Molecular-level CO2 adsorption behavior in amine-modified sorbents within a controlled CO2/H2O environment

This dataset supports the study "Discerning molecular-level CO2 adsorption behavior in amine-modified sorbents within a controlled CO2/H2O environment towards direct air capture", in which solid-state NMR spectroscopy was employed to elucidate CO2 adsorption from dilute, humidified CO2 streams onto an amine-modified benchmark direct air capture (DAC) adsorbent. The dataset includes 1D 1H/13C MAS, 2D 1H-13C HETCOR NMR, and 1H R2/R1ρ relaxometry, which reveal the influence of H2O on CO2 adsorption behavior. The results demonstrate the stepwise formation of ammonium carbamate, carbamic acid, and physisorbed CO2 as a function of CO2 concentration. Additionally, relaxation studies reveal both pore opening associated with sorbent swelling and varied H2O adsorption.