祝贺唐磊等同学的文章
“Selective synthesis of core-shell structured catalyst χ-Fe5C2 surrounded by nanosized Fe3O4 for conversion of syngas to liquid fuels”
被 Catal. Sci. Technol. 接受发表！
Lei Tang, Bai-Chuan Zhou, Xi Liu, Shuang Xu, Jia Wang, Wei Xu, Xiaohao Liu, Liwei Chen and An-Hui Lu*. Selective synthesis of core-shell structured catalyst χ-Fe5C2 surrounded by nanosized Fe3O4 for conversion of syngas to liquid fuels, Catal. Sci. Technol., 2022, Accepted. DOI:10.1039/D1CY02241E. [DOWNLOAD]
Abstract
Enhancing liquid hydrocarbons selectivity and simultaneously suppressing CO2 formation are highly desirable yet challenges in iron-based Fischer-Tropsch synthesis. Herein, we report an in-situ oxidation method for the fabrication of a functional configuration catalyst with a core-shell structure, i.e., χ-Fe5C2 core surrounded by nanosized Fe3O4 shell, which promotes the formation of long-chain hydrocarbons on inner χ-Fe5C2 and further the depletion of primarily formed CO2 on outer Fe3O4 via reverse water-gas shift reaction. Key to success is the pretreatment of Fe3O4 under a syngas atmosphere with a H2/CO ratio of 2 at a high pressure of 20 bar and high temperature of 400 ºC. The pretreatment leads to in-situ formed high oxidation chemical potential of atmosphere, and thus promotes the formation of the χ-Fe5C2@Fe3O4 core-shell structure. Moreover, the high-pressure pretreatment facilitates the formation of surface graphitized carbon layers, thus leading to enhanced selectivity of long-chain hydrocarbons due to the electronic promotion effect of the graphitic structures. Such functional configuration catalyst achieves a high C5+ hydrocarbons selectivity of 45% and simultaneous low CO2 selectivity of only 7% with a CO conversion of 19% at 230 ºC. These results offer a valuable reference about the rational fabrication of catalyst to suppress the commonly high CO2 selectivity.
