能源化学(英文) ›› 2013, Vol. 22 ›› Issue (4): 624-632.

• Articles • 上一篇    下一篇

Effect of manganese on the catalytic performance of an iron-manganese bimetallic catalyst for light olefin synthesis

Tingzhen Lia,b,c, Hulin Wanga, Yong Yanga, Hongwei Xianga, Yongwang Lia   

  1. a. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China;
    b. College of Chemistry and Environmental Engineering, Chongqing Three Gorges University, Chongqing 404000, China;
    c. Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, Jiangsu, China
  • 收稿日期:2013-04-06 修回日期:2013-06-20 出版日期:2013-07-20 发布日期:2013-07-27
  • 通讯作者: Hongwei Xiang
  • 基金资助:

    This work was supported by Natural Science Foundation of Chongqing Three Gorges University (12ZD14) and Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University.

Effect of manganese on the catalytic performance of an iron-manganese bimetallic catalyst for light olefin synthesis

Tingzhen Lia,b,c, Hulin Wanga, Yong Yanga, Hongwei Xianga, Yongwang Lia   

  1. a. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China;
    b. College of Chemistry and Environmental Engineering, Chongqing Three Gorges University, Chongqing 404000, China;
    c. Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, Jiangsu, China
  • Received:2013-04-06 Revised:2013-06-20 Online:2013-07-20 Published:2013-07-27
  • Supported by:

    This work was supported by Natural Science Foundation of Chongqing Three Gorges University (12ZD14) and Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University.

摘要: A systematic study was carried out to investigate the promotion effect of manganese on the performance of a coprecipitated iron-manganese bimetallic catalyst for the light olefins synthesis from syngas. The catalyst samples were characterized by N2 physisorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Mössbauer spectroscopy, H2-differential thermogravimetric analysis (H2-DTG), CO temperature-programmed reduction (CO-TPR) and CO2 temperature-programmed desorption (CO2-TPD). The Fischer-Tropsch synthesis (FTS) performance of the catalyst was measured at 1.5 MPa, 250 ℃ and syngas with H2/CO ratio of 2.0. The characterization results indicated that the addition of manganese decreases the catalyst crystallite size, and improves the catalyst BET surface area and pore volume. The presence of manganese suppresses the catalyst reduction and carburization in H2, CO and syngas, respectively. The addition of manganese improves the catalytic activity of water-gas shift reaction and suppresses the oxidation of iron carbides in the FTS reaction. The incorporation of manganese improves the catalyst surface basicity and results in a significant improvement in the selectivities to light olefins and heavy hydrocarbons (C5+), and furthermore an inhibition of methane formation in FTS. The pure iron catalyst (Mn-00) has the highest initial FTS catalytic activity (65%) and the lowest selectivity (17.35 wt%) to light olefins (C2=—C4=). The addition of an appropriate amount of manganese can improve the catalyst FTS activity.

关键词: light olefin, Fischer-Tropsch synthesis, iron-manganese, bimetallic catalyst, carburization

Abstract: A systematic study was carried out to investigate the promotion effect of manganese on the performance of a coprecipitated iron-manganese bimetallic catalyst for the light olefins synthesis from syngas. The catalyst samples were characterized by N2 physisorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Mössbauer spectroscopy, H2-differential thermogravimetric analysis (H2-DTG), CO temperature-programmed reduction (CO-TPR) and CO2 temperature-programmed desorption (CO2-TPD). The Fischer-Tropsch synthesis (FTS) performance of the catalyst was measured at 1.5 MPa, 250 ℃ and syngas with H2/CO ratio of 2.0. The characterization results indicated that the addition of manganese decreases the catalyst crystallite size, and improves the catalyst BET surface area and pore volume. The presence of manganese suppresses the catalyst reduction and carburization in H2, CO and syngas, respectively. The addition of manganese improves the catalytic activity of water-gas shift reaction and suppresses the oxidation of iron carbides in the FTS reaction. The incorporation of manganese improves the catalyst surface basicity and results in a significant improvement in the selectivities to light olefins and heavy hydrocarbons (C5+), and furthermore an inhibition of methane formation in FTS. The pure iron catalyst (Mn-00) has the highest initial FTS catalytic activity (65%) and the lowest selectivity (17.35 wt%) to light olefins (C2=—C4=). The addition of an appropriate amount of manganese can improve the catalyst FTS activity.

Key words: light olefin, Fischer-Tropsch synthesis, iron-manganese, bimetallic catalyst, carburization