EP2791078A1 - Process for preparing a sol-gel from at least three metal salts and use of the process for preparing a ceramic membrane - Google Patents

Process for preparing a sol-gel from at least three metal salts and use of the process for preparing a ceramic membrane

Info

Publication number
EP2791078A1
EP2791078A1 EP12766076.9A EP12766076A EP2791078A1 EP 2791078 A1 EP2791078 A1 EP 2791078A1 EP 12766076 A EP12766076 A EP 12766076A EP 2791078 A1 EP2791078 A1 EP 2791078A1
Authority
EP
European Patent Office
Prior art keywords
atom
sol
formula
preparing
chosen
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP12766076.9A
Other languages
German (de)
French (fr)
Inventor
Nicolas Richet
Thierry Chartier
Fabrice Rossignol
Aurélien VIVET
Pierre-Marie Geffroy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Centre National de la Recherche Scientifique CNRS
Universite de Limoges
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Centre National de la Recherche Scientifique CNRS
Universite de Limoges
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Centre National de la Recherche Scientifique CNRS, Universite de Limoges, LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude filed Critical Centre National de la Recherche Scientifique CNRS
Publication of EP2791078A1 publication Critical patent/EP2791078A1/en
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0039—Inorganic membrane manufacture
    • B01D67/0048—Inorganic membrane manufacture by sol-gel transition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/228—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion characterised by specific membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02—Inorganic material
    • B01D71/024—Oxides
    • B01D71/0271—Perovskites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/18—Processes for applying liquids or other fluent materials performed by dipping
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
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    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G15/00—Compounds of gallium, indium or thallium
    • C01G15/006—Compounds containing, besides gallium, indium, or thallium, two or more other elements, with the exception of oxygen or hydrogen
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    • C01—INORGANIC CHEMISTRY
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    • C04B2235/768—Perovskite structure ABO3
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/77—Density

Definitions

  • the present invention relates to catalytic membrane reactors or CMRs.
  • a Membrane Catalytic Reactor is composed of a mixed conductive dense membrane (electronic and ionic) of oxygen anions. Under the action of an oxygen partial pressure gradient imposed on either side of the membrane, the oxygen anions O 2 " , coming from the air, pass through the membrane of the oxidizing surface towards the reducing surface, to react with methane on the latter
  • Figure 1 illustrates the set of elementary steps in the transport of oxygen through a membrane, which are six in number:
  • each of the steps described above can be a limiting step in the transport of oxygen through the membrane.
  • the limiting step is the exchange of surfaces, and more particularly to the reducing surface of the membrane
  • PM Geffroy et al. "Oxygen semi-permeation, oxygen diffusion and surface exchange coefficient of La (i x ) Sr x Fe (i y ) Ga y 0 3 -d perovskite membranes ", Journal of Membrane Science, (2010) 354 (1-2) p.6-13; PM Geffroy et al., "Influence of oxygen surface exchanges on oxygen semi-permeation through the (i x ) Sr x Fe (i y ) Ga y o 3 -o dense membrane” Journal of Electrochemical Society, (201 1) , 158 (8), p.
  • the surface state of the membranes for the CMR application plays a major role in the performance of the process [PM Geffroy et al., "Oxygen semi-permeation, oxygen diffusion and surface exchange coefficient of the (i x ) Sr x Fe (i y.) Ga y 0 -d 3 perovskite membrane "Journal of membrane Science, (2010) 354 (1 -2) p.6-13; PM Geffroy et al., "Influence of oxygen surface exchanges on oxygen semi-permeation through the (1 x ) Sr x Fe ( 1y) Gay03-s dense membrane” Journal of Electrochemical Society, (201 1), 158 ( 8), p.
  • the cohesion of the entire layer is obtained by a modification of the grains of the powder, which is reflected more particularly by their magnification. There is therefore a decrease in the density of grain boundaries.
  • the current methods of synthesis of materials do not allow to obtain grains of very small diameter.
  • the tortuosity in the porosity increases; this therefore reduces the useful area on which surface exchange can take place.
  • One of the objects of the present invention is therefore to propose an operating protocol for obtaining a nano-structured architecture which, at high temperature, that is to say at a temperature above the crystallization temperature, is a ultra-divided perovskite composed of crystallites 10-100 nm in diameter.
  • the layer of material thus formed develops a large surface area and has a high density of grain boundaries. It also has an increased microstructural stability, whether grain size or grain boundary density, at high temperature (700 ° C to 1000 ° C) and over a long period (more than 2 000h ).
  • the methods generally used today to increase the exchange surface of the membranes are the deposition of a porous layer by screen printing, the use of a porous support where the porosity is created by the use of a porogenic agent and the use of mesoporous materials.
  • the screen printing ink is then deposited on the membrane using a squeegee that forces the ink to pass through the screen printing mask to print the desired patterns. The deposited thickness is between 20 ⁇ and ⁇ ⁇ .
  • Figure 2 is a photograph taken under a scanning electron microscope (SEM photo) of a porous surface deposited by screen printing on a support.
  • the subject of the present invention is therefore a process for preparing a perovskite phase sol with controlled stoichiometry having at least four cations and being stable over time. After dipping (dip coating in English), during the crystallization of this sol temperature, an ultra-divided or nano structured architecture layer composed of perovskite phase particles with a diameter of 10-100 nm is deposited on the surface of the membrane. .
  • An essential feature of this invention is the very large increase in grain boundaries at the membrane surface as well as the dramatic increase in the exchange surface area and oxygen flux through the membrane.
  • the subject of the invention is therefore a process for preparing a sol-gel of at least three metal salts Mi, M 2 and M 3 which are suitable for the preparation of a material of the type perovskite corresponding to the general formula (I):
  • x, y, u and ⁇ are such that the electrical neutrality of the crystal lattice is conserved, 0 ⁇ x ⁇ 0.9,
  • A represents an atom chosen from scandium, yttrium or in the families of lanthanides, actinides or alkaline earth metals;
  • a different from A represents an atom chosen from scandium, yttrium, aluminum, gallium, indium, thallium or in the families of lanthanides, actinides or alkaline earth metals;
  • B represents an atom chosen from transition metals
  • B ' different from B, represents an atom selected from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth, tin or lead;
  • B "different from B and B ', represents an atom selected from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth , tin, lead or zirconium;
  • said method comprising the following steps:
  • sol-gel of at least three metals Mi, M 2 , and M 3 suitable and intended for the preparation of a perovskite-type material is meant in particular a sol of three metals, a sol-gel of four metals or a sol-gel of five metals.
  • step a) of the process as defined above the anions of the water-soluble salts of said elements A, A ', B, B' and optionally B "are of valence lower than that of the cation corresponding.
  • the negative counterion is an anion of valence -1: according to this option, this anion is more particularly chosen from halide ions or the nitrate ion and preferably it is the nitrate ion.
  • the negative counterion is anion of valence -1 or valence -2: according to this option, this anion is more particularly chosen from halide ions, the nitrate ion or the sulfate ion, preferably it is the nitrate ion.
  • the negative counterion is anion of valence -1, valence -2 or valence -3, depending on this option, this anion is more particularly chosen from the halide ions, the nitrate ion, the sulfate ion or the phosphate ion, preferably it is the nitrate ion.
  • the water-soluble salts of said elements A, A ', B, B' and optionally B ", implemented in step a), are the nitrates of said elements.
  • B "(N se is) / Numbers of mole of water (N H 2o), is more particularly greater than or equal to 0.005 and less than or equal to 0.05.
  • hydro-alcoholic solution it is meant in the context of step b) of the process as defined above that the alcohol-water mixture contains at least about 70% by weight of alcohol and at most 30% by weight of alcohol. weight of water.
  • the alcohol used in step b) is ethanol.
  • step b) of process as defined above the molar ratio N (t ensioacti ) N ⁇ NH3) is greater than or equal to 10 "4 and less than or equal to 10 " 2
  • the nonionic surfactant used in step b) is chosen from block copolymers consisting of poly (alkyleneoxy) chains and more particularly from copolymers ( EO) n - (PO) m - (EO) n .
  • the nonionic surfactant used in step b) is a commercially available block copolymer (EO) 9 9 (PO) 7 o- (EO) 9 9 under the name PLURONIC TM F127
  • a and A ' are more particularly chosen from lanthanum (La), cerium (Ce), yttrium (Y), gadolinium (Gd), magnesium ( Mg), calcium (Ca), strontium (Sr) or barium (Ba).
  • A represents a lanthanum atom, a calcium atom or a barium atom.
  • a ' represents a strontium atom.
  • B and B ' are more particularly selected from iron (Fe), chromium (Cr), manganese (Mn), gallium (Ga), cobalt (Co) ), nickel (Ni) or titanium (Ti).
  • B represents an iron atom
  • B ' represents a gallium atom, a titanium atom or a cobalt atom.
  • B represents a zirconium atom.
  • u is more particularly equal to 0.
  • the subject of the invention is a process as defined above, for which the perovskite material of formula (I) is chosen from the following compounds:
  • the subject of the invention is also a process for preparing a substrate coated on at least one of its surfaces with a sol-gel film of a perovskite material, characterized in that it comprises:
  • step e) of dipping consists of immersing a substrate in the soil synthesized previously and removing it at a controlled and constant speed.
  • the movement of the substrate causes the liquid forming a surface layer.
  • This layer divides in two, the inner part moves with the substrate while the outer part falls into the container.
  • the progressive evaporation of the solvent leads to the formation of a film on the surface of the substrate.
  • e being the thickness of the deposit
  • ⁇ being a deposition constant dependent on the viscosity, the density of the soil and the liquid-vapor surface tension and v being the drawing speed.
  • the drying step g) is generally carried out in the open air or in a controlled atmosphere for a few hours.
  • Perovskite material sintered with a density greater than 90%, preferably greater than 95% more particularly denotes a ceramic composition (CC) comprising for 100% by volume, at least 75% by volume and up to 100% by volume of an electronically mixed conductive compound and oxygen anions O 2 " (Ci) chosen from doped ceramic oxides of formula (II):
  • x, y, u and ⁇ are such that the electrical neutrality of the crystal lattice is preserved
  • C represents an atom chosen from scandium, yttrium or in the families of lanthanides, actinides or alkaline earth metals;
  • C different from C, represents an atom selected from scandium, yttrium, aluminum, gallium, indium, thallium or in families of lanthanides, actinides or alkaline earth metals;
  • D represents an atom chosen from transition metals
  • D represents an atom chosen from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth, tin or lead;
  • D - D "different from D and D ', represents an atom chosen from transition metals, metals of the alkaline-earth family, aluminum, indium, gallium, germanium, antimony, bismuth , tin, lead or zirconium;
  • said ceramic composition (CC) comprises, for 100% by volume, at least 90% by volume and more particularly at least 95% by volume and up to 100% by volume of compound (Ci) and optionally up to at 10% in volume, and more particularly up to 5% by volume of compound (C 2 ).
  • the sintering undergone by the material of formula (II) before its implementation in step e) is carried out under air at a temperature above 1,000 ° C., or even above 1200 ° C for about 10 hours to reach the desired relative density.
  • the subject of the invention is a method for preparing a ceramic membrane (CM) characterized in that said substrate coated with a sol-gel obtained by the process as defined above, undergoes a step h) calcination under air.
  • the calcination step h) is generally carried out in air at a temperature of approximately 1000 ° C. for at least 1 hour, the temperature rise rate being around 1 ° C. per minute. The calcination of the substrates under air thus makes it possible to eliminate the nitrates but also to decompose the surfactant and thus to release the porosity.
  • the subject of the invention is a process for preparing an ultra-divided powder of perovskite-type material corresponding to the general formula (I), characterized in that the sol resulting from stage c) of method as defined above, undergoes a step i) of atomization to form a sol-gel powder; said sol-gel powder being then subjected to the calcination step in air, to form said ultra-divided or nanostructured powder (i.e., a nanoscale size of 10 to 100 nm).
  • the invention finally relates to the use of the membrane as defined above to produce oxygen from air, by electrochemistry through
  • Nitrates of lanthanum, strontium, iron and gallium, precursors of perovskite are mixed in the stoichiometric proportions necessary for the formation of a perovskite of structure La 0 , 8 Sr 0 , 2 Fe 0 , 7Ga 0 , 3 0 3- ⁇ with a nonionic surfactant, in an ammonia / ethanol solution. Evaporation of the solvents (ethanol and water) allows the gel solids to crosslink around surfactant micelles by forming bonds between the hydroxyl groups of one salt and the metal of another salt.
  • the control of hydrolysis / condensation reactions related to electrostatic interactions between inorganic precursors and surfactant molecules allows cooperative assembly of the organic and inorganic phases, which generates micellar aggregates of controlled size surfactants within an inorganic matrix. .
  • the phenomenon of self-assembly is induced by progressive evaporation of the solvent from a reagent solution, when the micellar concentration becomes critical.
  • the starting point of the self-setting process is the hydroalcoholic solution of inorganic precursors (La, Sr, Fe and Ga) and nonionic surfactant.
  • the nonionic surfactant used in the process belongs to the family of block copolymers, copolymers which have two parts of different polarities: a hydrophobic body and hydrophilic ends.
  • These copolymers consist of poly (alkylene oxide) chains, such as copolymers of general formula (EO) n - (PO) m - (EO) n , consisting of the chain of poly (ethylene oxide) (EO), hydrophilic at the ends and in its central part the poly (propylene oxide) (PO), hydrophobic.
  • the polymer chains remain dispersed in solution at a concentration below the critical micelle concentration (CMC).
  • CMC is defined as the limiting concentration beyond which the phenomenon of self-arrangement of surfactant molecules in the solution occurs. Beyond this concentration, the chains of the surfactant tend to be grouped by hydrophilic / hydrophobic affinity. Thus, the hydrophobic bodies are grouped together and form spherical micelles. The ends of the polymer chains are pushed outwardly of the micelles, and associate during the evaporation of the volatile solvent (ethanol) with the ionic species in solution which also have hydrophilic affinities.
  • ethanol volatile solvent
  • the size of the micelles is fixed by the length of the hydrophobic chain.
  • a block copolymer of (EO) 9 9- (PO) 7 o- (EO) 9 9 type commercially available under the reference Pluronic TM F127, micelles with a diameter of between 6 nm and 10 nm can be produced. produced. This is an example but other surfactants can be used to cover a range of micelles of diameter between 3nm and 10nm.
  • the gels obtained after evaporation of the solvents are calcined in air.
  • the removal of the surfactant during the heat treatment makes it possible to generate a cohesive matrix having a homogeneous and structured porosity.
  • FIG. 4 illustrates the principle of self-assembly after soaking a substrate in a soil, said self-assembly being induced by evaporation, leading to the formation of a sol-gel which, after calcination, leads to an ultra-divided support of perovskite phase with controlled microstructure.
  • Is prepared 20 cm 3 of aqueous solution containing lanthanum nitrate, strontium, iron and gallium, perovskite precursors, are mixed in the stoichiometric proportions required for the formation of a perovskite structure
  • a sol is synthesized according to the procedure described in the following experimental part. This soil was made to obtain stoichiometry Stoichiometry was verified by ICP (Inductively Coupled Plasma Atomic Emission) Spectrometric Analysis (see Table 2 below)
  • the substrates used in our study are perovskite membranes sintered at 1350 ° C for 10 hours in air (relative density of membranes ⁇ 97%, measurements made by the method of Archimedes' thrust). These membranes have the same La, Sr, Fe and Ga stoichiometry as that of the soil previously produced.
  • the membrane is stoichiometry
  • the sample is then dried under free air for 6 hours before undergoing heat treatment under air to remove nitrates and surfactant.
  • the membrane covered with a thin film was calcined in air at 1000 ° C for 1 h, with a temperature rise rate of 1 ° C / min.
  • Figure 6 is a diffractogram of sol-gel powder calcined at 1000 ° C. It shows the complete crystallization of perovskite type (structure AB0 3 )
  • the SEM-FEG micrographs reveal the formation of an ultra-divided deposit on the surfaces of the membrane.
  • the deposit is however different according to the exposed surface reducing gas ( Figure 7) or oxidizing gas (Figure 8) after aging.
  • Figure 7 On the surface in contact with the reducing atmosphere (illustrated by the SEM-FEG micrographs of FIGS. 7A to 7C), it results from the drying and the calcination of the soil deposit a coating of the surface of the membrane by an ultra-divided deposit composed of particles of a size of the order of 50-1000 nm.
  • the density of grain boundaries at the surface of the membrane is greatly increased. Clusters of grains in the form of pads of average diameter of the order of 200-500 nm greatly increase the exchange surface with the gas.
  • the crystallization of the perovskite phase results in an ultra-divided and highly porous deposit with crystallized particles having facets in contact with one another. . These particles are of a size of the order of one hundred nanometers and display a narrow particle size distribution.
  • Oxygen semi-permeation performance of dipstrate-deposited membranes was measured.
  • Material 3 LSFG8273 screen-coated with a porous layer of
  • the deposition of a perovskite sol on the surface of a membrane greatly exceeds the best performances already obtained by depositing a screen-printed layer.
  • the soaking rate affects the thickness of the deposited layer.
  • a faster speed (10 mm / s) increases the thickness of the deposited layer and increases the exchange surface as well as the density of surface grain boundaries. Performance is further improved.
  • the following table lists the results obtained at 900 ° C.
  • Diaphragms J0 2 (mole m “1 " s "1 )
  • the deposition of perovskite sol prepared by the process according to the invention has the first advantage of developing a large specific surface area and a high density of grain boundaries. Furthermore, this deposit is stable under partial pressure gradient oxygen, a necessary condition for the use of a CMR for steam reforming methane but also to produce oxygen by separation of the air through said ceramic membrane.
  • the second advantage comes from the thickness of the deposit and the deposition process. Indeed, the deposit is of a thickness 100 times smaller than by screen printing (material gain) and because of soaking, all dense diaphragm support geometries can be used (tubes, flat plates).
  • the atomization technique makes it possible to transform a sol into a solid dry form (powder) by the use of a hot intermediate.
  • the principle is based on the spraying into fine droplets of the soil (3), in a vertical cylindrical chamber (4) in contact with a hot air stream (2) in order to evaporate the solvent in a controlled manner.
  • the resulting powder is entrained by the heat flow (5) to a cyclone (6) which will separate the air (7) from the powder (8).
  • the powder recovered after the atomization is calcined under the same conditions as the substrates prepared by dipping ("dip-coated").
  • the microstructure of this powder is identical to that obtained on the deposit, namely an ultra-divided and porous microstructure with a crystallite size of the order of 10-100 nm.
  • the spherical granules are hollow and the wall of the granules itself has a high porosity.
  • the use of this powder to make porous layers would provide a dual-scale porosity and have a matrix with a high density of grain boundaries.

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Abstract

Process for preparing a sol-gel from at least four salts of metals M1, M2, M3 and M4 suitable and intended for the preparation of a perovskite type material corresponding to the general formula (I): A(1-X) A'x B(1-y-U) B'y B"u Ο3-δ, (I), said process comprising the following steps: - a step a) of preparing an aqueous solution of water-soluble salts of said elements A, A' optionally A", B and B', in the stoichiometric proportions necessary for obtaining the material as defined above; - a step b) of preparing an aqueous-alcoholic solution of at least one non-ionic surfactant in an alcohol chosen from methanol, ethanol, propanol, propanol, isopropanol or butanol, mixed with an aqueous solution of ammonia in a sufficient proportion to ensure the complete solubilisation of said non-ionic surfactant in said aqueous-alcoholic solution, the concentration of said non-ionic surfactant in said aqueous-alcoholic solution being less than the critical micelle concentration; - a step c) of mixing said aqueous solution prepared in step a) with said alcoholic dispersion prepared in step b) in order to form a sol; - a step d) of drying said sol obtained in step c), by evaporation of the solvent, in order to obtain a sol-gel. Use of the process for preparing a ceramic membrane.

Description

Procédé de préparation d'un sol-gel d'au moins trois sels de métaux et mise en œuvre du procédé pour préparer une membrane céramique La présente invention concerne les réacteurs membranaires catalytiques ou CMR The present invention relates to catalytic membrane reactors or CMRs.
(Catalytic Membrane Reactor en langue anglaise). Elle a pour premier objectif d'améliorer les performances en semi-perméation à l'oxygène des membranes céramiques mis en œuvre dans les réacteurs catalytiques membranaires. (Catalytic Membrane Reactor in English). Its primary objective is to improve the oxygen semi-permeation performance of ceramic membranes used in membrane catalytic reactors.
Un Réacteur Catalytique Membranaire est composé d'une membrane dense conductrice mixte (électronique et ionique) des anions oxygènes. Sous l'action d'un gradient de pression partielle d'oxygène imposé de part et d'autre de la membrane, les anions oxygène O2", provenant de l'air, traversent la membrane de la surface oxydante vers la surface réductrice, pour venir réagir avec le méthane sur cette dernière. La Figure 1 illustre l'ensemble des étapes élémentaires dans le transport de l'oxygène à travers une membrane, qui sont au nombre de six : A Membrane Catalytic Reactor is composed of a mixed conductive dense membrane (electronic and ionic) of oxygen anions. Under the action of an oxygen partial pressure gradient imposed on either side of the membrane, the oxygen anions O 2 " , coming from the air, pass through the membrane of the oxidizing surface towards the reducing surface, to react with methane on the latter Figure 1 illustrates the set of elementary steps in the transport of oxygen through a membrane, which are six in number:
- L'absorption de l'oxygène à la surface oxydante de la membrane ;  - The absorption of oxygen at the oxidizing surface of the membrane;
- La dissociation de l'oxygène et recombinaison en anions O2" ; - Dissociation of oxygen and recombination in O 2 - anions;
- La diffusion de l'oxygène à travers le volume de la membrane ;  - The diffusion of oxygen through the volume of the membrane;
- La recombinaison de l'oxygène ;  - The recombination of oxygen;
- La désorption de l'oxygène de la surface réductrice de la membrane ;  The desorption of oxygen from the reducing surface of the membrane;
- La réaction de l'oxygène pur avec le méthane  - The reaction of pure oxygen with methane
Or, chacune des étapes décrites précédemment peut être une étape limitante dans le transport de l'oxygène à travers la membrane.  However, each of the steps described above can be a limiting step in the transport of oxygen through the membrane.
Il a été déterminé que dans le cas de membranes pérovskite, l'étape limitante est les échanges de surfaces, et plus particulièrement à la surface réductrice de la membrane [P. M. Geffroy et al., "Oxygen semi-permeation, oxygen diffusion and surface exchange coefficient of La(i.X)SrxFe(i.y)Gay03-d pérovskite membranes", Journal of Membrane Science, (2010) 354(1 -2) p.6-13 ; P. M. Geffroy et al., « Influence of oxygen surface exchanges on oxygen semi-permeation through La(i.X)SrxFe(i.y)Gay03-ô dense membrane » Journal of Electrochemical Society, (201 1 ), 158 (8), p. B971 -B979;] Pour augmenter ces échanges, il faut donc modifier la surface d'échanges entre les gaz. Les deux possibilités envisagées sont soit d'augmenter la surface d'échanges en développant de la porosité à la surface de la membrane et dans un deuxième temps d'augmenter le nombre de sites actifs où ont préférentiellement lieu les échanges, soit d'augmenter la densité de joints de grains. Pour ce faire, il faut créer une architecture possédant une surface poreuse (on maximise la surface d'échanges par rapport à l'encombrement) possédant des grains de taille la plus petite possible. It has been determined that in the case of perovskite membranes, the limiting step is the exchange of surfaces, and more particularly to the reducing surface of the membrane [PM Geffroy et al., "Oxygen semi-permeation, oxygen diffusion and surface exchange coefficient of La (i x ) Sr x Fe (i y ) Ga y 0 3 -d perovskite membranes ", Journal of Membrane Science, (2010) 354 (1-2) p.6-13; PM Geffroy et al., "Influence of oxygen surface exchanges on oxygen semi-permeation through the (i x ) Sr x Fe (i y ) Ga y o 3 -o dense membrane" Journal of Electrochemical Society, (201 1) , 158 (8), p. B971 -B979;] To increase these exchanges, it is necessary to modify the surface of exchanges between the gases. The two possibilities envisaged are either to increase the exchange surface by developing porosity on the surface of the membrane and secondly to increase the number of active sites where exchanges are preferentially occurring, or to increase the density of grain boundaries. To do this, we must create an architecture with a porous surface ( maximizes the exchange surface with respect to the bulk) having grains of the smallest possible size.
L'état de surface des membranes pour l'application CMR joue un rôle primordial dans les performances du procédé [P. M. Geffroy et al., "Oxygen semi-permeation, oxygen diffusion and surface exchange coefficient of La(i.X)SrxFe(i.y)Gay03-d perovskite membranes", Journal of Membrane Science, (2010) 354(1 -2) p.6-13; P. M. Geffroy et al., « Influence of oxygen surface exchanges on oxygen semi-permeation through La(1. X)SrxFe(1.y)Gay03-s dense membrane » Journal of Electrochemical Society, (201 1 ), 158 (8), p. B971 -B979; H.J.M. Bouwmeester et al., "Importance of the surface exchange kinetics as rate limiting step in oxygen permeation through mixed-conducting oxides", Solid State lonics, (1994) 72(PART 2) p. 185-194; S. Kim et al., "Oxygen surface exchange in mixed ionic electronic conductor membranes. " Solid State lonics, (1999) 121 (1 ) p. 31 -36]. The surface state of the membranes for the CMR application plays a major role in the performance of the process [PM Geffroy et al., "Oxygen semi-permeation, oxygen diffusion and surface exchange coefficient of the (i x ) Sr x Fe (i y.) Ga y 0 -d 3 perovskite membrane "Journal of membrane Science, (2010) 354 (1 -2) p.6-13; PM Geffroy et al., "Influence of oxygen surface exchanges on oxygen semi-permeation through the (1 x ) Sr x Fe ( 1y) Gay03-s dense membrane" Journal of Electrochemical Society, (201 1), 158 ( 8), p. B971-B979; HJM Bouwmeester et al., "Importance of the exchange rate kinetics in oxygen permeation through mixed-conducting oxides", Solid State lonics, (1994) 72 (PART 2) p. 185-194; S. Kim et al., "Oxygen surface exchange in mixed ionic electronic conductor membranes." Solid State lonics, (1999) 121 (1) p. 31-36].
Pour optimiser le taux de conversion du méthane, il faut soit d'améliorer l'accessibilité des réactifs aux particules actives, soit d'augmenter la surface d'échanges entre l'oxygène et les particules de méthane.  To optimize the conversion rate of methane, it is necessary either to improve the accessibility of the reagents to the active particles, or to increase the exchange surface between the oxygen and the methane particles.
Cependant, Les deux principales barrières au développement de supports à forte surface spécifique sont le frittage, phénomène naturel apparaissant à haute température, et l'épaisseur de la couche poreuse  However, the two main barriers to the development of high surface area substrates are sintering, a natural phenomenon occurring at high temperatures, and the thickness of the porous layer
Lors du frittage pour éliminer les porogènes introduits dans les encres de sérigraphie ou lors du cofrittage, la cohésion de l'ensemble de la couche est obtenue par une modification des grains de la poudre, qui se traduit plus particulièrement par leur grossissement. Il y a donc une diminution de la densité de joints de grains. Or, les méthodes actuelles de synthèse des matériaux ne permettent pas d'obtenir des grains de très faible diamètre. De plus, si l'épaisseur de la couche est trop importante, la tortuosité dans la porosité augmente ; cela réduit donc la surface utile sur laquelle les échanges de surface peuvent avoir lieu.  During sintering to eliminate the porogens introduced into the screen printing inks or during cofiring, the cohesion of the entire layer is obtained by a modification of the grains of the powder, which is reflected more particularly by their magnification. There is therefore a decrease in the density of grain boundaries. However, the current methods of synthesis of materials do not allow to obtain grains of very small diameter. In addition, if the thickness of the layer is too great, the tortuosity in the porosity increases; this therefore reduces the useful area on which surface exchange can take place.
Un des objets de la présente invention est donc de proposer un protocole opératoire permettant l'obtention d'une architecture nano-structurée qui, à haute température, c'est-à-dire à une température supérieure à la température de cristallisation, est une pérovskite ultra-divisée composée de cristallites de 10-100 nm de diamètre. La couche de matériau ainsi formée développe une grande surface spécifique et possède une grande densité de joints de grains. Elle possède aussi une stabilité microstructurale accrue, qu'il s'agisse de la taille des grains ou de la densité des joints de grains, à haute température (700°C à 1000°C) et sur une longue période (plus de 2 OOOh).  One of the objects of the present invention is therefore to propose an operating protocol for obtaining a nano-structured architecture which, at high temperature, that is to say at a temperature above the crystallization temperature, is a ultra-divided perovskite composed of crystallites 10-100 nm in diameter. The layer of material thus formed develops a large surface area and has a high density of grain boundaries. It also has an increased microstructural stability, whether grain size or grain boundary density, at high temperature (700 ° C to 1000 ° C) and over a long period (more than 2 000h ).
Les méthodes généralement utilisées aujourd'hui, pour augmenter la surface d'échanges des membranes sont le dépôt d'une couche poreuse par sérigraphie, l'utilisation d'un support poreux où la porosité est créée par l'utilisation d'un agent porogène et l'utilisation de matériaux mésoporeux. The methods generally used today to increase the exchange surface of the membranes are the deposition of a porous layer by screen printing, the use of a porous support where the porosity is created by the use of a porogenic agent and the use of mesoporous materials.
La sérigraphie consiste tout d'abord à préparer une encre dite « de sérigraphie », composée de poudre de matériau, d'agent porogène par exemple l'amidon de maïs, l'amidon de riz ou la fécule de pomme de terre et d'un médium [S. Lee et al., «Oxygen- permeating property of LaSrBFe03.d (B=Co, Ga) perovskite membrane surface-modified by LaSrCo03 », Solid State lonics, (2003) 158(3-4) p. 287-296]. L'encre de sérigraphie est ensuite déposée sur la membrane à l'aide d'une raclette qui force l'encre à traverser le masque de sérigraphie pour imprimer les motifs désirés. L'épaisseur déposée est comprise entre 20μηι et Ι ΟΟμηη. La Figure 2 est une photo prise au microscope électronique à balayage (photo MEB) d'une surface poreuse déposée par sérigraphie sur un support. Screen printing consists first of all in preparing an ink called "screen printing", composed of powder of material, of pore-forming agent, for example corn starch, rice starch or potato starch. a medium [S. Lee et al., Oxygen permeating property of LaSrBFe0 3 . d (B = Co, Ga) perovskite surface-modified membrane by LaSrCo0 3 ", Solid State lonics, (2003) 158 (3-4) p. 287-296]. The screen printing ink is then deposited on the membrane using a squeegee that forces the ink to pass through the screen printing mask to print the desired patterns. The deposited thickness is between 20μηι and Ι ΟΟμηη. Figure 2 is a photograph taken under a scanning electron microscope (SEM photo) of a porous surface deposited by screen printing on a support.
Les supports poreux sont réalisés par cofrittage d'une membrane dense associée à u ne membrane comportant des porogènes (A. Julian et al., « Elaboration of Lao.8Sro.2Feo.7Gao.303-d Lao.8Mo.2Fe03-d (M = Ca, Sr and Ba) asymmetric membranes by tape-casting and co-firing » ; Journal of Membrane Science, (2009) 333(1 -2) p. 132-140; G. Etchegoyen et al., "An architectural approach to the oxygen permeability of a Lao.6Sr0.4Feo.9Gao.i03-d perovskite membrane. " Journal of the European Ceramic Society, (2006) 26(13) p. 2807-2815 »]. Les porogènes sont éliminés lors du traitement thermique pour laisser alors de la porosité résiduelle. Cette méthode a largement été décrite dans la littérature mais elle permet d'avoir plutôt un support mécanique pour les membranes qu'une surface d'échange étendue. Les Figures 3A et 3B sont des photos prises au microscope électronique à balayage (photo MEB) de bicouches supports poreux avec une membrane dense. The porous supports are made by co-sintering a dense membrane associated with a membrane comprising porogens (A. Julian et al., "Elaboration of Lao.8Sro.2Feo.7Gao.303-d Lao.8Mo.2Fe0 3 -d (M = Ca, Sr and Ba) Asymmetric Membranes by Tape-Casting and Co-firing "Journal of Membrane Science, (2009) 333 (1-2) pp. 132-140, G. Etchegoyen et al.," An Lao.6Sr 0 .4Feo.9Gao.i0 3 -d perovskite membrane. "Journal of the European Ceramic Society, (2006) 26 (13) pp. 2807-2815"] Porogens are removed during the heat treatment to leave residual porosity.This method has been widely described in the literature but it allows to have a mechanical support for the membranes rather than an extended exchange surface. photos taken with a scanning electron microscope (SEM photo) of porous media bilayers with a dense membrane.
L'élaboration de supports mésoporeux a été développée depuis une dizaine d'année pour diverses applications. Cependant ces procédés n'ont pas permis d'obtenir un support ultra divisé qui soit stabilisé lors de la cristallisation de la phase pérovskite.  The development of mesoporous media has been developed for about ten years for various applications. However, these processes did not make it possible to obtain an ultra-divided support which is stabilized during the crystallization of the perovskite phase.
La présente invention a ainsi pour objet un procédé de préparation d'un sol de phase pérovskite à stœchiométrie contrôlée possédant au moins quatre cations et stable dans le temps. Après trempage (dip coating en langue anglaise), lors de la cristallisation de ce sol en température, une couche d'architecture ultra divisée, ou nano structurée composée de particules de phase pérovskite de diamètre 10-100nm est déposée sur la surface de la membrane. Une caractéristique essentielle de cette invention concerne la très forte augmentation des joints de grains à la surface de la membrane ainsi que l'augmentation considérable de la surface d'échanges et du flux d'oxygène traversant la membrane. Selon un premier aspect, l'invention a donc pour objet un procédé de préparation d'un sol-gel d'au moins trois sels de métaux M-i, M2, et M3 aptes et destinés à la préparation d'un matériau de type pérovskite correspondant à la formule générale (I) :The subject of the present invention is therefore a process for preparing a perovskite phase sol with controlled stoichiometry having at least four cations and being stable over time. After dipping (dip coating in English), during the crystallization of this sol temperature, an ultra-divided or nano structured architecture layer composed of perovskite phase particles with a diameter of 10-100 nm is deposited on the surface of the membrane. . An essential feature of this invention is the very large increase in grain boundaries at the membrane surface as well as the dramatic increase in the exchange surface area and oxygen flux through the membrane. According to a first aspect, the subject of the invention is therefore a process for preparing a sol-gel of at least three metal salts Mi, M 2 and M 3 which are suitable for the preparation of a material of the type perovskite corresponding to the general formula (I):
(i-X) A'x B(i-y-U) B'y B"u Οβ-δ, (I), (i- X ) A ' x B (i -yU ) B' y B " u Οβ-δ, (I),
formule (I) dans laquelle :  formula (I) in which:
x, y, u et δ sont tels que la neutralité électrique du réseau cristallin est conservée, 0 < x < 0,9,  x, y, u and δ are such that the electrical neutrality of the crystal lattice is conserved, 0 <x <0.9,
0 < u < 0,5,  0 <u <0.5,
(y + u) < 0,5,  (y + u) <0.5,
0 < y≤0,5 et 0 < 5  0 <y≤0.5 and 0 <5
et formule (I) dans laquelle :  and formula (I) wherein:
- A représente un atome choisi parmi le scandium, l'yttrium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ;  A represents an atom chosen from scandium, yttrium or in the families of lanthanides, actinides or alkaline earth metals;
- A' différent de A, représente un atome choisi parmi le scandium, l'yttrium, l'aluminium, le gallium, l'indium, le thallium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ;  - A different from A, represents an atom chosen from scandium, yttrium, aluminum, gallium, indium, thallium or in the families of lanthanides, actinides or alkaline earth metals;
- B représente un atome choisi parmi les métaux de transition ;  B represents an atom chosen from transition metals;
- B' différent de B, représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain ou le plomb ;  B ', different from B, represents an atom selected from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth, tin or lead;
- B" différent de B et de B', représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain, le plomb ou le zirconium;  B "different from B and B ', represents an atom selected from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth , tin, lead or zirconium;
ledit procédé comprenant les étapes suivantes :  said method comprising the following steps:
- Une étape a) de préparation d'une solution aqueuse de sels hydrosolubles des dits éléments A, A', B, B' et optionnellement B", dans les proportions stœchiométriques nécessaires à l'obtention du matériau tel que défini ci-dessus ;  A step a) of preparing an aqueous solution of water-soluble salts of said elements A, A ', B, B' and optionally B ", in the stoichiometric proportions necessary to obtain the material as defined above;
- Une étape b) de préparation d'une solution hydro-alcoolique d'au moins agent tensioactif non-ionique dans un alcool choisi parmi le méthanol, l'éthanol, le propanol, le propanol, l'isopropanol ou le butanol, mélangé à une solution aqueuse d'ammoniac en une proportion suffisance pour assurer la solubilisation complète dudit agent tensioactif non-ionique dans ladite solution hydro-alcoolique, la concentration dudit agent tensioactif non-ionique dans ladite solution hydro-alcoolique étant inférieure à la concentration micellaire critique ;  A step b) of preparing an aqueous-alcoholic solution of at least one nonionic surfactant in an alcohol chosen from methanol, ethanol, propanol, propanol, isopropanol or butanol, mixed with an aqueous ammonia solution in an amount sufficient to ensure complete solubilization of said nonionic surfactant in said hydroalcoholic solution, the concentration of said nonionic surfactant in said aqueous-alcoholic solution being less than the critical micelle concentration;
- Une étape c) de mélange de ladite solution aqueuse préparée à l'étape a), avec ladite dispersion alcoolique préparée à l'étape b) pour former un sol ; - Une étape d) de séchage dudit sol obtenu à l'étape c), par évaporation du solvant, pour obtenir un sol-gel. A step c) of mixing said aqueous solution prepared in step a) with said alcoholic dispersion prepared in step b) to form a sol; - A step d) of drying said sol obtained in step c), by evaporation of the solvent, to obtain a sol-gel.
Par sol-gel d'au moins trois de métaux M-i , M2, et M3 aptes et destinés à la préparation d'un matériau de type pérovskite, on désigne notamment un sol de trois métaux, un sol-gel de quatre métaux ou un sol-gel de cinq métaux. By sol-gel of at least three metals Mi, M 2 , and M 3 suitable and intended for the preparation of a perovskite-type material, is meant in particular a sol of three metals, a sol-gel of four metals or a sol-gel of five metals.
Pour la mise en œuvre de l'étape a) du procédé tel que défini ci-dessus, les anions des sels hydrosolubles des dits éléments A, A', B, B' et optionnellement B", sont de valence inférieure à celle du cation correspondant. For the implementation of step a) of the process as defined above, the anions of the water-soluble salts of said elements A, A ', B, B' and optionally B "are of valence lower than that of the cation corresponding.
Ainsi, pour un élément A, A', B, B' ou B" de valence +2, le contre-ion négatif est un anion de valence -1 ; selon cette option, cet anion est plus particulièrement choisi parmi les ions halogénures ou l'ion nitrate et de préférence, il s'agit de l'ion nitrate.  Thus, for an element A, A ', B, B' or B "of valence +2, the negative counterion is an anion of valence -1: according to this option, this anion is more particularly chosen from halide ions or the nitrate ion and preferably it is the nitrate ion.
Pour un élément A, A', B, B' ou B" de valence +3, le contre-ion négatif est un anion de valence -1 ou de valence -2; selon cette option, cet anion est plus particulièrement choisi parmi les ions halogénures, l'ion nitrate ou l'ion sulfate; de préférence, il s'agit de l'ion nitrate.  For an element A, A ', B, B' or B "of valence +3, the negative counterion is anion of valence -1 or valence -2: according to this option, this anion is more particularly chosen from halide ions, the nitrate ion or the sulfate ion, preferably it is the nitrate ion.
Pour un élément A, A', B, B' ou B" de valence +4, le contre-ion négatif est un anion de valence -1 , de valence -2 ou de valence -3; selon cette option, cet anion est plus particulièrement choisi parmi les ions halogénures, l'ion nitrate, l'ion sulfate ou l'ion phosphate ; de préférence, il s'agit de l'ion nitrate.  For an A, A ', B, B' or B "element of valence +4, the negative counterion is anion of valence -1, valence -2 or valence -3, depending on this option, this anion is more particularly chosen from the halide ions, the nitrate ion, the sulfate ion or the phosphate ion, preferably it is the nitrate ion.
Selon un aspect particulier du procédé tel que défini ci-dessus, les sels hydrosolubles des dits éléments A, A', B, B' et optionnellement B", mis en œuvre à l'étape a), sont les nitrates des dits éléments.  According to a particular aspect of the process as defined above, the water-soluble salts of said elements A, A ', B, B' and optionally B ", implemented in step a), are the nitrates of said elements.
Selon un autre aspect particulier du procédé tel que défini ci-dessus, dans la solution aqueuse préparée à l'étape a), le ratio molaire :  According to another particular aspect of the process as defined above, in the aqueous solution prepared in step a), the molar ratio:
Nombre de moles desdits sels hydrosolubles des dits éléments A, A', B, B' et  Number of moles of said water-soluble salts of said elements A, A ', B, B' and
optionnellement B" (Nseis)/ Nombres de mole d'eau (NH2o), est plus particulièrement supérieur ou égal à 0,005 et inférieur ou égal à 0,05. optionally B "(N se is) / Numbers of mole of water (N H 2o), is more particularly greater than or equal to 0.005 and less than or equal to 0.05.
Par solution hydro-alcoolique, on désigne dans le cadre de l'étape b) du procédé tel que défini ci-dessus que le mélange alcool-eau contient d'au moins environ 70% en poids d'alcool et au plus 30% en poids d'eau.  By hydro-alcoholic solution, it is meant in the context of step b) of the process as defined above that the alcohol-water mixture contains at least about 70% by weight of alcohol and at most 30% by weight of alcohol. weight of water.
Selon un aspect particulier du procédé tel que défini ci-dessus, l'alcool mis en œuvre à l'étape b) est l'éthanol.  According to a particular aspect of the process as defined above, the alcohol used in step b) is ethanol.
Par proportion suffisance pour assurer la solubilisation complète dudit agent tensioactif non-ionique dans ladite solution hydro-alcoolique, on indique dans l'étape b) du procédé tel que défini ci-dessus que le ratio molaire N(tensioactif) N <NH3) est supérieur ou égal à 10"4 et inférieur ou égal à 10"2 By sufficient proportion to ensure complete solubilization of said nonionic surfactant in said aqueous-alcoholic solution, it is indicated in step b) of process as defined above that the molar ratio N (t ensioacti ) N <NH3) is greater than or equal to 10 "4 and less than or equal to 10 " 2
Selon un autre aspect particulier du procédé tel que défini ci-dessus, le tensioactif non-ionique mis en œuvre à l'étape b), est choisi parmi les copolymères blocs constitués de chaînes de poly(alkylèneoxy) et plus particulièrement parmi les copolymères (EO)n- (PO)m-(EO)n. According to another particular aspect of the process as defined above, the nonionic surfactant used in step b) is chosen from block copolymers consisting of poly (alkyleneoxy) chains and more particularly from copolymers ( EO) n - (PO) m - (EO) n .
Selon un autre aspect particulier du procédé tel que défini ci-dessus, le tensioactif non-ionique mis en œuvre à l'étape b) est un copolymère bloc (EO)99-(PO)7o-(EO)99 commercialisé sous le nom PLURONIC™F127 According to another particular aspect of the process as defined above, the nonionic surfactant used in step b) is a commercially available block copolymer (EO) 9 9 (PO) 7 o- (EO) 9 9 under the name PLURONIC ™ F127
Dans la formule (I) telle que définie ci-dessus, A et A' sont plus particulièrement choisis parmi le lanthane (La), le cérium (Ce), l'yttrium (Y), le gadolinium (Gd), le magnésium (Mg), le calcium (Ca), le strontium (Sr) ou le baryum (Ba).  In the formula (I) as defined above, A and A 'are more particularly chosen from lanthanum (La), cerium (Ce), yttrium (Y), gadolinium (Gd), magnesium ( Mg), calcium (Ca), strontium (Sr) or barium (Ba).
Selon un aspect tout particulier de la présente invention, dans la formule (I), A représente un atome de lanthane un atome de calcium ou un atome de baryum.  According to a very particular aspect of the present invention, in formula (I), A represents a lanthanum atom, a calcium atom or a barium atom.
Selon un autre aspect tout particulier de la présente invention, dans la formule (I), According to another very particular aspect of the present invention, in the formula (I),
A' représente un atome de strontium. A 'represents a strontium atom.
Dans la formule (I) telle que définie ci-dessus, B et B' sont plus particulièrement choisis parmi le fer (Fe), le chrome (Cr), le manganèse (Mn), le gallium (Ga), le cobalt (Co), le nickel (Ni) ou le titane (Ti).  In the formula (I) as defined above, B and B 'are more particularly selected from iron (Fe), chromium (Cr), manganese (Mn), gallium (Ga), cobalt (Co) ), nickel (Ni) or titanium (Ti).
Selon un autre aspect tout particulier de la présente invention, pour lequel dans la formule (I), B représente un atome de fer.  According to another very particular aspect of the present invention, in which in formula (I), B represents an iron atom.
Selon un autre aspect tout particulier de la présente invention, dans la formule (I), B' représente un atome de gallium, un atome de titane ou un atome de cobalt.  According to another very particular aspect of the present invention, in the formula (I), B 'represents a gallium atom, a titanium atom or a cobalt atom.
Selon un autre aspect tout particulier de la présente invention, dans la formule (I), B" représente un atome de zirconium.  According to another very particular aspect of the present invention, in the formula (I), B "represents a zirconium atom.
Dans la formule (I) telle que définie précédemment, u est plus particulièrement égal à 0.  In the formula (I) as defined above, u is more particularly equal to 0.
Selon un aspect plus particulier de la présente invention, celle-ci a pour objet un procédé tel que défini précédemment, pour lequel le matériau pérovskite de formule (I) est choisi parmi les composés suivants:  According to a more particular aspect of the present invention, the subject of the invention is a process as defined above, for which the perovskite material of formula (I) is chosen from the following compounds:
La(i -x) Srx Fe(i-y) Coy Οβ-β, La(i-X) Srx Fe(i-y) Gay Οβ-δ, La(i-X) Srx Fe(i-y) Tiy Οβ-δ, Ba(i-X) Srx Fe0. y) Coy 03-δ, Ca Fe(i-y) Tiy 03-δ, ou La(i-X)SrxFe03-6 The (i -x) Sr x Fe (i-y) Co y Οβ-β, the (-X i) Sr x Fe (i -y) Ga y Οβ-δ, La (i -X) Sr x Fe ( i -y) y Ti Οβ-δ, Ba (i -X) Sr x Fe 0. y) Co y 0 3 -δ, Ca Fe ( iy) TiyO 3 -δ, or La ( i- X ) Sr x FeO 3 -6
et, tout particulièrement parmi les composés suivants :  and most particularly from the following compounds:
La0,6 Sr0,4 Fe0,9 Ga0,i Οβ-δ, La0,5 Sr0,5 Feo,9 Ti0,i Οβ-β., The 0 , 6 Sr 0 , 4 Fe 0 , 9 Ga 0 , i Οβ-δ, the 0.5 Sr 0.5 Fe 0 , 9 Ti 0 , i Οβ-β.
Lao,6 Sro,4 Feo,9 Gao,i Οβ-δ , Lao,5 Sro,5 Feo,9 Tio,i Οβ-β., Lao,5 Sro,5 Feo,9 Tio,i Οβ-δ, Lao,6 O , 6 Sr o , 4 Fe o , 9 Ga o , i Οβ-δ, La o , 5 Sr o , 5 Fe o , 9 Ti o , i Οβ-β., O 0.5 Sr o , 5 Fe o , 9 Ti o , i Οβ-δ, the o , 6
Sr0,4 Fe0,g Ga0,i 03-δ, et La0,s Sr0,2 Fe0,7Ga0,3 03-δ- L'invention a aussi pour objet un procédé de préparation d'un substrat revêtu sur au moins une de ses surfaces, d'un film de sol-gel d'un matériau pérovskite caractérisé en ce qu'il comprend : Sr 0 , 4 Fe 0 , g Ga 0 , i 0 3 -δ, and La 0 , s Sr 0 , 2 Fe 0 , 7Ga 0 , 3 0 3 -δ- The subject of the invention is also a process for preparing a substrate coated on at least one of its surfaces with a sol-gel film of a perovskite material, characterized in that it comprises:
- Une étape e) de trempage d'un substrat constitué d'un matériau pérovskite fritté de densité supérieure à 90%, de préférence supérieure à 95%, dans le sol issu de l'étape c) du procédé tel que défini précédemment, pour obtenir un substrat trempé;  A step e) of dipping a substrate made of a sintered perovskite material with a density greater than 90%, preferably greater than 95%, in the soil resulting from stage c) of the process as defined above, for obtain a soaked substrate;
- Une étape f) de tirage dudit substrat trempé issu de l'étape e) à vitesse constante, pour obtenir un substrat revêtu d'un film dudit sol ;  A step f) of drawing said quenched substrate resulting from step e) at a constant speed, in order to obtain a substrate coated with a film of said ground;
- Une étape g) de séchage dudit substrat revêtu d'un film dudit sol obtenu à l'étape f), par évaporation du solvant, pour obtenir ledit substrat revêtu d'un sol-gel.  A step g) of drying said substrate coated with a film of said sol obtained in step f), by evaporation of the solvent, to obtain said substrate coated with a sol-gel.
Dans le procédé tel que défini ci-dessus, l'étape e) de trempage consiste à plonger un substrat dans le sol synthétisé précédemment et à le retirer à vitesse contrôlée et constante.  In the process as defined above, step e) of dipping consists of immersing a substrate in the soil synthesized previously and removing it at a controlled and constant speed.
Dans le procédé tel que défini ci-dessus, au cours de l'étape f) de tirage, le mouvement du substrat entraîne le liquide formant une couche de surface. Cette couche se divise en deux, la partie interne se déplace avec le substrat alors que la partie externe retombe dans le récipient. L'évaporation progressive du solvant conduit à la formation d'un film à la surface du substrat.  In the method as defined above, during the f) drawing step, the movement of the substrate causes the liquid forming a surface layer. This layer divides in two, the inner part moves with the substrate while the outer part falls into the container. The progressive evaporation of the solvent leads to the formation of a film on the surface of the substrate.
Il est possible d'estimer l'épaisseur du dépôt obtenu en fonction de la viscosité du sol et de la vitesse de tirage.  It is possible to estimate the thickness of the deposit obtained as a function of the viscosity of the soil and the drawing speed.
e = a K v2/3 e = a K v 2/3
e étant l'épaisseur du dépôt, κ étant une constante de dépôt dépendante de la viscosité, de la densité du sol et de la tension de surface liquide-vapeur et v étant la vitesse de tirage. e being the thickness of the deposit, κ being a deposition constant dependent on the viscosity, the density of the soil and the liquid-vapor surface tension and v being the drawing speed.
Ainsi, plus la vitesse de tirage est élevée, plus l'épaisseur du dépôt est importante. Thus, the higher the pulling speed, the greater the thickness of the deposit.
Dans le procédé tel que défini ci-dessus, l'étape g) de séchage est généralement effectuée à l'air libre ou sous atmosphère contrôlée pendant quelques heures.  In the process as defined above, the drying step g) is generally carried out in the open air or in a controlled atmosphere for a few hours.
Par matériau pérovskite fritté de densité supérieure à 90%, de préférence supérieure à 95%, on désigne plus particulièrement une composition céramique (CC) comprenant pour 100% volumique, au moins 75 % en volume et jusqu'à 100% en volume d'un composé conducteur mixte électronique et d'anions oxygène O2" (Ci) choisi parmi les oxydes céramiques dopés de formule (II) : Perovskite material sintered with a density greater than 90%, preferably greater than 95%, more particularly denotes a ceramic composition (CC) comprising for 100% by volume, at least 75% by volume and up to 100% by volume of an electronically mixed conductive compound and oxygen anions O 2 " (Ci) chosen from doped ceramic oxides of formula (II):
C(1-x-U) C x D(1-y-u) D'y D"u O», (II), C (1-x- U) C x D (1-yu) D'y D "u O", (II),
formule (II) dans laquelle :  formula (II) in which:
x, y, u et δ sont tels que la neutralité électrique du réseau cristallin est conservée, x, y, u and δ are such that the electrical neutrality of the crystal lattice is preserved,
0 < x < 0,9, 0 < u < 0,5, 0 <x <0.9, 0 <u <0.5,
(y + u) < 0,5,  (y + u) <0.5,
0 < y < 0,5 et 0 < δ  0 <y <0.5 and 0 <δ
et formule (II) dans laquelle  and formula (II) in which
- C représente un atome choisi parmi le scandium, l'yttrium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ; C represents an atom chosen from scandium, yttrium or in the families of lanthanides, actinides or alkaline earth metals;
- C différent de C, représente un atome choisi parmi le scandium, l'yttrium, l'aluminium, le gallium, l'indium, le thallium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ;  - C different from C, represents an atom selected from scandium, yttrium, aluminum, gallium, indium, thallium or in families of lanthanides, actinides or alkaline earth metals;
- D représente un atome choisi parmi les métaux de transition ;  D represents an atom chosen from transition metals;
- D' différent de D, représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain ou le plomb ;  - Of different from D, represents an atom chosen from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth, tin or lead;
- D" différent de D et de D', représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain, le plomb ou le zirconium ;  - D "different from D and D ', represents an atom chosen from transition metals, metals of the alkaline-earth family, aluminum, indium, gallium, germanium, antimony, bismuth , tin, lead or zirconium;
et optionnellement jusqu'à 25% en volume d'un composé (C2), différent du composé (Ci) choisi parmi l'oxyde de magnésium, l'oxyde de calcium, l'oxyde d'aluminium, l'oxyde de zirconium, l'oxyde de titane, les oxydes mixtes de strontium et d'aluminium ou, de baryum et de titane ou de calcium et de titane ; ladite composition céramique (CC) ayant subi une étape de frittage avant sa mise en œuvre à l'étape e). and optionally up to 25% by volume of a compound (C 2 ) different from the compound (Ci) selected from magnesium oxide, calcium oxide, aluminum oxide, zirconium oxide titanium oxide, mixed oxides of strontium and aluminum or barium and titanium or calcium and titanium; said ceramic composition (CC) having undergone a sintering step before its implementation in step e).
Selon un aspect particulier de la présente invention, ladite composition céramique (CC) comprend pour 100% volumique, au moins 90 % volumique et plus particulièrement au moins 95% volumique et jusqu'à 100% volumique de composé (Ci) et optionnellement jusqu'à 10% en volumique, et plus particulièrement jusqu'à 5% volumique de composé (C2). According to a particular aspect of the present invention, said ceramic composition (CC) comprises, for 100% by volume, at least 90% by volume and more particularly at least 95% by volume and up to 100% by volume of compound (Ci) and optionally up to at 10% in volume, and more particularly up to 5% by volume of compound (C 2 ).
Selon un aspect particulier du procédé tel que défini ci-dessus, le frittage subi par le matériau de formule (II) avant sa mise en œuvre à l'étape e), est effectué sous air à une température supérieure à 1.000°C, voire supérieure à 1200°C pendant environ 10 heure de façon à atteindre la densité relative souhaitée.  According to a particular aspect of the process as defined above, the sintering undergone by the material of formula (II) before its implementation in step e), is carried out under air at a temperature above 1,000 ° C., or even above 1200 ° C for about 10 hours to reach the desired relative density.
Selon un autre aspect particulier de la présente invention, les formules (I) et (II) telles que définie précédemment sont identiques.  According to another particular aspect of the present invention, formulas (I) and (II) as defined above are identical.
Selon un autre aspect, l'invention a pour objet, un procédé de préparation d'une membrane céramique (CM) caractérisé en que ledit substrat revêtu d'un sol-gel obtenu par le procédé tel que défini précédemment, subit une étape h) de calcination sous air. Dans le procédé tel que défini ci-dessus, l'étape h) de calcination est généralement effectuée sous air à une température d'environ 1000°C pendant au moins une 1 heure, la vitesse de montée en température étant autour de 1 °C par minute. La calcination des substrats sous air permet ainsi d'éliminer les nitrates mais aussi de décomposer le tensioactif et ainsi de libérer la porosité. According to another aspect, the subject of the invention is a method for preparing a ceramic membrane (CM) characterized in that said substrate coated with a sol-gel obtained by the process as defined above, undergoes a step h) calcination under air. In the process as defined above, the calcination step h) is generally carried out in air at a temperature of approximately 1000 ° C. for at least 1 hour, the temperature rise rate being around 1 ° C. per minute. The calcination of the substrates under air thus makes it possible to eliminate the nitrates but also to decompose the surfactant and thus to release the porosity.
Selon un autre aspect, l'invention a pour objet un procédé de préparation d'une poudre ultra-divisée de matériau de type pérovskite correspondant à la formule générale (I), caractérisé en ce que le sol issu de l'étape c) du procédé tel que défini précédemment, subit une étape i) d'atomisation pour former une poudre de sol-gel; ladite poudre de sol-gel étant ensuite soumise à l'étape h) de calcination sous air, pour former ladite poudre ultra-divisée ou nanostructurée (c'est-à-dire une taille de grains nanométrique de 10 à 100 nm).  According to another aspect, the subject of the invention is a process for preparing an ultra-divided powder of perovskite-type material corresponding to the general formula (I), characterized in that the sol resulting from stage c) of method as defined above, undergoes a step i) of atomization to form a sol-gel powder; said sol-gel powder being then subjected to the calcination step in air, to form said ultra-divided or nanostructured powder (i.e., a nanoscale size of 10 to 100 nm).
L'invention a enfin pour objet l'utilisation de la membrane telle que définie précédemment pour produire de l'oxygène à partir d'air, par électrochimie à travers  The invention finally relates to the use of the membrane as defined above to produce oxygen from air, by electrochemistry through
L'exposé expérimental suivant illustre l'invention sans toutefois la limiter.  The following experimental presentation illustrates the invention without limiting it.
Les nitrates de lanthane, de strontium, de fer et de gallium, précurseurs de la pérovskite, sont mélangés dans les proportions stœchiométriques nécessaires à la formation d'une pérovskite de structure La0,8 Sr0,2 Fe0,7Ga0,3 03-δ avec un agent tensioactif non-ionique, dans une solution ammoniaque/éthanol. L'évaporation des solvants (éthanol et eau) permet la réticulation du sol en gel autour de micelles de surfactant par la formation de liaisons entre les groupements hydroxyles d'un sel et le métal d'un autre sel. Le contrôle des réactions d'hydrolyse/condensation liées aux interactions électrostatiques entre les précurseurs inorganiques et les molécules de surfactant permet un assemblage coopératif des phases organique et inorganique, ce qui génère des agrégats micellaires de surfactants de taille contrôlée au sein d'une matrice inorganique. Le phénomène d'auto-assemblage est induit par évaporation progressive du solvant d'une solution de réactifs, lorsque la concentration micellaire devient critique. Nitrates of lanthanum, strontium, iron and gallium, precursors of perovskite, are mixed in the stoichiometric proportions necessary for the formation of a perovskite of structure La 0 , 8 Sr 0 , 2 Fe 0 , 7Ga 0 , 3 0 3- δ with a nonionic surfactant, in an ammonia / ethanol solution. Evaporation of the solvents (ethanol and water) allows the gel solids to crosslink around surfactant micelles by forming bonds between the hydroxyl groups of one salt and the metal of another salt. The control of hydrolysis / condensation reactions related to electrostatic interactions between inorganic precursors and surfactant molecules allows cooperative assembly of the organic and inorganic phases, which generates micellar aggregates of controlled size surfactants within an inorganic matrix. . The phenomenon of self-assembly is induced by progressive evaporation of the solvent from a reagent solution, when the micellar concentration becomes critical.
Ceci conduit soit à la formation de films à microstructure contrôlée dans le cas d'un dépôt sur substrat par trempage (dip coating en langue anglaise), soit à la formation d'une poudre à microstructure contrôlée après atomisation du sol.  This leads to the formation of controlled microstructure films in the case of dip coating (dip coating) or the formation of a controlled microstructure powder after atomization of the soil.
Le point de départ du processus d'auto-arrangement est la solution hydroalcoolique des précurseurs inorganiques (La, Sr, Fe et Ga) et du tensioactif non ionique.  The starting point of the self-setting process is the hydroalcoholic solution of inorganic precursors (La, Sr, Fe and Ga) and nonionic surfactant.
Le tensioactif non ionique mis en œuvre dans le procédé appartient à la famille des copolymères blocs, copolymères qui possèdent deux parties de polarités différentes : un corps hydrophobe et des extrémités hydrophiles. Ces copolymères sont constitués de chaînes de poly(oxyde d'alkylène), comme les copolymères de formule générale (EO)n- (PO)m-(EO)n, constitué par l'enchaînement de poly(oxyde d'éthylène) (EO), hydrophile aux extrémités et dans sa partie centrale le poly(oxyde de propylène) (PO), hydrophobe. Les chaînes de polymères restent dispersées en solution pour une concentration inférieure à la concentration micellaire critique (CMC). The nonionic surfactant used in the process belongs to the family of block copolymers, copolymers which have two parts of different polarities: a hydrophobic body and hydrophilic ends. These copolymers consist of poly (alkylene oxide) chains, such as copolymers of general formula (EO) n - (PO) m - (EO) n , consisting of the chain of poly (ethylene oxide) (EO), hydrophilic at the ends and in its central part the poly (propylene oxide) (PO), hydrophobic. The polymer chains remain dispersed in solution at a concentration below the critical micelle concentration (CMC).
La CMC est définie comme étant la concentration limite au delà de laquelle se produit le phénomène d'auto-arrangement des molécules de surfactant dans la solution. Au delà de cette concentration, les chaînes du surfactant ont tendance à se regrouper par affinité hydrophiles/hydrophobes. Ainsi, les corps hydrophobes se regroupent et forment des micelles de forme sphérique. Les extrémités des chaînes des polymères sont repoussées vers l'extérieur des micelles, et s'associent au cours de l'évaporation du solvant volatile (éthanol) avec les espèces ioniques en solution qui présentent également des affinités hydrophiles.  CMC is defined as the limiting concentration beyond which the phenomenon of self-arrangement of surfactant molecules in the solution occurs. Beyond this concentration, the chains of the surfactant tend to be grouped by hydrophilic / hydrophobic affinity. Thus, the hydrophobic bodies are grouped together and form spherical micelles. The ends of the polymer chains are pushed outwardly of the micelles, and associate during the evaporation of the volatile solvent (ethanol) with the ionic species in solution which also have hydrophilic affinities.
La taille des micelles est fixée par la longueur de la chaîne hydrophobe. Ainsi, en utilisant un copolymère bloc de type (EO)99-(PO)7o-(EO)99 disponible commercialement sous la référence Pluronic™F127, on produit des micelles de diamètre compris entre 6 nm et 10 nm peuvent être produites. Il s'agit là d'un exemple mais d'autres surfactants peuvent être employés pour couvrir une gamme de micelles de diamètre compris entre 3nm et 10nm. The size of the micelles is fixed by the length of the hydrophobic chain. Thus, using a block copolymer of (EO) 9 9- (PO) 7 o- (EO) 9 9 type commercially available under the reference Pluronic ™ F127, micelles with a diameter of between 6 nm and 10 nm can be produced. produced. This is an example but other surfactants can be used to cover a range of micelles of diameter between 3nm and 10nm.
Les gels obtenus après évaporation des solvants, sont calcinés sous air. L'élimination du tensioactif au cours du traitement thermique permet de générer une matrice cohésive présentant une porosité homogène et structurée.  The gels obtained after evaporation of the solvents are calcined in air. The removal of the surfactant during the heat treatment makes it possible to generate a cohesive matrix having a homogeneous and structured porosity.
La Figure 4 illustre le principe de l'auto-assemblage après trempage d'un substrat dans un sol, ledit auto-assemblage étant induit par évaporation conduisant à la formation d'un sol-gel conduisant après calcination à un support ultra-divisé de phase pérovskite à microstructure contrôlée.  FIG. 4 illustrates the principle of self-assembly after soaking a substrate in a soil, said self-assembly being induced by evaporation, leading to the formation of a sol-gel which, after calcination, leads to an ultra-divided support of perovskite phase with controlled microstructure.
On solubilise 0,9g de Pluronic™ F127 dans un mélange constitué 23cm3 d'éthanol absolu et de 4,5cm3 de solution ammoniacale (à 28% massique). Le mélange est ensuite chauffé à reflux pendant 1 heure. Is dissolved 0.9 g of Pluronic ™ F127 in a mixture of 23 cm 3 of absolute ethanol and 4.5 cm 3 of ammonia solution (28% by mass). The mixture is then refluxed for 1 hour.
On prépare 20 cm3 de la solution aqueuse contenant les nitrates de lanthane, de strontium, de fer et de gallium, précurseurs de la pérovskite, sont mélangés dans les proportions stœchiométriques nécessaires à la formation d'une pérovskite de structure La0,8 Sr0,2 Fe0,7Ga0,3 03-δ dans de l'eau osmosée (20 mL). Cette solution est ensuite ajoutée goutte à goutte à la solution de tensioactif. Is prepared 20 cm 3 of aqueous solution containing lanthanum nitrate, strontium, iron and gallium, perovskite precursors, are mixed in the stoichiometric proportions required for the formation of a perovskite structure The 0, 8 Sr 0 , 2 Fe 0 , 7Ga 0 , 3 0 3- δ in osmosis water (20 mL). This solution is then added dropwise to the surfactant solution.
Les rapports molaires mis en œuvre sont consignés dans le tableau 1 suivant : nH2o n nitrate 1 1 1 The molar ratios used are recorded in the following Table 1: n H 2o n nitrate 1 1 1
Tableau 1  Table 1
L'ensemble est chauffé à reflux pendant 1 heure puis refroidi jusqu'à température ambiante. On obtient le sol attendu, qui reste stable au cours du temps  The whole is refluxed for 1 hour and then cooled to room temperature. We obtain the expected soil, which remains stable over time
Un sol est synthétisé selon le mode opératoire décrit dans la partie expérimentale suivante. Ce sol a été réalisé pour obtenir la stœchiométrie La stœchiométrie a été vérifiée par Analyse spectrométrique ICP (Inductively Coupled Plasma Atomic Emission en langue anglaise) (voir Tableau 2 ci-dessous) A sol is synthesized according to the procedure described in the following experimental part. This soil was made to obtain stoichiometry Stoichiometry was verified by ICP (Inductively Coupled Plasma Atomic Emission) Spectrometric Analysis (see Table 2 below)
Tableau 2  Table 2
Après un vieillissement du sol pendant 48 heures dans une étuve ventilée, celui-ci est sous au trempage d'une membrane en pérovskite dense.  After an aging of the soil for 48 hours in a ventilated oven, it is under the soaking of a dense perovskite membrane.
Les substrats utilisés dans le cadre de notre étude sont des membranes en pérovskite frittées à 1350°C pendant 10h sous air (densité relative des membranes ≥ 97%, mesures effectuées par la méthode de la poussée d'Archimède). Ces membranes possèdent la même stœchiométrie en La, Sr, Fe et Ga que celle du sol réalisé précédemment.  The substrates used in our study are perovskite membranes sintered at 1350 ° C for 10 hours in air (relative density of membranes ≥ 97%, measurements made by the method of Archimedes' thrust). These membranes have the same La, Sr, Fe and Ga stoichiometry as that of the soil previously produced.
La membrane est de stœchiométrie L'échantillon est ensuite séché sous air libre pendant 6h avant de subir un traitement thermique sous air de manière à éliminer les nitrates et le surfactant. The membrane is stoichiometry The sample is then dried under free air for 6 hours before undergoing heat treatment under air to remove nitrates and surfactant.
La membrane recouverte d'un film mince a été calcinée sous air à 1000°C pendant 1 h, avec une vitesse de montée en température de 1 °C/min.  The membrane covered with a thin film was calcined in air at 1000 ° C for 1 h, with a temperature rise rate of 1 ° C / min.
La Figure 6 est un diffractogramme de la poudre de sol-gel calcinée à 1000°C. Elle met en évidence la cristallisation complète de type pérovskite (structure AB03) Figure 6 is a diffractogram of sol-gel powder calcined at 1000 ° C. It shows the complete crystallization of perovskite type (structure AB0 3 )
Les micrographies MEB-FEG (Figures 7 et 8) révèlent la formation d'un dépôt ultra divisé aux surfaces de la membrane. Le dépôt est cependant différent selon la surface exposée gaz réducteur (Figure 7) ou gaz oxydant (Figure 8) après vieillissement. Sur la surface en contact avec l'atmosphère réductrice (illustrée par les micrographies MEB-FEG des Figures 7A à 7C), il résulte du séchage et de la calcination du dépôt de sol un nappage de la surface de la membrane par un dépôt ultra divisé composé de particules d'une taille de l'ordre de 50-1 OOnm. La densité de joints de grain à la surface de la membrane est très fortement augmentée. Des amas de grains sous forme de plots d'un diamètre moyen de l'ordre de 200-500nm augmentent fortement la surface d'échange avec le gaz. The SEM-FEG micrographs (Figures 7 and 8) reveal the formation of an ultra-divided deposit on the surfaces of the membrane. The deposit is however different according to the exposed surface reducing gas (Figure 7) or oxidizing gas (Figure 8) after aging. On the surface in contact with the reducing atmosphere (illustrated by the SEM-FEG micrographs of FIGS. 7A to 7C), it results from the drying and the calcination of the soil deposit a coating of the surface of the membrane by an ultra-divided deposit composed of particles of a size of the order of 50-1000 nm. The density of grain boundaries at the surface of the membrane is greatly increased. Clusters of grains in the form of pads of average diameter of the order of 200-500 nm greatly increase the exchange surface with the gas.
Sur la surface oxydante (illustrée par les micrographies MEB-FEG des Figures 8A à 8C), il résulte de la cristallisation de la phase pérovskite un dépôt ultra-divisé et très poreux avec des particules cristallisées possédant des facettes en contact les unes avec les autres. Ces particules sont d'une taille de l'ordre de la centaine de nanomètres et affichent une distribution granulométrique resserrée.  On the oxidizing surface (illustrated by the SEM-FEG micrographs of FIGS. 8A to 8C), the crystallization of the perovskite phase results in an ultra-divided and highly porous deposit with crystallized particles having facets in contact with one another. . These particles are of a size of the order of one hundred nanometers and display a narrow particle size distribution.
Les performances en semi-perméation à l'oxygène des membranes ayant subi un dépôt de sol par dip coating ont été mesurées.  Oxygen semi-permeation performance of dipstrate-deposited membranes was measured.
La Figure 9 recense les courbes semi-perméation à l'oxygène sous un gradient air/argon en fonction de la température [J02 (en mole/m/s) = f(t°C)] pour les cinq matériaux suivants : Figure 9 shows the oxygen semi-permeation curves under an air / argon gradient as a function of the temperature [J0 2 (in mol / m / s) = f (t ° C)] for the following five materials:
Matériau 1 : Lao,8Sr0,2Feo,7Gao,303-5 (dénommé LSFG8273) revêtu d'une couche poreuse de LSFG8273) par le procédé selon l'invention (vitesse de trempage = 10 mm/s) Matériau 2 : LSFG8273 revêtu d'une couche poreuse de LSFG8273 par le procédé selon l'invention (vitesse de trempage = (5 mm/s) Material 1: Lao, 8Sr 0 , 2Feo, 7Gao, 3 -5 (called LSFG8273) coated with a porous layer of LSFG8273) by the process according to the invention (soaking rate = 10 mm / s) Material 2: LSFG8273 coated with a porous layer of LSFG8273 by the process according to the invention (soaking rate = (5 mm / s)
Matériau 3 : LSFG8273 revêtu par sérigraphie d'une couche poreuse de Material 3: LSFG8273 screen-coated with a porous layer of
LSFN8273 LSFN8273
Matériau 4 : LSFG8273 revêtu par sérigraphie d'une couche poreuse de LSFG8273  Material 4: LSFG8273 Silkscreened with a Porous Layer of LSFG8273
Matériau 5 : LSFG8273 seul.  Material 5: LSFG8273 alone.
Le dépôt d'un sol de pérovskite à la surface d'une membrane surpasse largement les meilleures performances déjà obtenues par dépôt d'une couche sérigraphiée. La vitesse de trempage influe sur l'épaisseur de la couche déposée. Une vitesse plus rapide (10 mm/s) augmente l'épaisseur de la couche déposée et augmente la surface d'échange ainsi que la densité de joints de grains en surface. Les performances sont encore améliorées. Le tableau suivant recense les résultats obtenus à 900°C.  The deposition of a perovskite sol on the surface of a membrane greatly exceeds the best performances already obtained by depositing a screen-printed layer. The soaking rate affects the thickness of the deposited layer. A faster speed (10 mm / s) increases the thickness of the deposited layer and increases the exchange surface as well as the density of surface grain boundaries. Performance is further improved. The following table lists the results obtained at 900 ° C.
Membranes J02 (mol. m"1.s"1) Diaphragms J0 2 (mole m "1 " s "1 )
(Matériau 5) 4,14 10"8 (Material 5) 4.14 10 "8
(Matériau 4) 7,1 1 10"8 (Matériau 3) 9,35 10"8 (Material 4) 7.1 1 10 "8 (Material 3) 9.35 10 "8
(Matériau 2) 15,3 10"8 (Material 2) 15.3 10 "8
(Matériau 1 ) 19,5 10"8 (Material 1) 19.5 10 "8
Le dépôt de sol de pérovskite préparé par le procédé selon l'invention, a pour premier avantage de développer une grande surface spécifique et une forte densité de joints de grains. Par ailleurs, ce dépôt est stable sous gradient de pression partielle en oxygène, condition nécessaire pour l'utilisation d'un CMR pour le vaporéformage du méthane mais aussi pour produire de l'oxygène par séparation de l'air à travers ladite membrane céramique. The deposition of perovskite sol prepared by the process according to the invention has the first advantage of developing a large specific surface area and a high density of grain boundaries. Furthermore, this deposit is stable under partial pressure gradient oxygen, a necessary condition for the use of a CMR for steam reforming methane but also to produce oxygen by separation of the air through said ceramic membrane.
Le second avantage vient de l'épaisseur du dépôt et du procédé du dépôt. En effet, le dépôt est d'une épaisseur 100 fois plus faible que par sérigraphie (gain de matière) et du fait du trempage, toutes les géométries de support de membranes denses peuvent être utilisées (tubes, plaques planes).  The second advantage comes from the thickness of the deposit and the deposition process. Indeed, the deposit is of a thickness 100 times smaller than by screen printing (material gain) and because of soaking, all dense diaphragm support geometries can be used (tubes, flat plates).
La technique d'atomisation permet de transformer un sol en forme sèche solide (poudre) par l'utilisation d'un intermédiaire chaud.  The atomization technique makes it possible to transform a sol into a solid dry form (powder) by the use of a hot intermediate.
L'appareil utilisé dans le cadre de notre étude est un modèle commercial de référence « 190 Mini Spray Dryer » de marque Buchi illustré par la Figure 5.  The equipment used in this study is a Buchi Brand 190 Mini Spray Dryer commercial model shown in Figure 5.
Le principe repose sur la pulvérisation en fines gouttelettes du sol (3), dans une enceinte cylindrique verticale (4) au contact d'un flux d'air chaud (2) afin d'évaporer le solvant de façon contrôlée. La poudre obtenue est entraînée par le flux de chaleur (5) jusqu'à un cyclone (6) qui va séparer l'air (7) de la poudre (8).  The principle is based on the spraying into fine droplets of the soil (3), in a vertical cylindrical chamber (4) in contact with a hot air stream (2) in order to evaporate the solvent in a controlled manner. The resulting powder is entrained by the heat flow (5) to a cyclone (6) which will separate the air (7) from the powder (8).
La poudre récupérée à l'issue de l'atomisation est calcinée dans les mêmes conditions que les substrats préparés par trempage ("dip coatés").  The powder recovered after the atomization is calcined under the same conditions as the substrates prepared by dipping ("dip-coated").
L'atomisation du sol, suivie d'une calcination de la poudre à 900°C, produit des granules sphériques de diamètre inférieur à 5 μιη (Figure 10). La microstructure de cette poudre est identique à celle obtenue sur le dépôt, à savoir une microstructure ultra divisée et poreuse avec une taille de cristallites de l'ordre de 10-100 nm.  The atomization of the soil, followed by calcination of the powder at 900 ° C., produces spherical granules with a diameter of less than 5 μιη (FIG. 10). The microstructure of this powder is identical to that obtained on the deposit, namely an ultra-divided and porous microstructure with a crystallite size of the order of 10-100 nm.
De plus, les granules sphériques sont creuses et la paroi des granules possède elle-même une porosité élevée. L'utilisation de cette poudre pour réaliser des couches poreuses permettrait d'obtenir une porosité à double échelle et possédant une matrice avec une forte densité de joints de grains.  In addition, the spherical granules are hollow and the wall of the granules itself has a high porosity. The use of this powder to make porous layers would provide a dual-scale porosity and have a matrix with a high density of grain boundaries.

Claims

Revendications claims
1 . Procédé de préparation d'un sol-gel d'au moins trois sels de métaux M-i, M2, et M3 aptes et destinés à la préparation d'un matériau de type pérovskite correspondant à la formule générale (I) :1. Process for preparing a sol-gel of at least three metal salts Mi, M 2 , and M 3 suitable for the preparation of a perovskite-type material corresponding to the general formula (I):
(i-X) A'x B(i-y-U) B'y B"u Οβ-δ, (I), (i- X ) A ' x B (i -yU ) B' y B " u Οβ-δ, (I),
formule (I) dans laquelle :  formula (I) in which:
x, y, u et δ sont tels que la neutralité électrique du réseau cristallin est conservée, 0 < x < 0,9,  x, y, u and δ are such that the electrical neutrality of the crystal lattice is conserved, 0 <x <0.9,
0 < u < 0,5,  0 <u <0.5,
(y + u) < 0,5,  (y + u) <0.5,
0 < y < 0,5 et 0 < δ  0 <y <0.5 and 0 <δ
et formule (I) dans laquelle :  and formula (I) wherein:
- A représente un atome choisi parmi le scandium, l'yttrium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ;  A represents an atom chosen from scandium, yttrium or in the families of lanthanides, actinides or alkaline earth metals;
- A' différent de A, représente un atome choisi parmi le scandium, l'yttrium, l'aluminium, le gallium, l'indium, le thallium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ;  - A different from A, represents an atom chosen from scandium, yttrium, aluminum, gallium, indium, thallium or in the families of lanthanides, actinides or alkaline earth metals;
- B représente un atome choisi parmi les métaux de transition ;  B represents an atom chosen from transition metals;
- B' différent de B, représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain ou le plomb ;  B ', different from B, represents an atom selected from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth, tin or lead;
- B" différent de B et de B', représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain, le plomb ou le zirconium;  B "different from B and B ', represents an atom selected from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth , tin, lead or zirconium;
ledit procédé comprenant les étapes suivantes :  said method comprising the following steps:
- Une étape a) de préparation d'une solution aqueuse de sels hydrosolubles des dits éléments A, A', B, B' et optionnellement B", dans les proportions stœchiométriques nécessaires à l'obtention du matériau tel que défini ci-dessus ;  A step a) of preparing an aqueous solution of water-soluble salts of said elements A, A ', B, B' and optionally B ", in the stoichiometric proportions necessary to obtain the material as defined above;
- Une étape b) de préparation d'une solution hydro-alcoolique d'au moins agent tensioactif non-ionique dans un alcool choisi parmi le méthanol, l'éthanol, le propanol, le propanol, l'isopropanol ou le butanol, mélangé à une solution aqueuse d'ammoniac en une proportion suffisance pour assurer la solubilisation complète dudit agent tensioactif non-ionique dans ladite solution hydro-alcoolique, la concentration dudit agent tensioactif non-ionique dans ladite solution hydro-alcoolique étant inférieure à la concentration micellaire critique ; - Une étape c) de mélange de ladite solution aqueuse préparée à l'étape a), avec ladite dispersion alcoolique préparée à l'étape b) pour former un sol ; A step b) of preparing an aqueous-alcoholic solution of at least one nonionic surfactant in an alcohol chosen from methanol, ethanol, propanol, propanol, isopropanol or butanol, mixed with an aqueous ammonia solution in an amount sufficient to ensure complete solubilization of said nonionic surfactant in said hydroalcoholic solution, the concentration of said nonionic surfactant in said aqueous-alcoholic solution being less than the critical micelle concentration; A step c) of mixing said aqueous solution prepared in step a) with said alcoholic dispersion prepared in step b) to form a sol;
- Une étape d) de séchage dudit sol obtenu à l'étape c), par évaporation du solvant, pour obtenir un sol-gel.  - A step d) of drying said sol obtained in step c), by evaporation of the solvent, to obtain a sol-gel.
2. Procédé tel que défini à la revendication 1 , dans le quel le tensioactif non- ionique mis en œuvre à l'étape b) est un copolymère bloc (EO)99-(PO)7o-(EO)99- 2. A method as defined in claim 1, in which the nonionic surfactant implemented in step b) is a block copolymer (EO) 9 9- (PO) 7 O- (EO) 9 9-
3. Procédé tel que défini à l'une des revendications 1 ou 2, pour lequel dans la formule (I), A représente un atome de lanthane, un atome de calcium ou un atome de baryum. 3. Method as defined in one of claims 1 or 2, wherein in the formula (I), A represents a lanthanum atom, a calcium atom or a barium atom.
4. Procédé tel que défini à l'une quelconque des revendications 1 à 3, pour lequel dans la formule (I), A' représente un atome de strontium. 4. Process as defined in any one of claims 1 to 3, wherein in the formula (I), A 'represents a strontium atom.
5. Procédé tel que défini à l'une quelconque des revendications 1 à 4, pour lequel dans la formule (I), B représente un atome de fer. 5. Process as defined in any one of claims 1 to 4, wherein in formula (I), B represents an iron atom.
6. Procédé tel que défini à l'une quelconque des revendications 1 à 5, pour lequel dans la formule (I), B' représente un atome de gallium, un atome de titane ou un atome de cobalt. 6. Process as defined in any one of claims 1 to 5, wherein in the formula (I), B 'represents a gallium atom, a titanium atom or a cobalt atom.
7. Procédé tel que défini à l'une quelconque des revendications 1 à 6, pour lequel dans la formule (I), B" représente un atome de zirconium. 7. Process as defined in any one of claims 1 to 6, wherein in the formula (I), B "represents a zirconium atom.
8. Procédé tel que défini à l'une quelconque des revendications 1 ou 7, pour lequel dans la formule (I), u est égal à 0. 8. Process as defined in any one of claims 1 or 7, wherein in the formula (I), u is equal to 0.
9. Procédé tel que défini à la revendication 8, pour lequel le matériau pérovskite de formule (I) est choisi parmi les composés suivants: 9. The process as defined in claim 8, wherein the perovskite material of formula (I) is chosen from the following compounds:
La(i -x) Srx Fe(i-y) Coy 03-δ, La(i-X) Srx Fe(i-y) Gay 03-δ, La(i-X) Srx Fe(i-y) Tiy 03-5, The (i -x) Sr x Fe (i-y) Co y 0 3-δ, La (i -X) Sr x Fe (i -y) Ga y 0 3-δ, La (i -X) Sr x Fe ( i- y ) Ti y 0 3-5 ,
Ba(i-X) Srx Fe(i-y) Coy 03-5, Ca Fe(i-y) Tiy 03-5 ou La(i-X)SrxFe03-5 Ba ( i -X) Sr x Fe ( i- y ) Co y 0 3-5 , Ca Fe ( i- y ) Ti y O 3-5 or La ( i- X) Sr x Fe0 3-5
10. Procédé tel que défini à la revendication 9, pour lequel le matériau pérovskite de formule (I) est choisi parmi les composés suivants: 10. Process as defined in claim 9, wherein the perovskite material of formula (I) is chosen from the following compounds:
La0,6 Sr0,4 Fe0,9 Ga0,i 03-δ, La0,5 Si"o,5 Fe0,9 Ti0,i Οβ-δ., 0 , 6 Sr 0 , 4 Fe 0 , 9 Ga 0 , i 0 3- δ, The 0 , 5 Si " o, 5 Fe 0 , 9 Ti 0 , i Οβ-δ.,
La0,6 Sro,4 Feo,9 Gao,i Οβ-β , The 0, 6 o Sr 4 Fe o, 9 Ga o, i Οβ-β,
Lao,5 Sro,5 Feo,9 Tio,i Οβ-δ., O , 5 Sr o , 5 Fe o , 9 Ti o , i Οβ-δ.,
Lao,5 Sro,5 Feo,9 Tio,i Οβ-β, O , 5 Sr o , 5 Fe o , 9 Ti o , i Οβ-β,
La0,6 Sr0,4 Fe0,g Ga0,i 03-δ, et 0 , 6 Sr 0 , 4 Fe 0 , g Ga 0 , i 0 3 -δ, and
Lao,8 Si"o,2 Feo,7Gao,3 Οβ-β. O , 8 Si " o, 2 Feo, 7Ga o , 3 Οβ-β.
1 1 . Procédé de préparation d'un substrat revêtu sur au moins une de ses surfaces, d'un film de sol-gel d'un matériau pérovskite caractérisé en ce qu'il comprend : 1 1. Process for the preparation of a substrate coated on at least one of its surfaces with a sol-gel film of a perovskite material, characterized in that it comprises:
- Une étape e) de trempage d'un substrat constitué d'un matériau pérovskite fritté de densité supérieure à 90%, de préférence supérieure à 95%, dans le sol issu de l'étape c) du procédé tel que défini à l'une quelconque des revendications 1 à 10, pour obtenir un substrat trempé;  A step e) of dipping a substrate made of a sintered perovskite material with a density greater than 90%, preferably greater than 95%, in the soil resulting from stage c) of the process as defined in FIG. any one of claims 1 to 10 for obtaining a quenched substrate;
- Une étape f) de tirage dudit substrat trempé issu de l'étape e) à vitesse constante, pour obtenir un substrat revêtu d'un film dudit sol ;  A step f) of drawing said quenched substrate resulting from step e) at a constant speed, in order to obtain a substrate coated with a film of said ground;
- Une étape g) de séchage dudit substrat revêtu d'un film dudit sol obtenu à l'étape f), par évaporation du solvant, pour obtenir ledit substrat revêtu d'un sol-gel.  A step g) of drying said substrate coated with a film of said sol obtained in step f), by evaporation of the solvent, to obtain said substrate coated with a sol-gel.
12. Procédé tel que défini à la revendication 1 1 , dans lequel ledit matériau pérovskite fritté de densité supérieure à 90%, de préférence supérieure à 95%, est une composition céramique (CC) comprenant pour 100% volumique, au moins 75 % en volume et jusqu'à 100% en volume d'un composé conducteur mixte électronique et d'anions oxygène O2" (Ci) choisi parmi les oxydes céramiques dopés de formule (II) : 12. The process as defined in claim 1 1, wherein said sintered perovskite material having a density of greater than 90%, preferably greater than 95%, is a ceramic composition (CC) comprising for 100% by volume, at least 75% by weight. volume and up to 100% by volume of a mixed electron conducting compound and O 2 " oxygen anions (Ci) chosen from doped ceramic oxides of formula (II):
C(1-x-U) C x D(1-y-u) D'y D"u O», (II), C (1-x- U) C x D (1-yu) D'y D "u O", (II),
formule (II) dans laquelle :  formula (II) in which:
x, y, u et δ sont tels que la neutralité électrique du réseau cristallin est conservée, 0 < x < 0,9,  x, y, u and δ are such that the electrical neutrality of the crystal lattice is conserved, 0 <x <0.9,
0 < u < 0,5,  0 <u <0.5,
(y + u) < 0,5,  (y + u) <0.5,
0 < y < 0,5 et 0 < δ  0 <y <0.5 and 0 <δ
et formule (II) dans laquelle :  and formula (II) in which:
- C représente un atome choisi parmi le scandium, l'yttrium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ;  C represents an atom chosen from scandium, yttrium or in the families of lanthanides, actinides or alkaline earth metals;
- C différent de C, représente un atome choisi parmi le scandium, l'yttrium, l'aluminium, le gallium, l'indium, le thallium ou dans les familles des lanthanides, des actinides ou des métaux alcalino-terreux ; - D représente un atome choisi parmi les métaux de transition ; - C different from C, represents an atom selected from scandium, yttrium, aluminum, gallium, indium, thallium or in families of lanthanides, actinides or alkaline earth metals; D represents an atom chosen from transition metals;
- D' différent de D, représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain ou le plomb ;  - Of different from D, represents an atom chosen from transition metals, alkaline earth metals, aluminum, indium, gallium, germanium, antimony, bismuth, tin or lead;
- D" différent de D et de D', représente un atome choisi parmi les métaux de transition, les métaux de famille des alcalino-terreux, l'aluminium, l'indium, le gallium, le germanium, l'antimoine, le bismuth, l'étain, le plomb ou le zirconium ;  - D "different from D and D ', represents an atom chosen from transition metals, metals of the alkaline-earth family, aluminum, indium, gallium, germanium, antimony, bismuth , tin, lead or zirconium;
et optionnellement jusqu'à 25% en volume d'un composé (C2), différent du composé (Ci) choisi parmi l'oxyde de magnésium, l'oxyde de calcium, l'oxyde d'aluminium, l'oxyde de zirconium, l'oxyde de titane, les oxydes mixtes de strontium et d'aluminium ou, de baryum et de titane ou de calcium et de titane ; ladite ledit composition céramique (CC) ayant subi une étape de frittage avant sa mise en œuvre à l'étape e). and optionally up to 25% by volume of a compound (C 2 ) different from the compound (Ci) selected from magnesium oxide, calcium oxide, aluminum oxide, zirconium oxide titanium oxide, mixed oxides of strontium and aluminum or barium and titanium or calcium and titanium; said ceramic composition (CC) having undergone a sintering step prior to its implementation in step e).
13. Procédé tel que défini à la revendication 12, dans lequel ladite composition céramique (CC) comprend pour 100% volumique, au moins 90 % volumique et plus particulièrement au moins 95% volumique et jusqu'à 100% volumique de composé (Ci) et optionnellement jusqu'à 10% en volumique, et plus particulièrement jusqu'à 5% volumique de composé (C2). 13. The process as defined in claim 12, wherein said ceramic composition (CC) comprises, for 100% by volume, at least 90% by volume and more particularly at least 95% by volume and up to 100% by volume of compound (Ci). and optionally up to 10% by volume, and more particularly up to 5% by volume of compound (C 2 ).
14. Procédé tel que défini à l'une des revendications 12 ou 13, dans lequel les formules (I) et (II) sont identiques. 14. The method as defined in one of claims 12 or 13, wherein formulas (I) and (II) are identical.
15. Procédé de préparation d'une membrane céramique (CM) caractérisé en que ledit substrat revêtu d'un sol-gel obtenu par le procédé tel que défini à l'une quelconque des revendications 1 1 à 14, subit une étape h) de calcination sous air. 15. A method for preparing a ceramic membrane (CM) characterized in that said substrate coated with a sol-gel obtained by the process as defined in any one of claims 1 1 to 14, undergoes a step h) of calcination under air.
16. Procédé de préparation d'une poudre ultra-divisée ou nanostructurée ayant des tailles comprises entre 10nm et 100nm d'un matériau de type pérovskite correspondant à la formule générale (I), caractérisé en ce que le sol issu de l'étape c) du procédé tel que défini à l'une quelconque des revendications 1 à 9, subit une étape i) d'atomisation pour former une poudre de sol-gel; ladite poudre de sol-gel étant ensuite soumise à l'étape h) de calcination sous air, pour former ladite poudre ultra-divisée ou nanostructurée. 16. Process for the preparation of an ultra-divided or nanostructured powder having sizes of between 10 nm and 100 nm of a perovskite-type material corresponding to the general formula (I), characterized in that the sol resulting from stage c ) of the process as defined in any one of claims 1 to 9, undergoes a step i) of atomization to form a sol-gel powder; said sol-gel powder being subsequently subjected to calcination step h) in air, to form said ultra-divided or nanostructured powder.
EP12766076.9A 2011-12-15 2012-09-26 Process for preparing a sol-gel from at least three metal salts and use of the process for preparing a ceramic membrane Withdrawn EP2791078A1 (en)

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Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105642131B (en) * 2014-11-13 2019-06-18 中国科学院大连化学物理研究所 A kind of method that nanoparticle stablizes perovskite structure oxygen permeation membrane
CN107710478B (en) * 2015-07-07 2020-08-25 日本碍子株式会社 Fuel cell
CN106976915B (en) * 2016-01-15 2018-11-23 南京工业大学 Calcium-doped cobalt aluminate blue nano pigment and preparation method thereof
KR101802067B1 (en) * 2016-05-02 2017-11-27 부산대학교 산학협력단 Synthesis method of oxide powder with perovskite structure and oxide powder formed by the synthesis method
CN108117086A (en) * 2016-11-26 2018-06-05 中国科学院大连化学物理研究所 A kind of preparation method of oxygen absorbent
CN108114688A (en) * 2016-11-26 2018-06-05 中国科学院大连化学物理研究所 A kind of oxygen absorbent for oxygen coalescence
RU2651009C1 (en) * 2017-05-15 2018-04-18 Федеральное государственное бюджетное учреждение науки Институт высокотемпературной электрохимии Уральского отделения Российской Академии наук Method for synthesis of nano-dimensional powder material based on lanthanum scandate
CN107814567B (en) * 2017-11-03 2020-10-02 天津师范大学 Extrinsic ferroelectric ceramic device with lower coercive field and preparation method thereof
CN107935590B (en) * 2017-12-08 2021-02-05 安阳工学院 Method for preparing Aurivillius phase SrBiFeCoTiO material by microwave sintering and prepared product
EP3735314A4 (en) 2018-01-04 2021-09-29 University of Washington Nanoporous selective sol-gel ceramic membranes, selective -membrane structures, and related methods
CN109876667A (en) * 2019-04-04 2019-06-14 江苏海发新材料科技有限公司 A kind of preparation method of porous stainless steel membrane
CN114044540B (en) * 2021-09-07 2022-12-30 南京航空航天大学 A-site and B-site co-doped perovskite type electromagnetic wave-absorbing material and preparation method thereof

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5061682A (en) * 1990-01-17 1991-10-29 The Washington Technology Center Ceramic precursor mixture and technique for converting the same to ceramic
JP4153132B2 (en) * 1999-09-27 2008-09-17 達己 石原 LaGaO3 system electron-oxygen ion mixed conductor and oxygen permeable membrane using the same
US6878487B2 (en) * 2001-09-05 2005-04-12 Samsung Sdi, Co., Ltd. Active material for battery and method of preparing same
JP4311918B2 (en) * 2002-07-09 2009-08-12 ダイハツ工業株式会社 Method for producing perovskite complex oxide
JP2006032132A (en) * 2004-07-16 2006-02-02 Hosokawa Funtai Gijutsu Kenkyusho:Kk Air electrode material powder of solid oxide fuel cell, air electrode and solid oxide fuel cell
JP2006082039A (en) * 2004-09-17 2006-03-30 Noritake Co Ltd Oxygen separation membrane element, its manufacturing method, oxygen manufacturing method, and reactor
EP1785408A1 (en) * 2005-11-15 2007-05-16 L'AIR LIQUIDE, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude Process of manufacturing porous ceramic supports having a controlled microstructure
RU2383495C2 (en) * 2007-12-12 2010-03-10 ГОУ ВПО Уральский государственный университет им. А.М. Горького Method of producing complex metal oxides
CN101306842B (en) * 2008-07-04 2010-12-08 华中科技大学 Method for preparing ceramic cathode nanometer powder of solid-oxide fuel battery
JP2010110671A (en) * 2008-11-04 2010-05-20 National Institute Of Advanced Industrial Science & Technology PEROVSKITE-BEARING Ni CATALYST MATERIAL FOR MODIFICATION AND METHOD OF MANUFACTURING SYNGAS USING THIS CATALYST MATERIAL
US8124037B2 (en) * 2009-12-11 2012-02-28 Delphi Technologies, Inc. Perovskite materials for solid oxide fuel cell cathodes
EP2374526A1 (en) * 2010-03-29 2011-10-12 Centre National de la Recherche Scientifique (C.N.R.S) Solid composite membrane exhibiting both oxygen conductivity and a substrate catalyst interface

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2013087241A1 *

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