On October 30, 2025, a research team led by Researcher Wen Xiaodong from the Institute of Coal Chemistry (ICC) of the Chinese Academy of Sciences (CAS), in collaboration with a team led by Professor Ma Ding from Peking University, published their latest research findings in Science. The research results are titled "Trace-level halogen dynamically suppresses CO₂ formation in fischer-tropsch synthesis for high-value olefins. The first author and the first institution of the paper are both ICC CAS. The research has achieved a significant breakthrough for the first time in iron-based Fischer-Tropsch synthesis catalysts, with CO₂ selectivity below 1% and olefin selectivity exceeding 85%, providing a brand-new idea for the clean and efficient utilization of high-carbon resources.

ABSTRACT: Sustainable production of fuels and olefins from syngas (carbon monoxide and hydrogen) through the Fischer-Tropsch synthesis process requires catalysts that deliver high selectivity, industrial productivity, and minimal carbon dioxide (CO₂) emissions. Current industrial iron catalysts form substantial CO₂ by-product that limits carbon efficiency. We report that introducing trace amounts [parts per million (ppm) level] of halogen-containing compounds into the feed gas can suppress CO₂ formation using iron-based catalysts and boost olefin selectivity over paraffin and olefin productivity. Cofeeding 20 ppm bromomethane over an iron carbide catalyst decreased CO₂ selectivity to <1% and increased olefin selectivity to ~85% among all carbon-containing products. Surface-bound halogens modulated the catalyst surface structure and selectively inhibited pathways responsible for CO₂ generation and olefin hydrogenation. This strategy provides a simple, scalable, and broadly applicable route for carbon-efficient syngas conversion.

Yi Cai et al., Trace-level halogen blocks CO₂ emission in Fischer-Tropsch synthesis for olefins production. Science 390, 516-520 (2025). DOI: 10.1126/science.aea1655