Adv. mater.: high efficient removal of trace propargyne from propylene mixture by "propargyne monomolecular cage", a research group of Professor Xing Huabin, Zhejiang University

In the complex mixture with similar structure, the deep removal of trace components has always been one of the technical challenges in the field of chemical separation This requires that the separation materials can not only effectively identify the small differences between similar molecular structures, but also have high adsorption capacity for the target molecules at very low concentrations The traditional porous adsorbent can not meet this demanding requirement, which greatly limits the development of energy-saving and efficient adsorption separation process Propylene is the second most important olefin raw material in the world (annual output is over 85 million tons) The propylene gas after cracking contains 1000-2000 ppm of propargyne, which needs to be removed to 1-5 ppm to meet the demanding requirements of downstream propylene polymerization The structure and size of propargyne and propylene (source: adv mater.) "tailored" is an effective method to design porous adsorbents Recently, the research group of low carbon hydrocarbon and drug separation of Zhejiang University cooperated with foreign countries to report for the first time the strategy of "propargylic monomolecular cage adsorption" According to the shape characteristics of propargyne molecules, a suitable Anion Pillared microporous material was constructed to enhance the "specificity" and "affinity" of propargyne molecules, so as to achieve the efficient removal of trace propargyne from propylene mixture The anionic pillared microporous materials have a cubic grid structure and the anions are layered arrays According to the three-dimensional size of propargyne molecules, the length, width and height of the pores are adjusted in a very high precision, and a single molecular cage of propargyne gas is constructed Propargyne molecules can be perfectly embedded in the pores, and show a strong "affinity" with the layered anions The "tailor-made" pore structure makes the material show the specific collection ability of propargyne At 25 ℃, 700 ppm, the adsorption capacity of propargyne is as high as 80 mg-1, and the saturated adsorption capacity is 106 mg-1 when the concentration is 3000 ppm, while the corresponding adsorption capacity of propylene is less than 3 mg-1, and the separation selectivity of propargyne and propylene is more than 250, which is the best material reported so far The results of fixed bed adsorption showed that trace propargyne (1000 ppm) could be removed in depth by solid cage adsorption The concentration of propargyne in propylene was less than 2 ppm, and the adsorption capacity was more than 9 times of the best material reported in literature DFT-D computational adsorption binding site (source: adv material.) was recently published on advanced materials (if = 19.79), and was selected as frontispiece paper Yang Lifeng and Cui Xili, Ph.D students of Zhejiang University, were co authors, Xing Huabin, Professor correspondent, Professor Banglin Chen of UTSA, and Wei Zhou of NIST The doctor participated in the research of the thesis Paper link: https://doi.org/10.1002/adma.201705374 corresponding author: Xing Huabin http://mypage.zju.edu.cn/xinghb