Activation of CO₂by ionic liquid EMIM–BF₄in the electrochemical system: a theoretical study

Abstract

The electrochemical reduction of CO2 to CO by an ionic liquid EMIM-BF4 is one of the most promising CO2 reduction processes proposed so far with its high Faradaic efficiency and low overpotential. However, the details of the reaction mechanism are still unknown due to the absence of fundamental understandings. In this study, the most probable and stable geometries of EMIM-BF4 and CO2 were calculated by quantum chemistry in combination with exhaustive search. A possible reaction pathway from CO2 to CO catalyzed by EMIM-BF4, including the most plausible intermediates and the corresponding transition states, was proposed. The role of EMIM-BF4 is explained as forming a complex of [EMIM-COOH](-) with CO2 followed by decomposing to CO.

Insights into Carbon Dioxide Electroreduction in Ionic Liquids: Carbon Dioxide Activation and Selectivity Tailored by Ionic Microhabitat

“…All species involved in CO 2 reduction were assumed to be adsorbed on the cathode surface. [22] In light of this reactionm echanism,i midazolium cations are reduced to neutralr adicals, which, in turn, transfere lectrons to CO 2 and form ac omplext hat can stabilize [CCO 2 ] À and prevent their dimerization to form oxalate. [18a] The presented mechanism (Scheme 1) is analogous to that proposed by Nakamura et al,a ccording to the theoretical calculations.…”

Overpotentials and Faraday Efficiencies in CO2 Electrocatalysis–the Impact of 1‐Ethyl‐3‐Methylimidazolium Trifluoromethanesulfonate

“…In addition, it is hypothesized that the [EMIM] + cation is electrostatically arranged at the cathode favoring CO 2 adsorption via [EMIM-CO 2 ] (ad) complex formation. [23][24][25] As a consequence, the 4869 × The onset potentials of 2861 × 10 −3 M (10 mol%) and higher concentrated electrolytes, however, saturate in the presence of CO 2 at about −1.46 V versus Ag/AgCl. Beyond, CO 2 reduction plateaus are noted at [EMIM]TFO concentrations of 3855 × 10 −3 M (20 mol%) and higher at voltages more negative than −1.46 V versus Ag/AgCl.…”

“…In line with in situ spectroscopic examinations, the imidazolium cation potentially forms a complex with CO 2 on the electrode surface. [23][24][25] It is believed that this may minimize the free energy for the initial electron transfer to the CO 2 , that is, the formation of the CO 2…”

MoP Nanoparticles Supported on Indium‐Doped Porous Carbon: Outstanding Catalysts for Highly Efficient CO2 Electroreduction

“…[42][43][44][45] One electron was transferred to aC O 2 molecule to form aC O 2 C À intermediate.Inthis process,the reaction barrier may be also reduced with the aid of the formation of [Bmim-CO 2 ] + ,which could reduce the overpotential. In the electrolysis,[ Bmim] + cation is electrostatically arranged at the MoP@In-PC surface,w hich favors CO 2 adsorption via [Bmim-CO 2 ] + complex formation.…”