Abstract: The present invention relates to a process for regenerating a catalyst for the cyclizing hydrolysis of an aminonitrile for the manufacture of lactams. It relates more particularly to the regeneration of the solid catalysts used in the processes for producing lactams by the cyclizing hydrolysis of aminonitriles. This regeneration process consists in treating the spent catalyst or the catalyst at the end of the cycle at a temperature of between 300° C. and 600° C. with an oxidizing atmosphere.

Abstract: The present invention relates to a process for the purification of aliphatic aminonitriles and more particularly of 6-aminocapronitrile. It consists more specifically in subjecting 6-aminocapronitrile to a hydrogenation with molecular hydrogen in the presence of a catalyst comprising at least one metal chosen from palladium, platinum, ruthenium, osmium, iridium or rhodium and a promoter agent or a preconditioning in order to improve the selectivity of the hydrogenation.

Abstract: The invention concerns the hydrogenation in amine function of a nitrile function of a dinitrile to obtain the corresponding aminonitrile. More precisely, the invention concerns the hemihydrogenation of a dinitrile into the corresponding aminonitrile, in a liquid medium, characterized in that it consists in operating in the presence of a Raney nickel or cobalt catalyst containing copper and/or silver and/or gold and in the presence of an alkaline or alkaline-earth metal hydroxide. The hemihydrogenation of adiponitrile provides amino-6 capronitrile, compound which can be easily transformed by cyclization hydrolysis into caprolactam, the starting product for the synthesis of polyamide-6.

Abstract: The invention relates to a process for the cyclizing hydrolysis of an aminonitrile compound into a lactam in the presence of a catalyst. The invention relates more particularly to a process for the cyclizing hydrolysis of an aminonitrile compound in the presence of a macroporous particulate catalyst obtained by deposition/impregnation of an oxygenated compound onto a macroporous support such as alumina. The invention applies in particular to the preparation of &egr;-caprolactam by cyclizing hydrolysis of aminocapronitrile.

Abstract: The desulfurization of industrial gases by the catalytic conversion of contaminating sulfur values therein, comprising, e.g., either Claus process or hydrolysis of organosulfur compounds, is carried out in the presence of an effective amount of a cerium oxide-based catalyst.

Abstract: A pollution control catalyst for a catalytic converter in the exhaust system of an internal combustion engine, which catalyst comprises a support impregnated with (i) at least one platinum group precious metal, and with (ii) cerium base metal, or a combination of cerium and at least one other base metal, is facilely prepared by (1) impregnating a catalyst support with precursor compounds of said cerium base metal, or of said cerium base metal and of at least one other base metal, (2) activating said impregnated support, under a neutral or oxidizing atmosphere, at a temperature ranging from 120.degree. to 800.degree. C.

Abstract: Provided is an improved catalyst and a process employing same in the treatment of exhaust gases generated by internal combustion engines. The catalyst comprises a support and an active phase comprising copper, cerium and/or iron, at least one metal selected from the group consisting of platinum and palladium, and at least one metal selected from the group consisting of iridium and rhodium. The catalyst is particularly active in the removal of carbon monoxide, unburned hydrocarbons and nitrogen oxides generally present in the exhaust gases of an internal combustion engine.

Abstract: A pollution control catalyst for a catalytic converter within the exhaust system of an internal combustion engine is facilely prepared by (i) coating/impregnating a catalyst support with palladium and at least one base metal catalyst, (ii) activating the step (i) catalyst, (iii) next coating/impregnating the step (ii) activated catalyst with at least one platinum group precious metal other than palladium, or combination of palladium and at least one other platinum group precious metal, and (iv) then activating the step (iii) catalyst.

Abstract: The exhaust gases from internal combustion engines are catalytically oxidized/reduced, to remove CO, unburned hydrocarbons and NO.sub.x therefrom, utilizing an improved stable and long-lived catalyst which comprises (1) a support substrate, e.g., a monolithic or particulate support, and (2) an active phase deposited thereon, said active phase (2) comprising (i) cerium, (ii) iron, (iii) at least one of the metals gallium and/or yttrium, (iv) at least one of the metals platinum and/or palladium, and (v) at least one of the metals iridium and/or rhodium.

Abstract: A pollution control catalyst for a catalytic converter comprising the exhaust system of an internal combustion engine, said catalyst including a refractory oxide support, and an activated phase therefor comprised of 0.3 to 7% by weight cerium based upon the weight of said support, 0.1 to 3.5% by weight iron, also based upon the weight of said support, at least one platinum or palladium metal, and at least one iridium or rhodium metal.

Abstract: A non-polluting oxyhydrochlorination process is provided in which the residual gaseous effluents are purified by catalytic oxidation in the presence of a catalyst comprising platinum and/or iridium deposited on a special alumina support of eta crystallographic structure and then washing the effluent before being discharged into the atmosphere.The process of the invention is particularly applicable to a residual effluent containing essentially carbon monoxide, carbon dioxide, ethylene, 1,2-dichloroethane, and at least one chlorinated hydrocarbon from among the group consisting of chloroform, carbon tetrachloride, ethyl chloride, 1,1-dichloroethane, 1,1,1- and 1,1,]-trichloroethanes, 1,1,2,2- and 1,1,1,2- tetrachloroethanes, vinyl chloride, 1,1- and 1,2-dichloroethylenes, trichloroethylene, perchloroethylene and chloral.

Abstract: A process for hydrodealkylating alkyl-substituted aromatic hydrocarbons, e.g., toluene, by reaction with hydrogen in the absence of water vapor under relatively mild reaction conditions, and a catalyst therefor are disclosed. The process is effected at a temperature of from about 450.degree. to 650.degree. C., preferably from about 520.degree. to 620.degree. C., and pressures of from about 1 to about 30, preferably from about 5 to about 20 bar, and a liquid hourly space velocity of from about 1 to about 10, preferably from about 3 to about 8, in the presence of a catalyst which comprises a noble metal component comprising rhodium and a support comprising a metal aluminate having a spinel structure and corresponding to the empirical formula M Al.sub.2 O.sub.4.X Al.sub.2 O.sub.3, wherein X represents a value of from 0 to about 200 and M represents a metal selected from the group consisting of nickel, cobalt, copper, zinc, iron, and magnesium.

Abstract: A process for hydrodealkylating alkyl-substituted aromatic hydrocarbons, e.g., toluene, by reaction with hydrogen in the absence of water vapor under relatively mild reaction conditions, and a catalyst therefor are disclosed. The process is effected at a temperature of from about 450.degree. and 650.degree. C., preferably from about 520.degree. to 620.degree. C., and pressures of from about 1 to about 30, preferably from about 5 to about 20 bar, and a liquid hourly space velocity of from about 1 to about 10, preferably from about 3 to about 8, in the presence of a catalyst which comprises a metal combination of rhodium and at least one metal selected from the group consisting of copper, nickel, cobalt, iron, and zinc, and a support comprising activated alumina having a specific surface of between about 100 and about 350 m.sup.2 /g and a total pore volume of from about 0.5 to about 0.8 cm.sup.3 /g.