Hydrogen bond network disruption enables efficient direct reactive capture of CO₂ from flue gas.

Abstract

Electrochemical CO₂ conversion offers a direct route to decarbonized fuels, but its deployment on industrial flue gas remains hindered by the low CO₂ content, high O₂ levels, and the resulting parasitic oxygen reduction. Binary solvent electrolytes offer a lever to tune the local reaction environment under such dilute and impurity-rich conditions. Here we show a direct reactive capture (DRC) strategy that converts CO₂ from dilute streams into CO with near-quantitative Faradaic efficiency in organic electrolytes under moderate pressure. We identify hydrogen-bond donation ability (HBD) as a decisive parameter governing competing hydrogen evolution and oxygen reduction reactions. Employing low-HBD electrolytes disrupts the hydrogen-bond network, suppresses competing reactions, and enables selective CO₂ conversion even at 1% CO₂ in the presence of O₂. When fed with 15% CO₂ and 8% O₂ balanced with N₂, the optimized system sustains >100 h operation with an energy consumption of 30.7 GJ ton^-1 CO, and achieves a solar-to-fuel efficiency of ~5.5%. This impurity-tolerant strategy addresses a key barrier for industrial CO₂ electrolysis and establishes a scalable route to solar-driven fuel production directly from flue gas.