Temperature-dependent pathways in carbon dioxide electroreduction.

Abstract

Temperature affects both the thermodynamics of intermediate adsorption and the kinetics of elementary reactions. Despite its extensive study in thermocatalysis, temperature effect is typically overlooked in electrocatalysis. This study investigates how electrolyte temperature influences CO₂ electroreduction over Cu catalysts. Theoretical calculations reveal the significant impact of temperature on *CO and *H intermediate adsorption thermodynamics, water microenvironment at the electrode surface, and the electron density and covalent property of the C-O bond in the *CH-COH intermediate, crucial for the reaction pathways. The theoretical calculations are strongly verified by experimental results over different Cu catalysts. Faradaic efficiency (FE) toward multicarbon (C₂₊) products is favored at low temperatures. Cu nanorod electrode could achieve a [Formula: see text] value of 90.1 % with a current density of ∼400 mA cm^-2 at -3 °C. [Formula: see text] and [Formula: see text] show opposite trends with decreasing temperature. The [Formula: see text] ratio can decrease from 1.86 at 40 °C to 0.98 at -3 °C.