Preparation and characterization of activated carbon for hydrogen storage from waste African oil-palm by microwave-induced LiOH basic activation

African palm shell-based activated carbon was prepared via a microwave-induced activation process using LiOH base as the activating agent. The effect on the activation process of various factors such as microwave intensity and duration of radiation at a LiOH/carbon ratio of 0.5 was studied. The optimal activation conditions were determined as: a microwave intensity of 800 W, a radiation time 15 min and a LiOH/carbon ratio of 0.5, under which a surface area of 1350 m2/g with a hydrogen capacity of 6.5 wt% could be achieved. The surface chemical properties were characterized using several methods including point of zero charge (pHpzc) measurement and FTIR spectra. Comparisons with the conventional thermal process demonstrated that the microwave-induced activation process had a faster activation rate and higher carbon yield. A textural analysis following the development of microporosity was also performed.