Abstract
Ionic liquids (ILs) and deep eutectic solvents (DESs) have tremendous potential for reactive capture and conversion (RCC) of CO2 due to their wide electrochemical stability window, low volatility, and high CO2 solubility. There is environmental and economic interest in the direct utilization of the captured CO2 using electrified and modular processes that forgo the thermal- or pressure-swing regeneration steps to concentrate CO2, eliminating the need to compress, transport, or store the gas. The conventional electrochemical conversion of CO2 with aqueous electrolytes presents limited CO2 solubility and high energy requirement to achieve industrially relevant products. Additionally, aqueous systems have competitive hydrogen evolution. In the past decade, there has been significant progress toward the design of ILs and DESs, and their composites to separate CO2 from dilute streams. In parallel, but not necessarily in synergy, there have been studies focused on a few select ILs and DESs for electrochemical reduction of CO2, often diluting them with aqueous or non-aqueous solvents. The resulting electrode-electrolyte interfaces present a complex speciation for RCC. In this review, we describe how the ILs and DESs are tuned for RCC and specifically address the CO2 chemisorption and electroreduction mechanisms. Critical bulk and interfacial properties of ILs and DESs are discussed in the context of RCC, and the potential of these electrolytes are presented through a techno-economic evaluation.
Original language | English |
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Pages (from-to) | 8563-8631 |
Number of pages | 69 |
Journal | Chemical Society Reviews |
Volume | 53 |
Issue number | 17 |
DOIs | |
State | Published - Jun 24 2024 |
Funding
This work was supported by the Center for Closing the Carbon Cycle, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award Number DE-SC0023427 (electrochemical conversion; S. D., A. B., M. G., R. D. R., J. S., R. S. B., J. M. V., J. Y. Y., C. H., C. G. M.-G., J. M. S., B. G.), Basic Energy Sciences, award # DE-SC0022214 (sorbents for CO capture; M. Z., R. D., B. G.), Breakthrough Electrolytes for Energy Storage (BEES2) under award # DE-SC0019409 (electrolyte properties; M. M., B. G.), and National Science Foundation Career award # 2045111 from the Division of Chemical, Bioengineering, Environmental and Transport Systems (interfacial analysis of ionic liquid electrolytes; O. K. C., B. G.). A. U. thanks the Fulbright T\u00FCrkiye's Visiting Scholar Program, the Ko\u00E7 University Visiting Scholar Program, and the Scientific and Technological Research Council of T\u00FCrkiye (TUBITAK) 2219 Program. B. K.'s efforts were supported by the Department of Energy, National Nuclear Security Administration (NNSA) grants (DE-NA0004112 and DE-NA0004007). 2