A microporous metal-organic framework for gas chromatographic separation of alkanes

Microporous metal-organic frameworks (MOF), new types of zeolite analogues, have been paid extensive attention because of their potential applications in gas storage, separation, and catalysis. The modular nature to construct such microporous materials has lead to a variety of microporous MOF whose pore size and shape can be systematically tuned by a judicious choice of metal-containing secondary building units and/or bridging linkers, and by making use of framework interpenetration or interwoven. Their selective adsorption and high thermal stability make them potentially useful for alkane separation which, however, has still not been developed. In petroleum industry, separation of alkane isomers is a very important process and some narrow-pore zeolites have been applied to sieve linear alkanes from the branched alkanes to boost octane ratings in gasoline. To match the alkane molecule sizes, a microporous MOF, Zn (BDC)(4,4′-Bipy)0.5 (MOF-508), was designed and synthesized to have a alpha-Po net whose pore has been tuned by double interpenetration to have one-dimensional small channel of about 4 × 4 Å. The first example of microporous MOF for its highly selective gas chromatographic separation of alkanes are presented. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).