Abstract:
The palm shell was used as precursor to prepare activated carbons with high specific surface area by KOH activation method. The specific surface area and micropore pore volume were taken as the inspection targets, the influence of different preparation process conditions was explored through single factor experiments and central composite design methods. The hydrogen storage performance of activated carbons prepared under the optimal conditions was studied. The results showed that the activation temperature and the weight ratio of KOH/palm shell char had significant effects on the surface area and micropore volume. The preparation parameters obtained after optimization were 795℃ for activation temperature and 3.64 for impregnation ratio. The average specific surface area and micropore volume of activated carbon prepared under these conditions were 3 491 m
2/g and 1.08 cm
3/g, respectively. The pore structure analysis results showed that palm shell-based activated carbon was mainly composed of micropores and mesopores, with the maximum microporosity of 89%. Furthermore, it could be seen from the SEM and TEM images that there were a large number of micropores and mesopores distributed in activated carbon. Meanwhile, palm shell activated carbon had excellent hydrogen storage performance. The excess and absolute hydrogen storage capacities were as high as 6.4% and 6.8% under the conditions of -196℃ and 4 MPa, respectively.