| 摘要 |
A porous crystalline material is described having the chabazite framework type and having a composition involving the molar relationship: <?in-line-formulae description="In-line Formulae" end="lead"?>X<SUB>2</SUB>O<SUB>3</SUB>:(n)YO<SUB>2</SUB>,<?in-line-formulae description="In-line Formulae" end="tail"?> wherein X is a trivalent element, such as aluminum, boron, iron, indium, and/or gallium; Y is a tetravalent element such as silicon, tin, titanium and/or germanium; and n is greater than 100 and typically greater than 200, such as about 300 to about 4000, for example from about 400 to about 1200. The material is synthesized in a fluoride medium and exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.
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