New Generation of Zeolite Materials for Environmental Applications

The influence of the morphology (microcrystals, nanocrystals, nanosponges and nanosheets) of MFI and∗BEA-type zeolites on their adsorption capacities and adsorption rate of n-hexane at 25 °C has been investigated. The capacity of n-hexane adsorption sensitive to micro- and mesopore volume is enhanced by the use of zeolite nanocrystals or hierarchical nanoporous materials (nanosheets and nanosponges). In the case of hierarchical zeolites MFI and∗BEA nanosponges, the n-hexane adsorption capacities reached values of about 790 and 693 mg/g, respectively, that are much higher than those in the corresponding microcrystals (130 and 103 mg/g, respectively). On the opposite the kinetics of n-hexane adsorption are slower in nanocrystals and hierarchical zeolites compared to big crystals, due to the lower crystallinity of the zeolitic material and the nature of the probe molecule.