CO2 capture of amino functionalized three-dimensional worm-hole mesostructured MSU-J silica

Tetraethylenepentamine (TEPA) was employed to functionalize the large-pore mesoporous silica (denoted MSU-J) with 3D worm-hole framework structures which was prepared through a supramolecular hydrogen-bonding assembly pathway from low-cost H₂NCH(CH₃)CH₂OCH₂CH(CH₃)]₃₃NH₂ (D2000) as structure-directing porogens and tetraethylorthosilioate as the silica source for capturing CO₂. The resultant adsorbents were characterized by FT-IR, Transmission electron microscopy (TEM), N₂ adsorption/desorption and thermogravimetric analysis. Textural properties, elemental analysis and TEM measurement of the samples showed a severe pore filling of MSU-J as TEPA loading was increased to 70 wt%. CO₂ adsorption isotherms measured at different temperatures revealed the optimal adsorption temperature is 25 °C. The adsorption capacity of MSU-J with different TEPA loading contents was calculated. As a result, 50 wt% of TEPA supported on as-synthesized MSU-J achieved the highest capacity with the value of 164.3 mg/g under the conditions of 99.99 % CO₂ at 25 °C and 0.1 MPa. Repeated adsorption/desorption cycles revealed that amine-impregnated materials was very efficient for less apparent decrease in CO₂ adsorption capacity even after 6 adsorption–regeneration cycles.