Aspects of the present invention relate to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO.sub.2 and X.sub.2O.sub.3, wherein said process comprises the steps of: (1) providing a mixture comprising one or more sources for YO.sub.2, one or more sources for X.sub.2O.sub.3, and one or more tetraalkylammonium cation R.sup.1R.sup.2R.sup.3R.sup.4N.sup.+-containing compounds as structure directing agent; (2) crystallizing the mixture obtained in step (1) for obtaining a zeolitic material having a CHA-type framework structure;
wherein Y is a tetravalent element and X is a trivalent element,
wherein R.sup.1, R.sup.2, and R.sup.3 independently from one another stand for alkyl,
wherein R.sup.4 stands for cycloalkyl, and
wherein the mixture provided in step (1) does not contain any substantial amount of a source for Z.sub.2O.sub.5, wherein Z is P, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.

The invention relates to the production of aromatic hydrocarbon by the conversion of a feed comprising C.sub.2+ non-aromatic hydrocarbon, e.g., natural gas. The invention is particularly useful in converting natural gas to liquid-phase aromatic hydrocarbon, which can be more easily transported away from remote natural gas production facilities. The conversion is carried out in the presence of a dehydrocyclization catalyst comprising dehydrogenation and molecular sieve components. The dehydrocyclization catalyst has an average residence time of 90 seconds or less.

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.

The present disclosure is directed to an emission treatment system for oxidation of hydrocarbons and carbon monoxide and for NO.sub.x abatement in an exhaust stream of a lean burn engine, the emission treatment system including a low-temperature NO.sub.x adsorber (LT-NA) that includes a molecular sieve impregnated with at least one PGM component positioned in fluid communication with the exhaust stream; and an oxidation catalyst that includes a refractory metal oxide support containing manganese impregnated with platinum positioned in fluid communication with the exhaust stream, each of the LT-NA and the oxidation catalyst being disposed on a substrate. The invention provides a catalyst article combining an oxidation catalyst with a LT-NA and a related method of treatment of an exhaust gas.

The present disclosure is directed to an emission treatment system for oxidation of hydrocarbons and carbon monoxide and for NO.sub.x abatement in an exhaust stream of a lean burn engine, the emission treatment system including a low-temperature NO.sub.x adsorber (LT-NA) that includes a molecular sieve impregnated with at least one PGM component positioned in fluid communication with the exhaust stream; and an oxidation catalyst that includes a refractory metal oxide support containing manganese impregnated with platinum positioned in fluid communication with the exhaust stream, each of the LT-NA and the oxidation catalyst being disposed on a substrate. The invention provides a catalyst article combining an oxidation catalyst with a LT-NA and a related method of treatment of an exhaust gas.

The present disclosure is directed to Low Temperature NOx-Absorber (LT-NA) catalyst compositions, catalyst articles, and an emission treatment system for treating an exhaust gas, each including the LT-NA catalyst compositions. Further provided are methods for reducing a NO.sub.x level in an exhaust gas stream using the catalyst article. In particular, the LT-NA compositions include a zeolite containing a first metal component including palladium and a second metal component which is an alkaline earth metal component, an oxide of an alkaline earth metal component, a rare earth metal component, an oxide of a rare earth metal component, or a combination thereof. The LT-NA compositions exhibit increased low temperature NO.sub.x adsorption capacity and enhanced hydrothermal stability.

The present disclosure is directed to Low Temperature NOx-Absorber (LT-NA) catalyst compositions, catalyst articles, and an emission treatment system for treating an exhaust gas, each including the LT-NA catalyst compositions. Further provided are methods for reducing a NO.sub.x level in an exhaust gas stream using the catalyst article. In particular, the LT-NA compositions include a zeolite containing a first metal component including palladium and a second metal component which is an alkaline earth metal component, an oxide of an alkaline earth metal component, a rare earth metal component, an oxide of a rare earth metal component, or a combination thereof. The LT-NA compositions exhibit increased low temperature NO.sub.x adsorption capacity and enhanced hydrothermal stability.

The present invention relates to a zeolite comprising zinc and platinum, and to a catalyst containing said zeolites.

The present invention relates to a zeolite comprising zinc and platinum, and to a catalyst containing said zeolites.

An oxidation catalyst composite, methods, and systems for the treatment of exhaust gas emissions from a diesel engine are described. More particularly, described is an oxidation catalyst composite including a first oxidation component comprising a first refractory metal oxide support, palladium (Pd) and platinum (Pt); a NO.sub.x storage component comprising one or more of alumina, silica, titania, ceria, or manganese; and a second oxidation component comprising a second refractory metal oxide, a zeolite, and Pt. The oxidation catalyst composite is sulfur tolerant, adsorbs NO.sub.x and thermally releases the stored NO.sub.x at temperature less than 350 C.