Solvent-free porous liquids for CO2 capture based on silica nanoparticles with different core structures

Type I porous liquids (PLs) containing porosity are promising candidates for gas sorption and separation, homogeneous catalysis , and so forth. In this research, large porous silica nanoparticles (PSNs) and hollow wormhole silica nanoparticles (HSNs) are reported to fabricate Type I PLs through a facile synthetic strategy, where polyether amine is linked to nanoparticles by the silane coupling agent for CO 2 capture. Experimental results showed that canopies endow PSNs and HSNs with excellent fluidity along with the thermal stability of PLs at high temperature. The CO 2 sorption capability and dispersion stability were profoundly influenced by the specific surface area and pore size of PLs cores. At 25 °C and 2 bar, the CO 2 sorption capacities of pure M2070, PL_1_M2070, PL_2_M2070, and PL_3_M2070 were 10.9317 cm 3 /g, 9.1295 cm 3 /g, 6.2504 cm 3 /g, and 5.3518 cm 3 /g, respectively. Results showed that CO 2 sorption capability of porous silica nanoparticle assisted PLs with a large specific surface area and small pore sizes was superior. If the pore size was large enough, canopy would enter and fill the pores of silica nanoparticles, preventing part pores and polyether amine from offering active CO 2 sorption sites, thereby minimizing the CO 2 sorption and affecting the stability of the PLs. Sorption kinetics fitting results showed that the CO 2 sorption of PLs was the combination of physical dissolution and chemisorption . Furthermore, the adsorption capacity of PL_1_M2070 was 90.5% of the original CO 2 adsorption capacity after 10 adsorption/desorption cycles, indicating excellent recyclability.