Data from: Molecular-level CO2 adsorption behavior in amine-modified sorbents within a controlled CO2/H2O environment
Data files
Sep 05, 2024 version files 51.81 MB
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MOUSE_H2O_D2O.zip
961.57 KB
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README.md
2.55 KB
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Solid-state_NMR_coadsorption.zip
50.84 MB
Abstract
Sorbents designed for direct air capture (DAC) play a crucial role in the pursuit of achieving net-zero carbon dioxide emissions. This study elucidates CO2 adsorption from dilute, humidified CO2 streams onto an amine-modified benchmark DAC adsorbent via solid-state NMR spectroscopy. Various NMR techniques, including 1D 1H MAS, 13C MAS, 2D 1H-13C HETCOR NMR, and 1H R2 and R1ρ relaxometry reveal the impact of CO2 partial pressure and H2O on CO2 adsorption behavior. We find that CO2 concentration governs the stepwise formation of ammonium carbamate, carbamic acid, and physisorbed CO2, where relative humidity (RH) at a desired low (<400ppm) CO2 loading affects total CO2 uptake. The relaxation studies reveal the cooperative or competitive nature of H2O-CO2 sorption in CO2-dilute humid gas, and in particular polymer swelling upon humidification. From those results, we demonstrate that the observed absorption capacity enhancement by humidity is caused by pore opening due to sorbent swelling, and not by bicarbonate formation. This NMR-discerned speciation provides insights into sorption behavior at different RHs in dilute CO2 gas streams, simulating real-world atmospheric conditions, and governs the design of efficient and adaptable material-process combinations for solid sorbent DAC.
README: Data from: Molecular-level CO2 adsorption behavior in amine-modified sorbents within a controlled CO2/H2O environment
https://doi.org/10.5061/dryad.h70rxwdsx
This dataset includes solid-state NMR data to report qualitative 1H and 13C, quantitative13C results under dry and humid conditions (30% RH and 80% RH), and time-resolved CPMG echo train decays to report time-dependent R2 in water of benchmark sorbent materials.
## Description of the data and file structure
1. Solid-state NMR_coadsorption contains solid-state NMR data on both 1H and 13C nuclei. The experiments were conducted at high magnetic fields with magic angle spinning (MAS).
The folder structure provides essential information on the experimental setup.
The subfolder starting with “Lewatit_activated..” represents activated materials, followed by the observed nuclei and measurement method.
The subfolder starting with “Lewatit_D2O_activated..” represents materials preprocessed with D2O before activation, followed by the observed nuclei and measurement method.
The subfolder starting with “Lewatit_DryCO2..” represents CO2 adsorption without water, followed by adsorption temperature, CO2 partial pressure, observed nuclei, measurement method. If air exposure occurs after the adsorption, the folder name includes “airexposure”.
The subfolder starting with “Lewatit_WetCO2..” represents CO2 adsorption in the presence of water, followed by adsorption temperature, relative humidity, CO2 partial pressure, observed nuclei, and measurement method.
The subfolder starting with “Lewatit_WetN2..” represents adsorption without CO2 (N2 only) in the presence of water, followed by adsorption temperature, relative humidity, water type (D2O or H2O), observed nuclei, and measurement method.
2. MOUSE_H2O_D2O contains CPMG data for time-resolved R2 measurements, collected using a PM 25 NMR-MOUSE interfaced to a Kea II spectrometer using Magritek's Prospa software. The subfolder names specify the solvent (either H2O or D2O) used and the duration of the experiment to monitor R2 profiles.
Within each subfolder, the experiments are labeled as cpmg#, where the number represents the specific experiment number. Each folder contains two primary data files: “data.csv”, which holds the raw echo train data and the corresponding time vector, and “spectrum.csv”, which contains the R2 distribution data derived through Laplace inversion performed by Prospa.