Cobalt supported on carbon nanofibers- a promising novel Fischer-Tropsch catalyst

Abstract

Abstract The potential of carbon nanofibers supported cobalt catalysts for the Fischer-Tropsch reaction is shown. Using the wet impregnation method cobalt on carbon nanofiber catalysts were prepared with cobalt loadings varying from 5 to 12 wt%. The cobalt particle size of the catalysts varied with increasing loading from 3 to 13 nm. Cobalt particles were localized both at the external and at the internal surface of the fibers. The activity at 1 bar syngas varied with increasing loading from 0.71 to 1.71 10−5 molco·gco−l·s−1. This might indicate that smaller particles are less active in the Fischer-Tropsch reaction, but may also be provoked by different fractions of cobalt present inside the fibers. Stable activity of 225 gCH2·1cat−1·h−1 for 400 h was obtained at pressures of 28–42 bar syngas. A C5+ selectivity of 86 wt% was found, which is remarkably high for an unpromoted catalyst.