Abstract: A metal-doped or metal-exchanged zeolite is disclosed, wherein the doping metal is present in the zeolite in the form of individual atoms i.e. as monomeric and/or dimeric species. Further, a process for the preparation of such a metal-doped or metal-exchanged zeolite is disclosed. The metal-doped zeolites are useful, in particular, as catalysts for the reduction of nitrogen oxides.

Abstract: A metal-doped or metal-exchanged zeolite is disclosed, wherein the doping metal is present in the zeolite in the form of individual atoms i.e. as monomeric and/or dimeric species. Further, a process for the preparation of such a metal-doped or metal-exchanged zeolite is disclosed. The metal-doped zeolites are useful, in particular, as catalysts for the reduction of nitrogen oxides.

Abstract: The present invention relates to a metal-doped or metal-exchanged zeolite, respectively, wherein the doping metal is present in the zeolite in the form of individual atoms i.e. as monomeric and/or dimeric species. The invention further relates to a process for the preparation of such a metal-exchanged zeolite. Said metal-doped zeolites are useful, in particular, for the reduction of nitrogen oxides.

Abstract: A molecular sieve is made by reacting an ammonium-exchanged low silica X-type zeolite precursor with lithium hydroxide, at a pressure of about 200 millibar or less, and at a temperature of about 60° or less. The zeolite precursor is preferably an X-type zeolite, in which the silicon to aluminum atomic ratio is less than about 1.02. The lithium is provided in an amount which is stoichiometrically equivalent to the amount of ammonium present. The molecular sieve is especially useful in separating air into components using PSA or VPSA processes, and has improved productivity and yield as compared with materials of the prior art. The advantages of the molecular sieve enable it to be provided in the form of beads having relatively large diameter, which reduces the pressure drop across the adsorber bed, and reduces required energy consumption.

Abstract: Zeolites exchanged with lithium ions and, optionally, with polyvalent cations are prepared by ion-exchanging a sodium-containing zeolite, a potassium-containing zeolite or a sodium- and potassium-containing zeolite with ammonium ions, thereby replacing the sodium and/or potassium ions with ammonium ions, and then reacting the ammonium ion-exchanged zeolite with a water-soluble lithium compound under conditions which result in the removal of ammonia from the reaction zone. Polyvalent ions, which may be present in the zeolite undergoing ion-exchange, will not be substantially replaced by the ammonium or lithium ions.