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 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.

Disclosed herein are modified zeolites and methods for making modified zeolites. In one or more embodiments disclosed herein, a modified zeolite may include a microporous framework including a plurality of micropores having diameters of less than or equal to 2 nm. The microporous framework may include at least silicon atoms and oxygen atoms. The modified zeolite may further include organometallic moieties each bonded to bridging oxygen atoms. The organometallic moieties may include a platinum atom. The platinum atom may be bonded to a bridging oxygen atom, and the bridging oxygen atom may bridge the platinum atom of the organometallic moiety and a silicon atom of the microporous framework.

Embodiments of the present disclosure relate to zeolites and method for making such zeolites. According to embodiments disclosed herein, a zeolite may have a microporous framework including a plurality of micropores having diameters of less than or equal to 2 nm and a plurality of mesopores having diameters of greater than 2 nm and less than or equal to 50 nm. The microporous framework may include an MFI framework type. The microporous framework may include silicon atoms, aluminum atoms, oxygen atoms, and transition metal atoms. The transition metal atoms may be dispersed throughout the entire microporous framework.

A method for aromatization of light alkanes, comprising: subjecting the light alkanes to dehydroaromatization reaction in the presence of aromatization catalysts including carriers and metal active components supported on the carriers, the metal active components include platinum, the carriers include zeolites and binders, and at least 80 wt. % of the metal active components are distributed on the zeolites. The method of the present disclosure may increase yield of the target product—aromatic hydrocarbons, and the regenerated catalyst can still maintain high catalytic performance. In addition, the method of the present disclosure can meet the requirements of industrial applications.

A process for producing methyl tert-butyl ether (MTBE) comprising introducing a butane feed stream (n-butane, i-butane) and hydrogen to a hydrogenolysis reactor comprising a hydrogenolysis catalyst to produce a hydrogenolysis product stream comprising hydrogen, methane, ethane, propane, i-butane, and optionally n-butane; separating the hydrogenolysis product stream into a first hydrogen-containing stream, an optional methane stream, a C.sub.2 to C.sub.3 gas stream (ethane, propane), and a butane stream (i-butane, optionally n-butane); feeding the butane stream to a dehydrogenation reactor to produce a dehydrogenation product stream, wherein the dehydrogenation reactor comprises a dehydrogenation catalyst, and wherein the dehydrogenation product stream comprises hydrogen, i-butane, and isobutylene; and feeding the dehydrogenation product stream and methanol to an etherification unit to produce an unreacted methanol stream, an unreacted isobutylene stream, and an MTBE stream.

A process for producing methyl tert-butyl ether (MTBE) comprising introducing a butane feed stream (n-butane, i-butane) and hydrogen to a hydrogenolysis reactor comprising a hydrogenolysis catalyst to produce a hydrogenolysis product stream comprising hydrogen, methane, ethane, propane, i-butane, and optionally n-butane; separating the hydrogenolysis product stream into a first hydrogen-containing stream, an optional methane stream, a C.sub.2 to C.sub.3 gas stream (ethane, propane), and a butane stream (i-butane, optionally n-butane); feeding the butane stream to a dehydrogenation reactor to produce a dehydrogenation product stream, wherein the dehydrogenation reactor comprises a dehydrogenation catalyst, and wherein the dehydrogenation product stream comprises hydrogen, i-butane, and isobutylene; and feeding the dehydrogenation product stream and methanol to an etherification unit to produce an unreacted methanol stream, an unreacted isobutylene stream, and an MTBE stream.

Method of making BTX compounds including benzene, toluene, and xylene, including feeding heavy reformate to a reactor containing a composite zeolite catalyst. The composite zeolite catalyst includes a mixture of layered mordenite (MOR-L) comprising a layered or rod-type morphology with a layer thickness less than 30 nm and ZSM-5. The MOR-L, the ZSM-5, or both include one or more impregnated metals. The method further includes producing the BTX compounds by simultaneously performing transalkylation and dealkylation of the heavy reformate in the reactor. The composite zeolite catalyst is able to simultaneously catalyze both the transalkylation and dealkylation reactions.

Method of making BTX compounds including benzene, toluene, and xylene, including feeding heavy reformate to a reactor containing a composite zeolite catalyst. The composite zeolite catalyst includes a mixture of layered mordenite (MOR-L) comprising a layered or rod-type morphology with a layer thickness less than 30 nm and ZSM-5. The MOR-L, the ZSM-5, or both include one or more impregnated metals. The method further includes producing the BTX compounds by simultaneously performing transalkylation and dealkylation of the heavy reformate in the reactor. The composite zeolite catalyst is able to simultaneously catalyze both the transalkylation and dealkylation reactions.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.