A possible buckybowl-like structure of zeolite templated carbon

Abstract

Ordered microporous carbon that was synthesized in the nanochannels of zeolite Y is characterized by an extremely large surface area, surprisingly uniform micropores and a long-range periodicity originating from the parent zeolite. However, the molecular structure of this zeolite templated carbon (ZTC) has been completely unknown. In this study, an attempt was made to construct a possible molecular model for ZTC. The proposed model is made up of buckybowl-like nanographenes assembled into a three-dimensionally regular network, which reflects all the experimental results obtained from Raman spectroscopy, electron energy-loss spectroscopy, and previously obtained analyses with several other means. Starting from this idealized model, possible forms of defects that would be included in the actual ZTC were also investigated. Moreover, the amount and the type of oxygen functional groups were analyzed and, as per the results, some functional groups were bound to the edge sites of each buckybowl unit in the molecular model. The elemental composition, pore curvature, pore size and pore volume and surface area estimated from such oxygen-containing model agree well with the corresponding experimentally obtained results. The present model can be considered as a reasonable starting point for future refinements of the structure of this quite novel carbon material.