Modified layered double hydroxides for efficient and reversible carbon dioxide capture from air

Direct air capture (DAC) is becoming a technically feasible negative emission technology; however, the fabrication of affordable adsorbents with large CO 2 capacities, fast kinetics, and high sorption-desorption stability are critical importance for large-scale deployment DAC process. In this study, amine functionalized, aqueous miscible organic Mg x Al-CO 3 layered double hydroxide (LDH) nanosheets used to efficiently rapidly from ambient air. 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TRI) treatment highly dispersed LDH produces sorbent exhibiting an impressive adsorption capacity 1.05 mmol g −1 at 25°C when exposed 400 ppm , which 30% higher than equivalent amine-functionalized SBA-15 supports. uptake reaches 70% maximum within 30 min twice as supported polyamines. The provide excellent thermal, hydrothermal, chemical stability, negligible performance degradation after 50 adsorption-desorption cycles. Amine monolayer-tethered, exfoliated hydroxides synthesized adsorbent shows in simulated Negligible observed cycles Zhu et al. synthesize modified (LDHs) Exposed hydroxyl groups on LDHs react aminosilanes form monolayer grafted nanosheets, allowing ultrafast capture. Platelet size, thickness, morphology have significant impact obtaining optimal grafting.