from the precursor (if the precursor is used) forms the desired oxide phase, and a large amount of (eg, burning) carbon particles are removed to create pores.

Steps (1) and (2) may occur sequentially or simultaneously.

In step 1, the elements of the oxide precursor need to be uniformly dispersed. If it is not uniformly dispersed, it may require extremely high temperatures to evenly disperse these elements and form the correct phase, and such temperatures may reduce the amount and size of the holes or completely remove the holes. If such elements are substantially non-homogeneous, the desired phase and/or phase purity, as well as particles of the correct size range, cannot be achieved.

At least some of the carbon particles need to be densely mixed with the oxide or oxide precursor. If the carbon-free particles are densely mixed with the oxide or oxide precursor, and alternatively, the carbon particles are only present in large agglomerates and the agglomerates are free of oxides or oxide precursors, the correct size of the pores cannot form. The size of the carbon particles, and the volume of such particles, can be selected to suit the desired pore size and pore volume.

Any method suitable for producing an oxide or oxide precursor of a substantially uniformly dispersed element can be used in the method of the present invention, as long as the correct size of carbon particles can be added to the process, so that at least some of the carbon particles are The mass is densely mixed and this method produces an oxide of the correct particle size.

Therefore, in a preferred embodiment of the present invention, the method further comprises providing a solution comprising a metal oxide cation of a mis-oxide precursor, a carbon particle source, and a nonionic, cationic or anionic surfactant. The solution, the surfactant and the carbon particles thus cause the surfactant micelles to form and the mixture forms a substantially uniform dispersion, and the mixture is heated in the first step of heating the carbon particles to form a misaligned metal oxide.

In a more preferred embodiment, the oxide precursor can be made according to the method described in the applicant's U.S. Patent No. 6,752,979, the entire disclosure of which is incorporated herein by reference. The method consists of: a) producing a solution containing one or more metal cations; b) mixing the solution of step (a) with a surfactant under conditions such that the surfactant micelles are formed in the solution, This forms a micellar liquid; and c) heating the micellar liquid of step b) above to form a metal oxide, the heating step being carried out at a temperature for a period of time to remove the surfactant, and thereby forming an irregular pore structure Metal oxide particles.

In a preferred embodiment of the invention, carbon black particles are added to the solution of a) or a mixture of b), and the heat treatment also removes (burns) the carbon particles in large amounts. Preferably, carbon particles are added to the solution of step a) prior to mixing.

In a more preferred embodiment, the carbon particles are intimately mixed with the cationic solution of step a) or with the mixture of step b), or both by the methods as discussed above. Preferably, the carbon black particles are dispersed in the starting solution and/or the solution-surfactant mixture by high speed shearing, sonication, vacuum treatment or a combination of these before being added to the liquid. Inside.

In a more preferred embodiment, a mixture of mis-oxides and carbon particles can be provided by mixing carbon particles with a miscellaneous oxide having a size range similar to or smaller than the target particle size.

Additionally or alternatively, the complex oxide can be formed by methods known in the art. The mis-oxide can be produced by a polymer-complex method, a coprecipitation method or a sol method, a thermal evaporation method, a hydrothermal method, or any other suitable method or a combination thereof. Examples of such methods are shown in U.S. Patent No. 6,139,916 (Liu et al.), U.S. Patent No. 5,797,715 (Higgens et al.), U.S. Patent No. 5,770,172 (Linehan et al.), and U.S. Patent No. 5,968,843. (Ong et al.), U.S. Patent No. 6,328,947 (Monden et al.), U.S. Patent No. 5,778,950 (Imamura et al.), and U.S. Patent Application Publication No. 2005/0008777 (McCleskey et al.). The entire disclosures of the patents and patent applications cited above are hereby incorporated by reference in their entirety. The method of the first aspect of the invention is particularly suitable for use in a process for the manufacture of metal oxides, wherein the solution containing one or more precursors is mixed with a surfactant or polymer, and thereafter, typically by heating The treatment forms a mismatched metal oxide.

The heat treatment step of the process of the present invention can be carried out using any suitable equipment known in the art, for example: tubular, belt or muffle furnaces, fluid bed furnaces, multi-chamber furnaces, rotary kiln furnaces, heated substrates, heat spray. Spray the crucible furnace, etc.

If the oxide or oxide precursor consists of unconnected individual particles, the heat treatment requires some connection between the particles prior to combustion of the carbon. If the network is not formed before carbon combustion, the holes will collapse.

The heat treatment then removes ("burns") the carbon to create pores and transforms the oxide precursor into the desired oxide crystalline structure.

The heating step results in the formation of a pore structure of the metal oxide and particles. Unlike the conventional techniques for producing a mismatched metal oxide, the method of the present invention suitably requires only a relatively low application temperature. In fact, application temperatures of less than about 350 ° C have been found to be suitable for the experimental operations performed today. Preferably, step (c) achieves a maximum application temperature of no more than about 750 ° C, more preferably about 650 ° C, and most preferably about 300 ° C - 350 ° C.

The heating step may involve rapid heating to the maximum desired temperature, or it may involve a more closely controlled heat treatment system.

Accordingly, in a more preferred embodiment of the invention, the heat treating step comprises subjecting the dispersion to a heat treatment for a predetermined time to a desired maximum temperature.

For example, the heating step can be carried out under controlled atmosphere. The heating step may involve heating to a drying temperature (generally below the boiling temperature of the mixture) to dry the mixture, then slowly increasing to the maximum application temperature, or a series of increasing increases before finally reaching the maximum application temperature. To the intermediate temperature. The time of the heating step can be varied widely, and the preferred period of step (c) is from 15 minutes to 24 hours, more preferably from 15 minutes to 2 hours, more preferably from 15 minutes to 1 hour.

The heat treatment distribution may range from about 100 ° C to 750 ° C, preferably from about 100 ° C to 650 ° C, and more preferably from 100 ° C to 300 ° C. It is to be understood that the selected heat treatment profile will depend on the particular composition of the mis-oxide to be treated.

The heat treatment step is preferably carried out under conditions of increasing oxygen. This can be achieved by providing a suitable air flow within the heated environment.

In a preferred embodiment, the heat treatment is required to promote oxygen permeation into the particles during the carbon combustion phase. Preferred equipment includes fluid bed furnaces and the like. Smaller oxide or oxide precursor/carbon particles also promote oxygen infiltration. Applicants have found that better oxygen infiltration results in better thermal stability. While not wishing to be obsessed with any particular theory, Applicants believe that better oxygen infiltration results in more complete carbon removal at lower temperatures, thus maintaining a more oxidizing atmosphere. Less oxygen causes carbon to stagnate at higher temperatures and traps reducing gases such as carbon monoxide, resulting in an environment of extreme reduction. This can result in the formation of certain metals and the retention of this metal to relatively high temperatures which can cause sintering and loss of surface area. Oxygen infiltration can be promoted by moving the oxide relative to the oxygen-containing atmosphere, thereby reducing the thickness of the boundary layer around the oxide and thereby increasing the rate at which oxygen diffuses into the oxide. It is suitable to treat the oxide in a fluidized bed furnace or in a furnace having an oxygen-containing atmosphere flowing therein.

Further, a heat treatment capable of burning carbon at a relatively low temperature (e.g., a temperature of about 100 ° C to 750 ° C, preferably 100 ° C to 650 ° C, more preferably about 100 ° C to 300 ° C) is preferred. Burning at a sufficiently high temperature causes uncontrolled exothermic combustion of carbon, which severely reduces surface area. Applicants also believe that carbon retention to high temperatures reduces high temperature stability by the mechanisms discussed previously.

The tight control of the combustion step needs to be maintained to avoid the desired temperature profile of the offset combustion step. For example, tight monitoring of the temperature during combustion can be used. If an undesired increase in temperature is observed (indicating that excessive energy is generated due to an increase in the exothermic rate of carbon combustion), the atmosphere supplied to the furnace can be controlled by lowering the partial pressure of oxygen. Additional nitrogen or other inert or non-reactive gases are injected in a manner that achieves this result. This not only reduces the partial pressure of oxygen, but also serves to cool the furnace. When it is also desired to maintain an oxidizing atmosphere during combustion of a carbon-containing pore formation, the method of controlling the temperature needs to be used only for a rapid response to an impending temperature deviation, or a significant deviation has occurred and it is required to rapidly reduce or stop the carbon. Oxidation reaction (for example, for safety reasons). Additionally, additional cooling may be provided instead of closely monitoring the temperature during combustion, and satisfactory results may be obtained by maintaining the temperature during combustion below a certain maximum temperature. The particular maximum temperature can vary widely depending on the particular compound metal oxide to be formed. Still further, the method of the present invention can operate under specific operating conditions, such as oxygen flow rate and furnace cooling, and maintaining a quality control agreement that rejects any unacceptable product. The presence of an unacceptable product can be determined by testing the product or by monitoring one or more operational parameters and rejecting any monitoring technique that occurs when one or more parameters are removed from a particular value range. For example, a simple thermocouple can be used to monitor the maximum temperature reached during the process and if the maximum temperature exceeds a certain maximum, the product can be rejected, or if visual inspection reveals that the mixture or product is red hot during processing, the product can be rejected. .

In a second aspect of the invention, there is provided a porous miscellaneous oxide material, wherein the miscible oxide material exhibits high temperature stability and comprises an oxidizing composition represented by the following formula: A _{1 - x} B _x MO ₃ Wherein A is a mixture of lanthanides; B is a divalent or monovalent cation; and M is selected from the group consisting of elements or elements of the group consisting of elements having an atomic order of 22 to 32, 40 to 51, and 73 to 83; x series 0.1 x The value of the range of 0.5.

Preferably, the miscible oxide material can be made by the method of the first aspect of the invention.

The miscible oxide material can have the correct phase (e.g., single or multiphase) having a greater than about 15 m ² /g (preferably greater than about 20 m ² /g, more preferably greater than about 30 m ² /g). The initial surface area and surface area after aging for 2 hours in air at 1000 ° C is greater than about 5 m ² /g, preferably greater than about 10 m ² /g, more preferably greater than about 15 m ² /g.

The misaligned oxide material can exhibit a substantially uniform composition.

The miscible oxide material may comprise a perovskite material.

The staggered oxide material typically exhibits an average particle size of from about 2 nm to about 150 nm, preferably from about 2 to 100 nm, and has a size range from about 7 nm to about 250 nm (more preferably about 10 nm to A hole of about 150 nm). However, the average particle size and pore size of the misaligned oxide material can vary depending on the particular compound oxide selected.

For example, for a heterochromic oxide material of the CeZrO ₂ type, the average particle size preferably falls below the lower limit of the range, for example, about 2 to 50 nm, more preferably about 2 to 10 nm, and the pore size is about 7 nm. Up to 50 nm, more preferably about 7 nm to 30 nm.

The bismuth manganate-type miscellaneous oxide material exhibits an average particle size of from about 2 nm to 100 nm (more preferably from about 2 to 30 nm), and the pore range is from about 15 nm to 200 nm (more preferably about 15 nm). Up to 150 nm).

More preferably, the misaligned oxide material can exhibit a range of pore sizes that are substantially dispersed.

In a third aspect, the present invention provides a method of making a porous, non-refractory metal oxide, the method comprising providing a mixture of: a) one or more precursor elements suitable for making the non-refractory metal oxide, non-refractory An oxide particle which is a precursor of a non-refractory oxide, or a mixture of two or more thereof; and b) a particulate carbon-containing material forming a void which is selected to provide about 7 nm Hole size up to 250 nm, and treatment of the mixture i) formation of a porous, non-flammable metal oxide having a particle size ranging from about 1 nm to 150 nm; and ii) The material forming the pores is removed under conditions in which the porous structure and composition of the refractory metal oxide are substantially retained.

Suitably, in the above step (i), one or more of the precursor elements of (a) above are incorporated in the non-refractory metal oxide phase.

The one or more precursor elements may comprise one or more selected from the group consisting of atomic orders of 3, 4, 11, 19-21, 23-32, 37-39, 41-51, 55-84 and 87-103. a metal compound of one or more metals of such metals. The one or more metal compounds may be oxides, acetates, carbonates, nitrates, and the like.

Unlike the first aspect of the invention, the method of the third aspect of the invention comprises forming a porous metal oxide having a specific particle size and pore size of the oxide phase having only a single metal (i.e., non-missing oxide). However, the third aspect of the invention is limited to the formation of a non-refractory metal oxide. The surprising result is that such non-refractory metal oxides can be formed in this manner because the presence of particles of carbon-containing pores is believed to cause non-refractory metal oxide reduction during the step of removing particles forming pores, Of course, the metal oxide phase is destroyed or largely jeopardized. However, the inventors of the present invention have found that the method of the third aspect of the invention can in fact form such non-refractory metal oxides.

In one embodiment, the method of the third aspect of the invention provides a precursor element in a solution or dispersion. For example, the solid phase mixture can be formed first, then dispersed or dissolved in a suitable solvent.

In one embodiment, the precursor elements and the material forming the pores may be mixed to form a solid phase mixture, and the oxide is subsequently formed by appropriate heat treatment as discussed below.

In a further embodiment, the oxide particles can be formed from a suitable precursor element and the material forming the pores is mixed with the oxide particles to form a mixture.

The mixture may additionally be provided as a solution or dispersion. For example, the solid phase mixture can be formed first, then dispersed or dissolved in a suitable solvent.

In a further embodiment, the precursor element may first form a solution and the material forming the pores is subsequently added to the solution. Alternatively, the precursor element and at least a portion of the pore-forming material may be mixed to form a solid phase mixture, and the mixture is dissolved in a suitable solvent.

If a dispersion or solution is formed, any suitable solvent can be used. Although inorganic and organic solvents such as acids (for example, hydrochloric acid or nitric acid), ammonia, alcohols, ethers and ketones can be used, water is preferred.

The method of the third aspect of the invention is particularly suitable for use in a method of making a metal oxide wherein a solution containing one or more precursors is mixed with a surfactant or polymer and thereafter treated, typically by heating, Forming a metal oxide.

Other features of the embodiments of the third aspect of the present invention are described with reference to various embodiments, and need not be described again for convenience and brevity.

The method of the third aspect of the invention has been used to produce copper oxide which exhibits a large specific surface area. Other oxides (co-oxides and oxides containing a single metal species) have also been produced by the process of the second aspect of the invention.

The methods of the first and third aspects of the invention are particularly suitable for the manufacture of metal oxide powders.

Simple illustration

Figure 1 shows the materials obtained in Examples 1 and 2, which were subsequently heat treated to a pore size distribution at 650 ° C. Figure 2 shows the surface area obtained after heat treatment at 650 ° C and 800 ° C in Examples 18-22. ₂ O ₃ content function; Figure 3 shows the pore volume obtained after heat treatment at 650 ° C in Examples 18-22 as a function of La ₂ O ₃ content; and 4a and 4b shows heat treatment to 540 ° C °Ce0 The XRD pattern of .45Zr0.45La0.1Ox, a) is obtained without carbon (Example 28), and b) is obtained by carbon (Example 29); Figures 5a and 5b show heat treatment to 800 °C The XRD pattern of Ce0.45Zr0.45La0.1Ox, a) was obtained without carbon (Example 28), and b) was obtained with carbon (Example 29).

Example Example 1

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ was prepared according to the following method. The solution was obtained by making 149 g of La(NO ₃ ) ₃ .6H ₂ O, 18.2 g of Sr(NO ₃ ) ₂ , 6.86 g of Pd(NO ₃ ) ₂ .x H ₂ O, 2.04 g of NiCO ₃ and 138.3 g of Mn ( NO ₃ ) _{2 was prepared by} dissolving in an aqueous solution containing 233 g/l of Mn in a solution containing 135 g of water and 12 g of HNO ₃ (70%), and 119 g of this solution was mixed with 72 g of Brij 30 surfactant. The mixture was slowly heated to 300 °C. Then, the dried product was heat-treated in a tube furnace having an air flow at 300 ° C, 350 ° C, 400 ° C, 450 ° C, 500 ° C, 600 ° C, and 650 ° C for 0.5 hours.

XRD shows that this material is a single phase perovskite. The surface area obtained after this heat treatment was 17.8 m ² /g. Figure 1 shows the hole size distribution. TEM showed an average particle size of ~50 nm. After heat treatment at 1000 ° C for 2 hours, the surface area was 6.9 m ² /g.

Example 2

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ was produced in the same manner as in Example 1, but before mixing with the surfactant, 16.15 g of carbon black (Cabot Monarch) 1300, an average primary particle size of 13 nm, a DBP oil absorption of 100 cc/g, and a nitrogen surface area of 560 m ² /g) were mixed into the solution with a magnetic stirrer. This solution/carbon black mixture was dispersed by a high speed shear, then mixed with a surfactant, and then dispersed again. The heat treatment applied was the same as in Example 1.

XRD shows that this material is a single phase perovskite. The surface area obtained after the heat treatment was 24.7 m ² /g. Figure 1 shows the hole size distribution. TEM showed an average particle size of ~50 nm. After heat treatment at 1000 ° C for 2 hours, the surface area was 10.04 m ² /g.

It is important to note that the inclusion of carbon black provides significantly larger holes and the material is more stable at high temperatures.

Example 3

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ was produced in the same manner as in Example 2, except that the heat treatment was carried out by directly placing the material heated to 300 ° C at 1000. °C composition. After heat treatment at 1000 ° C for 2 hours, the surface area was 1.9 m ² /g.

This example shows that the incorporation of carbon black into the perovskite itself is not sufficient to provide high temperature stability. The heat treatment conditions used in this example caused the surface area of the material to be broken. It is presumed that a large phase change in the temperature used in this embodiment results in uncontrolled carbon combustion from the oxide, which results in a very high temperature in the localized region. This is presumed to have caused sintering and reduction of metal oxides. In other words, the composition of the metal oxide and the pore structure are not maintained during the combustion of the carbon.

Example 4

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ was produced in the same manner as in Example 3 except that no air flow was present in the tube furnace. The rest of this program is the same.

XRD shows that the material is a perovskite phase. The maximum half of the full width of the peak (FWHM) is similar to the FWHM of the peaks of Examples 1 and 2, indicating that the particle size is similar (i.e., about 50 nm). The surface area obtained after this heat treatment was 22.1 m ² /g. After heat treatment at 1000 ° C for 2 hours, the surface area was 9.1 m ² /g.

This result is compared with that of Example 2 (10.2 m ² /g) to show an advantageous effect of increasing oxygen during heat treatment. The inventors of the present invention believe that less oxygen provides reducing conditions within the furnace which can result in the formation of metals within the material. This can result in sintering and reduced surface area and voids.

Example 5-8

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ was produced in a manner similar to that of Example 2 and with varying amounts of carbon black (Raven 850).

XRD showed that these materials were perovskite phases and the peak FWHMs were similar to Examples 1 and 2.

The surface area, pore volume and pore size distribution are shown in Table 1, and are clearly dependent on the amount of carbon black used.

Examples 9-11 La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ Examples with different carbon blacks

The examples show the effect of using different types of carbon black pore formations on the surface area and pore structure obtained by the complex oxide La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ .

The oxide was formed using the method described in Example 2, but using different types of carbon black.

XRD showed that all of the compounds were perovskite structures, and the peak FWHM series were similar to Examples 1 and 2, indicating that the particle size was about 50 nm. The results obtained for the surface area and pore structure are shown in Table 2.

Example 12-13

In Examples 12 and 13, La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ is in the same manner as in Examples 1 and 2 (carbon-free and carbon-free). Manufactured, but polyethylene glycol (molecular weight 4000) was used instead of the surfactant, XRD showed the perovskite phase, and the trace impurity peak of Example 12. The surface area and pore volume are shown in Table 3. Nagano explicitly increases the number of larger holes.

Example 14-15

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ is produced by a coprecipitation technique, and Examples 14 and 15 are individually and without carbon (17.8 g of Monarch 1300). And practice. The solution was produced in the same manner as in Example 1. Another solution was prepared by dissolving 55 grams of ammonium oxalate in 960 grams of water. These solutions were prepared by mixing each solution slowly to a stirred tank. The precipitate was washed, filtered, and dried at ~100 ° C, and then heat-treated in the same manner as in Example 1.

XRD shows the perovskite phase and some individual peaks. The surface area and pore volume are shown in Table 4.

Clearly, the effect of carbon on the pore distribution is smaller than that observed for the examples using surfactants and polyethylene glycols. Without being bound by any particular theory, the inventors believe that a larger liquid volume (generally necessary for co-precipitation) results in extremely dispersed precipitate particles and carbon particles. This makes it extremely difficult to sufficiently disperse the carbon particles in the precipitate to produce the desired pores.

Examples 16-21 Ce _{0 . 5 4} Zr _{0 . 3 7} La _{0 . 0 3} Pr _{0 . 0 6} O _x Examples with different types of carbon black

These examples show the use of different types of carbon black pore formations for the complex oxide Ce _{0 . 5 4} Zr _{0 . 3 7} La _{0 . 0 3} Pr _{0 . 0 6} O _x . Surface area and pore structure obtained .

The composition Ce _{0 . 5 4} Zr _{0 . 3 7} La _{0 . 0 3} Pr _{0 . 0 6} O _x is obtained by dissolving an appropriate amount of cerium nitrate, zirconium carbonate, cerium nitrate and cerium nitrate in water/nitric acid. Manufactured from a solution. 33 g of carbon black was dispersed in this solution using a high speed shear, 70 g of Erunon LA4 surfactant was added, and the mixture was dispersed again. The mixture was slowly heated to 300 °C. Then, the dried product was heat-treated in a tube furnace having an air flow at 300 ° C, 350 ° C, 400 ° C, 450 ° C, 500 ° C, 600 ° C, and 650 ° C for 0.5 hours.

XRD showed that the samples were single phase and the TEM showed that the materials produced in these examples had an average particle size of about 5-10 nm after heating to 650 °C. Other examples exhibit similar XRD peak FWHMs, indicating similar particle sizes.

The surface of the sample with different carbon blacks and the pore volume and the particle size and absorption of the carbon black are shown in Table 5 below. The surface area obtained after heat treatment at 1000 ° C for 2 hours is also shown.

Clearly, the pore structure and surface area can be altered by the use of carbon black with different morphological characteristics.

Examples 22-26 Examples with excess La content

La _{0 . 8} Sr _{0 . 2} Mn _{0 . 9} Ni _{0 . 0 4} Pd _{0 . 0 6} O ₃ +La ₂ O _{3 The} material was produced in a manner similar to the previous examples. The amount of La ₂ O ₃ varies between 2.5% by weight and 20% by weight. XRD showed perovskite phase, with increasing excess of La ₂ O _3. Increase the amount of La ₂ O ₃ phase. Figures 2 and 3 show the surface area obtained after heat treatment at 650 ° C and 800 ° C as a function of La ₂ O ₃ content.

This embodiment exemplifies that the pore structure of the oxide composition can be changed by incorporating a varying amount of the second phase.

Example 27 Excess CeO ₂ (7b)

La _{0 . 8} Sr _{0 . 2} Ni _{0 . 0 4} Pd _{0 . 0 6} Mn _{0 . 9} O ₃ + 10% by weight CeO ₂ was produced in a manner similar to that of Example 1. This composition is specifically selected to provide a perovskite phase and a separate CeO ₂ phase (this excess CeO ₂ cannot be incorporated into the perovskite phase). XRD shows that this material is a perovskite phase and CeO ₂ . The surface area obtained was 28.9 m ² /g, and the volume of pores between 3 nm and 200 nm was 0.26 cc/g, the pore volume between 10 nm and 200 nm was ~0.25 cc/g, and between 50 nm and 200 nm was ~0.175 cc/g. . After heat treatment at 1000 ° C for 2 hours, the surface area was 11.7 m ² /g.

Examples 28 and 29 by hydrothermal method Ce _{0 . 4 5} Zr _{0 . 4 5} La _{0 . 1} O _x

Ce _{0 . 4 5} Zr _{0 . 4 5} La _{0 . 1} O _x is produced using a hydrothermal process similar to known methods for similar compounds.

49.3 g of ammonium cerium (IV) nitrate, 27.4 g of zirconium carbonate, and 8.66 g of cerium nitrate were dissolved in a solution containing 940 g of water and 63 g of nitric acid (70%). The mixture was heated at ~95 °C for ~24 hours, causing the formation of precipitates. A 150 ml ammonia solution (%) was finally added, and the precipitate was washed, separated by filtration, and dried at ~100 °C. Then, heat treatment is performed. The temperature was increased from 150 ° C and carried out at 150 ° C, 200 ° C, 250 ° C, 300 ° C, 350 ° C, 400 ° C, and 450 ° C stages for 5 hours. The surface area after heat treatment was 145 m ² /g. The hole volume is shown in Table 6, and the XRD is shown in Figure 4.

Comparative Example 29

Ce _{0 . 4 5} Zr _{0 . 4 5} La _{0 . 1} O _x was produced in the same manner as in Example 28, except that 32 g of Raven 850 carbon black was added to this solution and dispersed by a high speed shear. Then, hydrothermal heating and heat treatment are carried out in the same manner. The surface area of this sample is ~100 m ² /g. The hole volume is shown in Table 6, and the XRD is shown in Figure 4. Compared with Example 28, it can be seen that the inclusion of carbon increases the volume of the larger pores. However, XRD shows that carbon incorporation results in the formation of cerium-rich oxides and zirconia-rich oxides with slightly fine phases. This is confirmed by the two peaks, and the individual peaks are shifted to the peak positions of CeO ₂ and ZrO ₂ . Therefore, carbon has affected the hydrothermal precipitation method, resulting in a large separation of different element species and an increase in pore volume. This effect is more clearly shown in Figure 5, which shows an additional XRD of the exemplary compound for 0.5 hour at 800 °C.

Example 30-32 CuO

CuO was produced using a method similar to the previous examples. Example 30 was slowly heat treated to 350 ° C and maintained at 150 ° C, 200 ° C, 250 ° C, 300 ° C and 350 ° C for 0.5 hours. Example 3 was similarly heat treated, but it was observed that this sample was considerably overheated during the heat treatment, exhibiting red heat in some areas, indicating that the sample suffered a temperature much higher than 350 °C. Example 32 had a slower heat treatment and was further carried out at 225 ° C for an additional 1 hour. This heat treatment was found to produce materials with more consistent properties, and high temperature shifts were not observed.

The XRD of all materials exhibits only the CuO phase. The obtained surface area and pore volume series are shown in Table 7.

These examples show that, surprisingly, heat sensitive materials can be made using the process of the invention using suitable heat treatment.

It is to be understood that the invention disclosed and defined in this specification can be applied to all the various combinations of two or more of the features described herein. All such different combinations constitute various alternative aspects of the invention.

It is also to be understood that the term "comprising" (or grammatical variant) used in this specification is equivalent to "containing" and does not exclude the presence of other elemental elements or features.

Figure 1 shows the materials obtained in Examples 1 and 2, which were then heat treated to 650 ° C, the pore size distribution (the pore size distribution of the metal oxides prepared in Examples 1 and 2); and Figure 2 shows Example 18 -22 Surface area obtained after heat treatment at 650 ° C and 800 ° C, which is a function of La ₂ O ₃ content (and the effect of the second La ₂ O ₃ relative surface area); Figure 3 shows Examples 18-22 to 650 The volume of the pore obtained after heat treatment at °C, which is a function of the La ₂ O ₃ content (the effect of excess La ₂ O ₃ on the pore volume); Figures 4a and 4b show the Ce0.45Zr0.45La0.1Ox heat treated to 540 °C. The XRD pattern, a) was obtained without carbon (Example 28), and b) was obtained with carbon (Example 29); Figures 5a and 5b showed Ce0.45Zr0.45La0.1Ox heat treated to 800 °C. The XRD pattern, a) was obtained without carbon (Example 28), and b) was obtained with carbon (Example 29).

Claims (23)

A method of making a porous, staggered oxide, the method comprising forming a mixture a) a precursor element suitable for the manufacture of the faulty oxide; or b) one or more suitable for the manufacture of the faulty oxide particle a material element and one or more metal oxide particles, wherein at least one of the precursor elements is present in solution; and c) a solid particulate carbon-containing material forming a void which is selected to provide a pore in the range of about 7 nm to 250 nm Dimensions, the solid particulate carbon-containing pore-forming material is dispersed throughout the mixture; and d) one or more surfactants present in an amount sufficient to form surfactant micelles to form a micellar liquid And heating the mixture to i) form the porous complex oxide, wherein the precursor element of two or more of (a) above or one or more of the precursor elements of (b) above One or more of the metal oxide particles are incorporated in one of the phases of the mixed metal oxide, and the misaligned metal oxide has a particle size ranging from 1 nm to 150 nm; and ii) Make the porous oxide Structure and composition of the material of the hole formed is substantially removed under the conditions of retention, in order to obtain a hole having a size error. 7 nm to 250 nm range of the hydrated metal oxide. The method of claim 1, wherein the single phase mismatched metal oxide is formed. The method of claim 1, wherein a mismatched metal oxide Phase and one or more other metal oxide phases are formed. The method of claim 1, wherein two or more of the miscible metal oxide phases with or without any other metal oxide phase are formed. The method of claim 1, wherein each phase of the metal oxide phase formed is phase purified. The method of claim 1, wherein the solid particulate carbon-containing pore-forming material comprises pore-forming particles having a particle size ranging from about 10 nm to 150 nm. The method of claim 1, wherein the pore-forming particles have a particle size ranging from about 10 nm to 100 nm. The method of claim 1, wherein the solid particulate carbon-containing material forming the pores comprises carbon black particles. The method of claim 1, wherein the component for forming the defective oxide is uniformly dispersed to form the precursor mixture. The method of claim 9, wherein the solid particulate carbon-containing pore-forming material is dispersed in the mixture using a method selected from the group consisting of high-speed shearing, ultrasonic mixing, rolling, ball milling or sanding. The method of claim 1, wherein the air is removed from the solid particulate carbon-containing material by vacuum prior to forming the mixture. The method of claim 1, wherein the method comprises providing a solution comprising a metal oxide cation-containing precursor element, a carbon particle source, and a nonionic, cationic or anionic surfactant, The solution, the surfactant, and the solid particulate carbonaceous material forming the pores form the mixture, such that the surfactant micelles are formed and the mixture forms a substantially uniform dispersion, and the mixture is subjected to the carbon particles The step of heating to form the staggered metal oxide under substantially removed conditions. The method of claim 12, wherein the method comprises the steps of: a) producing a solution containing one or more metal cations; b) reacting the solution of step a) with a surfactant to make sufficient micelles in the solution Mixing under the conditions of formation, thereby forming a micellar liquid; and c) heating the micellar liquid of the above step b) to form a metal oxide, the heating step being carried out at a temperature for a period of time to remove the surfactant And thereby forming metal oxide particles having a disordered pore structure, wherein the solid particulate carbon-containing pore-forming material comprises carbon black particles, and the carbon black particles are added to the solution of a), or b) The mixture, and the heat treatment also substantially removes the carbon black particles. The method of claim 13, wherein the carbon black particles are added to the solution of step a) prior to mixing. The method of claim 1, wherein the step of treating the mixture to form the miscible metal oxide and removing the solid particulate carbon-forming pores comprises heating the mixture to a temperature between 100 ° C and 750 ° C The temperature of the range. The method of claim 15, wherein the temperature falls within the range of 100 ° C to 650 ° C. For example, the method of claim 15 wherein the temperature falls within 100 Within the range of °C to 300 °C. The method of claim 1, wherein one or more of temperature, cooling rate or partial pressure of oxygen is controlled during the heat treatment step to remove the solid particulate carbon-containing material forming the pores The reduction of the mismatched metal oxide is minimal or avoided. The method of claim 18, wherein the temperature is controlled such that the specified maximum temperature is not exceeded during removal of the solid particulate carbon-containing material forming the void. The method of claim 1, wherein the metal oxide contains two or more atomic sequences of 3, 4, 11, 12, 19 to 32, 37 to 51, 55 to 84, and 87 to 103 metal. A method of producing a porous, staggered oxide according to claim 1, wherein the method comprises providing a mixture of: a) one or more precursor elements suitable for the manufacture of the non-refractory metal oxide, wherein the one or more At least one of the precursor elements is present in solution; and b) a particulate carbonaceous material forming pores selected to provide a pore size in the range of from about 7 nm to 250 nm, and c) a surfactant, The surfactant is present in an amount sufficient to form a surfactant micelle thereby forming a micellar liquid, and treating the mixture to (i) form the porous metal oxide, wherein the non-flammable metal oxide has a 1 nm to 150 nm The particle size of the range; and (ii) the porous structure and composition of the non-metal oxide are substantially retained The material forming the holes is removed under the conditions. The method of claim 21, wherein the method comprises the steps of: (a) producing a solution containing one or more metal cations; (b) causing the solution and the surfactant to gel the surfactant The bundle is mixed under the conditions formed in the solution, thereby forming a micellar liquid; and (c) heating the micelle liquid to form a metal oxide, the heating step being performed at a temperature for a period of time to remove the surfactant And thereby forming metal oxide particles, wherein carbon black particles are added to the solution, and the heat treatment also removes the carbon black particles in a large amount. The method of claim 21, wherein the particulate carbon-containing material forming the pores has a particle size ranging from 7 nm to 250 nm.