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Nanoparticle organic hybrid materials (NOHMs) have been proposed as excellent electrolytes for combined CO₂capture and electrochemical conversion due to their conductive nature and chemical tunability. However, CO₂capture behavior and transport properties of these electrolytes after CO₂capture 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 CO₂capture. Quantitative¹³C NMR spectra collected at variable temperatures reveal that absorbed CO₂exists as carbamates (RHNCOO⁻or RR′NCOO⁻) and carbonate/bicarbonate (CO₃²⁻/HCO₃⁻). The transport properties of PEI and NOHM-I-PEI studied using¹H 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. 

Lithium transference in a multivalent electrolyte containing bulky, star-shaped anions is compared using three experimental techniques, namely, electrochemical polarization, PFG-NMR and electrophoretic NMR. 

We demonstrate that contrary to previous reports, transference number decreases with increasing degree of polymerization in non-aqueous lithium-bearing polyelectrolyte solutions that have been proposed as next-generation battery electrolytes.