Abstract
The joint transport of linear C4-C6 alkanes and benzene has been studied over nanosized H-ZSM5 crystals by fast-time-resolved infrared spectroscopy. The internal and external concentration profiles during the coadsorption of alkanes and aromatics were directly monitored for a zeolite in which transport is controlled by the pore entrance step. The detailed kinetic analysis revealed a decrease in the adsorption and pore entrance rates of light hydrocarbon molecules upon addition of benzene by about 10-30%. This was caused by both a reduction in the rate constants and in the coverage at the external surface. On the other hand the apparent diffusion coefficient of benzene decreased up to 80% in comparison to the pure component. This decrease is attributed to a competitive adsorption at sites near the pore mouth. The extent increased with decreasing chain length of the cosorbed alkane, which corresponds to a simultaneous decrease in occupation of pore mouth sites by light hydrocarbons.
Original language | English |
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Pages (from-to) | 8424-8434 |
Number of pages | 11 |
Journal | Journal of Physical Chemistry C |
Volume | 118 |
Issue number | 16 |
DOIs | |
State | Published - 24 Apr 2014 |