Preparation of microporous carbon-ceramic cellular monoliths

Carbon-ceramic cellular monoliths were prepared by coating a ceramic cellul ar monolith with a polymeric solution (carbon precursor). Phenolic (resol a nd novolac) or furanic resins, and polysaccharides (sucrose and dextrose) w ere used as carbon precursors. The following procedure was adopted: (a) sub strate impregnation with a polymeric solution, (b) curing or drying, (c) ca rbonisation (700-1000 degreesC, N-2), and (d) physical (H2O, 700 degreesC) or chemical (ZnCl2) activation. In optimal conditions (e.g. phenolic novola c, 64 wt.%; two impregnation-curing-carbonisation cycles) the material obta ined exhibited a high carbon percentage (similar to 14 wt.%) with a micropo re volume and a specific surface area (relative to the mass of deposited ca rbon) of 0.32 cm(3)g(-1) and 427 m(2)g(-1), respectively. By physical activ ation (burnoff: 20 wt.%) the micropore volume increased to 0.44 cm(3) g(-1) and the specific surface area to 1450 m(2) g(-1). By means of chemical act ivation, a high carbon load (similar to 13 wt.%) was obtained in a single s tep, with a micropore volume of 0.36 cm(3) g(-1) and a specific surface are a of 791 m(2) g(-1). The activated material shows a uniform carbon distribu tion, good adsorption properties, good electrical conductivity (1.15 Omega (-1) cm(-1)) and a high mechanical strength (16 MPa). (C) 2001 Elsevier Sci ence B.V. All rights reserved.