(2026) Environmental Research_CO₂-assisted pyrolysis of Mn-loaded biomass for syngas generation and periodate-activating biochar production

Lee J.; Lee Y.-J.; Song H.; Kwon E.E.

(Academic Press Inc.) Environmental Research ISSN: 139351 Vol.306 Issue. Article No.125232 DOI: 10.1016/j.envres.2026.125232

Mn-biochar composite, which incorporates redox-active Mn sites into a carbon scaffold, is an active catalyst for periodate (PI) activation. Nevertheless, its scalable production remains challenging because conventional pyrolysis offers limited energy recovery. Here, Mn-impregnated switchgrass (SG) was pyrolyzed under CO₂-assisted conditions to redirect biomass carbon conversion from condensable oxygenates to syngas. The temporal evolution of gaseous products indicated that Mn impregnation into SG promoted syngas generation during CO₂-assisted pyrolysis. Correspondingly, analysis of biocrude composition indicated that Mn and CO₂ facilitated the secondary conversion of condensable oxygenates. Mn-biochar composite produced under CO₂-assisted pyrolysis (MnSGB (CO₂)) displayed pronounced redox features, indicating the presence of active Mn species. MnSGB (CO₂) showed lower charge-transfer resistance than Mn-free biochars. Consequently, MnSGB (CO₂) exhibited superior catalytic performance for PI activation, achieving >99% bisphenol A removal. Mechanistic investigations also suggested that enhanced catalytic activity was driven by Mn-mediated interfacial electron transfer and the resulting ¹O₂ generation. © 2026 Elsevier Inc.

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