Abstract: A process for isomerizing straight chain hydrocarbons having at least seven carbon atoms by forming a reaction mixture including at least one of the straight chain hydrocarbons and hydrogen and passing the reaction mixture over a catalyst including a molybdenum compound, at least the surface of which is formed of molybdenum carbide partially oxidized in the form of at least one oxycarbide.

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.

Abstract: The invention comprises a process for co-sintering of conductors of copper or copper-based alloy and a ceramic substrate, the substrate being produced from a ceramic powder of cordierite type, having a sintering temperature of lower than 950.degree. C.The process comprises the following steps:(a) shaping of the ceramic substrate from a powder of cordierite type,(b) deposit of copper on the ceramic substrate, and(c) co-sintering heat treatment, during which the organic compounds are removed, the copper is regenerated in a reducing atmosphere, and co-sintering of the conductors and the substrate is carried out in a flow of moist inert gas with a plateau at a temperature of between 1065.degree. and 1080.degree. C.The process according to the invention makes it possible to produce substrates of cordierite with internal and external conductors.

Abstract: The invention is directed to a process for the production of fine grains of silicon carbide which are formed by an agglomerate of submicronic grains having a specific surface area that is at least 100 m.sup.2 .multidot.g.sup.-1, which are intended in particular to serve as a carrier for catalysts for petrochemistry, and for catalytic reactions at elevated temperature which can attain 1000.degree. C., the process comprising reacting vapors of silicon monoxide SiO on carbon, being characterized by: generating vapors of SiO in a first reaction zone by heating a mixture SiO.sub.2 +Si at a temperature of between 1100.degree. and 1400.degree. C., under a pressure of between 0.1 and 1.5 hPa; and, in a second reaction zone, contacting the SiO vapors with reactive carbon in the divided state with a specific surface area that is at least equal to 200 m.sup.2 .multidot.g.sup.-1 at a temperature of between 1100.degree. and 1400.degree. C.