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Start Over Author "Freni S." Journal applied catalysis a: general
6 results on '"Freni S."'

5. Performance of Rh/Al2O3 catalyst in the steam reforming of ethanol: H2 production for MCFC

Author

Cavallaro, S., Chiodo, V., Freni, S., Mondello, N., and Frusteri, F.

Subjects
*ALCOHOL, *FUEL cells, *CARBONATITES
Abstract

The steam reforming of ethanol on 5% Rh/Al2O3 catalyst has been investigated to produce H2 adequate to feed a molten carbonate fuel cell (MCFC). The influence of reaction temperature, H2O/EtOH molar ratio, gas hourly space velocities (GHSV) and O2 were investigated in order to maximize the hydrogen content at the outlet of ethanol reformer. Endurance tests to assess the feasibility of a FC system fed by simulated bio-EtOH stream (H2O/EtOH molar ratio=8.4) were also performed. Experiments carried out at MCFC operative conditions allowed to obtain a H2 reach mixture close to 60% on dry basis. In steam reforming (SR) conditions an extensive formation of encapsulated carbon was registered while a great benefits, both in terms of catalyst stability and coke formation were evidenced adding 0.4 vol.% of oxygen in the reaction stream. Oxygen however promoted metal sintering. Consideration on reaction mechanism, mainly investigated to distinguish the reaction pathway influencing the H2 production, is reported. [Copyright &y& Elsevier]

Published
2003
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6. Ethanol auto-thermal reforming on rhodium catalysts and initial steps simulation on single crystals under UHV conditions

Author

Erik Vesselli, Giovanni Comelli, Francesco Frusteri, Stefano Cavallaro, Renzo Rosei, S. Freni, Vesselli, Erik, Comelli, Giovanni, Rosei, Renzo, Freni, S., Frusteri, F., and Cavallaro, S.

Subjects
Ethanol, Hydrogen, Thermal desorption spectroscopy, Rhodium, Reforming, Process Chemistry and Technology, Inorganic chemistry, chemistry.chemical_element, Decomposition, Oxygen, Catalysis, chemistry.chemical_compound, chemistry, Carbon, Carbon monoxide
Abstract

By means of ultra high vacuum temperature programmed desorption experiments, we studied the influence of oxygen on the decomposition of ethanol over rhodium(1 1 1) and (1 0 0) single crystal surfaces. Oxygen at low surface coverage (between 0.1 and 0.25 ML) promotes ethanol decomposition and the formation of carbon dioxide, while carbon monoxide production is not significantly affected, with respect to the reaction on clean samples. Oxygen coverage above 0.25 ML hinders hydrogen formation due to the prevalent oxidising action, which leads to water formation. These results are in line with data we obtained for ethanol decomposition over a 5% Rh/Al 2 O 3 catalyst under typical reforming working conditions (i.e. T = 923 K and P = 1 bar), thus indicating that an oxidising environment is required in order to avoid carbon poisoning and to promote C 2 -containing molecules decomposition. On the contrary, excess of oxygen leads to a strong reduction of hydrogen concentration in the reaction products.

Published
2005
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