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- W4386889637 abstract "The active and selective electrochemical reduction of CO2 to value-added chemical intermediates can offer a sustainable route for the conversion of CO2 to chemicals and fuels, thus helping to mitigate greenhouse gas emissions and enabling intermittent energy from renewable sources. Alkaline solutions are often the preferred media for the electrocatalytic CO2 reduction reaction (CO2RR) as they provide high current densities and low overpotentials while suppressing the hydrogen evolution side reaction. Recent experiments carried out on Au and Ag in KOH, as well as other electrolytes, including KHCO3, K2CO3, and KCl, showed that increasing electrolyte concentration lowered onset potentials, increased Faradaic efficiencies to CO, and improved current densities. Herein, we carry out potential-dependent ab initio molecular dynamic (AIMD) simulations along with density functional theory (DFT) calculations using explicit KOH electrolyte and H2O solution molecules to examine the influence of OH– anions and the KOH electrolyte on the elementary steps and their corresponding energetics in the mechanism for CO2 reduction. The simulations indicate that the first electron transfer step to CO2 to form the adsorbed *CO2(•−) radical anion is rate-limiting, while the subsequent proton and electron transfer steps are facile and downhill in energy at reducing potentials. The OH– anions present in the solution can adsorb on the Au cathode down to potentials as low as ∼ −3 V (SCE). This enables the OH– anions to transfer electrons to the Au cathode and into antibonding 2π* orbitals of CO2, thus facilitating the rate-determining adsorption and electron transfer to CO2 to form the adsorbed *CO2(•−) radical anion. Increasing the concentration of the K+OH– electrolyte reduces the barrier for the electrocatalytic reduction of CO2 and thus improves the current density, consistent with the reported experimental results. The *CO2(•−) radical anion that forms subsequently undergoes facile proton transfer from a vicinal water molecule in solution to form the hydroxy carbonyl (*HOCO) intermediate that readily undergoes subsequent proton and electron transfer from a second water molecule to form CO and OH– at a potential of ∼ −1.2 V SCE. While the formation of formate (HCOO–) is thermodynamically favorable, the direct hydrogenation of *CO2(•−) as well as the intramolecular proton transfer via *HOCO to form HCOO– are kinetically unfavored. The presence of OH– anions near the surface also facilitates the formation of bicarbonate (HCO3–) at lower potentials. The bicarbonate that forms can be converted to the reactive *HOCO intermediate at more negative potentials that subsequently reacts to form CO and regenerate OH–. The results discussed herein help provide a more detailed understanding of the interplay between the OH–, K+, H2O, and reaction intermediates on the Au surface in the electric double layer and their influence on the onset potential, electrocatalytic activity, and selectivity for CO2RR." @default.
- W4386889637 created "2023-09-21" @default.
- W4386889637 creator A5010646736 @default.
- W4386889637 creator A5010884148 @default.
- W4386889637 creator A5014100196 @default.
- W4386889637 creator A5028535705 @default.
- W4386889637 creator A5048127056 @default.
- W4386889637 creator A5086238816 @default.
- W4386889637 date "2023-09-20" @default.
- W4386889637 modified "2023-10-09" @default.
- W4386889637 title "Theoretical Insights into the Effects of KOH Concentration and the Role of OH<sup>–</sup> in the Electrocatalytic Reduction of CO<sub>2</sub> on Au" @default.
- W4386889637 cites W1108713415 @default.
- W4386889637 cites W1482545459 @default.
- W4386889637 cites W1601505572 @default.
- W4386889637 cites W1965819687 @default.
- W4386889637 cites W1970127494 @default.
- W4386889637 cites W1971044888 @default.
- W4386889637 cites W1979544533 @default.
- W4386889637 cites W1981368803 @default.
- W4386889637 cites W1986977956 @default.
- W4386889637 cites W1987223932 @default.
- W4386889637 cites W1993486179 @default.
- W4386889637 cites W1994204840 @default.
- W4386889637 cites W1999186005 @default.
- W4386889637 cites W2002616811 @default.
- W4386889637 cites W2004751437 @default.
- W4386889637 cites W2010491470 @default.
- W4386889637 cites W2012726087 @default.
- W4386889637 cites W2023856537 @default.
- W4386889637 cites W2031430816 @default.
- W4386889637 cites W2037284800 @default.
- W4386889637 cites W2039363562 @default.
- W4386889637 cites W2041511900 @default.
- W4386889637 cites W2044591029 @default.
- W4386889637 cites W2052515101 @default.
- W4386889637 cites W2060441729 @default.
- W4386889637 cites W2063031338 @default.
- W4386889637 cites W2072609386 @default.
- W4386889637 cites W2074342043 @default.
- W4386889637 cites W2074964984 @default.
- W4386889637 cites W2079061150 @default.
- W4386889637 cites W2079105963 @default.
- W4386889637 cites W2082327469 @default.
- W4386889637 cites W2082619226 @default.
- W4386889637 cites W2083222334 @default.
- W4386889637 cites W2083753650 @default.
- W4386889637 cites W2087698390 @default.
- W4386889637 cites W2104427828 @default.
- W4386889637 cites W2105565769 @default.
- W4386889637 cites W2111927542 @default.
- W4386889637 cites W2112596826 @default.
- W4386889637 cites W2122427541 @default.
- W4386889637 cites W2140581565 @default.
- W4386889637 cites W2166116801 @default.
- W4386889637 cites W2167872912 @default.
- W4386889637 cites W2175269331 @default.
- W4386889637 cites W2176450043 @default.
- W4386889637 cites W2227166172 @default.
- W4386889637 cites W228629631 @default.
- W4386889637 cites W2291985939 @default.
- W4386889637 cites W2294789198 @default.
- W4386889637 cites W2297227424 @default.
- W4386889637 cites W2316767583 @default.
- W4386889637 cites W2323309348 @default.
- W4386889637 cites W2328504595 @default.
- W4386889637 cites W2328702574 @default.
- W4386889637 cites W2334092527 @default.
- W4386889637 cites W2339405166 @default.
- W4386889637 cites W2340417484 @default.
- W4386889637 cites W2436418777 @default.
- W4386889637 cites W2481819809 @default.
- W4386889637 cites W2497854141 @default.
- W4386889637 cites W2504441095 @default.
- W4386889637 cites W2520778196 @default.
- W4386889637 cites W2522135447 @default.
- W4386889637 cites W2547631353 @default.
- W4386889637 cites W2560335630 @default.
- W4386889637 cites W2608775164 @default.
- W4386889637 cites W2618772590 @default.
- W4386889637 cites W2698517883 @default.
- W4386889637 cites W2736832726 @default.
- W4386889637 cites W2738629485 @default.
- W4386889637 cites W2742431575 @default.
- W4386889637 cites W2742615673 @default.
- W4386889637 cites W2749245729 @default.
- W4386889637 cites W2758128899 @default.
- W4386889637 cites W2759196277 @default.
- W4386889637 cites W2762738613 @default.
- W4386889637 cites W2765422782 @default.
- W4386889637 cites W2767138048 @default.
- W4386889637 cites W2767988853 @default.
- W4386889637 cites W2776913936 @default.
- W4386889637 cites W2790215394 @default.
- W4386889637 cites W2790568828 @default.
- W4386889637 cites W2795749769 @default.
- W4386889637 cites W2804235153 @default.
- W4386889637 cites W2808940939 @default.
- W4386889637 cites W2809323756 @default.