Concurrent activation and surface modification (CAM) process to produce surface-modified palm kernel shell-derived activated carbon (PKSdAC)

Activated carbon production via chemical activation followed by surface functionalization with metal groups aims to achieve surface functionalization for CO2, aromatic/metallic organic compounds, and dye adsorption. The prepared activated carbon possesses a porous structure containing metal functional groups with adsorptive properties. This work proposed integrating two synthesis steps to simplify the process and reduce resources and impact. The preparation of palm kernel shell (PKS) derived AC (PKSdAC) through a concurrent activation and surface modification (CAM) process combines sulphuric acid (H2SO4) activation (5-10% mass loading) with barium chloride (BaCl2) modification (10 wt.%) at an activation temperature of 400-700 degrees C. The barium (Ba) is produced through the reduction process. Incorporating Ba into PKSdAC is vital to initiate chemical CO2 and other related component adsorption. The optimization study identified that 7.5% H2SO4, 10 wt.% BaCl2, and 700 degrees C was optimal in obtaining a high 1.50 wt.% Ba impregnated in PKSdAC. CAM-PKSdAC synthesized at optimal conditions exhibited a sponge-like cubic meso-microporous carbon structure containing BaSO4 crystals with a surface area of 420 and 423 m2 g-1 for its micropore and mesopore structure. A total pore volume of 0.19 cm3 g-1 and an average pore diameter of 1.78 nm were achieved. Conventional surface modified-activated PKSdAC prepared at optimal conditions has a cubic porous structure and a crack surface containing little BaSO4 crystals with a higher surface area of 565 m2 g-1 and total pore volume of 0.18 cm3 g-1 and an average pore diameter of 1.27 nm.