Synthesis of chabazite-containing molecular sieves and their use in the conversion of oxygenates to olefins

摘要

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.