Fig. 1.

Characteristics of CO₂ reduction by the LMCe electrocatalyst. a linear sweep voltammogram (LSV) of galinstan with different concentrations of Ce measured in 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF₆) and 2 M H₂O in dimethylformamide (DMF) in N₂ and CO₂ saturated electrolyte. Inset shows a magnified view. b Chrono-amperometry results of liquid galinstan and solid gallium containing 3% Ce measured at −3 V vs. Ag/Ag⁺ in CO₂ saturated electrolyte. Inset shows chrono-amperometry result of a liquid galinstan alloy containing 3 wt% Ce (LMCe3%) at −2 V vs. Ag/Ag⁺ in CO₂ saturated electrolyte. Please note the Faradaic efficiency for the various products at −2 and −3 V vs. Ag/Ag⁺ which is shown in c. c Faradaic efficiencies of LMCe3% for the production of CO, H₂, and solid carbonaceous material at corresponding potentials measured in CO₂ saturated electrolytes. The Faradaic efficiency for the carbonaceous material was determined via a deduction process. Please refer to the Methods section for further details