Ultrafast preparation of honeycomb N‐doped carbon via flash joule heating for efficient capture of <scp> C ₂ H ₄ F ₂ </scp> refrigerant

Abstract Developing advanced adsorbents for efficient capture of phase‐out hydrofluorocarbons (HFCs) is imperative for reducing emissions of deleterious compounds (e.g., 1,1‐difluoroethane, C 2 H 4 F 2 ). Here, honeycomb N‐doped carbons (NPC‐FJH) with hierarchical porosity were rapidly prepared (~20 s) using flash Joule heating (FJH) for C 2 H 4 F 2 adsorption. The structural and adsorption properties of NPC‐FJH were compared with NPC‐TF obtained via tubular furnace (TF). NPC‐FJH have remarkable C 2 H 4 F 2 uptake capacities (12.37 mmol g −1 ), selectivities (up to 420) at 25°C and 100 kPa than their NPC‐TF counterparts. Density functional theory (DFT) revealed that N and adjacent C atoms enhance host‐guest interactions. Moreover, NPC 2.5 ‐FJH 800 demonstrates ultrafast adsorption kinetics (99 s to saturation) and a favorable diffusion coefficient ( D / r 2 = 3.49 ms −1 ). Breakthrough tests demonstrated that NPC 2.5 ‐FJH 800 achieved the selective separation of C 2 H 4 F 2 in ternary gas mixtures (N 2 /C 2 H 2 /C 2 H 4 F 2 ), with negligible capacity loss over 10 cycles, demonstrating its excellent reusability and significant potential for practical applications.