(643g) Novel Cobalt Catalyst Supported On Titania-Decorated Silicon Carbide for Fischer-Tropsch Synthesis
AIChE Annual Meeting
Thursday, November 7, 2013 - 10:30am to 10:50am
The interactions between cobalt nanoparticles and a TiO2-decorated silicon carbide (β-SiC) support were explored by a combination of energy-filtered transmission electron microscopy (EFTEM), 59Co zero-field nuclear magnetic resonance (59Co NMR), and other conventional characterization techniques. From 2D elemental maps deduced by 2D EFTEM and 59Co NMR analyses it was observed that nanoscale introduction of TiO2 into the β-SiC matrix significantly enhanced the formation of small and medium-sized cobalt particles active for Fischer-Tropsch synthesis. The results obtained revealed that adequate interactions between cobalt nanoparticles and TiO2 led to the formation of smaller cobalt particles (<15 nm), which possess a large fraction of surface atoms and, thus, significantly contribute to the enhancement of conversion and reaction rate. The cobalt time yield of the catalyst after modification increased to 7.5 × 10−5 molCO gCo s−1 at 230 °C, whereas the C5+ selectivity was maintained a high level (>90%). In addition, the distribution of meso- and macro-pores in the SiC-based support facilitated intimate contact between reactants and active sites and accelerated the evacuation of the products of reaction. A stable FTS specific rate of 0.56 g C5+ gcatalyst−1 h−1 together with a high C5+ selectivity of 91% were obtained with a 30 wt % cobalt loading.