Co-Ru/CNTs catalysts for Fischer–Tropsch synthesis using impregnation and chemical reduction methods

فاقد چكيده فارسي

Ruthenium (Ru) promoted cobalt (Co) catalyst supported on carbon nanotubes (CNTs) was evaluated in a fixed bed reactor for Fischer–Tropsch synthesis (FTS). The chemical reduction and impregnation methods are applied to synthesize nanocatalysts in this work. Chemical reduction method as a novel route including reduction of Co core by NaBH4 at the surface of CNTs and then reduction of Ru species though RuCl3 precursor with N2H4. The physicochemical properties and performance of the synthesized nanocatalyst by chemical reduction route was compared with the catalyst prepared by impregnation method. These catalysts were characterized by XRD and TPR techniques. The results show that the presence of RuO2 on the surface of the support using chemical reduction method favors the reducibility of cobalt oxides with a shift down in reduction temperature of about 30°C. Moreover, The catalytic evaluation of the catalysts indicated that Ru addition by chemical reduction increases the activity and selectivity towards C5+ catalyst in FTS. Moreover, comparing with those catalyst synthesized by impregnation, the use of chemical reduction led to enhancement of CO conversion from 37.89% to 46.78% and enhancement in FTS rate about 10%.