NH₃‑Mediated Reactive Capture and Conversion: Integrating CO₂ Absorption from Flue Gas with CO Production via NH₄HCO₃...

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.