Low-Cost and High-Performance Microporous Metal–Organic Framework for Separation of Acetylene from Carbon Dioxide

Abstract

Separation of acetylene (C2H2) from carbon dioxide (CO2) is very difficult and challenging because of their similar molecular sizes and associated physical properties. Realization of low-cost and high-performance porous materials is of importance to facilitate the implementation of energy-efficient adsorptive separation into practical gas separation applications. Here, we utilized a cheap and commercially available formic acid ligand to successfully construct a robust MOF material [Ni3(HCOO)6·DMF] (1·DMF), offering high chemical stability, low cost, and high selectivity toward C2H2 over CO2. The exceptional separation performance of the activated 1 is mainly attributed to the small pore size (4.3 Å) and functional O donor sites on the pore walls that provide strong binding affinity toward C2H2, as revealed by the detailed computational studies. This material thus exhibits ultrahigh low-pressure C2H2 uptake (38.2 cm3 cm–3 at 0.01 bar and 298 K) and possesses a high C2H2/CO2 selectivity (22.0 at ambient conditions), comparable to other leading porous materials. The high separation performance of 1 was further confirmed by the actual breakthrough experiments on a 50/50 C2H2/CO2 mixture