Fabrication of hollow activated carbon nanofibers (HACNFs) containing manganese oxide catalyst for toluene removal via two-step process of electrospinning and thermal treatment

The development of an effective adsorbent for volatile organic compounds has been pursued in recent years, and diverse porous materials have been identified as promising candidates. However, most of the porous adsorbents have a limitation: the removal efficiency decreases at high temperatures. In this study, electrospun double-layer polymethyl methacrylate/manganese acetate (core), polyacrylonitrile (shell)-based nanofibers (NFs) are carbonized and CO₂-activated to produce Mn₃O₄ nanoparticles embedded in hollow activated carbon NFs (Mn₃O₄/HACNFs). Owing to their hollow structure, the Mn₃O₄/HACNFs exhibit a great ability to adsorb toluene, with a longer breakthrough time of toluene adsorption than conventional activated carbon NFs. At 280 °C, the Mn₃O₄/HACNFs achieve catalytic oxidation of toluene (conversion to CO₂ = 99% ± 0.5). Furthermore, when tested under alternating-temperature conditions (260 and 280 °C) for 4 h, the Mn₃O₄/HACNFs exhibit no degradation of the catalytic activity.