Preparation and characterization of activated carbons from Paulownia wood by chemical activation with H3PO4

Abstract

High-surface area activated carbons were prepared by chemical activation of Paulownia (Paulownia elongata) wood with H3PO4 as a chemical activating agent.The chemical activation process was conducted at different impregnation ratios (1–4) and final carbonization temperatures (300–600 °C). The influences of carbonization temperature and impregnation ratio on the surface area, pore development and yield of activated carbon were investigated.The effect of the impregnation ratio on the porous structure of the activated carbon is stronger than that of the final carbonization temperature. H3PO4 was found to be more effective for developing microporous structure in the activated carbon. A final carbonization temperature of 400 °C and impregnation ratio of 4 were found to be suitable for producing high-surface-area activated carbon.The pore properties of the carbons including the BET surface area, pore volume, pore size distribution, and average pore diameter were determined by adsorption of N2 at 77 K using the BET, t-plot and density functional theory (DFT) methods. BET surface area and total pore volume values were achieved as high as 2806 m2/g and 1.746 cm3/g, respectively. Activated carbons were also examined with instrumental methods such as SEM and FTIR.