Abstract: The invention relates to a photocatalyst comprising a ?-SiC cellular foam and a photocatalytically active phase, deposited directly on said cellular foam or on an intermediate phase deposited on said cellular foam. The average size of the cells is between 2500 ?m and 5000 ?m. The foam can comprise nanotubes or nanofibers (particularly of carbon, SiC, and TiO2) that consist of, or carry as an intermediate phase, a photocatalytically active phase.

Abstract: The invention relates to a photocatalyst comprising a ?-SiC cellular foam and a photocatalytically active phase, deposited directly on said cellular foam or on an intermediate phase deposited on said cellular foam. The average size of the cells is between 2500 ?m and 5000 ?m. The foam can comprise nanotubes or nanofibers (particularly of carbon, SiC, and TiO2) that consist of, or carry as an intermediate phase, a photocatalytically active phase.

Abstract: A method of preparing a solid material based on tangled nanotubes and/or nanofibers, includes a step of growing carbon nanofibers and/or nanotubes with restraint in a contained reactor; and the materials thus obtained. The different uses of the materials are also disclosed.

Abstract: The invention relates to a chemical reactor with a nanometric superstructure, comprising at least one member wherein at least one reaction chamber is arranged, and said reaction chamber being filled at least partially with a high specific surface area material having a specific surface area greater than 5 m2/g, and characterised in that said high specific surface area material is selected from nanotubes or nanofibres. These nanotubes or nanofibres are preferably selected in the group consisting of carbon nanofibres or nanotubes, ?-SiC nanofibres or nanotubes, TiO2 nanofibres or nanotubes. They may be deposited on an intermediate structure selected in the group consisting of glass fibres, carbon fibres, SiC foams, carbon foams, alveolar ?-SiC foams, said intermediate structure filling the reaction chamber of said reactor at least partially.

Abstract: The invention relates to a photocatalyst comprising a cellular foam selected from carbon foam and the foam of a carbon material, such as a polymer, and a photocatalytically active phase, deposited directly on said cellular foam or on an intermediate phase deposited on said cellular foam. The average size of the cells is between 2500 ?m and 5000 ?m. The foam can comprise nanotubes or nanofibers (in particular TiO2).

Abstract: This invention relates to ?-SiC foam parts with a specific surface area preferably equal to at least 5 m2/g and with at least two zones A and B with a different cellular porosity distribution, wherein the parts were made by chemical transformation of a porous precursor medium comprising at least two blocks A? and B?, each having a different cellular porosity distribution, and in that the at least two zones A and B are derived from the chemical transformation of the two blocks A? and B?. This foam, optionally after deposition of an active layer, may be used as a filter medium in cartridges designed for the purification of exhaust gases. The invention also relates to manufacturing processes for preparing such a filter medium.

Abstract: A method of preparing a solid material based on tangled nanotubes and/or nanofibres, includes a step of growing carbon nanofibres and/or nanotubes with restraint in a contained reactor; and the materials thus obtained. The different uses of the materials are also disclosed.

Abstract: In a process for the conversion of carbon monoxide to C2+ hydrocarbons in the presence of hydrogen and of a catalyst comprising a metal and a support comprising silicon carbide, the support comprises more than 50% by weight of silicon carbide in the beta form. A process for the conversion of carbon monoxide to C2+ hydrocarbons in the presence of hydrogen and of a catalyst the effluent thus obtained are also disclosed.

Abstract: A SiC-based composite material capable of use as an inner coating for an aluminium smelting furnace or as an inner coating for a fused salt electrolytic cell, wherein said composite material has been prepared from a precursor mixture comprising at least one ?-SiC precursor and at least one carbonated resin, and wherein said composite material contains inclusions, and wherein at least one part thereof comprises ?-SiC, in a ?-SiC matrix.

Abstract: The invention relates to a method for obtaining synthesis gas by partial catalytic oxidation, consisting in bringing a hydrocarbon in a gaseous state into contact with an oxidizing gas, and therefore possibly a small amount of water vapor, in the presence of a catalyst comprising at least one silicon carbide at a temperature of more than 800° C. According to the invention, the silicon carbide has a specific surface which is determined by the BET method and which is less than or equal to 100 m2/g, the contact time between the mixture of gaseous hydrocarbon, oxidizing gas and silicon carbide being more than 0.05 seconds and the pressure inside the reactor being greater than atmospheric pressure.

Abstract: In a process for the conversion of carbon monoxide to C2+ hydrocarbons in the presence of hydrogen and of a catalyst comprising a metal and a support comprising silicon carbide, the support comprises more than 50% by weight of silicon carbide in the beta form. A process for the conversion of carbon monoxide to C2+ hydrocarbons in the presence of hydrogen and of a catalyst the effluent thus obtained are also disclosed.

Abstract: The invention concerns a method for so-called two-phase impregnation of a ?-SiC support with high specific surface area, said method comprising at least the following steps: (a) a first impregnating at least once said support with a polar agent A, (b) a second impregnating which consists in impregnating at least once said support with at least an agent B less polar than agent A. Said method enables the production of novel catalysts for heterogeneous catalysis.

Abstract: In a process for the conversion of carbon monoxide to C2+ hydrocarbons in the presence of hydrogen and of a catalyst comprising a metal and a support comprising silicon carbide, the support comprises more than 50% by weight of silicon carbide in the beta form. A process for the conversion of carbon monoxide to C2+ hydrocarbons in the presence of hydrogen and of a catalyst the effluent thus obtained are also disclosed.

Abstract: A process for the conversion of methane/carbon dioxide mixtures to a carbon monoxide/hydrogen mixture is provided in which use is made of a catalyst with a support comprising silicon carbide in the beta form.

Abstract: This invention relates to ?-SiC foam parts with a specific surface area preferably equal to at least 5 m2/g and with at least two zones A and B with a different cellular porosity distribution, wherein the parts were made by chemical transformation of a porous precursor medium comprising at least two blocks A? and B?, each having a different cellular porosity distribution, and in that the at least two zones A and B are derived from the chemical transformation of the two blocks A? and B?. This foam, optionally after deposition of an active layer, may be used as a filter medium in cartridges designed for the purification of exhaust gases. The invention also relates to manufacturing processes for preparing such a filter medium.

Abstract: The invention relates to a method for obtaining synthesis gas by partial catalytic oxidation, consisting in bringing a hydrocarbon in a gaseous state into contact with an oxidizing gas, and therefore possibly a small amount of water vapor, in the presence of a catalyst comprising at least one silicon carbide at a temperature of more than 800° C. According to the invention, the silicon carbide has a specific surface which is determined by the BET method and which is less than or equal to 100 m2/g, the contact time between the mixture of gaseous hydrocarbon, oxidizing gas and silicon carbide being more than 0.05 seconds and the pressure inside the reactor being greater than atmospheric pressure.

Abstract: A catalyst for chemical and petrochemical reactions and a process for its production. The catalyst comprises an oxide of one of the transition metals, rare earth elements, or actinide elements, e.g., molybdenum, having on its surface carbides and oxycarbides, the core being the metal or the metal oxide. In the process for catalyst production, the reaction gas mixture containing carbon products is passed onto the oxide, leading to a progressive carburization of the surface of the oxide and to a progressive increase in the efficiency of the catalyst.

Abstract: A method of producing heavy metal carbides of high specific surface area characterised in that a compound in the gazeous state of said heavy metal is caused to react with reactive carbon having a specific surface area at least equal to 200 m.sup.2.g.sup.-1 at a temperature comprised between 900.degree. and 1400.degree. C., and thus obtained carbides.

Abstract: A method of producing heavy metal carbides of high specific surface area characterized in that a compound in the gazeous state of said heavy metal is caused to react with reactive carbon having a specific surface area at least equal to 200 m.sup.2. g.sup.-1 at a temperature comprised between 900.degree. and 1400.degree. C., and thus obtained carbides.

Abstract: Process for activating carbides of heavy metals with a large specific surface with a view to their use as a catalyst for chemical or petrochemical reactions consisting of treating the said carbides by managed oxidation under an oxidizing gas stream at a temperature between 250.degree. and 450.degree. C., maintaining the temperature for at least 3 hours and then cooling to ambient temperature, still under said oxidizing stream.