Separation of Alkynes from Olefins for Polymer Production

Scientific Achievement
Chemoselective alkyne/olefin separation by a nickel decorated zeolite was found to occur via binding of acetylene to the confined Ni through formation of metastable [Ni(C2H2)3] complexes.
Significance and Impact
Understanding and controlling porous sorbants, like zeolites, can lead to cheaper and more efficient separation of alkynes from olefin, a costly step in the polymer processing of lower olefins (ethylene, propylene, etc.).
Research Details
- Ni-decorated faujasite, a zeolite, was produced confining atomically dispersed Ni into zeolite channels.
- In situ neutron diffraction and spectroscopy combined with density functional theory calculations revealed that the Ni sites interact much more strongly with alkynes than with olefins, leading to the excellent selectivity.
- The material also exhibits high dynamic uptake of alkynes, thanks to the large specific surface area of the porous faujasite.
“Control of zeolite pore interior for chemoselective alkyne/olefin separations”
Yuchao Chai1, Xue Han2, Weiyao Li2, Shanshan Liu1, Sikai Yao1, Chong Wang3, Wei Shi4, Ivan da-Silva5, Pascal Manuel5, Yongqiang Cheng6, Luke D. Daemen6, Anibal J. Ramirez-Cuesta6, Chiu C. Tang7, Ling Jiang3, Sihai Yang2, Naijia Guan1,4, Landong Li1,4,
Science, 368, 1002 (2020).
DOI: 10.1126/science.aay8447