Synergistic Effect of Active Sites and a Multiple-Micropore System for a Metal-Organic Framework Exhibiting High Separation of CO2/CH4 and C2H2/CH4.

Efficient gas separation and purification play a vital role in the current advanced development of industry, and the application of MOF adsorbents in this area with highly technical materials shows obvious advantages. On the basis of reticular chemistry, the 4-c lvt MOF adsorbent [CuDTTA]·3DMF·CH3CN has been constructed (CuDTTA; H2DTTA = 2,5-bis(1H-1,2,4-triazol-1-yl)terephthalic acid). CuDTTA reveals a multiple-micropore system and high-density active sites decorated on the channel surfaces, which are conducive to its extraordinary selectivity of CO2/CH4 and C2H2/CH4 (29 and 166, 1:1). In combination with an analysis of Qst values, CuDTTA possesses the synergistic effect of size sieving and abundant functional sites, significantly improving the gas adsorption and separation performance. Meanwhile, the results also reveal that functional sites have a stronger binding affinity toward C2H2 with respect to CO2. Such a conclusion renders CuDTTA to be a promising adsorbent material for industrial applications.