Engelhard titanium silicate ETS-10 is a microporous crystalline solid consisting mainly of an assemblage of titanium oxide (TiO2) and silicate (SiO2). The pore size in ETS-10 is uniform and similar in dimension to large-pore classical zeolites. It is also known to have high thermal stability. Metal-organic frameworks (MOFs) are another group of microporous structures made up of organic building blocks (linkers) that are coordinated with metal ions acting as joints. Therefore, compared to conventional zeolites, these metal-organic structures can give various pore properties and sizes by using different metal ions and organic linkers. A variety of MOF known, denoted as Cu-BTC (copper (II) benzene-1,3,5-tricarboxylate), has been synthesized in our laboratory. Synthesis of ETS-10 is also in progress.
Despite the promise of MOF and ETS-10 as potential new adsorbents for gas separation applications, only limited equilibrium studies on these materials are available in the literature. Transport behavior of gases in the micropores of these adsorbents is practically unknown.
We have, therefore, undertaken a program in our laboratory to systematically study adsorption and diffusion of gases in ETS-10, Cu-BTC and a few other varieties of MOF. Gases such as CO2, O2, N2, H2S, SO2, C2H4, C3H6, C2H6 and C3H8 have been shortlisted for their industrial relevance in CO2 capture and concentration, natural gas upgrading, air separation and olefin/paraffin separation. Progress made till the time of the conference will be covered in the proposed poster presentation.