Preparation and characterization of high surface area activated carbons from co-pyrolysis product of coal-tar pitch and rosin

• Low-cost activated carbons (ACs) can be prepared from coal-tar pitch and rosin.
• Co-pyrolysis product of coal-tar pitch and rosin is a suitable AC precursor.
• Adding rosin favors the porosity development in ACs during KOH activation.
• The ACs have high surface area as well as good electrochemical performance.

Co-pyrolysis product of coal-tar pitch and rosin was used as a precursor to prepare high surface area activated carbons (ACs) by KOH activation. The influences of AC precursor origin, KOH/AC precursor weight ratio and activation time on the pore characteristics of the ACs were investigated, and meanwhile their electrochemical performance was studied. The results show that adding rosin results in a decrease in the C/H atomic ratio of AC precursor as well as a significant increase in its mesophase content, which favors the porosity development in ACs during KOH activation. The effect of adding rosin on the porosity characteristics of the ACs can be illustrated by increases in the BET surface area from 1846 to 2847 m2/g and the total pore volume from 1.09 to 1.57 cm3/g. In addition, the ACs possess good electrochemical performance, as indicated by that they have a maximum specific capacitance of 203 F/g and exhibit good rectangular-shaped I–V curves in cyclic voltammetry.