Hydrogen adsorption on modified activated carbon

The aim of this work is to investigate hydrogen adsorption on prepared super activated carbon (AC). Litchi trunk was activated by potassium hydroxide under N₂ or CO₂ atmosphere. Nanoparticles of palladium were impregnated in the prepared-AC. Hydrogen adsorption was accurately measured by a volumetric adsorption apparatus at 77, 87, 90 and 303 K, up to 5 MPa. Experimental results revealed that specific surface area of the prepared-AC increased according to KOH/char ratio. The maximum specific surface area reached up to 3400 m²/g and total pore volume of 1.79 cm³/g. The maximum hydrogen adsorption capacity of 2.89 wt.% at 77 K and under 0.1 MPa, was obtained on these materials. The hydrogen adsorption capacity of the 10 wt.% Pd-AC was determined as 0.53 wt.% at 303 K and under 6 MPa. This amount is higher than that on the pristine AC (0.41 wt.%) under the same conditions.