E than the equilibrium potentials. Thermodynamically, a high-energy barrier is essential
E than the equilibrium potentials. Thermodynamically, a high-energy barrier is essential for the initiation with the CO2 radical (CO2 ) with an equilibrium prospective of -1.90 V vs. a normal hydrogen electrode (SHE), pH = 7), which influences the CO2 ERR substantially [40].Table 1. Solutions of CO2 ERR with equilibrium potentials. Reprinted with permission from [41] 2019, American Chemical Society. Reaction 2H2 O O2 4H 4e- 2H 2e- 2H2 xCO2 nH ne- product yH2 O CO2 2H 2e- HCOOH (aq) CO2 2H 2e- CO(g) H2 O CO2 6H 6e- CH3 OH (aq) H2 O CO2 4H 4e- C(s) 2H2 O CO2 8H 8e- CH4 (g) 2H2 O 2CO2 2H 2e- (COOH)two (s) 2CO2 8H 8e- CH3 COOH (aq) 2H2 O 2CO2 10H 10e- CH3 CHO (aq) 3H2 O 2CO2 12H 12e- C2 H5 OH (aq) 3H2 O 2CO2 12H 12e- C2 H4(g) 4H2 O 2CO2 14H 14e- C2 H6 (g) four H2 O 3CO2 16H 16e- C2 H5 CHO (aq) 5H2 O 3CO2 18H 18e- C3 H7 OH (aq) 5H2 O xCO nH ne- solution yH2 O CO 6H 6e- CH4 (g ) H2 O 2CO 8H 8e- CH3 CH2 OH (aq) H2 O 2CO 8H 8e- C2 H4 (g) 2H2 O E0 /(V vs. Reversible Hydrogen Electrode RHE) 1.23 0 (Solution) Name, Abbreviation Oxygen Evolution Reaction, OER Hydrogen Evolution Reaction, HER CO2 Reduction, CO2 R Formic acid Carbon monoxide Methanol, MeOH Graphite Methane Oxalic acid Acetic acid Acetaldehyde Ethanol, EtOH Ethylene Ethane Propionaldehyde Propanol, PrOH CO Reduction, COR Methane Ethanol, EtOH Ethylene-0.12 -0.ten 0.03 0.21 0.17 -0.47 0.11 0.06 0.09 0.08 0.14 0.09 0.0.26 0.19 0.In CO2 ERR, the faradaic efficiency has to be considered due to the fact it represents the efficiency with which charges (electrons) are transported in a method, advertising an electrochemical reaction. Alternatively, the current density, which can be defined because the price of chargeMolecules 2021, 26,6 ofpassed across a specified cross-section unit location per unit time [42], is impacted by the conductivity and JNJ-42253432 Antagonist thickness on the thin film around the electrode [43]. The main issue connected with this technology is locating a catalytic system that could effectively convert CO2 to the preferred value-added solution at a low power requirement. This is as a result of linear structure of CO2 , which makes it electrochemically stable. This results in a method with low overpotential, high faradaic efficiency, higher existing density, higher selectivity towards a particular item having a good yield, and higher CO2 solubility in the electrolyte. A lot of reviews have reported on the function with the electrode as a catalyst employing metals for example copper [44], silver [45], gold [46], lead, and indium [47], alloys at various scales (nano, micro), structures, and morphology [480], and coated metals [51] as well as metal oxides [52]. Hori et al. reported the effects of different metals on CO2 ERR and highlighted the electrode’s role in terms of selectivity and minimizing the overpotential [53]. The troubles that happen to be faced throughout the adsorption of CO2 around the electrode surface will be the reason for the PHA-543613 web increased amount of power which is required for the activation on the reaction [39,54]. On the other hand, in terms of the electrolytes, potassium bicarbonate salt has been widely employed [55,56]. Dunwell and Lu [57] reported that bicarbonate salt features a significant function in the CO2 ERR rather than merely acting as a pH buffer or proton donor. They recommended that the bicarbonate raises the CO2 ERR rates by increasing the helpful reducible CO2 concentration inside a solution. A developing interest in ionic liquids as electrolytes has been reported, as they will enhance the catalytic activit.