Efficient conversion of syngas to linear α-olefins by phase-pure χ-Fe5C2

• 成果类型: Article
• 署名作者: Wang, Peng; Chiang, Fu-Kuo; Chai, Jiachun; Dugulan, A. Iulian; Dong, Juan; Chen, Wei; Broos, Robin J. P.; Feng, Bo; Song, Yuanjun; Lv, Yijun; Lin, Quan; Wang, Rongming; Filot, Ivo A. W.; Men, Zhuowu; Hensen, Emiel J. M.
• 署名单位: Eindhoven University of Technology; Delft University of Technology; University of Science & Technology Beijing
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6565
• DOI: 10.1038/s41586-024-08078-5
• 发表日期: 2024-11-07
• 关键词: fischer-tropsch synthesis; iron; catalyst; carbide; ethylene; nanoparticles; performances; metal

摘要

Oil has long been the dominant feedstock for producing fuels and chemicals, but coal, natural gas and biomass are increasingly explored alternatives(1,2,3). Their conversion first generates syngas, a mixture of CO and H-2, which is then processed further using Fischer-Tropsch (FT) chemistry. However, although commercial FT technology for fuel production is established, using it to access valuable chemicals remains challenging. A case in point is linear alpha-olefins (LAOs), which are important chemical intermediates obtained by ethylene oligomerization at present(4,5,6,7,8). The commercial high-temperature FT process and the FT-to-olefin process under development at present both convert syngas directly to LAOs, but also generate much CO2 waste that leads to a low carbon utilization efficiency(9,10,11,12,13,14). The efficiency is further compromised by substantially fewer of the converted carbon atoms ending up as valuable C-5-C-10 LAOs than are found in the C-2-C-4 olefins that dominate the product mixtures(9,10,11,12,13,14). Here we show that the use of the original phase-pure chi-iron carbide can minimize these syngas conversion problems: tailored and optimized for the process of FT to LAOs, this catalyst exhibits an activity at 290 degrees C that is 1-2 orders higher than dedicated FT-to-olefin catalysts can achieve above 320 degrees C (refs. (12,13,14,15)), is stable for 200 h, and produces desired C-2-C-10 LAOs and unwanted CO2 with carbon-based selectivities of 51% and 9% under industrially relevant conditions. This higher catalytic performance, persisting over a wide temperature range (250-320 degrees C), demonstrates the potential of the system for developing a practically relevant technology.