Abstract: A process for preparing a sintered silicon carbide body including sintering a sample including silicon carbide particles to form a shaped sintered silicon carbide body, the particles containing a silicon carbide core and a surface layer containing carbon and oxygen, the sample having at least 90 weight % being C or Si and having a carbon to silicon molar ratio molC/molSi higher than 1 and a carbon in excess to oxygen molar ratio Cex/molO which is higher than 0.5 and lower than 5.3.

Abstract: A production method is provided in which submicronic particles containing silicon are incorporated into a matrix, wherein, during the incorporation of the particles, the particles are in a compacted state with a bulk density of more than 0.10 grams per cubic centimeter, and the compacted particles have a specific surface area at least 70% of that of the particles considered separately without contact between each other.

Abstract: A production method is provided in which submicronic particles containing silicon are incorporated into a matrix, wherein, during the incorporation of the particles, the particles are in a compacted state with a bulk density of more than 0.10 grams per cubic centimeter, and the compacted particles have a specific surface area at least 70% of that of the particles considered separately without contact between each other.

Abstract: For preparing a reforming catalyst comprising a support, a group VIIIB metal and a group VIIB metal, comprises the following steps in the order a) then b) or b) then a): a step a) impregnating the support with an aqueous solution of hydrochloric acid comprising a group VIIIB metal; a step b) impregnating the support with an aqueous solution comprising a group VIIB metal and a sulphur-containing complexing agent in a reducing environment, or a step b) impregnation with an aqueous solution comprising a group VIIB metal, then with a solution comprising a sulphur-containing complexing agent in a reducing environment. The reducing environment is any reducing atmosphere comprising more than 0.1% by weight of a reducing gas or a mixture of reducing gases; or reducing solutions comprising, with respect to the group VIIB metal, in the range 0.1 to 20 equivalents of reducing metals, reducing organic compounds or inorganic reducing compounds.

Abstract: The invention relates to a method of preparing a dehydrogenation catalyst comprising a group VIII metal, a group IVA metal and a refractory oxide support. The method comprises stages of preparing the dry impregnation aqueous solution containing said group VIII metal, ammonia, either in solution or in gas form, and a complexing agent. It then comprises stages of aging the aqueous solution, of dry impregnation of the support, of maturing the impregnated support, of drying the impregnated support and of calcining the dried support.

Abstract: The invention relates to a method of preparing a reforming catalyst comprising a group VIII metal, a halogen, at least one metal selected from the group made up of the group VIIB metals and group IVA metals, a refractory oxide support. The method comprises stages of preparing a dry impregnation aqueous solution containing ammonia, either in solution or in gas form and a complexing agent, of aging the aqueous solution, of dry impregnation of the support, of maturing the impregnated support, of drying and of calcination.

Abstract: The invention concerns a process for preparing a catalyst comprising at least one metal from group VIII, rhenium or iridium and a sulphur-containing support, said catalyst having a sodium content which is strictly less than 50 ppm by weight and a sulphur content in the range 1500 to 3000 ppm by weight. The invention also concerns the use of said catalyst in a catalytic reforming reaction.

Abstract: The invention relates to a method of preparing a dehydrogenation catalyst comprising a group VIII metal, a group IVA metal and a refractory oxide support. The method comprises stages of preparing the dry impregnation aqueous solution containing said group VIII metal, ammonia, either in solution or in gas form, and a complexing agent. It then comprises stages of aging the aqueous solution, of dry impregnation of the support, of maturing the impregnated support, of drying the impregnated support and of calcining the dried support.

Abstract: The invention relates to a method of preparing a reforming catalyst comprising a group VIII metal, a halogen, at least one metal selected from the group made up of the group VIIB metals and group IVA metals, a refractory oxide support. The method comprises stages of preparing a dry impregnation aqueous solution containing ammonia, either in solution or in gas form and a complexing agent, of aging the aqueous solution, of dry impregnation of the support, of maturing the impregnated support, of drying and of calcination.

Abstract: For preparing a reforming catalyst comprising a support, a group VIIIB metal and a group VIIB metal, comprises the following steps in the order a) then b) or b) then a): a step a) impregnating the support with an aqueous solution of hydrochloric acid comprising a group VIIIB metal; a step b) impregnating the support with an aqueous solution comprising a group VIIB metal and a sulphur-containing complexing agent in a reducing environment, or a step b) impregnation with an aqueous solution comprising a group VIIB metal, then with a solution comprising a sulphur-containing complexing agent in a reducing environment. The reducing environment is any reducing atmosphere comprising more than 0.1% by weight of a reducing gas or a mixture of reducing gases; or reducing solutions comprising, with respect to the group VIIB metal, in the range 0.1 to 20 equivalents of reducing metals, reducing organic compounds or inorganic reducing compounds.