Highly efficient and reversible CO2 adsorption by amine-grafted platelet SBA-15 with expanded pore diameters and short mesochannels

Abstract

The ever-increasing concentration of CO₂ in the atmosphere has raised great concerns over carbon capture techniques. To enhance the CO₂ adsorption capacity, a kind of platelet SBA-15 with short channels and large pore diameters has been prepared and grafted with various aminosilanes (mono-, di-, and tri-amine). Thorough analysis of the support structure and sorbent performance was estimated through a combination of amine loading, CO₂ adsorption capacity and CO₂/N₂ selectivity. It was shown that compared to traditional fiber SBA-15, amine loading for these novel sorbents was increased from 3.56 to 5.90 mmol g⁻¹ (a 66% increase), and the CO₂ adsorption capacity was increased from 1.23 to 2.67 mmol g⁻¹ (a 120% increase). Also, the selectivity of CO₂/N₂ was remarkably enhanced from 37 to 169. The CO₂ adsorption enthalpy reached 67 kJ mol⁻¹. Moreover, these sorbents are regenerable and exhibit good stabilities. Thus, this approach offers an alternative for the development of technological innovation towards efficient and reversible processes for carbon capture.