Catalysis Today, Vol.27, No.1-2, 187-193, 1996
Molecular-Oxygen as Environmental Acceptable, Selective and the Most Strong Oxidant in Liquid-Phase Oxidation
Innovative catalytic processes based on oxidation of anionic forms of organic substrates (mainly oxi- and oro-derivatives) by dioxygen open up new perspectives in environmentally acceptable production of a wide range of products. A new catalytic system, in many cases, permits to refuse the use of ecologically dangerous oxidising agents such as nitric acid, hypochlorite, permanganate without loss in the selectivity and the rate of processes. Distinctive feature of the proposed catalytic system consists, apparently, in simultaneous transfer of two electrons from the anionic form of the substrate coordinated on a Me(n+) centre to molecular oxygen. This permits the latter to react as a most strong and selective oxidant in contrast with wide distributed auto-oxidation processes which proceed via a thermodynamically unfavourable one-electron pathway of dioxygen reduction. The proposed oxidation mechanisms are tested using several oxidation processes interesting from a practical point of view.