II International Symposium on Carbon for Catalysis ABSTRACTS

OP-<strong>II</strong>-10
The dehydrogenation reaction of decalin was tested monitoring the hydrogen evolution
volumetrically in a batch reactor at atmospheric pressure, under nitrogen atmosphere, heating
over the boiling point of the reactant and refluxing. The tested factors were the percentage of
Pt in the catalyst (1%, 3%), the temperature (513K, 533K) and the decalin/catalyst ratio (2,
2.7, 3.3 and 4 ml/g).
Results and discussion
The conversion of decalin after 2.5h and the initial hydrogen evolution rate were calculated
from the measured hydrogen volumes. They are shown as a function of the decalin/catalyst
ratio (Figures 1 and 2).
50%
30
Decalin conversion (%)
45%
40%
35%
30%
25%
20%
15%
10%
5%
0%
1.50 2.50 3.50 4.50
Initial H 2 evolution rate (mmol/h)
25
20
15
10
5
0
1.50 2.50 3.50 4.50
ratio dec/cat (ml/g)
ratio dec/cat (ml/g)
1%Pt 533K 3%Pt 513K 3%Pt 533K
1%Pt 533K 3%Pt 513K 3%Pt 533K
Fig 1. Relationship between conversion of decalin and
decalin/catalyst ratios. Two catalysts (1% Pt and 3% Pt)
and two temperatures (513 K and 533K)
Fig 2. Relationship between initial rate and
decalin/catalyst ratios. Two catalysts (1% Pt and 3% Pt)
and two temperatures (513 K and 533K)
The highest conversion and the highest rate were attained at the highest temperature (533K)
and the highest platinum content. Concerning the decalin/catalyst ratio, there is an optimum
value that maximizes conversion and rate. This is because a special state designated as
“liquid-film state” [1] is formed when the amount of decalin is not as low to become dry and
as high to make the catalyst in a suspended state. This optimal decalin/catalyst ratio is
between 2 and 3.3 ml/g.
The ongoing research is focusing on determining exactly the optimal conditions and
characterizing the catalyst.
References
[1] Hodoshima S., Arai H., Takaiwa S., Saito Y., Int. J. Hydrogen Energy 28 (2003) 1255
[2] Okhlopkova L.B., Lisitsyn A.S., Likholobov V.A., Gurrath M., Boehmb H.P., Applied
Catalysis 204 (2000) 230.
[3] Kariya N, Fukuoka A., Ichikawa M., Applied Catálisis 233 (2002) 98
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