Fenton-like oxidation and KOH activation on the CO2 adsorption performance of wood-based hierarchical porous carbon

Biomass-derived porous carbon is a promising low-cost candidate for CO₂ capture, yet its pore structure and adsorption performance require optimization. Herein, poplar wood powder was pretreated via Fenton-like oxidation (Fe³⁺/H₂O₂) followed by potassium hydroxide (KOH) activation to prepare Fenton-like porous carbon (FAC). This combined strategy boosted the specific surface area (SSA) by 4.2-9.7 times and yielded a pore volume of 1.62 cm³/g. FAC exhibited excellent CO₂ uptake (4.15 mmol/g at 25°C, 6.60 mmol/g at 0°C), high cyclic stability over 20 runs, and a CO₂/N₂ selectivity of 17.6 (15/85 mixture, 298 K, 1 atm). Raman, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) characterizations verified that ·OH radicals disrupted wood crosslinks, and the synergy of porosity and surface chemistry dominated the multilayer physical adsorption. This work offers a scalable adsorbent for efficient carbon capture applications.