Rhone-poulenc Chimie

Eric Garcin

Francis Luck

William Fogel

Raymond Surantyn

Michel Costantini

Michel Gubelmann

Jean-Michel Popa

Eric Quemere

Claude-Bernard Cartier

Impure gas streams containing contaminating amounts of NO.sub.x, e.g., automotive exhaust fumes and industrial waste gases, are purified by contacting same, in the presence of ammonia, at an elevated temperature, with a catalyst composition which comprises an inorganic oxide support substrate having a catalytically effective amount of a metal oxide active phase deposited thereon, such support substrate comprising at least one alumina, aluminate, titanium dioxide and/or zirconium dioxide and such catalytically active phase comprising at least one vanadium oxide and/or molybdenum oxide and/or tungsten oxide, the surface of the support substrate being chemically bonded to the metals V and/or Mo and/or W and the catalyst being devoid of V.sub.2 O.sub.3 and/or MoO.sub.3 and/or WO.sub.3 crystalline phases, and thereby selectively reducing such NO.sub.x values while minimizing the formation of N.sub.2 O.

V/Mo/W catalysts for the selective reduction of nitrogen oxides

Phosphomagnesia compositions settable into improvedly water-insensitive cements that retain their mechanical properties comprise an intimate admixture of (i) a binder phase including (a) at least one phosphorous compound (P.sub.2 O.sub.5 or derivative/precursor thereof) and (b) at least one magnesium compound reactive therewith in the presence of water, (ii) an effective amount of cementitious aggregate, and (iii) a water sensitivity-reducing amount of at least one silicone homogeneously distributed therethrough.

Process for producing phosphomagnesia cements having reduced sensitivity

Phosphomagnesia cements having reduced sensitivity to water

Alumina-based adsorbents containing at least one compound of an alkali or alkaline earth metal, wherein the alkali or alkaline earth metal values are present in an amount ranging from 15 mmole to 100 mmole per 100 g of alumina, are useful for the adsorptive purification of polyolefins prepared by the polymerization of olefins in the presence of a metallic coordination catalyst, to remove contaminating catalyst metal values therefrom with but negligible monomer/solvent isomerization.

Alumina-based adsorbents for the purification of polyolefins

The phenols and phenol ethers, e.g., phenol itself, are effectively hydroxylated by reacting hydrogen peroxide therewith, in the presence of a catalytically effective amount of titanium dioxide.

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Lyon, France

Eric Garcin