145 results about "Chabazite" patented technology

A crystalline material substantially free of framework phosphorus and comprising a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship:(n)X2O3:YO2,wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to about 0.5. The material exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.

The synthesis of a crystalline material, in particular a high silica zeolite, having a chabazite-type framework is aided by the addition to the synthesis mixture of seeds of an AEI framework-type material. The chabazite-type product has a relatively small crystal size and exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.

The synthesis of a crystalline material, in particular, a high silica zeolite, comprising a chabazite-type framework molecular sieve is conducted in the presence of an organic directing agent having the formula:[R1R2R3N—R4]+Q−wherein R1 and R2 are independently selected from hydrocarbyl groups and hydroxy-substituted hydrocarbyl groups having from 1 to 3 carbon atoms, provided that R1 and R2 may be joined to form a nitrogen-containing heterocyclic structure, R3 is an alkyl group having 2 to 4 carbon atoms and R4 is selected from a 4- to 8-membered cycloalkyl group, optionally, substituted by 1 to 3 alkyl groups each having from 1 to 3 carbon atoms; and a 4- to 8-membered heterocyclic group having from 1 to 3 heteroatoms, said heterocyclic group being, optionally, substituted by 1 to 3 alkyl groups each having from 1 to 3 carbon atoms and the or each heteroatom in said heterocyclic group being selected from the group consisting of O, N, and S, or R3 and R4 are hydrocarbyl groups having from 1 to 3 carbon atoms joined to form a nitrogen-containing heterocyclic structure; and Q− is a anion.

The synthesis of a crystalline aluminophosphate or silicoaluminophosphate molecular sieve having a chabazite-type framework type is conducted in the presence of an organic directing agent having the formula (I)[R1R2R3N—R4]+X−  (I)wherein R1, R2 and R3 are independently selected from the group consisting of alkyl groups having from 1 to 3 carbon atoms and hydroxyalkyl groups having from 1 to 3 carbon atoms; R4 is selected from the group consisting of 4- to 8-membered cycloalkyl groups, optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms; 4- to 8-membered heterocyclic groups having from 1 to 3 heteroatoms, said heterocyclic groups being optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms and the heteroatoms in said heterocyclic groups being selected from the group consisting of O, N, and S; and aromatic groups optionally substituted by 1 to 3 alkyl groups, said alkyl groups having from 1 to 3 carbon atoms; and X− is an anion.

A catalyst composition includes a heterobimetallic zeolite characterized by a chabazite structure loaded with copper ions and at least one trivalent metal ion other than Al3+. The catalyst composition decreases NOx emissions in diesel exhaust and is suitable for operation in a catalytic converter.

A chabazite (CHA) zeolite catalyst containing iron and copper is provided as an SCR catalyst for reducing nitrogen oxides (NOx) from vehicle engine exhausts. The catalyst is formed by incorporating iron during synthesis of the chabazite zeolite, followed by incorporating copper in an ion-exchange step. The resulting catalyst reduces nitrogen oxides over a wide range of temperatures from about 200° C. to about 700° C.