Chapter 7: Environmentally-friendly Liquid-phase Oxidation Reactions Using Polyoxometalate Compounds

This chapter describes the development of environmentally benign liquid-phase oxidation reactions using polyoxometalate-based molecular catalysts. The general features of polyoxometalates and the methods for designing precise active site structures based on polyoxometalates are explained first. Then, the characteristics of peroxometalates, mixed-addenda polyoxometalates, and metal-substituted polyoxometalates, as well as several selected examples of their utilization for environmentally benign liquid-phase oxidation reactions (including photocatalytic oxidation reactions) using H₂O₂ or O₂ as an oxidant are introduced.