The scope of this work investigates the relationship between the amount of oxygen-functional
groups and hydrogen adsorption capacity with different concentrations of phosphoric
acid. The amount of oxygen-functional groups of activated carbons (ACs) is characterized
by X-ray photoelectron spectroscopy. The effects of chemical treatments on the pore structures
of ACs are investigated by N2/77 K adsorption isotherms. The hydrogen adsorption
capacity is measured by H2 isothermal adsorption at 298 K and 100 bar. In the results, the
specific surface area and pore volume slightly decreased with the chemical treatments due
to the pore collapsing behaviors, but the hydrogen storage capacity was increased by the
oxygen-functional group characteristics of AC surfaces, resulting from enhanced electron
acceptor-donor interaction at interfaces.
Key words: hydrogen storage, activated carbon, chemical treatments