A COMPENDIUM OF POTENTIAL-ENERGY MAPS OF ZEOLITES AND MOLECULAR-SIEVES

We present potential maps of xenon in 20 different zeolites and molecu lar sieves. The potential maps reveal both the accessible pore volume and localized adsorption sites and so are important in understanding a dsorption and diffusion processes in nanoporous materials. We examine zeolites and molecular sieves with one-dimensional channel-like nanopo res (zeolite-Theta 1, AlPO4-5, zeolite-Omega, zoelite-L, ZSM-12, AlPO4 -8, and VPI-5), with two-dimensional intersecting channel-like nanopor es (ZSM-5 [silicalite], ZSM-11, ferrierite, mordenite, and zeolite-Bet a), and with three-dimensionally connected cagelike nanopores (zeolite -A, zeolite-Rho, zeolite-Y, sodalite, chabazite, cloverite, cation-poo r zeolite-A, and cation-rich zeolite-A). We report the fraction of por e volume accessible, the maximum energy well depth at the adsorption s ites, and the activation energy to move between sites. We note several examples of surprising similarities and differences between various m olecular sieves. In several instances, we show that these potential pr ofiles are relevant for other small Lennard-Jones-like molecules. By c omparison with published Monte Carlo and molecular dynamics simulation s, we show that the density distributions of adsorbates at low density are well predicted by the potential maps.