Effect of surface acidity of activated carbon on hydrogen storage

Hydrogen adsorption studies at 78 K and pressures up to 40 atmosphere were conducted on nine commercial activated carbon samples. The amount of hydrogen adsorbed increased with increasing surface area. Surface modification consisting of controlled high-temperature reduction and oxidation revealed that BET surface area was not affected by these treatments. The surface acidity, however, increased with increasing oxygen treatment. The amount of hydrogen adsorbed also increased as the surface acidity of the activated carbons increased.