(2027) Bioresource Technology_Redox-Active MnO_x-Biochar synthesis for bisphenol a removal with simultaneous CO-Rich syngas generation via Mn-Catalyzed CO₂-mediated biomass thermochemical treatment

Lee Y.-J.; Yang C.; Moon D.H.; Kwon E.E.

(Elsevier Ltd) Bioresource Technology ISSN: 9608524 Vol.463 Issue. Article No.135717 DOI: 10.1016/j.biortech.2026.135717

Adsorptive removal of aqueous organic pollutants is often limited by mass-transfer kinetics to the adsorbent surface. To address this constraint, integrated adsorption-oxidation processes have been widely explored as a strategic measure because they enable in situ degradation of adsorbent-bound organic pollutants, thereby regenerating active sites and prolonging removal performance. However, many such systems require energy inputs and chemical oxidants, which hinder practical implementation. Here, we evaluate MnO_x-loaded corncob (CC) biochar produced under a CO₂ atmosphere (MnCCB (CO₂)) as a bifunctional adsorption-oxidation material for bisphenol A (BPA) removal. Physicochemical characterization showed that CO₂-assisted fabrication yielded MnO_x with a higher oxidation state in MnCCB (CO₂) than that in the N₂-derived analogue (MnCCB (N₂)). MnCCB (CO₂) exhibited increased micro-/mesopore volume and a higher specific surface area. Consistent with these structural advantages, MnCCB (CO₂) achieved a BPA removal rate constant of 8.48 × 10^-2 min⁻¹, outperforming MnCCB (N₂) and pristine CC biochars produced under either N₂ or CO₂. Beyond pollutant removal, Mn-catalyzed CO₂ mediated thermochemical treatment also enhanced syngas formation during MnCCB (CO₂) production. This improvement is attributed to selective catalytic reactions between bio-oil and CO₂, during which CO₂ is converted to CO in the presence of MnO_x. Overall, this work demonstrates the potential of CO₂-assisted thermochemical treatment for the simultaneous production of functional biochar and syngas. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean Government (MSIT) (Grant No. RS-2023-NR077231 ).