A Metal–Organic Framework with Suitable Pore Size and Specific Functional Sites for the Removal of Trace Propyne from Propylene

• Published in: Angewandte Chemie International Edition Vol. 57; no. 46; pp. 15183 - 15188
• Main Authors: Li, Libo, Wen, Hui‐Min, He, Chaohui, Lin, Rui‐Biao, Krishna, Rajamani, Wu, Hui, Zhou, Wei, Li, Jinping, Li, Bin, Chen, Banglin
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 12.11.2018
• Edition: International ed. in English
• Subjects: Acetylene; Binding sites; gas separation; Metal-organic frameworks; Metals; Pore size; Porosity; porous materials; Propylene; propylene purification; propyne; Purification; Selectivity; size sieving; porous materials; size sieving; propylene purification; gas separation; propyne
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201809869

Separation of propyne/propylene (C3H4/C3H6) is more difficult and challenging than that of acetylene/ethylene (C2H2/C2H4) because of their closer molecular sizes. A comprehensive screening of a series of metal–organic frameworks with broad types of structures, pore sizes, and functionalities was carried out. UTSA‐200 was identified as the best separating material for the removal of trace C3H4 from C3H4/C3H6 mixtures. Gas sorption isotherms reveal that UTSA‐200 exhibits by far the highest C3H4 adsorption capacity (95 cm3 cm−3 at 0.01 bar and 298 K) and record C3H4/C3H6 selectivity, which was mainly attributed to the suitable dynamic pore size to efficiently block the larger C3H6 molecule whilst the strong binding sites and pore flexibility capture smaller C3H4. This material thus provides record purification capacity for the removal of C3H4 from a 1:99 (or 0.1:99.9, v/v) C3H4/C3H6 mixture to produce 99.9999 % pure C3H6 with a productivity of 62.0 (or 142.8) mmol g−1. Record removal: A series of metal–organic frameworks with broad types of structures, pore sizes, and functionalities were used to identify UTSA‐200 as the best separating agent for removal of trace C3H4 from C3H4/C3H6 mixtures. The efficiency is mainly attributed to the optimally dynamic pore size to efficiently block the larger C3H6 whilst retaining strong binding sites to selectively take up C3H4, thus producing high‐purity C3H6 (99.9999 %).