Catalytic Decomposition of Hydrogen Peroxide over Nanoporous Activated Carbon: Effects of Oxidative and Thermal Treatments

Nanoporous activated carbon (AC) is a promising material for adsorption and catalysis. The properties of AC are determined by the structure consisting of nanosized graphene clusters, at the edges of which there are different oxygen-containing functional groups. For the oxidation of AC was used 5, 10 and 20% solution of nitric acid, the thermal treatment was carried out in argon at 500 and 800°C. The reaction of decomposition of hydrogen peroxide in the presence of the catalysts: the oxidized AC and thermally treated oxidized AC, was studied. The catalytic activity of oxidized nanoporous AC samples is determined by the concentration of the surface oxygen-containing groups. The most active catalysts have an insignificant content of the groups in the surface layer, up to 1 mmol g
^-1
. The oxidation of AC reduces by 5-8 times the catalytic activity of the carbon surface, which is due to the deactivation of catalytic active sites because of oxidation. The reactivity of the surface of the oxidized AC is partially restored by the thermal treatment at 500°C and almost completely at 800°C, which is associated with the removal of the oxygen-containing functional groups and the regeneration of active sites of AC.