Molecular-level insight on CO2 electroreduction to formate facilitated
by triazole ionic liquid interfacial microhabitat
Abstract
The interfacial microhabitat induced by triazole ionic liquid
([124Triz]−) electrolyte can effectively enhance formate selectivity
for electrochemical CO2 reduction reaction. However, the catalytic
mechanism remains unclear. Herein, we combined molecular dynamics
simulation and density functional theory to reveal the regulatory
mechanism. The results showed that the dipolar interaction between CO2
and [124Triz]− cooperating the hydrogen bonds between [124Triz]−
and H2O facilitate the accumulation of H atoms around C atoms of CO2.
Meanwhile, the strong polar [124Triz]− induces negative
electrostatic potential for the H atoms of H2O near anions. As a result,
the negative H atoms are more likely to attack the positive C atoms of
CO2, which results in a lower free energy of -0.10 eV for the formation
of *HCOO intermediate and promotes the formation of formate. Thus, the
[124Triz]− contributes to high formate selectivity owing to the
combined effects of strong CO2-dipole interaction and hydrogen bonds
with H2O.