Carbon Dioxide Capture by Amine-Impregnated Mesocellular-Foam-Containing Template

By impregnating polyethylenimine (PEI) into silica mesocellular foam with the template remaining (MCF­(a)), a novel sorbent with both high CO₂ adsorption capacity and high thermal stability was obtained. The remaining P123 template in the MCF played a great role in promoting the CO₂ adsorption capacity, which could be 4.5 mmol·g^–1 (adsorbent) when the amount of amine loading and the adsorption temperature were optimized as 60% and at 70 °C for the sample MCF­(a)/PEI. Meanwhile, MCF­(a)/PEI had a high thermal stability and selectivity, after 10 adsorption–desorption cycles, MCF­(a)/PEI almost held a constant adsorption capacity; for different compositions of CO₂ and N₂ mixed gases, it always kept a high adsorption selectivity of CO₂/N₂. The mechanism of the template synergistic effect was elucidated by the result of a second-order rate law through CO₂ adsorption kinetic studies. Moreover, as predicted by the Langmuir adsorption model with <i>n</i> = 2 (two active adsorption sites for one CO₂ molecule), the adsorption enthalpy was calculated as about −85 kJ·mol^–1, a value which belonged to typical chemical adsorption

Interfacial Growth of Metal Organic Framework/Graphite Oxide Composites through Pickering Emulsion and Their CO₂ Capture Performance in the Presence of Humidity

We proposed an in situ interfacial growth method induced by the Pickering emulsion strategy to produce metal organic framework (MOF)/graphite oxide (GO) composites of Cu₃(BTC)₂/GO, in which GO was demonstrated to be a promising stabilizer for producing the Pickering emulsion and provided a large interfacial area for the in situ growth of Cu₃(BTC)₂ nanoparticles. When Cu₃(BTC)₂/GO composites were used as adsorbents for CO₂ capture from the simulated humid flue gas, they showed both significantly improved thermodynamic and dynamic properties. Because most of the H₂O molecules were adsorbed on the highly exfoliated GO sheets in Cu₃(BTC)₂/GO-m, CO₂ uptake reached 3.30 mmol/g after exposure to the simulated flue gas for 60 min and remained unchanged for up to 120 min. This highlighted its potential application for real CO₂ capture. More importantly, the in situ interfacial growth of nanoparticles induced by Pickering emulsions would be a promising strategy for designing and fabricating nanocomposites