Structure and Catalytic Performance of CoAl2O4-Al2O3 Supported Cobalt Catalyst for Fischer-Tropsch Synthesis
Litao Jiaa, Jiankang Hana,b,Bo Houa, Debao Lia*
a State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China.
b University of Chinese Academy of Sciences, Beijing 100039, China
*Corresponding author: Tel. /Fax: +86 351 4040410. E-mail addresses: firstname.lastname@example.org
The FischerĘCTropsch synthesis (FTS) can convert syngas (CO +H2) into clean and renewable transportation fuels, which has received an increasing interest from academia and industry. Amongst the reported catalysts, cobalt-based catalysts showed low activity for the water-gas shift reaction, deactivated less rapidly and yielded a high fraction of linear parrifin. Alumina as a kind of traditional support for F-T synthesis catalysts, has high mechanical strength and good friction resistance. While, the strong interactions between the alumina and cobalt reduced the reduction degree of cobalt, which strongly influence the performance of the catalyst.
In the present study, the Al2O3 was modified by CoAl2O4 microcrystalline through impregnation method. And then the modified Al2O3 acted as support for cobalt. The as-prepared catalysts were characterized by BET, XRD, H2-TPR, XPS and H2-chemisorption, and applied in FischerĘCTropsch synthesis (FTS). The results show that the existence of CoAl2O4 on surface of the Al2O3 effectively weakened the interaction between Co and Al2O3, thus greatly improve the reduction of catalysts and catalytic activity. With the increase of CoAl2O4 content, the reduction degree and catalytic activity of catalysts increase, which reach the maximum with 20 wt% CoAl2O4 content. The catalytic performance showed that, with the modification CoAl2O4, the CH4 selectivity was decreased and the C5+ selectivity was enhanced. In addition, CoAl2O4 modification also improves the catalyst stability.
Keywords: Fischer-Tropsch synthesis, cobalt/Alumina catalysts, CoAl2O4 modified Al2O3,
See more of this Group/Topical: Catalysis and Reaction Engineering Division