Plasma-Assisted Preparation of Highly Dispersed Cobalt Catalysts for Enhanced Fischer–Tropsch Synthesis Performance

Glow discharge plasma (GDP) was used for the preparation of Co/TiO2 Fischer–Tropsch synthesis (FTS) catalysts promoted by Pt. This technique was compared with conventional thermal calcination for decomposing cobalt precursor. In this study, Pt was added as a reduction promoter in order to improve the reducibility of Co/TiO2 catalysts because the strong interaction between Co and TiO2 is detrimental to the FTS performances. It was found that plasma treatment can effectively decompose the cobalt precursor at a low temperature in a short time (1–4 h). As compared to thermal calcination, the cobalt species prepared by GDP is highly dispersed on TiO2 support. CoPt/TiO2 catalyst with homogeneously and highly dispersed cobalt particles (∼1 nm) was achieved by prolonging plasma treatment from 1 to 4 h. This is difficult to accomplish via conventional calcination method on preparing this loading cobalt catalyst (12 wt %) without the use of extra chemicals and a complicated process. Furthermore, we found that a short time plasma treatment (<3 h) not only increased the amount of active sites but also enhanced their specific reactivity, leading to much higher FT reaction rate.