Abstract: The invention concerns a heat-stable mesostructured material, for use as heterogeneous catalyst, wherein the mesostructured walls comprise: (a) a mineral matrix; and (b) dispersed within said mineral matrix (a), particles of nanometric dimensions based on at least a rare earth T and on at least a transition element M different from said rare earth. The invention also concerns a method for obtaining such a material.

Abstract: The present invention relates to a process facilitating the regeneration of a catalyst based on a zeolite, employed in an acylation reaction.

Abstract: The present invention relates to a process facilitating the regeneration of a catalyst based on a zeolite, employed in an acylation reaction.

Abstract: The present invention relates to an improved active support, cerium/zirconium mixed oxides or cerium/zirconium solid solutions, for improved dehydrogenation catalysts useful in converting alkylaromatics to alkenylaromatics, e.g., ethylbenzene to styrene.

Abstract: The present invention relates to a process for the preparation of pentenenitriles. In this process the 3- or 4-pentenenitriles are produced by reacting 2-methylglutarimide, ethylsuccinimide, and/or their precursors, such as 4-cyanovalerimide, 2-methyl-4-cyanobutyrimide, 4-cyanovaleric acid, 2-methyl-4-cyanobutyric acid, 3-cyanovalerimide, 2-ethyl-3-cyanopropionimide, 3-cyanovaleic acid, and 2-ethyl-3-cyanopropionic acid, in the vapor phase at temperatures of 200.degree. to 600.degree. C. in the presence of an acidic solid catalyst, such as acidic molecular sieves, acidic clays, bridged or pillared clays, bulk oxides, and acidic phosphates.

Abstract: Carbocyclic/aliphatic ethers, for example anisole, quaicol, guaethol, p-methoxyphenol and ethylene dioxybenzene, are selectively prepared, in good yield, by reacting a phenolic compound, for example a phenol, hydroquinone, pyrocatechin, naphthol, or the like, with an alcohol, for example methanol, ethanol, isopropanol, ethylene glycol, etc., in gaseous phase, in the presence of a catalytically effective amount of a trivalent rare earth metal orthophosphate, for example a lanthanum, cerium or samarium orthophosphate, optionally doped with an alkali or alkaline earth metal, preferably cesium.

Abstract: The present invention relates to a process for the preparation of carboxylic acids by controlled oxidation of the corresponding alkanes.The process according to the invention consists in reacting the alkane with a source of oxygen, the reaction being performed in the presence of a catalyst in which the active phase is based on vanadium, titanium, molybdenum, phosphorus and oxygen.

Abstract: Needle-shaped solid crystallites of specific LaCeTb phosphates, well suited for the production of green phosphors therefrom, are essentially pure white in color after calcination at 900.degree. C. and have the formula (I):La.sub.x Ce.sub.y Tb.sub.(1-x-y) PO.sub.4 (I)in which x and y are numbers, with x ranging from 0.4 to 0.6 and x+y being greater than 0.8.

Abstract: Novel cerium/lanthanum/terbium (LaCeTb) mixed phosphates, especially useful in luminescence for the production of green phosphors, have the formula (I):La.sub.x Ce.sub.y Tb.sub.1-x-y PO.sub.4in which X ranges from 0.4 to 0.6 and x+y is greater than 0.8, display a lightness (L.sup.*) of greater than 98% after calcination at a temperature above 700.degree. C. in air, and the cerium (IV) and/or terbium (IV) contents of which are very low, even after calcination in air at a temperature above 500.degree. C.

Abstract: Novel cerium/lanthanum/terbium (LaCeTb) mixed phosphates, especially useful in luminescence for the production of green phosphors, have the formula (I):La.sub.x Ce.sub.y Tb.sub.1-x-y PO.sub.4in which x ranges from 0.4 to 0.6 and x+y is greater than 0.8, display a lightness (L*) of greater than 98% after calcination at a temperature above 700.degree. C. in air, and the cerium (IV) and/or terbium (IV) contents of which are very low, even after calcination in air at a temperature above 500.degree. C.

Abstract: Needle-shaped solid crystallites of specific LaCeTb phosphates, well suited for the production of green phosphors therefrom, are essentially pure white in color after calcination at 900.degree. C. and have the formula (I):La.sub.x Ce.sub.y Tb.sub.(1-x-y) PO.sub.4 (I)in which x and y are numbers, with x ranging from 0.4 to 0.6 and x+y being greater than 0.8.