The ITQ-37 mesoporous chiral zeolite
2009 (English)In: Nature, ISSN 0028-0836, Vol. 458, no 7242, 1154-1157 p.Article in journal (Refereed) Published
The synthesis of crystalline molecular sieves with pore dimensions that fill the gap between microporous and mesoporous materials is a matter of fundamental and industrial interest(1-3). The preparation of zeolitic materials with extralarge pores and chiral frameworks would permit many new applications. Two important steps in this direction include the synthesis(4) of ITQ-33, a stable zeolite with 18 x 10 x 10 ring windows, and the synthesis(5) of SU-32, which has an intrinsically chiral zeolite structure and where each crystal exhibits only one handedness. Here we present a germanosilicate zeolite (ITQ-37) with extralarge 30-ring windows. Its structure was determined by combining selected area electron diffraction ( SAED) and powder X-ray diffraction (PXRD) in a charge-flipping algorithm(6). The framework follows the SrSi2 (srs) minimal net(7) and forms two unique cavities, each of which is connected to three other cavities to form a gyroidal channel system. These cavities comprise the enantiomorphous srs net of the framework. ITQ-37 is the first chiral zeolite with one single gyroidal channel. It has the lowest framework density (10.3 T atoms per 1,000 angstrom(3)) of all existing 4-coordinated crystalline oxide frameworks, and the pore volume of the corresponding silica polymorph would be 0.38 cm(3) g(-1).
Place, publisher, year, edition, pages
2009. Vol. 458, no 7242, 1154-1157 p.
IdentifiersURN: urn:nbn:se:su:diva-31943DOI: 10.1038/nature07957ISI: 000265754600044ISBN: 0028-0836OAI: oai:DiVA.org:su-31943DiVA: diva2:279048