NH ₃ -Mediated Reactive Capture and Conversion: Integrating CO ₂ Absorption from Flue Gas with CO Production via NH ₄ HCO ₃ Electrolysis

Efficient carbon capture and utilization require strategies that minimize energy penalties of CO2 regeneration and compression. Reactive capture and conversion (RCC) address this challenge by integrating capture with direct electrochemical conversion. Here, we show an NH3-mediated tandem RCC system that couples capture of CO2 from simulated flue gas (10% v/v CO2 in N2) with electroreduction of NH4HCO3 to CO over a Ni single-atom catalyst (Ni-SAC). Speciation modeling and capture experiments revealed that a deep CO2 capture with C/N ratio of 0.65 was achieved using 2.5 M NH3 from simulated flue gas. Electrolysis of the resulting NH4HCO3 on the Ni-SAC delivered an 85% CO Faradaic efficiency at 100 mA/cm2 with excellent tolerance to NH3/NH4+ as confirmed by DFT calculations and ab initio molecular dynamics (AIMD) simulations. Further, the techno-economic analysis established a levelized total cost of CO manufacturing of $25.43/kmol, gauging the practical viability. Overall, this study holds great potential to decarbonize the chemical manufacturing industry while reducing synthetic production costs.