One-pot endo/exotemplating of hierarchical micro-mesoporous carbons

Hierarchical micro-mesoporous carbons have been obtained by a simple one-pot procedure by adjusting the hydrogen bond interaction between Pluronic 123 surfactant, carbon precursor and tetraethoxysilane (TEOS) in acidic media through changes in carbon precursor nature and concentration. This has resulted in modifications in the packing of surfactant micelles, leading to silicas and carbons with different textural and structural characteristics. Conventional soft templating with SBA-15 type silica was carried out but two new variables were included, namely the addition of organic molecules of different nature and size to the reaction medium and the use of H2SO4 instead of HCl to promote dehydration and polymerization of carbon precursors. Due to the TEOS-carbon precursor interaction an “in situ” infiltration of the latter occurred simultaneously to SBA-15 formation. This fact avoids the pre-synthesis of hard template and post-synthesis treatments of mesoporous carbons to generate microporosity. BET surface areas between 800 and 1000 m2/g were obtained, with micropore and mesopore volumes up to 0.35 and 1.13 cm3/g, respectively. Even thought we had to face the difficulty of suitable infiltration and consequently replication of the mesoporous template, long-range order was observed for some carbons as evidenced by means of Transmission Electron Miscroscopy and X-ray Diffraction.