II International Symposium on Carbon for Catalysis ABSTRACTS

PP-I-45
Table 1: Characteristics of carbon-mineral composites produced at different temperatures
FCB temperature, °C A BET , m 2 /g V pore , cm 3 /g Ash, %
450 32 0.04 35
500 176 0.15 56
550 246 0.21 69
600 233 0.22 76
In these composites, the ash residue contains mainly nanospheres of amorphous silica
which may behave as a mineral structure-forming agent – template – during the further
treatment to synthesize microporous carbons, the carbon nanostructure with 1 to 1.5 nm
graphenes being arranged around the template.
The obtained carbon-mineral composites are activated in melted KOH and/or NaOH at
700–900 °C to produce potassium silicates through the interaction between amorphous silica
and KOH. After this activation, the materials are cooled and the silicate templates are
removed by dissolving in water.
One of the principal parameters affecting the textural characteristics of thus obtained
SMPC’s is the activation temperature [3, 4]. Table 2 summarizes the data on properties of
SMPC’s synthesized at different temperatures. А BET , V pore and V μ are determined from the
nitrogen adsorption isotherms at 77 K.
Table 2: Characteristics of carbonaceous nanostructural SMPC’s materials synthesized at
different temperatures
Activation temperature, o C A BET , m 2 /g V pore /V μ , cm 3 /g Micropore proportion %
700 3170 1.77/1.45 81.9
750 3450 2.01/1.68 83.6
800 3360 2.18/1.87 92.3
850 3170 2.26/1.74 77.0
900 3210 2.97/1.48 49.8
The total pore volume increases with the activation temperature. At the temperatures
below 800°C, the increase is due to the micropore formation. At the further temperature
elevation, the micropore volume decreases but the mesopore volume increases due to burning
processes.
Generally, the specific surface area is proportional to the micropore volumes (Fig. 1). The
TEM studies revealed that the SMPC material consists of nanosized individual graphenes
arranged in a disordered cell-like structure (Fig. 2).
In the synthesized microporous carbons, not only the specific surface areas and micropore
volumes are superior to those of AX-21. The characteristic features of SMPC’s are much
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