High-efficiency toluene degradation over Co@N-doped hollow carbon by plasma catalysis: O₃-induced bifunctional sites and synergy

Plasma-coupled catalysis as a promising technology for organic volatile compounds (VOCs) degradation is still great limited by inferior energy yield and CO_x selectivity. Here, doubly functionalized porous hybrid carbon-based materials consisting of highly dilute Co nanoparticles (NPs) as the cores and nitrogen-doped hollow carbon as the shells (Co@N-HC) were rationally designed and synthesized by pyrolysis the bimetallic-zeolitic imidazolate framework@polydopamine composite, which integrate the advantageous of isolated Co NPs and N-HC, exhibiting 100 % CO_x selectivity and an exceptional energy yield of 76.1 g/kWh at a specific input energy of 28 J/L in toluene plasma catalytic degradation, outperforming its counterparts. Ozone-induced oxidation of Co NPs and N species produces bifunctional surface reactive Co-O* and N-O* species, accelerating the cleavage of C-C bonds of aromatic and reactive organic intermediates such as benzaldehyde and 2,6,11-trimethyl-dodecane. Moreover, the Co@N-HC catalyst strongly suppresses the formation of O₃ and NO_x byproducts, showcasing significant environmental benefits.