II International Symposium on Carbon for Catalysis ABSTRACTS

OP-I-21
CARBON AEROGELS AS CATALYST SUPPORTS
Stolarski M., Brodzik K., Walendziewski J., Broniek E., Łużny R.
Faculty of Chemistry, Department of Fuels Chemistry and Technology,
Wrocław University of Technology, 50-344 Wrocław, ul. Gdańska 7/9, Poland
e-mail: marek.stolarski@pwr.wroc.pl
Aerogels are highly porous materials, made using sol-gel process to form solventcontaining
gels which are supercritical dried for purpose to prevent shrink or collapse the
weak structure of the solid matrix. Organic and carbon aerogels were prepared for the first
time by Penkala et al at, 1987. These aerogels consist of cross-linked organic polymer and
they must be carbonized in an inert atmosphere to form carbon aerogels. The carbon aerogels
prepared in the form of monoliths, powders or microspheres are characterized by high specific
surface area and porosity, low thermal conductivity and electrical resistance and high
capacitance. Taking into account their unique properties carbon aerogels are promising
materials for numerous practical applications such as isolation materials, electrodes and
specially as adsorbents and catalyst supports.
Organic RF aerogels are the most frequently prepared in multistage process which
include aqueous polycondensation of resorcinol with formaldehyde at temperature 70-95 o C
in the presence of Na 2 CO 3 as a catalyst, exchanging of water from gel structure to acetone,
exchanging of acetone to CO 2 before drying of the obtained gel and carbon dioxide
supercritical drying of gels. The classic method of organic aerogel synthesis is timeconsuming
and including gel drying lasts about two weeks while two last steps take four days.
RF aerogels are the precursors of carbon aerogels and the porous structure of carbon
aerogels depends on the porous properties of RF aerogels. Therefore, it is interesting to
exploit a low-cost and time-saving preparation method of RF organic aerogels.
In this paper the results of studies on the influence of the catalyst type and molar ratio
resorcinol to catalyst (R/C), concentration of resorcinol in water and curing time on porous
structure of monolith and spherical RF aerogels type prepared by supercritical acetone and
carbon dioxide drying and carbon aerogels derived from RF aerogels are presented.
RF hydrogels were synthesized by aqueous polycondensation of resorcinol (R) with
formaldehyde (F) in a molar ratio of 1:2. Sodium hydroxide, potassium hydroxide and sodium
carbonate were used as catalysts (C). The followed process parameters were studied:
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