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.

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.

To be able to produce an SCR catalyst (2), in particular one having a zeolite fraction (Z) as catalytically active fraction, in a reliable process and at the same time achieve good catalytic activity of the catalyst (2), an inorganic binder fraction (B) which is catalytically inactive in the starting state and has been treated to develop catalytic activity is mixed into a catalyst composition (4). The inorganic binder component for the binder fraction (B) is, in the starting state, preferably porous particles (10), in particular diatomaceous earth, which display mesoporosity. To effect catalytic activation, the individual particles (10) are either coated with a catalytically active layer (12) or transformed into a catalytically active zeolite (14) with maintenance of the mesoporosity.

An ammonia slip control catalyst having a layer containing perovskite and a separate layer containing an SCR catalyst is described. The ammonia slip catalyst can have two stacked layers, with the top overlayer containing an SCR catalyst, and the bottom layer containing a perovskite. The ammonia slip catalyst can alternatively be arranged in sequential layers, with the SCR catalyst being upstream in the flow of exhaust gas relative to the perovskite. A system comprising the ammonia slip catalyst upstream of a PGM-containing ammonia oxidation catalyst and methods of using the system are described. The system allows for high ammonia oxidation with good nitrogen selectivity. Methods of making and using the ammonia slip catalyst to reduce ammonia slip and selectively convert ammonia to N.sub.2 are described.

An ammonia slip control catalyst having a layer containing perovskite and a separate layer containing an SCR catalyst is described. The ammonia slip catalyst can have two stacked layers, with the top overlayer containing an SCR catalyst, and the bottom layer containing a perovskite. The ammonia slip catalyst can alternatively be arranged in sequential layers, with the SCR catalyst being upstream in the flow of exhaust gas relative to the perovskite. A system comprising the ammonia slip catalyst upstream of a PGM-containing ammonia oxidation catalyst and methods of using the system are described. The system allows for high ammonia oxidation with good nitrogen selectivity. Methods of making and using the ammonia slip catalyst to reduce ammonia slip and selectively convert ammonia to N.sub.2 are described.

Provided is a catalyst for the selective reduction of NOx comprising a two molecular sieve materials having a CHA structure, wherein the first molecular sieve has a mean crystal size of about 0.01 to 1 m and the second molecular sieve has a mean crystal size of about 1-5 m, and wherein the first molecular sieve contains a first extra-framework metal, the second molecular sieve contains a second extra-framework metal, and wherein said first and second extra-framework metals are independently selected from the group consisting of cesium, copper, nickel, zinc, iron, tin, tungsten, molybdenum, cobalt, bismuth, titanium, zirconium, antimony, manganese, chromium, vanadium, niobium, and combinations thereof.

The invention relates to catalysts and their use in processes for dehydrocyclization of light paraffinic hydrocarbon feedstock to higher-value hydrocarbon, such as aromatic hydrocarbon, to dehydrocyclization catalysts useful in such processes, and to the methods of making such catalysts. One of more of the dehydrocyclization catalysts comprising a crystalline aluminosilicate zeolite having a constraint index of less than or equal to about 12, at least one Group 3 to Group 13 metal of the IUPAC Periodic Table and phosphorous.

The invention relates to producing aromatic hydrocarbon by aromatization of non-aromatic hydrocarbon, including feed pretreatment, aromatization of the aromatization feed's C.sub.2 hydrocarbon and C.sub.3+ non-aromatic hydrocarbon, and recovery of an aromatic product. The invention also relates to modules for carrying out the pretreatment, aromatization, and recovery, and also modules for auxiliary function such as power generation.

The invention relates to the conversion of paraffinic hydrocarbon to oligomers of greater molecular weight and/or to aromatic hydrocarbon. The invention also relates to equipment and materials useful in such conversion, and to the use of such conversion for, e.g., natural gas upgrading. Corresponding olefinic hydrocarbon is produced from the paraffinic hydrocarbon in the presence of a dehydrogenation catalyst containing a catalytically active carbonaceous component. The corresponding olefinic hydrocarbon is then converted by oligomerization and/or dehydrocyclization in the presence of at least one molecular sieve catalyst.

A catalyst for the carbonylation of dimethyl ether to methyl acetate. The catalyst comprises a zeolite, such as a mordenite zeolite, at least one Group IB metal, such as copper, and/or at least one Group VIII metal, such as iron, and at least one Group IIB metal, such as zinc. Such a catalyst with combined metals provides enhanced catalytic activity, improved stability, and improved selectivity to methyl acetate, and does not require a halogen promoter, as compared to a metal-free or copper only zeolite.