Hydrophobic Metal–Formate Composites for Efficient CO₂ Capture

Carbon capture, utilization, and sequestration (CCUS) have emerged as pivotal mitigation strategies in addressing climate change induced by greenhouse gas emissions. In this pursuit, our objective is to enhance the efficacy of adsorptive CO₂ capture by harnessing state-of-the-art framework sorbents engineered for exceptional CO₂ selectivity, high intrinsic stability in the presence of moisture, and facile regeneration. To this end, a series of ultramicroporous mixed aluminum and iron formate framework materials, Fe-ALFs, were synthesized. Furthermore, their moisture stability has been significantly enhanced by passivation with polyvinylidene fluoride (Fe-ALF-PVDF). Gas sorption and breakthrough measurements demonstrate that Fe-ALF-PVDF exhibits outstanding CO₂ adsorption capacities (4.6 mmol/g at 298 K) and remarkable CO₂/N₂ selectivity (387). In addition, it can be economically produced from readily available chemicals and is easy to regenerate. Fe-ALF-PVDF presents an innovative adsorbent material for efficiently capturing CO₂ from humid postcombustion flue gases and other moisture-rich gas streams.