On the mechanism of air nitrogen fixation on activated carbon surface in water

High-performance liquid chromatography and gas chromatography were used to reveal formation of hydroxyl radicals in air-saturated water containing activated carbon. Probable mechanisms of OH^· formation are considered. The role of OH^· radicals in the formation of carbene centers on the activated carbon surface is discussed. For interpreting the experimental data on atmospheric nitrogen fixation on activated carbon surface, probable mechanisms of nitrogen activation are explored by quantum-chemical methods. Highly reactive OH^· radicals are unable to react with molecular nitrogen under mild conditions. A high reactivity of singlet and triplet carbenes of different nature on activated carbon surface with respect to N₂ molecules was revealed by density functional theory methods.