Significant progresses has been made in the field of gas adsorption and separation by some scientific research institutions such as the School of Materials Science and Engineering of Nankai University, the University of Manchester, the Dalian Institute of Chemical Physics, the Chinese Academy of Sciences, the Rutherford Appleton Laboratory and the Oak Ridge National Laboratory. On May 29, Science has published their work Control of zeolite pore interior for chemoselective alkyne/olefin separations. Nankai University is identified as the first contributor, and the researcher Li Landong of Nankai University and Dr. Yang Sihai of the University of Manchester are the co-correspondent authors.
Lower olefins represented by ethylene and propylene, are the most basic raw materials for chemical industry. With a global production capacity of nearly 400 million tons per year, they are mainly used to produce important chemicals such as synthetic fibers, rubber, and plastics. The production process of lower olefins will introduce a small amount of alkyne impurities, which will greatly affect its polymerization and subsequent machining. The purification of lower olefins is today’s largest and most important chemical separation process in the world. Porous adsorbent represented by metal organic framework materials can selectively adsorb alkynes to achieve alkyne / olefin separation, which is expected to replace the current expensive and cumbersome selective hydrogenation alkynes-removal process. However, the adsorption separation process, based on the complex interaction between alkyne / olefin gas molecules and porous adsorbent, is difficult to achieve both the high adsorption capacity and the separation selectivity, hence this has become a challenge in this field. Moreover, the cyclic stability and the cost of porous adsorbent will also further restrict its industrial application.
In response to these problems, the researchers started with cheap and readily available materials, designed and constructed zeolite localized coordinatively unsaturated centers to achieve chemically selective alkyne / olefin adsorption and separation, and proposed a new strategy based on chemical bond. This strategy can fundamentally solve the problem that it is difficult to balance adsorption capacity and separation selectivity. It also has the universality of methodology. This study proposes a new strategy for the separation of alkyne / olefin based on chemical bonds, which is expected to promote the application of zeolite materials in the related industries. This strategy uses advanced spectroscopy techniques to reveal the specific chemical behavior of small molecules in confined spaces from multiple levels of molecules, clusters, and surfaces, providing new ideas for the design and development of adsorption catalytic materials.
The work has been supported by the National Natural Science Foundation of China, 100 Young Academic Leader Training Program of Nankai University and others.
Link to the article: https://science.sciencemag.org/content/368/6494/1002
(Reported by Chao Ma, Translated by Xinghua Li, Edited by Davide Francolino and JianjingYun)