Fischer–Tropsch synthesis over iron catalysts supported on carbon nanotubes

Abstract

Carbon nanotubes (CNTs) were synthesized in a catalytic reaction over an iron catalyst using CaCO 3 as a support. The purification of the carbon nanotubes (CNTs) and the oxidation of the CNTs surfaces were performed with HNO 3. Iron-based catalysts supported on carbon nanotubes for use in the Fischer–Tropsch (FT) reaction were prepared either by incipient wetness or a deposition precipitation method using urea and then promoted with potassium and/or copper. The FT synthesis was carried out in a fixed-bed micro reactor (275 °C, 8 bar, CO/H 2 = 2). The effect of Cu and promoters on CO conversion, product selectivity and FT synthesis activity were investigated and compared with data reported on other carbon-based supports. The potassium promoted catalysts gave higher yields of CO 2 and C 2 olefins and the lowest methane selectivity when compared to the unpromoted catalysts. Copper, while enhancing catalyst activity, did not have an effect on the FT product selectivity.