CHED 947 |
| To efficiently separate CO2 from multi-species gas streams, sorbents must have high CO2 selectivity, and CO2 mobility within the materials must not be a limiting factor. Zeolites are one attractive option as sorbents. We present here our studies of non-isotropic diffusion of CO2/N2 mixtures onto three all-silica zeolites: silicalite, ITQ-3, and ITQ-7. Our results show that significant diffusion occurs in all cases, its details depend on the geometry of the materials, and the presence of CO2 affects the rate of diffusion of N2 but that the reverse is not true. We have also identified the preferred CO2 and N2 sites within these zeolites. We have shown that N2 and CO2 have the similar preferred sites, but that CO2 adsorbs much more strongly to them – which explains both the strong selectivity of these materials and the ability of CO2 to affect the rate of N2 diffusion through them. |
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Undergraduate Research Poster Session: Physical Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |