Fig. 2: Optimization of the capture solution and system stability.

a, b FE towards CO and full cell voltage for a 1 M K-GLY capture solution with 0.1 M of various supporting electrolytes: potassium chloride (KCl), potassium bromide (KBr), potassium iodide (KI), potassium nitrate (KNO₃), potassium sulfate (K₂SO₄), and monopotassium phosphate (KH₂PO₄). c FE towards CO and full cell voltage for a 1 M K-GLY capture solution with KH₂PO₄ supporting electrolyte concentration varying from 0 to 0.3 M. d FE towards CO and full cell voltage for an unsupported 1 M K-GLY capture solution and the optimized capture solution (2 M K-GLY with 0.1 M KH₂PO₄). e stability test of reactive CO₂ capture for 32 h at an applied current density of 50 mA cm⁻² using 1 L of catholyte and anolyte. Error bars represent the standard deviation of at least three independent measurements. Source data are provided as a Source Data file.