Length dependency of hydrocarbon adsorption on nanostacked MFI zeolite by tracer chromatography

摘要

The adsorption behaviour of a series of n-alkanes, alkyl aromatics, and alcohols on different morphology TS-1 (Titanium Silicalite-1) zeolites were studied using the tracer chromatographic technique at the temperatures in the 473-573 K range. The adsorption studies were performed with nanostacked TS-1 (NSTS-1) and nonstacked TS-1 (TS-1). The NSTS-1 exhibits the stacked morphologies due to dehydration of hydroxyl groups on the external surface of crystallites through the selective absorption of microwave onto Ti species. The Henry constants and adsorption enthalpies have been estimated. The straight channels of the NSTS-1 having long pathway gave different selectivity in the Henry constants of long-chained hydrocarbons due to strong interaction with straight channel in stacked morphology, which gave the larger Henry constant than the TS-1. The Henry constants linearly increase with the increasing carbon number since more interactions are possible for long chains.