Carbon capture in polymer-based electrolytes

• DOI: 10.1126/sciadv.adk2350
• Publication Date: 2024-04-19T17:58:55Z
• Authors: Yang Wang; Tony G. Feric; Jing Tang; Chao Fang; Sara T. Hamilton; David M. Halat; Bing Wu; Hasan Celik; Guanhe Rim; Tara DuBridge; Julianne Oshiro; Rui Wang; Ah-Hyung Alissa Park; Jeffrey A. Reimer
• Keywords: Climate Action; Chemical Sciences; Nanotechnology; Bioengineering; Physical and Materials Sciences; Physical Chemistry; 01 natural sciences; Macromolecular and Materials Chemistry; 0104 chemical sciences

Nanoparticle organic hybrid materials (NOHMs) have been proposed as excellent electrolytes for combined CO 2 capture and electrochemical conversion due to their conductive nature and chemical tunability. However, CO 2 capture behavior and transport properties of these electrolytes after CO 2 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 2 capture. Quantitative 13 C NMR spectra collected at variable temperatures reveal that absorbed CO 2 exists as carbamates (RHNCOO − or RR′NCOO − ) and carbonate/bicarbonate (CO 3 2− /HCO 3 − ). The transport properties of PEI and NOHM-I-PEI studied using 1 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.