title: Design of zeolite by inverse sigma transformation.
abstract: Although the search for new zeolites has traditionally been based on trial and error, more rational methods are now available. The theoretical concept of inverse σ transformation of a zeolite framework to generate a new structure by removal of a layer of framework atoms and contraction has for the first time been achieved experimentally. The reactivity of framework germanium atoms in strong mineral acid was exploited to selectively remove germanium-containing four-ring units from an UTL type germanosilicate zeolite. Annealing of the leached framework through calcination led to the new all-silica COK-14 zeolite with intersecting 12- and 10-membered ring channel systems. An intermediate stage of this inverse σ transformation with dislodged germanate four-rings still residing in the pores could be demonstrated. Inverse σ transformation involving elimination of germanium-containing structural units opens perspectives for the synthesis of many more zeolites.
authors.affiliation: Center for Surface Chemistry and Catalysis, KU Leuven, 3001 Heverlee, Belgium.
authors.forename: Elke
authors.initials: E
authors.lastname: Verheyen
authors.forename: Lennart
authors.initials: L
authors.lastname: Joos
authors.forename: Kristof
authors.initials: K
authors.lastname: Van Havenbergh
authors.forename: Eric
authors.initials: E
authors.lastname: Breynaert
authors.forename: Nataliia
authors.initials: N
authors.lastname: Kasian
authors.forename: Elena
authors.initials: E
authors.lastname: Gobechiya
authors.forename: Kristof
authors.initials: K
authors.lastname: Houthoofd
authors.forename: Charlotte
authors.initials: C
authors.lastname: Martineau
authors.forename: Manuel
authors.initials: M
authors.lastname: Hinterstein
authors.forename: Francis
authors.initials: F
authors.lastname: Taulelle
authors.forename: Veronique
authors.initials: V
authors.lastname: Van Speybroeck
authors.forename: Michel
authors.initials: M
authors.lastname: Waroquier
authors.forename: Sara
authors.initials: S
authors.lastname: Bals
authors.forename: Gustaaf
authors.initials: G
authors.lastname: Van Tendeloo
authors.forename: Christine E A
authors.initials: CE
authors.lastname: Kirschhock
authors.forename: Johan A
authors.initials: JA
authors.lastname: Martens