Carbon dioxide capture on primary amine groups entrapped in activated carbon at low temperatures

•Selective CO2 uptake under ambient conditions was tested.•Aminoclay (H2N-CL), 3-aminopropyltriethoxysilane (APTES), and dopamine were selected.•The CO2 adsorption capacity of coated H2N-CL on AC is higher than that of AC.•The coating of H2N-CL into AC exhibits a selectivity value of 18.7 for CO2/N2.

For purposes of selective CO2 uptake under ambient conditions, a few number of primary amine groups are selected, including aminoclay (H2N-CL), 3-aminopropyltriethoxysilane (APTES), and dopamine hydrochloride (DA). Coatings of both H2N-CL into activated carbon (AC) show enhanced CO2 adsorption capacity at 273 and 298 K and 1 atm, resulting in 3.069/1.950 mmol/g, compared to 2.872/1.824 mmol/g of pristine AC. However, APTES and DA coated AC at 273 and 298 K and 1 atm are reduced to 2.433/1.762 and 0.429/0.389 mmol/g. Particularly, the coating of H2N-CL nanoparticles into AC exhibits enhanced selectivity of 8.8/18.7, compared to 7.6/15.9 in pristine AC for CO2/N2 at 273 and 298 K at 1 atm.

Graphical abstractSelective CO2 and N2 sorption capacity for H2N-CL-AC at 298 K.Figure optionsDownload full-size imageDownload as PowerPoint slide