Abstract: The invention concerns a catalyst comprising a porous support, palladium, at least one metal selected from the group constituted by alkalis and alkaline-earths, in which: the specific surface area of the porous support is in the range 50 to 210 m2/g; the palladium content in the catalyst is in the range 0.05% to 2% by weight; at least 80% by weight of the palladium is distributed in a crust at the periphery of the support, the thickness of said crust being in the range 20 to 200 ?m; the metallic dispersion D is in the range 25% to 70%; the density of the palladium particles in the crust is in the range 1500 to 4100 particles of palladium per ?m2; and said alkali and/or alkaline-earth metal is distributed homogeneously across the support. The invention also concerns the preparation of the catalyst and its use in selective hydrogenation.

Abstract: The invention concerns a process for preparing metallic nanoparticles with an anisotropic nature by using two different reducing agents, preferably with different reducing powers, on a source of a metal selected from columns 8, 9 or 10 of the periodic table of the elements.

Abstract: The invention concerns a catalyst comprising a porous support, palladium, at least one metal selected from the group constituted by alkalis and alkaline-earths, in which: the specific surface area of the porous support is in the range 50 to 210 m2/g; the palladium content in the catalyst is in the range 0.05% to 2% by weight; at least 80% by weight of the palladium is distributed in a crust at the periphery of the support, the thickness of said crust being in the range 20 to 200 ?m; the metallic dispersion D is in the range 25% to 70%; the density of the palladium particles in the crust is in the range 1500 to 4100 particles of palladium per ?m2; and said alkali and/or alkaline-earth metal is distributed homogeneously across the support. The invention also concerns the preparation of the catalyst and its use in selective hydrogenation.

Abstract: The invention concerns a process for preparing metallic nanoparticles with an anisotropic nature by using two different reducing agents, preferably with different reducing powers, on a source of a metal selected from columns 8, 9 or 10 of the periodic table of the elements.

Abstract: The invention concerns a process for preparing a catalyst precursor comprising the following steps: 1)a) preparing a colloidal solution A with a defined pH containing oxy(hydroxide) particles of a cation Mz+ selected from the group constituted by cations from columns IIA, IIIA, IIIB, IVB and IVA of the periodic table; or 1)b) using a commercial aqueous colloidal solution (solution A) with a defined pH containing oxy(hydroxide) particles of a cation Mz+ selected from the group constituted by cations from columns IIA, IIIA, IIIB, IVB and IVA of the periodic table; 2) adding in an aqueous solution B containing a precursor salt of a group VIII metal with a concentration of 0.001 to 1 mole/litre, the precursor salt of the metal being soluble under the pH conditions used in step 1. The invention also concerns the catalyst obtained from a catalyst precursor and its application in selective hydrogenation.

Abstract: The invention relates to a process for preparation of anisotropic metallic nanoparticles comprising at least: a) One stage that is brought into contact with an aqueous solution that comprises at least one source of a metal that is selected from the columns 8, 9 or 10 of the periodic table and at least one soluble surfactant, b) One stage for formation of anisotropic metallic nanoparticles of at least one of said metals, by adding at least one reducing agent to the solution that is obtained in stage a), c) Said particles are: c1) separated from liquid and optionally dried, or c2) deposited on a substrate by impregnation with the suspension obtained in stage b) or after resuspension of the nanoparticles that are obtained at the end of stage c1), whereby the substrate is an oxide of unordered texture, and after separation of the possible residual liquid, the material that is obtained is dried at a temperature that is less than or equal to 120° C.

Abstract: The invention relates to a synthesis process for hydrocarbons using a mixture containing carbon monoxide and hydrogen, called Fischer-Tropsch synthesis in the presence of a catalyst comprising a support, at least one group VIII metal said process being characterized in that at least 80% of the group VIII metallic particles of the catalyst have a size comprised between D−(D.0.2) and D+(D.0.2), where D represents the average size of the metallic particles. The process can be used in a fixed-bed reactor of the catalyst or in a reactor operating in liquid phase of the catalyst.

Abstract: The invention relates to a process for the conversion of synthesis gases into a mixture of essentially linear and saturated hydrocarbons, characterized by the use of a catalyst prepared by a gelling procedure, incorporating cobalt, copper and ruthenium, the cobalt, copper and ruthenium being dispersed on a support having at least one oxide of a metal chosen from within the group formed by silica and alumina, the cobalt content, expressed by cobalt weight based on the catalyst weight, being between 1 and 60% by weight, the ruthenium content, expressed by ruthenium weight based on the cobalt weight, being between 0.1 and 20%, and the copper weight, expressed by copper weight based on the cobalt weight, being between 0.1 and 10%.

Abstract: A process for obtaining a tertiary olefin, e.g. isobutylene in a very pure state by decomposing the corresponding ether, e.g. methyl tert. butyl ether, in the presence of a catalyst constituted by silica, modified by the addition of at least one element or compound of an element preferably chosen from the group constituted by rubidium, cesium, magnesium, calcium, strontium, barium, gallium, lanthanum, cerium, praseodymium, neodymium and uranium and optionally by the addition of at least one element or compound of an element chosen from the group constituted by aluminium, titanium and zirconium.

Abstract: The present invention relates to a process for preparing a precursor of a catalyst containing copper, aluminum and zinc.This precursor is formed by the mixing of two ternary precursors, at different stages of their manufacturing, these two ternary precursors being different from one another in their metallic stoichiometry (atomic ratios between Cu, Zn and Al), in their crystallographic structure and in their elemental morphology.The catalyst obtained from this precursor can be used in particular for the synthesis of methanol.

Abstract: The present invention relates to a process for preparing a precursor of a catalyst containing copper, aluminum and zinc.This precursor is formed by the mixing of two ternary precursors, at different stages of their manufacturing, these two ternary precursors being different from one another in their metallic stoichiometry (atomic ratios between Cu, Zn and Al), in their crystalographic structure and in their elemental morphology.The catalyst obtained from this precursor can be used in particular for the synthesis of methanol.

Abstract: A process for manufacturing a mixture of saturated primary alcohols by reacting carbon oxides with hydrogen in the presence of a catalyst formed essentially of the following elements: copper, cobalt, zinc, at least one metal A selected from the group consisting of alkali and alkaline earth metals and optionally zirconium and/or at least one metal M selected from the group formed of scandium, yttrium and rare earth metals and/or at least one metal N selected from group VIII noble metals, the proportion by weight of each metal element being: copper: 15-55%, colbalt: 5-25%, zinc: 15-70%, metal A: 0.01-5%, zinconium: 0-55%, metal M: 0-20%, metal N: 0-1%, the total amount by weight of zinc and zirconium in percent by weight of all the metals being from 15 to 70% and the atomic ratios between these metals being: Cu/Co: 0.2:1 to 5:1 and Zn/(Zn+Zr): 0.05:1 to 1:1 and (Zn+Zr)/Co: 0.5:1 to 8:1.The catalyst may be prepared by complexing or by coprecipitating catalytic elements.