Electrochemical CO Reduction: A Property of the Electrochemical Interface

TY - JOUR

T1 - Electrochemical CO Reduction: A Property of the Electrochemical Interface

AU - Bagger, Alexander

AU - Arnarson, Logi

AU - Hansen, Martin H.

AU - Spohr, Eckhard

AU - Rossmeisl, Jan

PY - 2019/1/30

Y1 - 2019/1/30

N2 - Electrochemical CO reduction holds the promise to be a cornerstone for sustainable production of fuels and chemicals. However, the underlying understanding of the carbon-carbon coupling toward multiple-carbon products is not complete. Here we present thermodynamically realistic structures of the electrochemical interfaces, determined by explicit ab initio simulations. We investigate how key CO reduction reaction intermediates are stabilized in different electrolytes and at different pH values. We find that the catalytic trends previously observed experimentally can be explained by the interplay between the metal surface and the electrolyte. For the Cu(100) facet with a phosphate buffer electrolyte, the energy efficiency is found to be limited by blocking of a phosphate anion, while in alkali hydroxide solutions (MOH, M = Na, K, Cs), OH∗ intermediates may be present, and at high overpotential the H∗ coverage limits the reaction. The results provide insight into the electrochemical interface structure, revealing the limitations for multiple-carbon products, and offer a direct comparison to experiments.

AB - Electrochemical CO reduction holds the promise to be a cornerstone for sustainable production of fuels and chemicals. However, the underlying understanding of the carbon-carbon coupling toward multiple-carbon products is not complete. Here we present thermodynamically realistic structures of the electrochemical interfaces, determined by explicit ab initio simulations. We investigate how key CO reduction reaction intermediates are stabilized in different electrolytes and at different pH values. We find that the catalytic trends previously observed experimentally can be explained by the interplay between the metal surface and the electrolyte. For the Cu(100) facet with a phosphate buffer electrolyte, the energy efficiency is found to be limited by blocking of a phosphate anion, while in alkali hydroxide solutions (MOH, M = Na, K, Cs), OH∗ intermediates may be present, and at high overpotential the H∗ coverage limits the reaction. The results provide insight into the electrochemical interface structure, revealing the limitations for multiple-carbon products, and offer a direct comparison to experiments.

U2 - 10.1021/jacs.8b08839

DO - 10.1021/jacs.8b08839

M3 - Journal article

C2 - 30618253

SN - 0002-7863

VL - 141

SP - 1506

EP - 1514

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 4

ER -