II International Symposium on Carbon for Catalysis ABSTRACTS

PP-I-15
Titania was prepared by hydrolysis of TiCl 4 solution using polyethylene imine (PEI) when
deposited onto the CNF/CF [4]. Gold colloids were prepared from a HAuCl 4 solution and added
dropwise to the suspended TiO 2 /CNF/CF to produce the catalyst [5,6]. The catalysts are being
characterised by several methods such as BET, XRD, TPO, SEM and TEM.
Productivity C/gcat] [g
80
70
60
50
40
30
20
10
0
Lower space
velocity
Higher space
velocity
0.00 1.00 2.00 3.00 4.00 5.00
Time [hour]
Figure 1: The obtained amount of CNF from the
growing process
resistance [Ω]
1.00
0.80
0.60
0.40
0.20
0.00
0 100 200 300
temperature [ o C]
Figure 2: Logarithmic plot of the resistance in the
carbon composite as a function of temperature
The results show that the homogeneity of the nickel dispersion on the CF/CNF composite
depends on the preparation conditions. The composite pieces were weighted before and after
the growth of CNF. Larger weight differences are seen for the pieces grown at low space
velocity and also the calculated amount of CNF per gram Ni was lower as shown in figure 1.
The surface area of the carbon composite was measured to be around 100 m 2 /g. The total
surface area did not change after deposition of the titania but an increase in the amount of
mesopores is observed. Earlier results have shown that the oxide on CNF have different
surface properties than the unsupported oxide particles that contribute to improved catalytic
stability [6]. This indicates that the CNF are capable of stabilising the mesoporous structure of
titania at elevated temperatures. Results from XRD show that titania is predominantly present
as anatase and that the CNF are highly crystalline. The Au particle size obtained with
deposition of Au-sol is from 2 to 7 nm. Temperature testing by application of power in the CF
gave a lower temperature increase compared to the carbon composite. The resistance in the
CNF/CF decreases with increasing temperatures as shown in figure 2. The system gives a
stable temperature and rapid temperature responses are obtained. The catalysts are currently
being tested for CO oxidation activity.
References
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2. M. Haruta, S. Tsubota, T. Kobayashi, H. Kageyama, M.J. Genet, B. Delmon, J. Catal.
144 (1993) 175
3. Q. Fu, S. Kudriavtseva, H. Saltsburg, M. Flytzani-Stephanopoulos, Chemical
Engineering Journal, 93 (2003) 41
4. J. Sun, M. Iwasa, L. Gao, Q. Zhang, Carbon 42 (2004) 885
5. J.D. Grunwaldt, C. Kiener, C. Wögerbauer, A. Baiker, J. Catal. 181 (1999) 223
6. N. Hammer, I Kvande, V. Gunnarsson, B. Tøtdal, X. Xu, D. Chen, M. Rønning, in
preparation
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