Abstract: A process for the production of catalyst coated membranes, especially catalyst coated membranes for use in fuel cells, that includes applying followed by drying of an electrocatalyst coating composition, a polymeric dispersion and a second electrocatalyst coating composition onto the surface of a temporary substrate, followed by separation of the temporary substrate.

Abstract: The present invention provides a method for preparing silica containing molecular sieves which may be mixed with an organic polymer to create a mixed matrix membrane. Further, this invention includes a method of making such a mixed matrix membrane and the membrane itself. A process for separating component gases from a mixture using the subject mixed matrix membrane is also described. The method for preparing silica containing molecular sieves comprises super water washing silica containing molecular sieves to produce water washed molecular sieves which are substantially free of surface remnants. Super water washing also ideally lowers the concentration of alkali metals in the molecular sieves.

Abstract: A laminated zeolite composite is provided, including a MFI membrane constituted by a MFI type zeolite having a SiO2/Al2O3 (molar ratio) of 40 to 100, and a porous substrate constituted by a MFI type zeolite having a SiO2/Al2O3 (molar ratio) of 20 to 400, wherein the MFI membrane is formed on the porous substrate. The composite has high separation characteristics and high permeability.

Abstract: A method for making transparent continuous zeolite film is provided. First a transparent precursor sol is prepared, and the precursor sol is processed to a specific concentration. The precursor solution is coated on a surface of a substrate which is heated under an ambiance of 120˜250° C. in temperature and a humidity less than saturated humidity. The packing of zeolite nanocrystals in the film converted from coated precursor sol has preferred orientation and the film shows super-hydrophobic property.

Abstract: A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo5Si3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

Abstract: A sealing technique is established in which a seal can be easily formed and which is excellent in reliability and a heat cycle property in a high temperature region of 800° C. or higher, so as to provide a composite body preferably used for a device for producing pure oxygen, oxygen-rich air, and the like, a membrane reactor represented by that for partial oxidation of a hydrocarbon gas, a solid oxide fuel cell, an oxygen purification device, a heat exchanger, or the like. The present invention makes it possible to increase a possibility of practical use in a wide area which has been delayed in development owing to a bottleneck of improvement in a sealing property. Particularly, its application to the device for producing pure oxygen, oxygen-rich air, or the like, the membrane reactor represented by that for partial oxidation of the hydrocarbon gas, the solid oxide fuel cell, the oxygen purification device, the heat exchanger, or the like can greatly contribute to acceleration of the development.

Abstract: Mixed matrix membranes are prepared from zeolites and polymers, such as polyimides, in a void free fashion where either no voids or voids of less than several Angstroms are present at the interface of the polymer and the zeolite by bonding (hydrogen, ionic, or covalent) functional groups on the zeolite with functional groups on the polymer. The mixed matrix membranes may be cast or formed by ISAM processes, and may be present on a variety of supports including hollow fibers.

Abstract: Zeolite membranes that can be used to continuously separate components of mixtures are disclosed. The zeolite membranes are prepared by isomorphous substitution, which allows systematic modification of the zeolite surface and pore structure. Through proper selection of the basic zeolite framework structure and compensating cations, isomorphous substitution permits high separation selectivity without many of the problems associated with zeolite post-synthesis treatments. The inventive method for preparing zeolite membranes is alkali-free and is much simpler than prior methods for making acid hydrogen zeolite membranes, which can be used as catalysts in membrane reactors.

Abstract: Layers comprising a molecular sieve layer on a porous or non-porous support, having uniform properties and allowing high flux are prepared from colloidal solutions of zeolite or other molecular sieve precursors (particle size less than 100 nm), by deposition, e.g., by spin or dip-coating, or by in situ crystallization.

Abstract: A method for carbonizing a zeolite comprises depositing a carbon coating on the zeolite pores by flowing an inert carrier gas stream containing isoprene through a regenerated zeolite at elevated temperature. The carbonized zeolite is useful for the separation of light hydrocarbon mixtures due to size exclusion and the differential adsorption properties of the carbonized zeolite.

Abstract: A process is described for the manufacture of a crystalline molecular sieve layer on a support, which process comprises impregnation of the support with an impregnating material prior to deposition of a crystalline molecular sieve layer and subsequent removal of substantially all the impregnating material.

Abstract: The present invention relates to a method for preparing a composite silica membrane with thermal stability by a soaking-rolling method, and more particularly to a method for preparing a composite silica membrane with improved thermal stability by rolling the surface of a porous support with silica xerogel, soaking-rolling the surface with ?-alumina, coating, drying, and sintering the porous support surface, thereby forming a fine coating membrane on the porous support surface.

Abstract: A zeolite laminated composite of the present invention is characterized in that it has a separation membrane being constituted by a zeolite, and a porous substrate being constituted by a zeolite and having a catalyst function, and that the separation membrane is formed on the porous substrate. The composite shows a small pressure loss and hardly generates defects such as cracks in the separation membrane even under a high temperature condition.

Abstract: An oxide ion conductor is manufactured having a relatively high mechanical strength while the ionic conduction thereof is maintained at a satisfactory level. The oxide ion conductor is represented by the formula Ln11-xAxGa1-y-z-wB1yB2zB3wO3-d. In the oxide ion conductor, Ln1 is at least one element selected from the group consisting of La, Ce, Pr, Nd, and Sm, A is at least one element selected from the group consisting of Sr, Ca, and Ba, B1 is at least one element selected from the group consisting of Mg, Al, and In, B2 is at least one element selected from the group consisting of Co, Fe, Ni, and Cu, and B3 is at least one element selected from the group consisting of Al, Mg, Co, Ni, Fe, Cu, Zn, Mn, and Zr, wherein x is 0.05 to 0.3, y is 0.025 to 0.29, z is 0.01 to 0.15, w is 0.01 to 0.15, y+z+w is 0.035 to 0.3, and d is 0.04 to 0.3.

Abstract: A hydrophilic coating can be optionally corrosion resistant and/or microbial resistant for a substrate such as a heat exchanger. The coating is provided by a zeolite layer that can be formed from a synthesis solution comprising a structure directing agent, a base, a silicon source, an aluminum source, and a solvent. In one preferred embodiment, the synthesis solution comprises tetrapropylammonium hydroxide, sodium hydroxide, aluminum oxide, tetraethylorthosilicate, and water. The layer is characterized by a zeolite MFI structure and by a composition having the formula of Mn/m[AlnSi(96-n)O192], or [AlnSi(96-n)O192].4[(CH3CH2CH2)4N—OH] wherein M is a metal ion of valence m+ (e.g., Na+) and 27>n>=0. After formation of the coating, the organic structure directing agent can be left intact inside the zeolite coating to make the coating corrosion resistant.

Abstract: A photocatalyst according to the invention comprises a photocatalytic film of a compound of titanium and oxygen and is characterized in that the photocatalytic film is made porous and has 0.02 or higher value as a value calculated by dividing the arithmetical mean deviation of profile Ra with the film thickness. The photocatalytic film can also be specified by the intensity ratio between x-ray diffraction peaks of the anatase structure of titanium oxide. Such a porous photocatalytic material can be obtained by a reactive sputtering method in conditions of adjusting film formation parameters such as the film formation rate, the sputtering pressure, the substrate temperature, the oxygen partial pressure and the like in proper ranges, respectively, and the photocatalyst material is provided with excellent decomposition and hydrophilization capability.

Abstract: Described is a supported zeolite membrane that consists of a zeolite/substrate composite layer that exhibits, in the n-butane/isobutane separation, a permeance of n-butane of at least 6.10−7 mol/m2.s.Pa and a selectivity of at least 250 at the temperature of 180° C. Said zeolite/substrate composite layer is thin and continuous. This membrane is used in processes for gas separation, vapor separation and liquid separation.

Abstract: A zeolite laminated composite of the present invention is characterized in that it has a separation membrane being constituted by a zeolite, and a porous substrate being constituted by a zeolite and having a catalyst function, and that the separation membrane is formed on the porous substrate. The composite shows a small pressure loss and hardly generates defects such as cracks in the separation membrane even under a high temperature condition.

Abstract: Zeolite membranes that can be used to continuously separate components of mixtures are disclosed. The zeolite membranes are prepared by isomorphous substitution, which allows systematic modification of the zeolite surface and pore structure. Through proper selection of the basic zeolite framework structure and compensating cations, isomorphous substitution permits high separation selectivity without many of the problems associated with zeolite post-synthesis treatments. The inventive method for preparing zeolite membranes is alkali-free and is much simpler than prior methods for making acid hydrogen zeolite membranes, which can be used as catalysts in membrane reactors.

Abstract: The invention relates to a method for producing a membrane filter body comprising the following steps: at least one porous functional layer (H) which is made of zeolitic particles is provided; a liquid is applied to said functional layer (II), containing precursors suitable for forming zeolite; the functional layer (II) and the liquid disposed thereon are subjected to a pressure and a specific temperature in order to form a closed a molecular screening layer (I).

Abstract: The invention is related to a zeolite membrane composite composition comprising a first zeolite or zeolite-like layer, a second independently selected catalytic, permselective, or combined catalytic-permselective layer, and a porous support, the porous support having a first surface in contact with the first zeolite layer and a second surface in contact with the second layer. In another embodiment, the invention is directed toward a zeolite membrane composite composition comprising a supported zeolite or zeolite-like layer, the support having a catalytic functionality contained thereon.

Abstract: Reactor membranes for used in oxidation reactions of hydrocarbons involving oxygen comprising a selective oxidation catalyst on a mixed conducting, oxide ion selective ceramic membrane of the composition (Sr1-xCax)1-yAyMn1-zBzO3-&dgr;, where A is Ba, Pb, Na, K, Y, an element of the lanthanide group or a combination thereof, B is Mg, Al, Ga, In, Sn, an element of the 3d or 4d period or a combination thereof, x is from 0.2 to 0.8, y is from 0 to 0.4, z is from 0 to 0.6, and &dgr; is a number, dependent on x, y and z, that renders the composition charge neutral.

Abstract: Compositions and methods for the manufacture of electrodes for fuel cells. The compositions and methods are particularly useful for the manufacture of anodes and cathodes for proton exchange membrane fuel cells, particularly direct methanol fuel cells. The methods can utilize direct-write tools to deposit ink compositions and form functional layers of a membrane electrode assembly having controlled properties and enhanced performance.

Abstract: A catalyst includes a metal carrier, an adhesive layer formed on the metal carrier, the adhesive layer containing crystalline silicate and silica, and a catalyst layer formed on the adhesive layer. Adhesiveness between the metal carrier and the catalyst layer becomes favorable by interposing the adhesive layer therebetween.

Abstract: A method for producing a silicon oxide-based ceramic membrane on a surface of a porous substrate from a silica source and an aqueous alkaline solution (or an aqueous alkaline solution of an alumina source) by a gas phase reaction comprises the step of heating the silica source and the aqueous alkaline solution (or the aqueous alkaline solution of an alumina source) in an airtight vessel without mixing them.

Abstract: The present invention relates to a method for the preparation of a zeolite-substrate composite comprising a patterned zeolite monolayer or multilayer on a substrate, which comprises forming a pattern of a linking compound on the substrate by a selective irradiation with a UV ray, a selective application of a linking compound or a blocking compound, or a selective deposition of a metal, and combining zeolite particles on the portion whereon the linking compound is patterned. The substrate is selected from a group consisting of a substrate having surface hydroxyl groups, a metal capable of being reacted with thiol or amino groups, and a polymeric material having various surface functional groups. The present invention also relates to a zeolite-substrate composite comprising a patterned zeolite monolayer or multilayer on a substrate prepared by said method.

Abstract: A process is described for the manufacture of crystalline molecular sieve layers with good para-xylene over meta-xylene selectivity's good para-xylene permeances and selectivities. The process requires impregnation of the support prior to hydrothermal synthesis using the seeded method and may be undertaken with pre-impregnation masking. The crystalline molecular sieve layer has a selectivity (&agr;x) for para-xylene over meta-xylene of 2 or greater and a permeance (Qx) for para-xylene of 3.27×10−8 mole(px)/m2.s.Pa(px) or greater measured at a temperature of ≧250° C. and an aromatic hydrocarbon partial pressure of ≧10×103 Pa.

Abstract: A method for producing a zeolite composite membrane in which a zeolite membrane is formed on a porous substrate includes the steps of: coating a zeolite membrane on a porous substrate made of zeolite having the same or a similar composition as the zeolite membrane and containing the same template as the zeolite membrane; and calcining the porous substrate having the zeolite membrane thereon to remove the template from the zeolite membrane and the porous substrate at once. A zeolite composite membrane that does not have cracks can be obtained by almost equalizing thermal expansion coefficients of the porous substrate and the zeolite membrane.

Abstract: The present invention is a method for synthesizing zeolite membranes, particularly a method for synthesizing supported zeolite membranes by wet gel crystallization in a vapor-phase. The method of the present invention is a method for synthesizing zeolite membranes comprising the steps of first coating a support surface with a wet gel precursor sol to form a uniform layer of the precursor sol on the support surface. The wet gel precursor sol comprises a silicate or aluminosilicate species and a template or structure-directing agent.

Abstract: Structure-directing agents, such as quaternary ammonium, are removed from silicalite or zeolite crystals by oxidative attack (e.g., using CO2, H2O or NH3) first, by using a combination of ammonia, water and hydrogen peroxide at an elevated temperature; second, by using choline, hydrogen peroxide and a surfactant; third, by using ozonated water; and fourth, by exposing the crystals to an oxygen-containing plasma. Thin porous films of silicalite or zeolite crystals are useful, for example, in forming low dielectric constant insulating layers in semiconductor chip fabrication. In order for the silicalite or zeolite crystals to form a low dielectric constant film, however, the entrained molecules of the structure-directing agent must be removed.

Abstract: The invention relates to mixed phase materials for the preparation of catalytic membranes which exhibit ionic and electronic conduction and which exhibit improved mechanical strength compared to single phase ionic and electronic conducting materials. The mixed phase materials are useful for forming gas impermeable membranes either as dense ceramic membranes or as dense thin films coated onto porous substrates. The membranes and materials of this invention are useful in catalytic membrane reactors in a variety of applications including synthesis gas production. One or more crystalline second phases are present in the mixed phase material at a level sufficient to enhance the mechanical strength of the mixture to provide membranes for practical application in CMRs.

Abstract: An improved porous substrate for zeolite membranes is formed by coating the substrate with a layer of zeolite particles of a narrow particle distribution size of between 20 and 0.01 microns.

Abstract: A method of preparing catalyst agglomerates for electrochemical devices is provided. The method comprises dispersing particles of a catalyst in a non-aqueous solvent to form a dispersion of the catalyst, adding an ion conducting polymer in a dilute solution to the dispersion of the catalyst under agitation to form catalyst agglomerates, and stirring the dispersion of the catalyst and the catalyst agglomerates to control the growth of the agglomerates. A directly applicable catalyst composition is also provided. The catalyst composition comprises the catalyst agglomerates prepared according to the present invention, a solvent to plasticize surfaces of the catalyst agglomerates and the membrane, and a non-aqueous carrier solvent.

Abstract: The invention is related to a zeolite membrane composite composition comprising a first zeolite or zeolite-like layer, a second independently selected catalytic, permselective, or combined catalytic-permselective layer, and a porous support, the porous support having a first surface in contact with the first zeolite layer and a second surface in contact with the second layer.

Abstract: The invention relates to mixed phase materials for the preparation of catalytic membranes which exhibit ionic and electronic conduction and which exhibit improved mechanical strength compared to single phase ionic and electronic conducting materials. The mixed phase materials are useful for forming gas impermeable membranes either as dense ceramic membranes or as dense thin films coated onto porous substrates. The membranes and materials of this invention are useful in catalytic membrane reactors in a variety of applications including synthesis gas production. One or more crystalline second phases are present in the mixed phase material at a level sufficient to enhance the mechanical strength of the mixture to provide membranes for practical application in CMRs.

Abstract: Composite membranes capable of separating p-xylene from mixtures including p-xylene and m-xylene, and processes for purifying p-xylene using the membranes, are disclosed. The membranes are polymer membranes with a thickness of between about 10 and 1000 microns that include non-interconnected zeolite particles less than 5 microns. In one embodiment, a relatively thin polymer layer (0.5-3 microns) that includes zeolite particles is adjacent to a relatively thick polymer layer which may or may not include zeolite particles, where the thickness of the two layers is between about 10 and 1000 microns. The preferred ratio of zeolite/polymer is about 0.2 by weight. A preferred method for preparing the composite is by dispersing the zeolite in a polymer solution, casting a film of the polymer solution, and evaporating the solvent to form a polymeric film. The polymer permits passage of p-xylene and m-xylene in the vapor state, such that p-xylene diffuses at the same or a faster rate through the polymer.

Abstract: This invention presents a new class of multicomponent metallic oxides which are particularly suited toward use in fabricating components used in processes for producing syngas. The non-stoichiometric, A-site rich compositions of the present invention are represented by the formula (LnxCa1−x)y FeO3−&dgr;wherein Ln is La or a mixture of lanthanides comprising La, and wherein 1.0>x>0.5, 1.1≧y>1.0 and &dgr; is a number which renders the composition of matter charge neutral. Solid-state membranes formed from these compositions provide a favorable balance of oxygen permeance and resistance to degradation when employed in processes for producing syngas. This invention also presents a process for making syngas which utilizes such membranes.

Abstract: A simplified method of forming a porous crystalline titanium silicate membrane comprises preforming a mass of titanium dioxide particles into a consolidated preform such as by pressing into a thin film, and contacting the thin film of titanium dioxide with an aqueous alkaline silicate synthesis solution at a temperature and for a period of time sufficient to form the titanium silicate in-situ.

Abstract: The invention relates to mixed phase materials for the preparation of catalytic membranes which exhibit ionic and electronic conduction and which exhibit improved mechanical strength compared to single phase ionic and electronic conducting materials. The mixed phase materials are useful for forming gas impermeable membranes either as dense ceramic membranes or as dense thin films coated onto porous substrates. The membranes and materials of this invention are useful in catalytic membrane reactors in a variety of applications including synthesis gas production. One or more crystalline second phases are present in the mixed phase material at a level sufficient to enhance the mechanical strength of the mixture to provide membranes for practical application in CMRs.

Abstract: A hydrophobic composite Pd-membrane catalyst, useful for the non-hazardous direct oxidation of hydrogen by oxygen to hydrogen peroxide, without a gas phase mixing of hydrogen and oxygen or air, having the general formula: HPM (c)/SOMF (b)/MxPd1−x (a)/IPM wherein, IPM is an inorganic porous membrane, MxPd1−x is a metal alloy, permeable only to hydrogen gas, Pd is a palladium metal; M is a metal other than palladium, or a mixture of two or more thereof; x is a mole fraction of the metal M in the metal alloy (MxPd1−x), a, in the round bracket, is a weight of the metal alloy per unit area of IPM; SOMF is a surface oxidized thin metal film comprising palladium b, in the round bracket, is a thickness of SOMF; HPM is a hydrophobic polymer membrane and c, in the round bracket , is a weight of the HPM per unit area of SOMF and a process for producing the said catalyst.

Abstract: The present invention is directed at a supported zeolite structure comprising substantially-sintered monolithic porous ceramic substrate having coated thereon a uniformly thin, essentially continuous zeolite crystal layer covering at least one surface and associated pores of the porous ceramic material. The zeolite crystal layer is comprised of a single layer of zeolite crystals and is free of any growth enhancing, selectivity enhancing, or reparation layer and exhibits an oriented structure whereby the crystals exhibit a substantially columnar cross-section. Preferably, the porous ceramic substrate support comprises, on an analyzed oxide basis, 10-90%, by weight alumina and exhibits a crystal phase assemblage selected from the group consisting of cordierite, mullite, alumina, and/or mixtures thereof. A method for forming a zeolite membrane disclosed herein is also provided.

Abstract: The above objects are achieved by providing a novel process for the production of hydrogen peroxide, by the non-hazardous direct oxidation of hydrogen by oxygen to hydrogen peroxide, without the formation of an explosive H2 and O2 gas mixture, using a novel tubular hydrophobic composite Pd-membrane catalyst, represented by a formula: HPM (c)/SOMF (b)/MxPd1−x(a)/IPM Wherein: IPM is an inorganic porous membrane, permeable to all gases and vapors, in a form of tube having a thickness of at least 0.5 mm and internal diameter of at least 0.6 cm; Mx Pd1−x is a metal alloy, permeable only to hydrogen gas, deposited on the inner side of IPM; Pd is a palladium metal; M is a metal selected from copper, silver, gold, noble metals other than palladium, or a mixture of two or more thereof; x is a mole fraction of the metal M in the metal alloy (MxPd1−x) in the range from about 0.03 to about 0.6; (a) is a weight of the metal alloy per unit area of IPM in the range from about 5.0 g.

Abstract: A porous composite structure, and in particular a membrane, for separating fluids is described. The composite structure comprises at least a porous support and a zeolite layer applied to the support and the zeolite is a zeolite of the T type or of an erionite type.

Abstract: This invention relates to catalytic reactor membranes having a gas-impermeable membrane for transport of oxygen anions. The membrane has an oxidation surface and a reduction surface. The membrane is coated on its oxidation surface with an adherent catalyst layer and is optionally coated on its reduction surface with a catalyst that promotes reduction of an oxygen-containing species (e.g., O2, NO2, SO2, etc.) to generate oxygen anions on the membrane. The reactor has an oxidation zone and a reduction zone separated by the membrane. A component of an oxygen containing gas in the reduction zone is reduced at the membrane and a reduced species in a reactant gas in the oxidation zone of the reactor is oxidized. The reactor optionally contains a three-dimensional catalyst in the oxidation zone. The adherent catalyst layer and the three-dimensional catalyst are selected to promote a desired oxidation reaction, particularly a partial oxidation of a hydrocarbon.

Abstract: The present invention relates to a novel hydrophobic multicomponent catalyst useful in the direct oxidation of hydrogen to hydrogen peroxide and to a method for the preparation of such catalyst. More specifically, this invention relates to a novel hydrophobic muticomponent catalyst comprising a hydrophobic polymer membrane deposited on a Pd containing acidic catalyst, useful for the direct oxidation of hydrogen by oxygen to hydrogen peroxide, an a method for preparing the same.

Abstract: A gas diffusion electrode for solid polymer electrolyte fuel cell comprising a gas diffusion electrode and a catalyst layer, characterized in that said catalyst layer is provided with a catalytic substance and an ion exchange resin having pores. In this arrangement, a three-phase boundary can be provided also inside the catalyst layer while maintaining sufficient electron conductivity, capability of supplying reaction gas and protonic conductance, making it possible to enhance the polarization characteristics and power density thereof.

Abstract: Low temperature hydrothermal treatment of an LTL zeolite-producing mixture produces a colloidal suspension of the zeolite; the suspension may be used as seeds in Al— and Ga—LTL zeolite manufacture.

Abstract: A process for converting organic compounds using composite materials in membrane reactors. The composite materials include a gas-tight ceramic, a porous metallic support, and an interfacial zone therebetween eliminate the need for mechanical seals between two such dissimilar materials. Oxygen ion-conducting dense ceramic membranes are formed on a porous metallic alloy to provide an interfacial zone identifiable by a gradient of composition in at least one metallic element across the interfacial zone between the dense ceramic membrane and the porous support. Processes using composite materials in accordance with the invention are, for example, used for production of synthesis gas comprising carbon monoxide and molecular hydrogen, whereby the synthesis gas is, advantageously, free of deleterious and/or inert gaseous diluents such as nitrogen.

Abstract: A family of innovative composite zeolite materials and methods for making the same are disclosed. Zeolites 3A and 13X have been incorporated into hybrid polysiloxane polymers to form composite materials which are useful as membranes for separating a variety of gaseous and liquid materials. Thermal curing, thermal drying and UV curing were utilized to initiate polymer crosslinking reactions and bond the polymers to zeolite surfaces. Thin film samples exhibited nitrogen adsorption as high as 126 cc/g and specific surface area of up to 390 m2/g. Infrared characterization spectra and TEM analysis indicated that polymeric matrices bonded to zeolite surfaces. Pore size of the composite membrane films may be tailored for specific separation applications through choice of zeolite and polymer compositions, curing method, and post-synthesis membrane treatments.

Abstract: Composite materials of the invention, which include a gas-tight ceramic, a porous metallic support, and an interfacial zone therebetween eliminate the need for mechanical seals between two such dissimilar materials. Oxygen ion-conducting dense ceramic membranes are formed on a porous metallic alloy to provide an interfacial zone identifiable by a gradient of composition in at least one metallic element across the interfacial zone between the dense ceramic membrane and the porous support. Processes using composite materials in accordance with the invention are, for example, used for production of synthesis gas comprising carbon monoxide and molecular hydrogen, whereby the synthesis gas is, advantageously, free of deleterious and/or inert gaseous diluents such as nitrogen.