A passive NO.sub.x adsorber is disclosed. The passive NO.sub.x adsorber is effective to adsorb NO.sub.x at or below a low temperature and release the adsorbed NO.sub.x at temperatures above the low temperature. The passive NO.sub.x adsorber comprises a noble metal and a molecular sieve having an LTL Framework Type. The invention also includes an exhaust system comprising the passive NO.sub.x adsorber, and a method for treating exhaust gas from an internal combustion engine utilizing the passive NO.sub.x adsorber.

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir and Pt.

The present invention provides an iron-loaded aluminosilicate zeolite having a maximum pore opening defined by eight tetrahedral atoms and having the framework type CHA, AEI, AFX, ERI or LTA, wherein the iron (Fe) is present in a range of from about 0.5 to about 5.0 wt. % based on the total weight of the iron-loaded aluminosilicate zeolite, wherein an ultraviolet-visible absorbance spectrum of the iron-loaded synthetic aluminosilicate zeolite comprises a band at approximately 280 nm, wherein a ratio of an integral, peak-fitted ultraviolet-visible absorbance signal measured in arbitrary units (a.u.) for the band at approximately 280 nm to an integral peak-fitted ultraviolet-visible absorbance signal measured in arbitrary units (a.u.) for a band at approximately 340 nm is >about 2. The present invention further provides a method of making an metal-loaded aluminosilicate zeolite having a maximum pore opening defined by eight tetrahedral atoms from pre-existing aluminosilicate zeolite crystallites, wherein the metal is present in a range of from 0.5 to 5.0 wt. % based on the total weight of the metal-loaded aluminosilicate zeolite.

The present disclosure generally provides a catalyst composition comprising a zeolite containing iron and/or copper with a reduced amount of extra-framework aluminum. The catalyst composition is useful to catalyze the reduction of nitrogen oxides in exhaust gas in the presence of a reductant.

A faujasite-type zeolite has an IR spectrum in which the IR spectrum has an absorption band 1 including surface silanol groups and having a local maximum in a range from 3730 cm.sup.−1 to 3760 cm.sup.−1, and an absorption band 2 including acidic hydroxyl groups and having a local maximum in a range from 3550 cm.sup.−1 to 3700 cm.sup.−1, a ratio (h1/h2) of a peak height (h1) of the absorption band 1 to a peak height (h2) of the absorption band 2 being less than 1.2.

Catalyst composition which comprises a first zeolite having a BEA* framework type and a second zeolite having a MOR framework type and a mesopore surface area of greater than 30 m.sup.2/g is disclosed. These catalyst compositions are used to remove catalyst poisons from untreated feed streams having one or more impurities which cause deactivation of the downstream catalysts employed in hydrocarbon conversion processes, such as those that produce mono-alkylated aromatic compounds.

A method for isomerising dehydration in the presence of a specific catalyst, to produce at least one alkene, carried out on a feedstock containing a non-linear primary monoalcohol, where the catalyst includes a zeolite having a series of 8MR channels and a binder having certain pore volume, which catalyst is multilobe-shaped and has characteristics including certain average mesopore volume Vm, and mesopores having a certain diameter, an average certain macropore volume VM, the macropores having a certain diameter, and certain average micropore volume Vμ, the micropores having a certain diameter, and the catalyst has a certain exposed geometric area.

Provided is a beta-type zeolite which has a high catalytic activity and is not easily deactivated.

The beta-type zeolite of the invention has a substantially octahedral shape, has a Si/Al ratio of 5 or more, and is a proton-type zeolite. The Si/Al ratio is preferably 40 or more. This beta-type zeolite is preferably obtained by transforming a raw material beta-type zeolite synthesized without using a structure directing agent into an ammonium-type zeolite through ion exchange, then, exposing the beta-type zeolite to water vapor, and subjecting the exposed beta-type zeolite to an acid treatment.

The present invention is a process for dehydrating an alcohol to prepare a corresponding olefin, comprising: (a) providing a composition (A) comprising at least an alcohol having at least 2 carbon atoms, optionally water, optionally an inert component, in a dehydration unit, (b) placing the composition (A) into contact with an acidic catalyst in a reaction zone of said dehydration unit at conditions effective to dehydrate at least a portion of the alcohol to make a corresponding olefin, (c) recovering from said dehydration unit an effluent (B) comprising : at least an olefin, water, undesired by-products including aldehydes and light products, optionally unconverted alcohol(s), optionally the inert component,
wherein, said composition (A)-providing step (a) comprises adding an effective amount of one or more sulfur containing compound capable to reduce the undesired by-products by comparison with a non introduction of such sulfur containing compound.

The component introduced at step (a) can be chosen from the group consisting of thiols, sulfides, disulfides.

Catalysts including at least one microporous material (e.g., zeolite), an organosilica material binder, and at least one catalyst metal are provided herein. Methods of making the catalysts, preferably without surfactants and processes of using the catalysts, e.g., for aromatic hydrogenation, are also provided herein.