Synthesis of nanocarbons via ethanol dry reforming over a carbon steel catalyst

In previous publications it was shown that carbon steel is an effective ethanol dry reforming catalyst, if carbon nancifilaments (CNF) constitute a desired product of the reaction. The objective of the present work was to investigate this catalytic reaction step and to present data on CNF and other reaction products as a function of catalyst nature and preparation as well as of experimental conditions. The methodology included 2 experimental set-ups: a bench-scale, fixed-bed reactor equipped with an on-line gas chromatograph for exit gas analysis and a differential reactor. Field emission gun scanning electron microscopy and X-ray diffraction analyses were used to characterize catalyst surface and CNF. The results showed that the formation of micro- and nanoparticles of magnetite on the steel surface was a necessary step for the activation and enhancement of its catalytic properties. The so-activated catalyst reformed ethanol with CO2 into H-2, CO, H2O and CNF, via the formation of iron carbide particles (Fe3C). These iron carbide particles were derived from magnetite particles, via reduction and carbon sequestration reactions, and were the basis for catalytic CNF production. (C) 2008 Elsevier B.V. All rights reserved.