Uniformity dispersive, anti-coking core@double-shell-structured Co@SiO2@C: Effect of graphitic carbon modified interior pore-walls on C5+ selectivity in Fischer-Tropsch synthesis

Zhijiang Ni; Shifei Kang; Jirong Bai; Yaguang Li; Yongkui Huang; Zhilei Wang; Hengfei Qin; Xi Li

doi:10.1016/j.jcis.2017.05.096

Uniformity dispersive, anti-coking core@double-shell-structured Co@SiO₂@C: Effect of graphitic carbon modified interior pore-walls on C₅₊ selectivity in Fischer-Tropsch synthesis

J Colloid Interface Sci. 2017 Nov 1:505:325-331. doi: 10.1016/j.jcis.2017.05.096. Epub 2017 May 26.

Authors

Zhijiang Ni¹, Shifei Kang², Jirong Bai¹, Yaguang Li², Yongkui Huang¹, Zhilei Wang¹, Hengfei Qin³, Xi Li⁴

Affiliations

¹ Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
² School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
³ Jiangsu Key Laboratory of E-waste Recycling, School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China. Electronic address: jlgqinhf@jsut.edu.cn.
⁴ Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China. Electronic address: xi_li@fudan.edu.cn.

PMID: 28601741
DOI: 10.1016/j.jcis.2017.05.096

Abstract

Highly dispersed Co nanoparticles with proper interaction with mesoporous support are benefit for the suppression of self-aggregation, which enhances its Fischer-Tropsch synthesis (FTs) activity. However, construct such Co based supported catalysts with high activity and stability in FTs by conventional mesoporous support, especially the common used mesoporous SiO₂, has proven challenging due to their undesirable hydrothermal stability and poor reducibility. Herein, we developed a unique core@double-shell Co@SiO₂@C structure with optimized interface of the mesoporous catalyst by introducing graphitic carbon layer which can weaken the interaction between metallic Co and silica. Transmission electron microscopy (TEM) images, together with Nitrogen adsorption-desorption characterization result, proved the well-defined core@double-shell structure of graphitic carbon modified catalyst. The Co@SiO₂@C-2 material produced after optimizing the calcination temperature to 600°C process large surface area and pore volume, and show higher CO conversion (62.2%) and C₅₊ selectivity (62.2%) than Co₃O₄@SiO₂ in a period of 100h. The significant improvement in the FTS performance of Co@SiO₂@C is not only attributed to a good synergistic effect by a combination of the Co dispersion and reducibility. The unique core@double-shell structure with graphitic carbon modified interior pore-walls also contributes to the formation of heavy hydrocarbon, as well as the protecting with the metallic Co particles away from oxidation and aggregation.

Keywords: Co@SiO(2)@C; Core@double-shell; Fischer-Tropsch synthesis; Graphitic carbon; Rigid porous frameworks.