Capture of carbon dioxide by polyamine-immobilized mesostructured silica: A solid-state NMR study

Abstract

Highly efficient polyamine-modified mesostructured silica adsorbents fabricated invoking a facile one-pot process under microwave-assisted heating show superior CO2 uptake capacity up to 4.43 mmol g−1 comparable to polyamine-immobilized mesoporous SBA-15 silicas prepared by the conventional post-synthesis route is reported. Solid adsorbents modified with various alkanolamines were examined. The influences of type and loading of polyamines, surfactant template, textural and surface properties of the support on CO2 uptake performance, efficiency, and recyclability of the adsorbents were explored by adsorption/desorption kinetics as well as various solid-state 1D multinucleus and 2D heteronucleus correlation spectroscopy techniques. The results so obtained afford detailed information regarding to the interactions among the guest amines, surfactant template, silica surfaces, and adsorbed CO2, which are helpful for verification of adsorption structures and assessment of adsorption performances to render future design and fabrication of amine-based solid adsorbents for efficient and prospective applications in CO2 capture.