II International Symposium on Carbon for Catalysis ABSTRACTS

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temperature is set at 380 °C and the gaseous reactants consist of 2% O 2 and 2% ethylbenzene
in volume, balanced with Ar.
The experimental results obtained are listed in Table 1, including the weight loss, the side
compressive strength, and the catalytic activity and selectivity of the CNF composite after gas
oxidative treatment, as compared to the composite without treating. The conversion of
ethylbenzene and the selectivity to styrene over the composite given in Table 1 are
determined when the ODE reaction has proceeded for about 300 min, nearly reaching a steady
state. It is clear that stronger oxidation degree of the composite results in higher catalytic
activity but lower mechanical strength.
Table 1 Weight loss, mechanical strength, conversion and selectivity for ODE of the CNF composite
CNF composite Weight loss (%) Strength (N•mm -1 ) Conversion (%) Selectivity (%)
Untreated 0 31.8 28.1 88.1
300-2% a 0.8 24.1 27.8 89.5
350-2% 2.5 19.3 33.1 94.6
400-2% 7.9 13.5 34.2 94.7
450-2% 12.4 16.1 39.9 95.8
300-5% 0.5 24.1 37.2 93.3
350-5% 4.4 15.8 38.0 92.9
400-5% 12.3 6.5 42.5 93.6
450-5% 24.2 2.9 47.6 93.7
300-10% 1.0 22.4 40.2 90.3
350-10% 5.8 15.4 41.5 95.1
400-10% 14.0 6.0 46.7 93.1
450-10% 45.9 - b 58.4 89.4
a. 300-2% means the composite is treated at 300 °C with 2% O 2 ; b. the composite is brittle after treating.
The N 2 -physisoption and TPD measurements of the CNF composite are made to find out
the variations of the texture and the surface chemistry of the composite treated under different
oxidation conditions. The metal content in the composite from growing catalyst is also
analyzed. The influence of gas oxidative treatment on the mechanical and the catalytic
properties of the CNF composite is discussed on the basis of characterization results.
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