Flexible HOFs Integrated with Nanoheaters for Promoted Adsorption Swing

Hydrogen-bonded organic frameworks (HOFs) are promising porous materials for gas separation, but their low thermal conductivity results in high regeneration energy consumption. This work fabricates a flexible-HOF-based magnetic adsorbent (MN@FHOF-x) and utilizes magnetically induced heating to achieve the efficient adsorption swing of the HOF component in C₂H₆ capture. Fe₃O₄ nanoparticles were embedded in the HOF-FJU-1 particles, which have a 3-fold interpenetrated rhombic network structure and feature reversible open/closed pore transformation. At 25 °C without a magnetic field, the open-pore structure of HOF-FJU-1 provides abundant adsorption sites for C₂H₆. Under an alternating magnetic field, Fe₃O₄ nanoparticles generate heat rapidly via Néel relaxation, inducing the HOF framework to transform into a closed-pore state and release C₂H₆. The optimal sample exhibits a working capacity of 9.3 cm³ g^-1 (25-50 °C), outperforming some representative adsorbents such as ZIF-7 (6.5 cm³ g^-1) and NUM-9 (8.5 cm³ g^-1). This study provides a structure-performance-tailored strategy for developing advanced adsorbents for gas separation by combining flexible porous frameworks with magnetic nanoheaters.