Homogeneous green oxidation

VI. The Activity-Stability Parameterization of Homogeneous Green Oxidation Catalysts... 

To date, many soluble transition metal-based homogeneous catalysts including POMs have been developed for H202- and 02-based green oxidations. They are usually dissolved in reaction solutions, making all catalytic sites accessible to... 

The matrix of the volcanic clays SD 47 and SD 48 changes to an isotropic red at 800 °C and becomes black at about 1100 °C. The amphibole shows a color change The initial homogeneously green specimens develop red borders due to increasing oxidation at 700 °C, a process... 

The field of gold-catalysed oxidation reactions is clearly dominated by heterogeneous catalysts and many reports have been published on this topic. " Although much less predominant, some examples of efficient homogeneous gold-promoted oxidations using green oxidants have been reported. 

Abstract The catalytic oxidation is an area of the key technologies for converting petroleum-based feedstocks to useful chemicals such as diols, epoxides, alcohols, and carbonyl compounds. Many efficient homogeneous and heterogeneous oxidation systems based on polyoxometalates (POMs) with green oxidants such as H2O2 and O2 have been developed. This chapter summarizes the remarkable oxidation catalyses by POMs with multimetallic active sites. The multifunctionality of multimetallic active sites in POMs such as cooperative activation of oxidants, simultaneous activation of oxidants and substrates, stabilization of reaction intermediates, and multielectron transfer leads to their remarkable activities and selec-tivities in comparison with the conventional monometallic complexes. Finally, the future opportunities for the development of shape- and stereoselective oxidation by POM-based catalysts are described. 

While many efficient green oxidations based on POMs have been developed as mentioned above, most of them are homogeneous and share common drawbacks of... 

---