Development of niobium-promoted cobalt catalysts on carbon nanotubes for Fischer-Tropsch synthesis

Cobalt-based catalysts were prepared by a wet impregnation method on carbon nanotubes (CNTs) support and promoted with niobium. Samples were characterized by nitrogen adsorption, TEM, XRD, TPR, TPO and H2-TPD. Addition of niobium increased the dispersion of cobalt but decreased the catalysts reducibility. Fischer-Tropsch synthesis (FTS) was carried out in a fixed-bed microreactor at 543 K, 1 atm and H2/CO = 2 for 5 h. Addition of niobium enhanced the C5+ hydrocarbons selectivity by 39% and reduced methane selectivity by 59%. These effects were more pronounced for 0.04%Nb/Co/CNTs catalyst, compared with those observed for other niobium compositions.