Exceptionally Stable Microporous Organic Frameworks with Rigid Building Units for Efficient Small Gas Adsorption and Separation
Weiqiu Wen, Peter S. Shuttleworth, Hangbo Yue, Juan P. Fernandéz‐Blázquez, Jianwei Guo
Abstract
Three microporous organic frameworks (hereafter denoted as MPOF-Ads) based on a rigid adamantane core have been successfully synthesized via Sonogashira–Hagihara polycondensation coupling in high yields, 83.7–94.6%. The obtained amorphous MPOF-Ads networks have high Brunauer–Emmett–Teller surface areas (up to 737.3 m2 g–1), narrow pore size distribution (0.95–1.06 nm), and superior thermal (the initial decomposition temperature T5% under an N2 atmosphere can reach 410 °C) and chemical stability (no apparent degradation in common organic solvents or strong acid/base solutions after 7 days). At 273 K and 1.0 bar, these MPOF-Ads networks present good uptake capacities for small gas molecules (13.9 wt % CO2 and 1.66 wt % CH4) for which the presence of high surface area, predominant microporosity, and narrow pore size distribution are beneficial. In addition, the as-prepared MPOF-Ads networks possess moderate isosteric heats for CO2 (Qst = 19.5–30.3 kJ mol–1) and show desired CO2/N2 and CO2/CH4 selectivity (36.3–38.4 and 4.1–4.3 based on Henry’s law and 17.88–24.92 and 4.24–5.70 based on ideal adsorbed solution theory, respectively). With the demonstrated properties, the synthesized MPOF-Ads networks display potential for small gas storage and separation that can be used in harsh environments because of their superior physical and chemical stability.