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

Abstract

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.