Cascade Reactions for Enhanced CO2 Capture: Concurrent Optimization of Porosity and N-Doping

Abstract

Carbon capture emerges as a pivotal decarbonization technology for addressing global warming challenges. Porous carbons, despite their cost-effectiveness and ease of regeneration for CO₂ capture, typically exhibit limited capacity owing to insufficient adsorption sites. Here, nitrogen-doped porous carbons (NPCs) are introduced that overcome the prevalent trade-offs between specific surface area and N-doped content in NPCs fabrication through cascade reactions. The optimized NPC, which features hierarchical porosity ranging from ultra-micropores to macropores, shows a superior CO₂ capture capacity of 4.46 mmol g⁻¹, ranking in the top 10% of the reported NPCs. This capacity exceeds that of the NPC fabricated with the conventional method by 58% and surpasses the control porous carbon by 106%. Langmuir adsorption modeling and mathematic correlation analysis revealed that this enhanced capacity is attributed to significantly improved ultra-micropores volume and nitrogen-species content. Moreover, this optimized NPC demonstrates exceptional stability, preserving its adsorption performance over 110 adsorption–desorption cycles under simulated flue gas conditions. This research not only highlights the integration of templating and N-doping within NPCs fabrication but also offers an effective strategy to optimize porosity and nitrogen functionality in carbon materials, advancing beyond conventional methodologies.