Abstract
Adsorption of n-alkanes from pentane to decane (C5-C10) in zeolites LTA (ITQ-29 and 5A) and faujasite (FAU, dealuminated high-silica Na-FAU, NaY, and NaX) as well as branched hexane isomers in FAU was investigated by means of experimental quasi-equilibrated temperature-programmed desorption and adsorption (QE-TPDA) and theoretical Monte Carlo molecular simulations. A novel QE-TPDA method of studying porosity provided high-quality desorption-adsorption profiles and adsorption isobars of hydrocarbons. A unique two-step adsorption of long-chain alkanes in LTA zeolites was observed and explained in detail based on the results of the theoretical calculations. Although adsorption of n-alkanes in FAU is a one-step process, it also does not occur in a uniform manner because of strong lateral interactions at high loadings. We also investigated the influence of cation content on adsorption equilibrium and energetics for the studied adsorbent-adsorbate systems, finding a nonlinear relation between heat of adsorption and content of cations in FAU. Investigations on packing of the molecules of n-alkanes were also performed, revealing relations between chain length of the probe molecule and sorption capacity of the studied materials.
| Original language | English |
|---|---|
| Pages (from-to) | 29665-29678 |
| Number of pages | 14 |
| Journal | Journal of Physical Chemistry C |
| Volume | 123 |
| Issue number | 49 |
| DOIs | |
| Publication status | Published - 12 Dec 2019 |
| Externally published | Yes |
Funding
This work was supported by the National Science Centre, Poland, grant no. 2016/21/N/ST5/00868, and from Spanish Ministerio de Economía y Competitividad (CTQ2016-80206-P), and by the Andalucía Region (FQM-1851). The authors also thank C3UPO for the HPC support. The authors obtained financial resources as part of financing the doctoral scholarship from the National Science Center, Poland, grant no. 2018/28/T/ST5/00274.