129Xe NMR studies on carbon replicas of Y zeolite Original Research Article

129Xe NMR spectroscopy of xenon gas adsorbed on carbon replicas of Y zeolite was carried out at room temperature. Corresponding carbon replicas have been prepared by using ethylene and HY zeolite in a pressure reactor. Xenon gas was adsorbed on the resulting carbon samples in the pressure range from 40 to 150 kPa. The plot of the chemical shift against xenon pressure was found to be a linear function in the investigated pressure range from 40 to 150 kPa. Intense and narrow peaks have been observed for the synthesized carbon samples indicating chemically pure samples. By comparison of the estimated chemical shift parameter δN→0 and the slope δ1 of the shift versus density plots the existence of different pore sizes could be revealed. These observed differences can be attributed to different types of micropores generated by shrinkage effects during carbon liberation from the parent zeolite host. The obtained carbon replicas of Y zeolite were further characterized by elemental analysis, XPS, 13C MAS NMR and ESR spectroscopy.