Carbon capture in polymer-based electrolytes

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

doi:10.1126/sciadv.adk2350

Carbon capture in polymer-based electrolytes

Sci Adv. 2024 Apr 19;10(16):eadk2350. doi: 10.1126/sciadv.adk2350. Epub 2024 Apr 19.

Authors

Yang Wang¹, Tony G Feric^{2

3}, Jing Tang^{1

4

5}, Chao Fang^{1

6}, Sara T Hamilton^{3

7}, David M Halat^{1

6}, Bing Wu¹, Hasan Celik⁸, Guanhe Rim^{3

7}, Tara DuBridge¹, Julianne Oshiro¹, Rui Wang^{1

6}, Ah-Hyung Alissa Park^{2

3

7}, Jeffrey A Reimer^{1

6

7}

Affiliations

¹ Department of Chemical and Biomolecular Engineering, College of Chemistry, UC Berkeley, Berkeley, CA 94720, USA.
² Department of Chemical Engineering, Columbia University, New York, NY 10027, USA.
³ Lenfest Center for Sustainable Energy, Columbia University, New York, NY 10027, USA.
⁴ Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
⁵ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
⁶ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁷ Department of Earth and Environmental Engineering, Columbia University, New York, NY 10027, USA.
⁸ College of Chemistry Nuclear Magnetic Resonance Facility (CoC-NMR), University of California, Berkeley, CA 94720, USA.

Abstract

Nanoparticle organic hybrid materials (NOHMs) have been proposed as excellent electrolytes for combined CO₂ capture and electrochemical conversion due to their conductive nature and chemical tunability. However, CO₂ capture behavior and transport properties of these electrolytes after CO₂ 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 CO₂ capture. Quantitative ¹³C NMR spectra collected at variable temperatures reveal that absorbed CO₂ exists as carbamates (RHNCOO^- or RR'NCOO^-) and carbonate/bicarbonate (CO₃^2-/HCO₃^-). The transport properties of PEI and NOHM-I-PEI studied using ¹H 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.