Carbon capture in polymer-based electrolytes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38640239.
- Also identified by DOI 10.1126/sciadv.adk2350 and PMC identifier 11029803.
- Licence recorded as CC BY-NC.
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Abstract
Nanoparticle organic hybrid materials (NOHMs) have been proposed as excellent electrolytes for combined CO<sub>2</sub> capture and electrochemical conversion due to their conductive nature and chemical tunability. However, CO<sub>2</sub> capture behavior and transport properties of these electrolytes after CO<sub>2</sub> capture have not yet been studied. Here, we use a variety of nuclear magnetic resonance (NMR) techniques to explore the carbon speciation and transport properties of branched polyethylenimine (PEI) and PEI-grafted silica nanoparticles (denoted as NOHM-I-PEI) after CO<sub>2</sub> capture. Quantitative <sup>13</sup>C NMR spectra collected at variable temperatures reveal that absorbed CO<sub>2</sub> exists as carbamates (RHNCOO<sup>-</sup> or RR'NCOO<sup>-</sup>) and carbonate/bicarbonate (CO<sub>3</sub><sup>2-</sup>/HCO<sub>3</sub><sup>-</sup>). The transport properties of PEI and NOHM-I-PEI studied using <sup>1</sup>H pulsed-field-gradient NMR, combined with molecular dynamics simulations, demonstrate that coulombic interactions between negatively and positively charged chains dominate in PEI, while the self-diffusion in NOHM-I-PEI is dominated by silica nanoparticles. These results provide strategies for selecting adsorbed forms of carbon for electrochemical reduction.