Liquid‐in‐Aerogel Porous Composite Allows Efficient CO₂ Capture and CO₂/N₂ Separation

Abstract

The pursuit of efficient CO2 capture materials remains an unmet challenge. Especially, meeting both high sorption capacity and fast uptake kinetics is an ongoing effort in the development of CO2 sorbents. Here, a strategy to exploit liquid‐in‐aerogel porous composites (LIAPCs) that allow for highly effective CO2 capture and selective CO2/N2 separation, is reported. Interestingly, the functional liquid tetraethylenepentamine (TEPA) is partially filled into the air pockets of SiO2 aerogel with left permanent porosity. Notably, the confined liquid thickness is 10.9–19.5 nm, which can be vividly probed by the atomic force microscope and rationalized by tailoring the liquid composition and amount. LIAPCs achieve high affinity between the functional liquid and solid porous counterpart, good structure integrity, and robust thermal stability. LIAPCs exhibit superb CO2 uptake capacity (5.44 mmol g−1, 75 °C, and 15 vol% CO2), fast sorption kinetics, and high amine efficiency. Furthermore, LIAPCs ensure long‐term adsorption–desorption cycle stability and offer exceptional CO2/N2 selectivity both in dry and humid conditions, with a separation factor up to 1182.68 at a humidity of 1%. This approach offers the prospect of efficient CO2 capture and gas separation, shedding light on new possibilities to make the next‐generation sorption materials for CO2 utilization.

Sustainable Dual-Template Fabrication of Hierarchical Pore Structure for Enhanced and Stable CO2 Capture

“…The adsorption halftime (t 50% ), which represents the time to accomplish half of the adsorbent's capacity, was employed to evaluate the adsorption kinetics. 43 Notably, a nearly identical adsorption half-time was observed for adsorbents with and without the FC process (Figure S16). The utilization of FC transformed carbon materials from a powder form into structured monoliths, which is preferred in practical applications due to their mechanical stability and resistance to dispersion under high gas flows (Figure S17).…”

“…HPC–BFC–ZnO exhibited the highest uptake capacity among the adsorbents, recording 84.41 mg g –1 (1.92 mmol g –1 ). The adsorption halftime ( t 50% ), which represents the time to accomplish half of the adsorbent’s capacity, was employed to evaluate the adsorption kinetics . Notably, a nearly identical adsorption half-time was observed for adsorbents with and without the FC process (Figure S16).…”