Enhanced VOC recycling by nano-Fe/FeOx decorated nanoporous carbon†

The recycling of industrial VOCs has attracted enormous interest for its significant roles in mitigating VOC emissions and reducing human and environmental risks. Here, we report a highly efficient multifunctional Fe/FeO_x/NPC adsorbent, which shows high adsorption capacity for toluene (200 mg g⁻¹) and ethyl acetate (154 mg g⁻¹) and 100% regeneration efficiency without deactivation after five cycles. By introducing nano-Fe/FeO_x, the S_BET and pore volume of NPC are increased from 163.66 m² g⁻¹ and 0.142 mL g⁻¹ to 361.30 m² g⁻¹ and 0.22 mL g⁻¹, respectively. It is achieved by a multifunctional adsorbent that provides efficient adsorption and thermal effect sites (Fe⁰, FeO_x and graphitic carbon), which cooperatively facilitates adsorption–regeneration. More significantly, the thermal effect sites and diverse pore structures play a crucial role in the successive and synergetic separation and desorption of VOCs from the multifunctional adsorbent. The thermal effect sites on Fe/FeO_x/NPC can effectively inhibit the conversion of the thermal activation reaction of VOCs into high-boiling carbonates, thereby avoiding the formation of heel build-up and deactivation of adsorbents. Our research introduces an efficient VOC recycling approach enabled by subtle control of VOC regeneration on a multifunctional interface.