INFLUENCE OF TWO-STEP REDUCTION ON STRUCTURE AND CATALYTIC PERFORMANCE OF CO-ZrO2CATALYSTS FOR FISCHER-TROPSCH SYNTHESIS
IntroductionDuo to the high activity, high selectivity to linear hydrocarbons and low activity for the water gas shift (WGS) reaction, Co-based catalysts are considered to be the most potential catalysts for FTS based on natural gas conversion. The active species of the catalysts used in the FTS is the metallic phase, which is produced by pretreatment of the precursors in the reduction atmosphere prior to use in the reaction. Meanwhile, the promoters of Co-based catalysts play important role for improving the catalytic performance. Recently, zirconia has been widely investigated as a potential promoter and pure support with many merits, such as increasing the reducibility of cobalt oxide, maintaining the activity by preventing the formation of coke, acting as a source of hydrogen spillover, enhancing the dispersion and modification of the metal-support interaction et al 1. However, less attention has been paid to determine how the activating agent (H2, CO or syngas) influences on the reduction behavior and catalyst performance for zirconia supported Co-based catalysts. For Co-based catalysts, it is often useful to reduce the catalyst ex;situ and passivation is employed to protect the surface of the reduced catalyst from rapid oxidation. The ROR (reduction-oxidation-reduction) technique is used to enhance the dispersion of the metallic cobalt 2. Recently, many studies aim to investigate the effect of passivation process on the FT behavior. However, how the pretreatment at the different atmospheres and passivation exposing to air influences on the physical properties, and the catalytic performances of catalysts is less understood. Accordingly, this work is undertaken with the aim to investigate how the different reducing agents affect the physical properties and passivation, furthermore to clarify how the re-activation of catalysts and their performances change after second-step reduction in H2 atmosphere.
Litao Jia Kegong Fang Debao Li Yuhan Sun
State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan, 030001, China
国际会议
The 7th China-Korea Workshop on Clean Energy Technology(第七届中韩清洁能源技术研讨会)
太原
英文
235-236
2008-06-25（万方平台首次上网日期，不代表论文的发表时间）