Weight directed metal oxidation

In the development of effective catalytic oxidation systems, there is a qualitative correlation between the desirability of the net or terminal oxidant, (OX in equation 1 and DO in equation 2) and the complexity of its chemistry and the difficulty of its use. The desirability of an oxidant is inversely proportional to its cost and directly proportional to the selectivity, rate, and stability of the associated oxidation reaction. The weight % of active oxygen, ease of deployment, and environmental friendliness of the oxidant are also key issues. Pertinent data for representative oxidants are summarized in Table I (4). The most desirable oxidant, in principle, but the one with the most complex chemistry, is O2. The radical chain or autoxidation chemistry inherent in 02-based organic oxidations, whether it is mediated by redox active transition metal ions, nonmetal species, metal oxide surfaces, or other species, is fascinatingly complex and represents nearly a field unto itself (7,75). Although initiation, termination, hydroperoxide breakdown, concentration dependent inhibition... 

Processing aids are used to directly influence the synthesis process function as reaction controllers. Depending on their chemical state they can function as reaction accelerators (the actual catalysts and starters or initiator substances), crosslinkers and/or hardeners, reaction inhibitors or catalyst deactivators, molecular weight controllers, chain splitters or lengtheners. From a chemical standpoint (structure and method of function) the radical builders, mainly peroxides and azo compounds, are treated separately from the catalysts which are mainly metals, metal oxides, salts (redox systems) and organo-metal compounds. The carrier substances, promoters and deactivators are placed in the catalyst class of substances. 

Note. If the wet precipitate is heated directly, caking occurs which renders the complete oxidation of the carbonaceous matter very slow. If alkali metals were originally present, the ignited oxide must be washed with hot water, filtered, and re-ignited to constant weight. 

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