Facile Fabrication of Biochar from Palm Kernel Shell Waste and its Novel Application to Magnesium-Based Materials for Hydrogen Storage

In this investigation, an easily-operated and cost-effective method is utilized to synthesize biochar in ambient air, and the prepared biochar is used in a novel manner as a milling aid for fabricating Mg-biochar composites for hydrogen storage. X-ray diffractometry reveals that increasing the content of palm kernel shell biochar (PKSBC) from 5 wt.% to 20 wt.% enhances the hydrogen absorption performance by increasing the conversion of Mg into MgH₂ from 83% to 93%. A 40 °C reduction in decomposition temperature of MgH₂ is recorded from differential scanning calorimetry curves when the content of PKSBC is increased to 20 wt.%. Magnesium is milled and hydrided under the same experimental conditions and used as a reference material. It is proposed that these property enhancements can be attributed to the fact that PKSBC acts as an anti-sticking agent for elemental Mg powders, helping in the achievement of a more dispersed composite with reduced Mg particle size due to its layered-like carbon structure.