Abstract
Magnetic field-assisted concentration swing adsorption (CSA) provides an electrification-compatible alternative to conventional temperature swing adsorption (TSA) by enabling rapid heating/cooling and energy-efficient regeneration under near-isothermal conditions, thereby eliminating the need for sensible heat input. Here, Fe3O4 nanoparticles were integrated with fibrous nanosilica (FNS) and polyethylenimine (PEI) to construct a magnetically responsive adsorbent for near-isothermal CSA of CO2. Benefiting from the radially fibrous pore structure of FNS, Fe3O4/FNS-PEI70 exhibited fast adsorption kinetics (<2 min) and a high CO2 adsorption capacity (4.2 mmol/g) at 80 degrees C. Magnetic induction enabled efficient adsorbent regeneration and acheived 92.6% CO2 desorption at the same temperature. Humidity significantly enhanced CO2 capture (10.6 mmol/g at RH = 80%) without affecting the CSA process, whereas SO2 caused irreversible deactivation and NO showed negligible adsorption. Under concentration swing conditions studied, a theoretical regeneration energy of 2.0 MJ/ kg(CO2) was estimated for magnetic field-assisted CSA process, which was significantly lower than that of TSA, highlighting its promise as an energy-efficient and scalable pathway for electrified CO2 capture.