Mo-Substituted Keggin Tungstosilicate Microtubes: Preparation and Characterization

The synthesis and characterization of microtubes of SiMoW₁₁ Keggin polyoxometalates containing either an Mo­(V) or Mo­(VI) atom is reported. The introduction of a Mo atom into the Keggin-type tungstosilicate microtubes endows them with new properties. The Mo-substituted microtubes may exert both W and Mo functionalities in electrocatalytic reactions and in the immobilization of noble metal nanoparticles. The degree of reduction of the Mo component in the SiMoW₁₁ microtubes is controllable simply by tuning the amount of reductant present in the mother liquor. Mo-substituted Keggin tungstosilicate microtubes in their reduced state are more stable than the all-tungsten Keggin tungstosilicate heteropoly blue microtubes