CO₂ Electroreduction in Ionic Liquids: A Review

Abstract

The increasing emission of carbon dioxide (CO2) caused by the unrestrained consumption of fossil fuels in recent hundreds of years, has caused global environmental and social problems. Meanwhile, CO2 is a cheap, abundant and renewable C1‐feedstock, which can be converted into alcohols, ethers, acids and other value‐added chemicals. Compared with the thermal reactions, electrochemical reduction of CO2 is more attractive because of its advantages by using the seasonal, geographical and intermittent energy (tide, wind and solar) under mild conditions. In recent years, taking ionic liquids (ILs) as electrolytes in the CO2 electrochemical reduction reaction has been paid much more attention due to the advantages of lowering the overpotential of CO2 electroreduction and improving the Faradaic efficiency. In this paper, we summarized the recent progresses of electrochemical reduction of CO2 in ILs electrolytes, and analyzed the reaction mechanism of CO2 reaction in the electrode‐electrolyte interface region by experimental and simulation methods. Finally, the research which needs to be highlighted in this area was proposed.

Ionic Liquids: Potential Materials for Carbon Dioxide Capture and Utilization

“…Scheme 2 shows steps through which CO 2 is reduced to various useful products, at different standard potentials (E 0 ). The hydrogen formed in these reactions is an undesired major byproduct and should be avoided (Feng et al, 2018a). To eliminate H 2 from the process, a non-aqueous medium is required and room temperature ionic liquids (RTIL) are ideal in this regard.…”

“…The RTIL cation was noted to reduce the H 2 generation thereby assisting in the reduction of CO 2 to CO. Later, several ILs comprised of imidazolium, pyrrolidinium, ammonium, phosphonium cation and (bis(trifluoromethylsulfonyl)imide ([NTf 2 ]), tris(pentafluoroethyl)trifluorophosphate ([FAP]), and tetrafluoroborate [BF 4 ]) anion and role of substituents on the cationic core was investigated in the reduction of CO 2 to CO (Alvarez-Guerra et al, 2015;Lim and Kim, 2017). In all these SCHEME 2 | Various electrochemical reduction pathways for CO 2 (Feng et al, 2018a). studies Au, Ag, Pt, and glassy carbon-based cathodes were used as electro-catalysts (Alvarez-Guerra et al, 2015).…”

Structural Changes of Au(111) Single‐Crystal Electrode Surface in Ionic Liquids

“…Ionic liquids (ILs) are organic salts in the liquid state even at room temperature and are characterized by a nearly zero vapor pressure, high intrinsic electrical conductivity, and a broad (up to 4–6 V wide) electrochemical stability window . Due to their excellent physico‐chemical properties, ILs have a unique potential as electrochemical media, which makes them a key material for a wide range of technologies: electroplating, batteries, supercapacitors, electrocatalysis and electrosynthesis, or recovery of metals from secondary raw materials . Despite the great interest in ILs, the use of ILs in electrochemical applications is largely hindered by the lack of a detailed understanding of the electrode/IL interface properties .…”

Colorimetric Probe Coupled to Dispersive Liquid–Liquid Microextraction for Determination of Dopamine in Serum

“…Under optimal conditions, a wide linear response to DA concentration and absorbance was obtained. 10 Zhang's group reported a colorimetric and visual read-out procedure for the determination of DA using AuNPs as colorimetric probes. The probes worked over a DA concentration range of 0.033 μM to 3330 μM DA, and levels as low as 0.033 μM could be quantified.…”