文献类型：期刊文献

英文题名：Direct Conversion of Syngas to Light Olefins through Fischer- Tropsch Synthesis over Fe-Zr Catalysts Modified with Sodium

作者：Ma, Zhunzhun[1];Ma, Hongfang[1];Zhang, Haitao[1];Wu, Xian[1];Qian, Weixin[1];Sun, Qiwen[2];Ying, Weiyong[1]

机构：[1]East China Univ Sci & Technol, Engn Res Ctr Large Scale Reactor Engn & Technol, Sch Chem Engn, State Key Lab Chem Engn,Minist Educ, Shanghai 200237, Peoples R China;[2]State Key Lab Coal Liquefact & Coal Chem Technol, Shanghai 201203, Peoples R China

年份：2021

卷号：6

期号：7

起止页码：4968

外文期刊名：ACS OMEGA

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000623040500048)】；

基金：The authors gratefully acknowledge the financial supports from the National Natural Science Foundation of China (grant no. 21706068), the National High Technology Research and Development Plan of China (863 plan, 2011AA05A204), and the Fundamental Research Funds for the Central Universities (no. 50321012017013).

语种：英文

摘要：Fe-Zr-Na catalysts synthesized by coprecipitation and impregnation methods were implemented to investigate the promoting effects of Na and Zr on the iron-based catalyst for high-temperature Fischer-Tropsch synthesis (HTFT). The catalysts were characterized by Ar adsorption-desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, CO temperature-programmed desorption, H-2 temperature-programmed desorption, X-ray photoelectron spectroscopy, and Mossbauer spectroscopy (MES). The results indicated that Na changed the active sites on the catalyst surface for the CO and hydrogen adsorption, owing to the electron migration from Na to Fe atoms, which resulted in an enhanced CO dissociative adsorption and a decrease in hydrogen adsorption on the metallic Fe surface. The decreased H/C ratio on the catalyst surface accounted for the increased chain propagation and weakened hydrogenation of light olefins. Besides, Na could also facilitate the carbonization of catalysts and protect the iron carbide against oxidation, which provides more active sites for HTFT reaction and is beneficial to the C-C coupling. Zr could decrease the hematite crystallite size and stabilize the active phase to improve the HTFT activity. At an optimal Na loading of 1.0 wt %, the Fe-Zr-1.0Na catalyst exhibited the highest light olefin selectivity of 35.8% in the hydrocarbon distribution at a CO conversion of 95.2%.