Abstract: Normal methods of impregnating silicalite with noble metals leads either to metal loadings under 8% at high (greater than 60%) dispersion or loading of over 8% noble metal at low dispersion. To obtain silicalite impregnated with a noble metal at more than 8 weight percent loading and with at least 60% dispersion it has been found necessary to pretreat the silicalite with a base and to impregnate the base treated silicalite with a noble metal compound in two stages separated by calcination. Platinized silicalite so prepared may be dispersed in a poly(tetrafluoroethylene) matrix and used as a fixed bed to catalyze isotopic exchange gaseous hydrogen and water vapor arising from a mass of liquid water flowing over the fixed catalyst bed.

Abstract: This invention relates to a method for catalytically reducing one or more nitrogen oxides from a gaseous stream containing one or more nitrogen oxides and one or more sulfur oxides which comprises contacting said gaseous stream and ammonia with a microporous non-zeolitic molecular sieve composition at effective reduction conditions, wherein said microporous non-zeolitic molecular sieve composition is (i) optionally acid treated with an inorganic or organic acid, (ii) hydrogen-forming cation exchanged and (iii) optionally metal cation exchanged, prior to said contacting in said method.

Abstract: This invention relates to a method for catalytically reducing one or more nitrogen oxides from a gaseous stream containing one or more nitrogen oxides and optionally one or more sulfur oxides which comprises contacting said gaseous stream and ammonia with a microporous molecular sieve composition at effective reduction conditions in which the amount of ammonia in said method is excessive over the stoichiometric amount necessary for catalytically reducing one or more nitrogen oxides from said gaseous stream, wherein said microporous molecular sieve composition is (i) optionally acid treated with an inorganic or organic acid, (ii) hydrogen-forming cation exchanged and (iii) optionally metal cation exchanged, prior to said contacting in said method, and wherein at least a portion of excessive ammonia in said method is oxidized without substantial adverse effect on catalytically reducing one or more nitrogen oxides from said gaseous stream.

Abstract: Carbon monoxide-containing gas streams are passed over a catalyst to deposit a surface layer of active surface carbon thereon essentially without the formation of inactive coke. The active carbon is thereafter reacted with steam or hydrogen to form methane. Enhanced catalyst stability for long term, cyclic operation is obtained by the incorporation of an alkali or alkaline earth dopant in a silica binding agent added to the catalyst-support additive composition.

Abstract: Carbon monoxide-containing gas streams are passed over a catalyst capable of catalyzing the disproportionation of carbon monoxide so as to deposit a surface layer of active surface carbon on the catalyst essentially without formation of inactive coke thereon. The surface layer is contacted with steam and is thus converted to methane and CO.sub.2, from which a relatively pure methane product may be obtained. For practical commercial operations utilizing the two-step process of the invention of a cyclic basis, nickel, cobalt, ruthenium, thenium and alloys thereof are especially prepared for use in a metal state, with CO disproportionation being carried out at temperatures up to about 350.degree. C. and with the conversion of active surface carbon to methane being carried out by reaction with steam. The catalyst is employed in such cyclic operations without the necessity for employing a regeneration step as part of each processing cycle.