(583dp) SiO2 Supported Cobalt-Based Catalyst Prepared By Dielectric-Barrier Discharge Plasma for Fischer-Tropsch Synthesis From Syngas

SiO₂ Supported Cobalt-Based Catalyst Prepared
by Dielectric-barrier

Discharge Plasma for Fischer-Tropsch Synthesis from
Syngas

Tingjun Fu, Yunhui Jiang, Zhenhua Li

Key Lab for Green Chemical
Technology of Ministry of Education, School of Chemical Engineering and
Technology, Tianjin University, Tianjin 300072, China

Co/SiO₂ and zirconium promoted
Co/Zr/SiO₂ catalysts were prepared by using dielectric-barrier
discharge (DBD) plasma instead of conventional thermal calcination method. The Fischer-Tropsch Synthesis (FTS) performance was evaluated in a fixed bed
reactor. The results indicated that DBD plasma promotes the FTS activity and heavy
hydrocarbon formation compared with the conventional thermal
calcination method. The increase of CO conversion was unnoticeable on
Co/SiO₂ catalyst prepared by DBD plasma while the increase of CO
conversion was significant on the Co/Zr/SiO₂ catalyst prepared by
DBD plasma. The heavy hydrocarbonselectivity and
the chain growth probability (¦Á
value) enhanced on all the catalysts
treated by DBD plasma. In order to study the effect of DBD plasma treatment on
the FTS performance, the catalyst was characterized by N₂-physisorption,
H₂-TPR, H₂-TPD, TEM and XRD. It was proved
that DBD plasma not only decreases the precursor decomposition time but also
achieves a better cobalt dispersion, smaller Co₃O₄
cluster size and more uniform cobaltdistribution.
Unfortunately, cobalt reducibility was hindered to some extent in Co/SiO₂ catalyst
prepared by DBD plasma while the additive zirconium significantly
prevented the decrease
of cobalt
reducibility and increased cobalt dispersion and the FTS
performance.

Keywords: Fischer-Tropsch synthesis; Cobalt; Silica; Zirconium; Plasma