Effects of Cu and K promoters on the catalytic performance of iron- based nanocatalyst for Fischer-Tropsch synthesis

摘要

Iron-based nanocatalyst was prepared via impregnation method on SiO_2 support. The effects of promoters, namely, K and Cu, on the physical properties and catalytic performance in FTS have been investigated. The FTS performance of the synthesized nanocatalysts was examined in a fixed-bed microreactor at temperature of 523K, atmospheric pressure, 1.5 reactant ratio (H_2/CO) and space velocity of 3L/g-cat.h. In FTS reaction, Cu promoter resulted in a lower CO conversion and C_(5+) hydrocarbons selectivity but higher selectivity to the lighter hydrocarbons (C_1-C_4) compared to those obtained using the K promoter. Higher CO conversion (28.9%) and C_(5+) hydrocarbons selectivity (54.4%) were obtained using K as a promoter compared to that of Cu promoter. However, the K-promoted nanocatalyst resulted in a lower CO conversion but higher selectivity of the heavy hydrocarbons (C_(5+)) compared to those obtained using the un-promoted nanocatalyst.