Structural studies of zeolitic materials with the NIST BT-1 neutron powder diffractometer

Abstract

Zeolites and related microporous materials have common and diverse applications. They are used as catalysts to produce gasoline and pharmaceuticals. For medical and industrial purposes, they are employed to separate N₂,O₂ and other gases. Formulated in household detergents, they remove the calcium ions that make water “hard.” Zeolites also sequester radioactive ions for environmental remediation. Many new applications, in areas such as batteries and fuel cells, are being investigated. Knowledge of structures has been quite important for developing new materials, as well as for tailoring properties of existing materials. Neutron powder diffraction is very valuable for this work, since single crystals are rarely available and because understanding the siting of light atoms is paramount. This review explores the advantages of the BT-1 neutron powder diffractometer for this work and presents recent work done using BT-1, primarily using examples in which neutron and X-ray work have been combined to produce results otherwise unattainable.