This study investigates the preparation, characterization, and catalytic activity of a novel palladium-doped copper molybdate polyoxometalate (Pd@CuMoO₄). Using a mere 19 ppm of palladium, Pd@CuMoO4 demonstrated excellent yields in both Suzuki-Miyaura and Sonogashira-Hagiwara coupling reactions of aryl halides with boronic acids and alkynes, respectively. The synergistic effects between the different metals in this catalyst were confirmed to be responsible for its high catalytic performance. Additionally, Pd@CuMoO₄ was successfully recovered and recycled multiple times in the Suzuki-Miyaura reaction with minimal loss of activity. The structural integrity of the reused catalyst was evaluated through various analytical techniques.

This review describes major advances in the use of functionalized molecular metal oxides (polyoxometalates, POMs) as water oxidation catalysts under electrochemical conditions. The fundamentals of POM-based water oxidation are described together with a brief overview of general approaches to designing POM water oxidation catalysts. Next, the use of POMs for homogeneous, solution-phase water oxidation is described together with a summary of theoretical studies shedding light on the POM-WOC mechanism. This is followed by a discussion of heterogenization of POMs on electrically conductive substrates for technologically more relevant application studies. Stability of POM water oxidation catalysts are discussed on selected examples where detailed data is already available. The review finishes with an outlook on future perspective and emerging themes in electrocatalytic polyoxometalate-based water oxidation research.