Fig. 4: Electrochemical performances of captured CO₂ electrolysis.

a FE(CO)s using NiN₃–Pc–CNT at different catholyte flowrates with 1M post-capture K-Gly. b FE(CO)s of NiN₃–Pc–CNT, NiPc–CNT and Ag using 1M post-capture K-Gly at 80 mL min⁻¹. c EE(CO)s and full cell voltage of NiN₃–Pc–CNT and NiPc–CNT using 1 M post-capture K-Gly at 80 mL min⁻¹. d Comparison of the maximum FE(CO) and current density over NiN₃–Pc–CNT and the start-of-the-art catalysts used in reactive capture. NiN₃–Pc–CNT shows distinct CO FE in reactive capture (yellow star, at 100 mA cm⁻²; orange star, at 200 mA cm⁻²). Hydroxide-based systems are reported in refs. ^4,5, amine-based systems are reported in refs. ^7,8,9,13. e FE(CO)s comparison using different amino-acid-salt solutions at 80 mL min⁻¹. f FE(CO)s using 1M post-capture K-Gly from simulated flue gas (pH 8.3) and air (pH 9.6) at 80 mL min⁻¹. The error bars indicate one standard deviation based on three measurements. Source data are provided as a Source data file.