High-graphitization carbon layers coated with Fe − N − C sites for efficient and robust catalytic CO2 decomposition of amine-solvent

Catalytic solvent regeneration is widely considered a promising solution for addressing the intensive heat duty of amine-based carbon dioxide (CO₂) capture. This highly challenging application has motivated researchers to develop excellent catalysts with high activity and durability. In this study, we engineered active and durable Fe − N − C catalyst coated with high-graphitization carbon layers (labeled Phen − Fe − N − C) through a secondary thermal pyrolysis treatment. The multiple graphite layers and atomic metal sties were verified by experimental characterization and coordination structure analysis. The improved graphite layers further enhanced the activity of Fe − N − C sites, providing more acid sites for proton-electron transfer and C − N breaking during solvent regeneration (or CO₂ desorption). Thus, the maximal CO₂ desorption rate increased by 50 % when Fe − N − C was used compared with that of the blank case, and the rate further increased by 27 % when Phen − Fe − N − C was used. After 15 days of hydrothermal testing, the single Fe atom over the spent catalysts presented no significant aggregation or dissolution in the solvent, validating the durability of Phen − Fe − N − C. This work demonstrates a feasible and novel strategy to improve M − N − C materials for efficient and robust CO₂ desorption from amine solvents toward energy-saving CO₂ capture.