Abstract: A composite catalyst containing:an MFI zeolite in hydrogen form, the framework containing at least one of the elements silicon, aluminium and/or gallium; a matrix; gallium; at least one noble metal of the platinum family, at least one additional metal selected from the group made up to tin, germanium, indium, copper, iron, molybdenum, gallium, thallium, gold, silver, ruthenium, chromium, tungsten and lead, and possibly a compound selected from the group made up of alkali and alkaline earth metals.Its preparation and its use in reactions for aromatising hydrocarbons containing 2 to 9 carbon atoms per molecule.

Abstract: A process for preparing aluminophosphate compounds (and substituted derivatives) of the structural type VFI. This preparation process is characterized in that the speed of increase in temperature of the reaction mixture is greater than 250.degree. C./hour, the total time of heating of the reaction mixture, including the rise in temperature and the plateau heating, being less than one hour. The temperature of the plateau heating is between 100.degree. and 200.degree. C.The synthetic compounds in accordance with the invention possess(a) a general formula approximating to the following:1 Al.sub.2 O.sub.3 0.75-1.25 P.sub.2 O.sub.5 0-0.5 XO.sub.n/2 0-0.05 R y H.sub.2 OwhereX represents a heteroatom chosen from the group consisting of silicon, cobalt, magnesium and zinc;n is the degree of oxidation of the heteroatom X;y, the number of water molecules contained in the said compound, is greater than 0.

Abstract: The object of the invention is a synthetic crystalline zeolite of the mordenite type characterized by:a) the following approximate general formula:Na.sub.2 O, Al.sub.2 O.sub.3, xSiO.sub.2where x is a number ranging from 9 to 30, andb) an X-ray diffraction diagram represented in table I of the description,c) a fluorine content ranging from about 0.005 to 2.0% by weight,and in that it has been synthetized in a fluoride medium.The invention also relates to a process for preparing said zeolite.This zeolite can notably be utilized in adsorption and in catalysis.

Abstract: The object of the invention is a synthetic crystalline zeolite of the beta type characterized by:a) the following approximate general formula:M.sub.2/n O, Al.sub.2 O.sub.3, xSiO.sub.2where M represents a proton and/or a metallic cationn is the valence of Mx is a number ranging from 5 to 800,b) an X-ray diffraction diagram represented in table I of the description, andc) a fluorine content ranging from about 0.005 to 2.0% by weight, said zeolite having been furthermore synthetized in a fluoride medium.

Abstract: A catalytic component having controlled strucuture for use in combination with a cocatalyst for the polymerization of ethylene, and being the product of the process of subjecting a component consisting essentially of titanium, magnesium, and chlorine to a reduction treatment and after such treatment contacting the component with a transition metal chlorine-containing compound and process of polymerizing ethylene using such catalytic component to produce polymers having a broad molecular weight distribution.

Abstract: A process for the manufacture of a linear polyethylene with narrow molecular-weight distribution comprising polymerizing ethylene alone or a mixture of ethylene and an alpha-olefin in which ethylene represents at least about 70% by weight of the total monomers involved, in a gas-phase polymerization medium in the presence of a catalytic component containing at least one transition metal, magnesium, and a halogen, a co-catalyst comprising an alkylaluminum compound, and a monoether, the monoether having the general formula R'OR", wherein R' and R" are the same or different and each is a C.sub.1 to C.sub.8 linear or branched hydrocarbon radical or being a cyclic monoether with the oxygen forming a ring having 4 to 12 carbon atoms.