北京低碳清洁能源研究院Zhuowu Men等，报道了用相纯χ-Fe5C2将合成气高效转化为线性α-烯烃。2024年10月16日出版的《自然》杂志发表了这一最新研究成果。

据悉，长期以来，石油一直是生产燃料和化学品的主要原料，但煤炭、天然气和生物质能也日益成为人们探索的替代品。它们的转化首先产生合成气，一种CO和H₂的混合物，然后进行进一步处理，形成费托化学（FT）。然而，尽管用于燃料生产的商业化FT技术已经建立，但将其用于获取有价值的化学品仍然具有挑战性。

线性α-烯烃（LAOs）就是一个很好的例子，它是目前通过乙烯低聚得到的重要的化学中间体。目前正在开发的商业化高温FT工艺和FT制烯烃工艺，都将合成气直接转化为LAO，但也产生大量的二氧化碳废物，导致碳利用效率低。由于转化成有价值的C5-C10 LAO的碳原子，比主导产品混合物的C2-C4烯烃中的碳原子少得多，效率进一步降低。

在该研究中，课题组展示了用原始相纯碳化χ铁，可以最大限度地减少这些合成气转化问题——针对FT到LAO的过程进行了定制和优化，该催化剂的活性在290°C，比专用FT-to-烯烃催化剂320°C以上高1-2个数量级，在200h下稳定，在工业相关条件下产生所需的C2-C10 LAOs和不需要的CO2碳基选择性分别为51%和9%。这种较高的催化性能，在较宽的温度范围内（250-320°C）持续存在，证明了该系统在开发实际相关技术方面的潜力。

附：英文原文

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

Author: 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.

Issue&Volume: 2024-10-16

Abstract: Oil has long been the dominant feedstock for producing fuels and chemicals, but coal, natural gas and biomass are increasingly explored alternatives1,2,3. Their conversion first generates syngas, a mixture of CO and H2, 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 α-olefins (LAOs), which are important chemical intermediates obtained by ethylene oligomerization at present4,5,6,7,8. 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 efficiency9,10,11,12,13,14. The efficiency is further compromised by substantially fewer of the converted carbon atoms ending up as valuable C5–C10 LAOs than are found in the C2–C4 olefins that dominate the product mixtures9,10,11,12,13,14. Here we show that the use of the original phase-pure χ-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°C that is 1–2 orders higher than dedicated FT-to-olefin catalysts can achieve above 320°C (refs.12,13,14,15), is stable for 200h, and produces desired C2–C10 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°C), demonstrates the potential of the system for developing a practically relevant technology.

DOI: 10.1038/s41586-024-08078-5

Source: https://www.nature.com/articles/s41586-024-08078-5